The AHU is normally a large metal box which connects to the ductwork that channels conditioned air throughout a building and returns it back to the AHU. Inside this large metal box there are a number of ventilators with different jobs to do.
AHU’s supply fresh air to the room. The units take air from the outside, filter it and recondition it (cooled by a cooling coil or heated by a heating coil).
Where hygienic needs for air quality are lower, the air from the rooms can be re-circulated for energy saving purposes. The AHU is usually fitted with a cooling/heat exchanger for increasing capacity and energy saving.
How they work
The easiest way of explaining how AHUs work is to run through the components and their functions:
Usually made of metal and painted to prevent corrosion, the housing contains all the components of the AHU. The coil and fans are insulated in the housing to prevent condensation.
The filters are used to remove contaminants from the air. Different filters are available for different AHUs:
HEPA filters are often used where businesses have particular concerns for their staff and sensitive equipment as these filters are efficient at removing airborne bacteria and can remove viruses from the air
Bag filters provide a medium to high efficiency of filtration
Panel filters provide a minimum low efficiency filtration
Electrostatic filters use highly charged electrodes that ionise the air
Carbon filters remove smells and gases
The fan within the AHU moves the air to different sections of the building. There are a variety of fans available (forward Curved, Backward Curved, Airfoil and Backward Inclined). The designer will use software to select the right fan, depending on the static pressure and air volume in the AHU.
Over the years technology is improving to make better use of energy and follow the greener agenda. As a result of this the variable air volume (VAV) system is popular as, depending on the need, the volume of the air being discharged can be varied. If the system load and thermal load are low, the speed of the fan will be low and if the loads are high the fan will speed up. Instead of a conventional motor a frequency inverter varies the speed of the fan for better control.
The mixing box is the location where the outside air and the air which has been returned are mixed and the perfect combination of air is sent to the space for conditioning. This is a simple method of heat recovery. Several other methods are available such as thermal wheel and cross plate heat exchangers, which method to use will depend on the application.
A cooling coil dehumidifies and cools the air. Depending on the AHU system, either a chilled water cooling coil or a direct expansion cooling coil will be used.
During the winter, internal air can become very dry and uncomfortable and this is where humidifiers come in handy:
Some common humidifiers include:
Steam Grid Type — the water is heated up to produce the steam
Steam Pan Type which heats up water using a heating coil and pan. The water evaporates and creates humidity
Spray Type which has a spray nozzle that sprays water
Types of air handling unit
There are two main types of air handling unit — the ‘blow-through’ and the ‘draw-through’.
The blow-through AHU has a fan which blows the air through the mixing box, cooling coil and filters before it goes to the ducting network.
The draw-through AHU can be vertical or horizontal. It has a fan which pulls the air through the mixing box, cooling coil and filters before it goes to the ducting network.
You can also get different sizes of AHU. Terminal units are small, simple units, also called fan coil units or blower units. These units may only include a coil, blower and air filter. A makeup air unit (MAU) is a larger AHU that does not recirculate the air and conditions 100% outside air. This unit is also known as a fresh air handling unit (FAHU).
Installation and commissioning: do have the AHU installed by the best engineers and do not skimp on commissioning, it will save you money.
Factory made or made on site (flatpack): there is always a solution that fits.
Refurbish units to breathe new life into old units.
Reconfigure or upgrade components to improve operating efficiencies and save energy.
Energy Efficient & Sustainable Air Handling units
Sustainable Air Handling Units
By making sustainable decisions upfront, air handling units that help companies yield energy savings for the life of their buildings, lowering overall costs and improving their bottom lines.
Sustainable AHUs are not only built to last, they are designed to reduce the environmental impacts and optimize energy use from today’s buildings. We incorporate a wide range of sustainable air handling features and processes into our products, including:
Low leakage fit-and-finish construction
Hygienic unit design and wash-down construction
Recycled – and recyclable – materials
The result for our clients is:
High energy efficiency in operations
Minimum maintenance requirements and replacement costs
“Urban heat islands” occur when cities replace natural land cover with dense concentrations of pavement, buildings, and other surfaces that absorb and retain heat. This effect increases energy costs (e.g., for air conditioning), air pollution levels, and heat-related illness and mortality.
Climate change will likely lead to more frequent, more severe, and longer heat waves during summer months.
The city of Chicago could see 30 more days per year rise above 100 degrees Fahrenheit (°F) under “high” greenhouse gas emissions scenarios.
Under lower emissions, Chicago’s new summer heat index could increase to around 93 °F by the end of the century—similar to current summer conditions in Atlanta, Georgia.
City officials worry that intense summer heat could lead to uncomfortable conditions for residents, as well as reduced tourist attraction in summer months.
Extreme heat events often affect our most vulnerable populations first.
Trees, green roofs, and vegetation can help reduce urban heat island effects by shading building surfaces, deflecting radiation from the sun, and releasing moisture into the atmosphere.
Elevated temperatures from heat islands can affect a community’s environment and quality of life in multiple ways.
Increased Energy Consumption
Heat islands increase demand for air conditioning to cool buildings. In an assessment of case studies spanning locations in several countries, electricity demand for air conditioning increased approximately 1–9% for each 2°F increase in temperature. Countries where most buildings have air conditioning, such as the United States, had the highest increase in electricity demand.This increase demand contributes to higher electricity expenses.
Heat islands increase both overall electricity demand, as well as peak energy demand. Peak demand generally occurs on hot summer weekday afternoons, when offices and homes are running air-conditioning systems, lights, and appliances. During extreme heat events, which are exacerbated by heat islands, the increased demand for air conditioning can overload systems and require a utility to institute controlled, rolling brownouts or blackouts to avoid power outages.
Elevated Emissions of Air Pollutants and Greenhouse Gases
As described above, heat islands raise demand for electricity in summer. Companies that supply electricity typically rely on fossil fuel to meet much of this demand, which in turn leads to an increase in air pollutant and greenhouse gas emissions.
These pollutants are harmful to human health and also contribute to complex air quality problems such as the formation of ground-level (smog), fine particulate matter, and acid rain. Increased use of fossil-fuel-powered plants also increases emissions of greenhouse gases, such as carbon dioxide, which contribute to global climate change.
In addition to their impact on energy-related emissions, elevated temperatures can directly increase the rate of ground-level ozone formation. Ground-level ozone is formed when nitrogen oxides and volatile organic compounds react in the presence of sunlight and hot weather. If all other variables are equal, such as the level of precursor emissions in the air and wind speed and direction, more ground-level ozone will form as the environment becomes sunnier and hotter.
Compromised Human Health and Comfort
Heat islands contribute to higher daytime temperatures, reduced nighttime cooling, and higher air pollution levels. These, in turn, contribute to heat-related deaths and heat-related illness such as general discomfort, respiratory difficulties, heat cramps, heat exhaustion, and non-fatal heat stroke.
Heat islands can also exacerbate the impact of naturally occurring heat waves, which are periods of abnormally hot, and often humid, weather. Sensitive populations, such as children, older adults, and those with existing health conditions, are particularly at risk during these events.
Excessive heat events, or abrupt and dramatic temperature increases, are particularly dangerous and can result in above-average rates of mortality. From 2004 to 2018 the Centers for Disease Control and Prevention recorded 10,527 heat-related deaths in the United States, an average of 702 per year. These numbers include deaths where heat was the underlying cause and deaths where heat was a contributing cause.
Impaired Water Quality
High temperatures of pavement and rooftop surfaces can heat up stormwater runoff, which drains into storm sewers and raises water temperatures as it is released into streams, rivers, ponds, and lakes. Water temperature affects all aspects of aquatic life, especially the metabolism and reproduction of many aquatic species. Rapid temperature changes in aquatic ecosystems resulting from warm stormwater runoff can be particularly stressful, and even fatal, to aquatic life.
One study found that urban streams are hotter on average than streams in forested areas, and that temperatures in urban streams rose over 7°F during small storms due to heated runoff from urban materials.
Green infrastructure is one option to cool stormwater runoff and improve water quality. It can include the use of downspout disconnections, rain gardens, planter boxes, bioswales, permeable pavements, green streets and alleys, green parking, and green roofs; as well as land conservation efforts.
To reduce the urban heat island effect:
Build green infrastructure improvements into regular street upgrades and capital improvement projects to ensure continued investment in heat-reducing practices throughout your community.
Plant trees and other vegetation—Space in urban areas might be limited, but you can easily integrate small green infrastructure practices into grassy or barren areas, vacant lots, and street rights-of-way.
City officials in Louisville, Kentucky, recently awarded a $115,700 contract for a tree canopy assessment to help the city use trees to address urban heat, stormwater management, and other concerns. “Knowing where we lack canopy, down to the street and address level, will help our efforts exponentially,” remarked Mayor Greg Fischer.
Make traditional water quality practices serve double duty by adding trees in or around roadside planters and other green infiltration-based practices to boost roadside cooling and shading.
Transform your community one project at a time by planting native, drought-tolerant shade trees and smaller plants such as shrubs, grasses, and groundcover wherever possible.
Build green roofs—Green roofs are an ideal heat island reduction strategy, providing both direct and ambient cooling effects. In addition, green roofs improve air quality by reducing the heat island effect and absorbing pollutants.
A move by the power ministry to increase the default temperature in air conditioners to 24 degree celsius will help you save almost Rs 4,000 on annual electricity bills, apart from reducing energy consumption.
The Ministry of Power (Bureau of Energy Efficiency) has said that all room air conditioners (AC) will have to ensure a default temperature setting of temperature in the appliances at 24 degree celsius from January 1, 2020.
How you save
A common misconception is that setting the thermostat at 18 degrees will cool down a room faster. However, that’s not true. It will take the same amount of time for the room to reach 26 degrees—which is significantly cooler than the average current outdoor temperature of 40 degrees in Delhi—whether you set the temperature at 18 degrees or 26 degrees. Of course, 18 degrees will be much cooler than 26 degrees, if that’s what you prefer.
The Bureau of Energy Efficiency (a body of the Ministry of Power) has said that the reduction in AC temperatures to 24 degrees from the conventional 18-21 degrees can result in 24 percent of energy savings.
Countries like Japan and the US have already put in regulations for the functioning of air conditioners. Japan introduced a default setting for air conditioners at 28 degrees celsius. In the United States, some places have enforced limits on lowering the air condition beyond 26 degrees celsius.
The Bureau of Energy Efficiency estimates that, considering the current market trend, the total connected load in India due to air conditioning will be about 200 GW by 2030. This may further increase as only 6 percent of households are using one or more air conditioners at present.
If the measures are followed by all consumers, India can save about 23 billion units of electricity. The total installed capacity of air conditioner is about 80 million TR (tons of refrigeration or amount of cooling required to convert 1000 Kg of water into one tonne of ice in 24 hours), which will increase to about 250 million TR in 2030. The demand for room ACs in India is expected to touch one billion units by 2050, compared to 6.5 million units right now. On the other hand, ACs account for 10 percent of global energy consumption.
Would it be feasible to have the AC temperature at 24 degrees in a humid weather?
The Normal human body temperature is 36-37 degree celsius. Hence, to take a temperature closer to 24 degrees is considered to be healthier for individuals in tropical regions like India. The ministry says that, as per the comfort chart, temperatures up to 25 degrees are quite comfortable for human body, along with the desired humidity and air movement values.
According to ASHRAE Standard 55-2013 Thermal Environmental Conditions for Human Occupancy, The thermal comfort zone is the condition of mind which expresses satisfaction with the thermal environment. This condition is defined using temperature, humidity level and air flow experienced by the human body, apart from individual parameters such as clothing and metabolism. Technical analysis indicates that, in order to achieve the desired comfort level at a steady state, the temperature setting can be 24-25 degree celsius.
Things to remember
The power consumption of an AC doesn’t just depend on the temperature you set it at. How much power your AC consumes depends on its star rating, the outside temperature, the hours of usage, size of the room, number of people in the room, insulation in the room, etc.
If you are setting the AC at low temperature and using a quilt or a blanket, it is not only unhealthy, it is also pure wastage of energy.
Normal human body temperature is approximately 36-37 degrees and putting your body through extreme high temperature on the outside and low temperature on the inside can affect your health.
Builders all over the globe are gravitating towards greener technology methods that can make buildings energy-efficient and sustainable. Homeowners are also showing interest in projects that deploy raw material and construction techniques with a lower carbon footprint and that are not detrimental to the environment. These techniques are being extensively used in modern construction right from the inception phase and in every aspect of the project construction; design, selection of raw material, the systems that run the construction, and the operation.
Renewable energy sources help in the creation of self-powered buildings. These structures generate their own power to support their energy requirement. In most cases, it is done through solar and wind power. The use of solar power isn’t a new technology. It has been around for long, but now it is widely used by builders as an effective and green alternative to traditional energy sources.
Thermal insulation of a building plays a very important role in improving the quality of life of the people residing or working there. Using hollow clay bricks like the Porotherm Thermo bricks is one such greener technology innovations in the field of modern construction for green insulation. These bricks are eco-friendly, made from easily available raw material that is clay, and rank high on the sustainability meter.
Using bio-degradable raw material is one of the ways of creating a sustainable structure. A lot of waste products and toxin materials are generated during the construction of a building. This waste piles up in landfills for centuries before degrading. We can avoid this by going in for bio-degradable raw materials like bamboo, recycled glass, and organic paints. A relatively newer but effective sustainable material that can be used is eco-concrete. It is practical, durable, strong, and acts as an air purifier with its smog-eating properties. These raw materials do not pose any threat to the environment and improve the productivity and health of people.
Using water-efficient technologies in the construction process is one of the green and sustainable ways of making the structure adhere to green standards and green technology. These technologies include re-use and application of efficient water supply systems and deploy methods like rainwater harvesting, dual plumbing, grey-water re-use, and water conservation fixtures. The use of these water-efficient technologies can lower water wastage by as much as 15%.
Cool roofs reflect more of the sun’s rays than other roofs and prevent the warm or cool air inside from escaping through the top of a building. A cool roof keeps the temperature inside a building low (a cool roof can cut that down by more than 50 degrees) that reduces the strain on the air conditioning systems. This, in turn, reduces the emissions from the heating and cooling units.
Smart glass is an electrochromic glass that uses a tiny burst of electricity to charge ions on a window layer. It controls the amount of light that the glass will reflect. It is different from the low emittance windows that block partial radiation of the sun as with smart glass, you can choose the amount of light you want to block. This technology is especially beneficial for skyscrapers that use a lot of glass in their façade. The smart glass windows tint automatically during peak sun hours and become transparent in the evenings, night. This glass is expected to reduce HVAC costs by almost 25 %.
A structure becomes great not only by its design but also by its impact on the environment. It is time for the buildings to enter into a symbiotic and healthy relationship with the environment by using green technology-based construction methods.
Natural lighting, also known as daylighting, is a technique that efficiently brings natural light into your home using exterior glazing (windows, skylights, etc.), thereby reducing artificial lighting requirements and saving energy. Natural lighting has been proven to increase health and comfort levels for building occupants.
Daylight is the source of beneficial vitamin D which our body needs to stay healthy. A building could be designed in such a way that there is maximum natural light inside the house. Some of the fundamental benefits of daylight are:
Sunlight during the day helps in healing the body
It’s good for strong bones as it contains vitamin D
Keeps the environment inside the house clean and pleasant.
Builds good immune system of the members of the family
Daylight also keeps the happy mode on inside the house for every member of the family
There can be various ways of modeling a house with a good amount of natural light and ventilation. Discussed below are the sources that could be used to do so-
1. Design of the house
The house could be designed by the architect in such a way that the shape and size of the windows can be defined clearly. The shading and glazing styles must be in such a way that it suits the building. The windows must be planned in such a way that there is maximum daylight inside the house.
The placement of the windows in the house must be in such a way that natural light could comfort the house throughout the day. Windows facing north can give maximum daylight. However, the thermal heat is lost during the winters. South facing well-glazed windows can bring in a good amount of heat and be beneficial during summers and winters.
Glazing is the most effective way of getting maximum natural light inside the house. Few small strip windows in the ceiling could be designed which will increase the natural light and give a trendy look to your house. Around 30 percent of the ceiling can be used for glazed windows.
Solar panels could be installed on the roofs to generate electricity to reduce the consumption of electricity in the house. The monthly electricity bills reduce because of such panels and it is a good option to pledge for green living. These panels absorb heat during the sun hours and store it in such a way which can be used during the night. The solar panels can also be used to generate electricity in case of power shutdowns. There could be the use of tubular Skylights. These natural light saves lots of electricity as they are installed on the roof. It absorbs the natural light and then flows in a tube and brings in natural light inside the house.
While getting your house painted use of sober colours helps in giving a bright look to the house. Light colours could be helpful in keeping the house cool. The trim of the windows can be painted in white which can help in giving an elegant look to the house.
A jali is a commonly used element of Indian architecture. Jali walls have numerous advantages over a solid wall since jali walls can be used in places where there is no need of a solid wall. From providing privacy to cooling the indoors, jalis make for a sensible design element particularly suited for our climatic conditions. And also saves materials and increase the speed of construction.
Natural light is an essential and free resource. This resource is given less importance. However, it has maximum advantages if the house is well planned with lots of sunlight helps to keep the home environment fresh, clean and keeps the members of the family healthy.
We breath oxygen and exhale carbon-di-oxide (CO2), this is called the respiration process. When we are indoors, the level of CO2 in the air increases due to the respiration cycle. Along with CO2, body odor, moisture and other pollutants within the house make the air inside stale. Breathing stale air is unhealthy. To maintain freshness in space, the stale air must be replaced by fresh air regularly. Fresh outdoor air, is taken from the external environment, and the replaced indoor air in turn carries away with it the pollutants from inside your home. This process of replacing stale air inside your home with fresh air from the environment outside through windows and door openings, without the use of fans is Natural Ventilation.
Almost all historic buildings were ventilated naturally, although many of these have been compromised by the addition of partition walls and mechanical systems. With an increased awareness of the cost and environmental impacts of energy use, natural ventilation has become an increasingly attractive method for reducing energy use and cost and for providing acceptable indoor environmental quality and maintaining a healthy, comfortable, and productive indoor climate rather than the more prevailing approach of using mechanical ventilation. In favorable climates and buildings types, natural ventilation can be used as an alternative to air-conditioning plants, saving 10%–30% of total energy consumption.
In hotter places natural ventilation also help bring the room temperature down. This cooling effect can help reduce use of fans, coolers and avoid air-conditioners to significantly bring down your energy bills. You can employ the following strategies to improve the natural ventilation in your home:
We can design openings (such as windows) in your home’s building envelope so that they are in the path of wind flows from outside.
These openings must be placed at a suitable height in the direction of the natural breeze outside your home to allow air to flow through your rooms at body level to help make you feel more comfortable.
Winds flowing at suitable height improve comfort
Place windows to facilitate wind circulation throughout the space. When wind flows in from one side, circulates through the space and exits from an opposite side, it is called Cross Ventilation. Cross Ventilation improves ventilation by distributing the flow of air throughout the space.
Strategies to improve ventilation through appropriate window placement
You can enhance the flow of air inside your home by using ‘jaalis’ (lattice wall) and ventilators. Smaller windows funnel air into your home. Air passing through these small windows speeds up towards a larger opening in the opposite wall that serves as an exit. This engineered wind flow makes your home cooler. Traditionally, this was practiced in hot climates with ‘jaalis’. ‘jaalis’ are small apertures, that aid in accelerating passing wind passing to enhance ventilation.
Winds speed up as they pass from smaller to larger windows.
High openings such as clerestory windows and ventilators act as effective exhausts for the hot air that accumulates near the ceiling of your home. Warmer air is lighter than cooler air, and therefore it rises up. This concept of rising hot air is called the Stack effect.
Windows near the ceiling aid in removing accumulated hot air.
In humid climates such as in Coastal regions, ventilation can bring in much needed relief, because cool breeze replaces moist warm air faster away from our bodies causing the sensation of comfort. In desert like climates, natural ventilation can bring in unwanted heat as well which can cause discomfort. Wind passing over water bodies or through ‘khus’ pads, like in desert coolers, can provide cooler air. In colder areas, cold winds can cause discomfort. Obstructions around the house may be used to slow the cold winds. In the plains, which see both hot summers and cool winters, the in-between period is especially suited for natural ventilation when ‘Natural cooling’ can help avoid use of air-conditioners.
Naturally ventilated buildings should be designed to provide thermal comfort, to achieve adequate moisture and contaminant removal, and to meet or exceed Government Energy Conservation Performance Standards.
When we make our own home, It is very important to think about the energy consumption for that. When we make home we already decide on all the external fittings and appliances that you would like to install but we don’t think about the measures to reduce electricity bill. These might include things like fans, LED bulbs, curtains, cabinets and other furniture, but have you spared a moment to become aware of the materials used in your walls?
In general, people just think about the type of paint that they would like to use externally so that it looks good, without giving a thought to the actual walling material used. We spend a major portion of our lives in our house. It is important for us to understand how using better construction materials can make a big difference in terms of living comfort and cost savings while contributing to the lowering of global climate change. Let’s talk about some measures to reduce electricity bill
RCC, Concrete Bricks or Porotherm Bricks?
Traditionally in India, builders and construction companies use concrete bricks or RCC shear walls, because they are cheaper and easily available. Bringing down the cost of the project for them. The Bureau of Energy Efficiency is introducing new legislation to make the use of green energy materials in the construction industry mandatory. Newer measurements of sustainable building materials factor in measures like U Value and RETV. (Residential Envelope Thermal Value)
RETV – What Is It and How Does It Matter?
The ‘U value’ measures the thermal conductivity or transmission of any material. The lower the value, the better the thermal comfort. RETV is an extension of the U Value, used to measure the thermal performance of the building envelope (external-facing wall, doors, windows and glass surfaces), or it can be seen as an indicator of thermal comfort. In short, if the RETV is lower, the house will be naturally cooler in summer and warmer in winter, without any use of external air conditioning. Globally, the RETV value of 15 or less is considered to be ideal for use in walling materials.
More Than 24K INR in Savings – Too Good to be True?
A recent report conducted by GKSPL ( Greentech Knowledge Solutions Pvt. Ltd.), did a comparative study on the different available walling materials. The report is titled “Calculation of RETV for Residential Projects: A Comparative Study of Different Walling Materials for Various Climate Zones” and is available here. (Add a link to the report ) The findings of this report are an eye-opener for consumers, who had no idea of the cost savings
Involved in using RETV compliant walling material. For a typical 100 m2 (appx. 1080 Sq. Ft) built-up area, the walling area is approximately 150 m2. It is assumed that 1725 bricks are required.
The study found the RETV value of the clay-based Porotherm bricks to be between 6.9 to 10.5 across different climate zones, while the corresponding values for concrete blocks and RCC walls were between 13.5 to 22.5. A huge difference!
By using RETV compliant bricks like Porotherm, the temperature in the house was lower, in the range of 3° C to 7° C between the Porotherm house and the Concrete block house. Using a Coefficient of Performance of 3.0 for the air conditioner, for the same built-up area, RCC shear walls would consume 6,233 kWh units annually, while Porotherm Thermobricks would consume just 3,400 kWh units, which makes a difference of around 2,833 kWh annually. This leads to a direct annual cost saving of ₹ 26,913. (Electricity unit rate in Hyderabad is ₹ 9.50 / kWh)
It is imperative to talk to your builder, contractor, or architect to ensure that they use RETV compliant walling material. It results in savings of more than 24K INR, along with the reduced need for external air conditioning. These materials also provide better circulation and superior air quality in the house. Do your bit to save our planet and your own hard-earned money. Go green!
When insulating your home, you can choose from many types of insulation. To choose the best type of insulation, you should first determine the following:
Where you want or need to install/add insulation
The recommended R-values for areas you want to insulate.
The maximum thermal performance or R-value of insulation is very dependent on proper installation. Homeowners can install some types of insulation — notably blankets and materials that can be poured in place. (Liquid foam insulation materials can be poured, but they require professional installation). Other types require professional installation.
When hiring a professional certified installer:
Obtain written cost estimates from several contractors for the R-value you need, and don’t be surprised if quoted prices for a given R-value installation vary by more than a factor of two.
Ask contractors about their air-sealing services and costs as well, because it’s a good idea to seal air leaks before installing insulation.
To evaluate blanket installation, you can measure batt thickness and check for gaps between batts as well as between batts and framing. In addition, inspect insulation for a tight fit around building components that penetrate the insulation, such as electrical boxes. To evaluate sprayed or blown-in types of insulation, measure the depth of the insulation and check for gaps in coverage.
If you choose to install the insulation yourself, follow the manufacturer’s instructions and safety precautions carefully and check local building and fire codes. Do-it-yourself instructions are available from the fiberglass and mineral wool trade group. The cellulose trade group recommends hiring a professional, but if there isn’t a qualified installer in your area or you feel comfortable taking on the job, you may be able to find guidance from manufacturers.
The table below provides an overview of most available insulation materials, how they are installed, where they’re typically installed, and their advantages.
Foam board, to be placed on outside of wall (usually new construction) or inside of wall (existing homes):Some manufacturers incorporate foam beads or air into the concrete mix to increase R-values
Unfinished walls, including foundation wallsNew construction or major renovationsWalls (insulating concrete blocks)
Require specialized skillsInsulating concrete blocks are sometimes stacked without mortar (dry-stacked) and surface bonded.
Insulating cores increases wall R-value.Insulating outside of concrete block wall places mass inside conditioned space, which can moderate indoor temperatures.Autoclaved aerated concrete and autoclaved cellular concrete masonry units have 10 times the insulating value of conventional concrete.
Foil-faced kraft paper, plastic film, polyethylene bubbles, or cardboard
Unfinished walls, ceilings, and floors
Foils, films, or papers fitted between wood-frame studs, joists, rafters, and beams.
Do-it-yourself.Suitable for framing at standard spacing.Bubble-form suitable if framing is irregular or if obstructions are present.Most effective at preventing downward heat flow, effectiveness depends on spacing.
Foam board or liquid foam insulation coreStraw core insulation
Unfinished walls, ceilings, floors, and roofs for new construction
Construction workers fit SIPs together to form walls and roof of a house.
SIP-built houses provide superior and uniform insulation compared to more traditional construction methods; they also take less time to build.
Blanket: Batt and Roll Insulation
Blanket insulation — the most common and widely available type of insulation — comes in the form of batts or rolls. It consists of flexible fibers, most commonly fiberglass. You also can find batts and rolls made from mineral (rock and slag) wool, plastic fibers, and natural fibers, such as cotton and sheep’s wool. Learn more about these insulation materials.
Batts and rolls are available in widths suited to standard spacing of wall studs, attic trusses or rafters, and floor joists: 2 inch x 4 inch walls can hold R-13 or R-15 batts; 2 inch x 6 inch walls can use R-19 or R-21 products. Continuous rolls can be hand-cut and trimmed to fit. They are available with or without facings. Manufacturers often attach a facing (such as kraft paper, foil-kraft paper, or vinyl) to act as a vapor barrier and/or air barrier. Batts with a special flame-resistant facing are available in various widths for basement walls and other places where the insulation will be left exposed. A facing also helps facilitate fastening during installation.
See the table below for an overview of standard and high-performance (medium-density and high-density) fiberglass blankets and batts characteristics.
Fiberglass Batt Insulation Characteristics
This table is for comparison of fiberglass batts only. Determine actual thickness, R-value, and cost from manufacturer and/or local building supplier.
COST (CENTS/SQ. FT.)
3 1/2 (high density)
6 to 6 1/4
5 1/4 (high density)
8 to 8 1/2
8 (high density)
9 1/2 (standard)
Concrete Block Insulation
Concrete blocks are used to build home foundations and walls, and there are several ways to insulate them. If the cores aren’t filled with steel and concrete for structural reasons, they can be filled with insulation, which raises the average wall R-value. Field studies and computer simulations have shown, however, that core filling of any type offers little fuel savings, because heat is readily conducted through the solid parts of the walls such as block webs and mortar joints.
It is more effective to install insulation over the surface of the blocks either on the exterior or interior of the foundation walls. Placing insulation on the exterior has the added advantage of containing the thermal mass of the blocks within the conditioned space, which can moderate indoor temperatures.
Some manufacturers incorporate polystyrene beads into concrete blocks, while others make concrete blocks that accommodate rigid foam inserts.
In the United States, two varieties of solid, precast autoclaved concrete masonry units are now available: autoclaved aerated concrete (AAC) and autoclaved cellular concrete (ACC). This material contains about 80% air by volume and has been commonly used in Europe since the late 1940s. Autoclaved concrete has ten times the insulating value of conventional concrete. The blocks are large, light, and easily sawed, nailed, and shaped with ordinary tools. The material absorbs water readily, so it requires protection from moisture. Precast ACC uses fly ash instead of high-silica sand, which distinguishes it from AAC. Fly ash is a waste ash produced from burning coal in electric power plants.
Hollow-core units made with a mix of concrete and wood chips are also available. They are installed by stacking the units without using mortar (dry-stacking) and filling the cores with concrete and structural steel. One potential problem with this type of unit is that the wood is subject to the effects of moisture and insects.
Concrete block walls are typically insulated or built with insulating concrete blocks during new home construction or major renovations. Block walls in existing homes can be insulated from the inside. Go to insulation materials for more information about the products commonly used to insulate concrete block.
Foam Board or Rigid Foam
Foam boards — rigid panels of insulation — can be used to insulate almost any part of your home, from the roof down to the foundation. They are very effective in exterior wall sheathing, interior sheathing for basement walls, and special applications such as attic hatches. They provide good thermal resistance (up to 2 times greater than most other insulating materials of the same thickness), and reduce heat conduction through structural elements, like wood and steel studs. The most common types of materials used in making foam board include polystyrene, polyisocyanurate (polyiso), and polyurethane.
Insulating Concrete Forms
Insulating concrete forms (ICFs) are basically forms for poured concrete walls, which remain as part of the wall assembly. This system creates walls with a high thermal resistance, typically about R-20. Even though ICF homes are constructed using concrete, they look like traditional stick-built homes.
ICF systems consist of interconnected foam boards or interlocking, hollow-core foam insulation blocks. Foam boards are fastened together using plastic ties. Along with the foam boards, steel rods (rebar) can be added for reinforcement before the concrete is poured. When using foam blocks, steel rods are often used inside the hollow cores to strengthen the walls.
The foam webbing around the concrete-filled cores of blocks can provide easy access for insects and groundwater. To help prevent these problems, some manufacturers make insecticide-treated foam blocks and promote methods for waterproofing them. Installing an ICF system requires an experienced contractor, available through the Insulating Concrete Form Association.
Loose-Fill and Blown-In Insulation
Loose-fill insulation consists of small particles of fiber, foam, or other materials. These small particles form an insulation material that can conform to any space without disturbing structures or finishes. This ability to conform makes loose-fill insulation well suited for retrofits and locations where it would be difficult to install other types of insulation.
The most common types of materials used for loose-fill insulation include cellulose, fiberglass, and mineral (rock or slag) wool. All of these materials are produced using recycled waste materials. Cellulose is primarily made from recycled newsprint. Most fiberglass products contain 40% to 60% recycled glass. Mineral wool is usually produced from 75% post-industrial recycled content. The table below compares these three materials.
Recommended Specifications by Loose-Fill Insulation Material
Density in lb/ft3 (kg/m3)
Weight at R-38 in lb/ft2 (kg/m2)
For Attic Applications
OK for 1/2″ drywall, 24″ on center?
OK for 1/2″ drywall, 16″ on center?
OK for 5/8″ drywall, 24″ on center?
Some less common loose-fill insulation materials include polystyrene beads and vermiculite and perlite. Loose-fill insulation can be installed in either enclosed cavities such as walls, or unenclosed spaces such as attics. Cellulose, fiberglass, and rock wool are typically blown in by experienced installers skilled at achieving the correct density and R-values. Polystyrene beads, vermiculite, and perlite are typically poured.
The Federal Trade Commission has issued the “Trade Regulation Rule Concerning the Labeling and Advertising of Home Insulation” (16 CFR Part 460). The Commission issued the R-value Rule to prohibit, on an industry-wide basis, specific unfair or deceptive acts or practices. The Rule requires that manufacturers and others who sell home insulation determine and disclose each products’ R-value and related information (e.g., thickness, coverage area per package) on package labels and manufacturers’ fact sheets. R-value ratings vary among different types and forms of home insulations and among products of the same type and form.
. For loose-fill insulation, each manufacturer must determine the R-value of its product at settled density and create coverage charts showing the minimum settled thickness, minimum weight per square foot, and coverage area per bag for various total R-values.
This is because as the installed thickness of loose-fill insulation increases, its settled density also increases due to compression of the insulation under its own weight. Thus, the R-value of loose-fill insulation does not change proportionately with thickness. The manufacturers’ coverage charts specify the bags of insulation needed per square foot of coverage area; the maximum coverage area for one bag of insulation; the minimum weight per square foot of the installed insulation; and the initial and settled thickness of the installed insulation needed to achieve a particular R-value.
Radiant Barriers and Reflective Insulation Systems
Unlike most common insulation systems, which resist conductive and sometimes convective heat flow, radiant barriers and reflective insulation work by reflecting radiant heat. Radiant barriers are installed in homes — usually in attics — primarily to reduce summer heat gain, which helps lower cooling costs. Reflective insulation incorporates radiant barriers — typically highly reflective aluminum foils — into insulation systems that can include a variety of backings, such as kraft paper, plastic film, polyethylene bubbles, or cardboard, as well as thermal insulation materials.
Radiant heat travels in a straight line away from any surface and heats anything solid that absorbs its energy. When the sun heats a roof, it’s primarily the sun’s radiant energy that makes the roof hot. A large portion of this heat travels by conduction through the roofing materials to the attic side of the roof. The hot roof material then radiates its gained heat energy onto the cooler attic surfaces, including the air ducts and the attic floor. A radiant barrier reduces the radiant heat transfer from the underside of the roof to the other surfaces in the attic. To be effective, it must face an air space.
Radiant barriers are more effective in hot climates, especially when cooling air ducts are located in the attic. Some studies show that radiant barriers can lower cooling costs 5% to 10% when used in a warm, sunny climate. The reduced heat gain may even allow for a smaller air conditioning system. In cool climates, however, it’s usually more cost-effective to install more thermal insulation.
Rigid Fiber Board Insulation
Rigid fiber or fibrous board insulation consists of either fiberglass or mineral wool material and is primarily used for insulating air ducts in homes. It is also used when there’s a need for insulation that can withstand high temperatures. These products come in a range of thicknesses from 1 inch to 2.5 inches.
Installation in air ducts is usually done by HVAC contractors, who fabricate the insulation at their shops or at job sites. On exterior duct surfaces, they can install the insulation by impaling it on weld pins and securing with speed clips or washers. They can also use special weld pins with integral-cupped head washers. Unfaced boards can then be finished with reinforced insulating cement, canvas, or weatherproof mastic. Faced boards can be installed in the same way, and the joints between boards sealed with pressure-sensitive tape or glass fabric and mastic.
Sprayed-Foam and Foamed-In-Place Insulation
Liquid foam insulation materials can be sprayed, foamed-in-place, injected, or poured. Foam-in-place insulation can be blown into walls, on attic surfaces, or under floors to insulate and reduce air leakage. Some installations can yield a higher R-value than traditional batt insulation for the same thickness, and can fill even the smallest cavities, creating an effective air barrier. You can use the small pressurized cans of foam-in-place insulation to reduce air leakage in holes and cracks, such as window and door frames, and electrical and plumbing penetrations.
Types of Foam Insulation
Today, most foam materials use foaming agents that don’t use chlorofluorocarbons (CFCs) or hydrochlorofluorocarbons (HCFCs), which are harmful to the earth’s ozone layer.
There are two types of foam-in-place insulation: closed-cell and open-cell. Both are typically made with polyurethane. With closed-cell foam, the high-density cells are closed and filled with a gas that helps the foam expand to fill the spaces around it. Open-cell foam cells are not as dense and are filled with air, which gives the insulation a spongy texture.
The type of insulation you should choose depends on how you will use it and on your budget. While closed-cell foam has a greater R-value and provides stronger resistance against moisture and air leakage, the material is also much denser and is more expensive to install. Open-cell foam is lighter and less expensive but should not be used below ground level where it could absorb water. Consult a professional insulation installer to decide what type of insulation is best for you.
Some less common types include Icynene foam and Tripolymer foam. Icynene foam can be either sprayed or injected, which makes it the most versatile. It also has good resistance to both air and water intrusion. Tripolymer foam—a water-soluble foam—is injected into wall cavities. It has excellent resistance to fire and air intrusion.
Liquid foam insulation — combined with a foaming agent — can be applied using small spray containers or in larger quantities as a pressure-sprayed (foamed-in-place) product. Both types expand and harden as the mixture cures. They also conform to the shape of the cavity, filling and sealing it thoroughly. Slow-curing liquid foams are also available. These foams are designed to flow over obstructions before expanding and curing, and they are often used for empty wall cavities in existing buildings. There are also liquid foam materials that can be poured from a container.
Installation of most types of liquid foam insulation requires special equipment and certification and should be done by experienced installers. Following installation, an approved thermal barrier equal in fire resistance to half-inch gypsum board must cover all foam materials. Also, some building codes don’t recognize sprayed foam insulation as a vapor barrier, so installation might require an additional vapor retarder.
Foam insulation products and installation usually cost more than traditional batt insulation. However, foam insulation has higher R-values and forms an air barrier, which can eliminate some of the other costs and tasks associated with weatherizing a home, such as caulking, applying housewrap and vapor barrier, and taping joints. When building a new home, this type of insulation can also help reduce construction time and the number of specialized contractors, which saves money.
Structural Insulated Panels
Structural insulated panels (SIPs) are prefabricated insulated structural elements for use in building walls, ceilings, floors, and roofs. They provide superior and uniform insulation compared to more traditional construction methods (stud or “stick frame”), offering energy savings of 12% to 14%. When installed properly, SIPs also result in a more airtight dwelling, which makes a house quieter and more comfortable.
SIPs not only have high R-values but also high strength-to-weight ratios. A SIP typically consists of 4- to 8-inch-thick foam board insulation sandwiched between two sheets of oriented strand board (OSB) or other structural facing materials. Manufacturers can usually customize the exterior and interior sheathing materials to meet customer requirements. The facing is glued to the foam core, and the panel is then either pressed or placed in a vacuum to bond the sheathing and core together. SIPs can be produced in various sizes or dimensions. Some manufacturers make panels as large as 8 by 24 feet, which require a crane to erect.
The quality of SIP manufacturing is very important to the long life and performance of the product. The panels must be glued, pressed, and cured properly to ensure that they don’t delaminate. The panels also must have smooth surfaces and edges to prevent gaps from occurring when they’re connected at the job site. Before purchasing SIPs, ask manufacturers about their quality control and testing procedures and read and compare warranties carefully. SIPs are available with different insulating materials, usually polystyrene or polyisocyanurate foam.
SIPs are made in a factory and shipped to job sites. Builders then connect them together to construct a house. For an experienced builder, a SIPs home goes up much more quickly than other homes, which saves time and money without compromising quality. These savings can help offset the usually higher cost of SIPs.
Many SIP manufacturers also offer “panelized housing kits.” The builder need only assemble the pre-cut pieces, and additional openings for doors and windows can be cut with standard tools at the construction site.
When installed according to manufacturers’ recommendations, SIPs meet all building codes and pass the American Society for Testing and Materials (ASTM) standards of safety. In buildings constructed of SIPs, fire investigators have found that the panels held up well. For example, in one case a structure fire exceeded 1,000°F (538°C) in the ceiling areas and 200°F (93°C) near the floors, and most wall panels and much of the ceiling remained intact. An examination of the wall panels revealed that the foam core had neither melted nor delaminated from the skins. In similar cases, a lack of oxygen seemingly caused the fire to extinguish itself. The air supply in an airtight SIP home can be quickly consumed in a fire.
Areas of Concern
Fire safety is a concern, but when the interior of the SIP is covered with a fire-rated material, such as gypsum board, it protects the facing and foam long enough to give building occupants a chance to escape. As in any house, insects and rodents can be a problem. In a few cases, insects and rodents have tunneled throughout the SIPs, and some manufacturers have issued guidelines for preventing these problems, including:
Applying insecticides to the panels Treating the ground with insecticides both before and after initial construction and backfilling Maintaining indoor humidity levels below 50% Locating outdoor plantings at least two feet (0.6 meters) away from the walls Trimming any over-hanging tree limbs.
Boric acid-treated insulation panels are also available. These panels deter insects, but are relatively harmless to humans and pets.
Because it is so airtight, a well-built SIP structure requires controlled fresh-air ventilation for safety, health, and performance, and to meet many building codes. A well-designed, installed, and properly operated mechanical ventilation system can also help prevent indoor moisture problems, which is important for achieving the energy-saving benefits of an SIP structure.
To know more about Insulation materials check here !
Light Emitting Diode (LED) and Compact Fluorescent Lights (CFL) bulbs have revolutionized energy-efficient lighting. Energy Saving LED vs CFL.
CFLs are simply miniature versions of full-sized fluorescents. They screw into standard lamp sockets, and give off light that looks similar to the common incandescent bulbs— not like the fluorescent lighting we associate with factories and schools.
LEDs are small, very efficient solid bulbs. New LED bulbs are grouped in clusters with diffuser lenses, which have broadened the applications for LED use in the home. LED technology is advancing rapidly, with many new bulb styles available. Initially more expensive than CFLs, LEDs now bring more value since they last longer.
The Status of Energy Efficient Lighting
With a burgeoning supply of far more efficient light bulb options, the EU began a phased ban of incandescents in 2009. Canada followed suit banning the manufacture and import of higher wattage incandescent bulbs beginning in 2014.
In 2007, the U.S. set new energy efficiency guidelines for all bulbs, which effectively phased out the least efficient incandescent bulbs. Incandescents are now available only if they meet the new energy standard.
According to Energy Efficiency Services Limited, India rapid adoption of LED bulbs would save hundreds of millions of tons of greenhouse gases from entering the atmosphere.
Australia, China, and numerous countries in Asia and Latin America have likewise phased out or banned incandescent bulbs. These changes are estimated to save each country that switches to energy efficient bulbs millions of dollars annually.
According to the Bureau of energy efficiency, rapid adoption of LED bulbs would collectively save $265 billion over the next 20 years. This switch would also help eliminate the need to build 40 new power plants and save hundreds of millions of tons of greenhouse gases from entering the atmosphere.
LED Light Bulbs
LEDs (Light Emitting Diodes) are solid light bulbs that are extremely energy-efficient. When first developed, LEDs were limited to single-bulb use in applications such as instrument panels, electronics, pen lights and, more recently, strings of indoor and outdoor Christmas lights.
Manufacturers have expanded the application of LEDs by “clustering” the small bulbs. The first clustered bulbs were used for battery-powered items such as flashlights and headlamps. Today, LED bulbs are made using as many as 180 bulbs per cluster, and encased in diffuser lenses, which spread the light in wider beams. Now available with standard bases that fit common household light fixtures, LEDs are the next generation in home lighting.
A significant feature of LEDs is that the light is directional, as opposed to incandescent bulbs, which spread the light more spherically. This is an advantage with recessed lighting or under-cabinet lighting, but it is a disadvantage for table lamps. New LED bulb designs address this directional limitation by using diffuser lenses and reflectors to disperse the light more like an incandescent bulb.
The high cost of producing LEDs has been a roadblock to widespread use. However, researchers at Purdue University have developed a process for using inexpensive silicon wafers to replace the expensive sapphire-based technology. This has rapidly brought LEDs into competitive pricing with CFLs and incandescent bulbs. LED bulbs are now the standard for most lighting needs.
Benefits of LED Lightbulbs
LED bulbs last up to 10 times longer than compact fluorescents and 40 times longer than typical incandescent bulbs.
Since LEDs do not have a filament, they are not damaged under circumstances when a regular incandescent bulb would be broken. Because they are solid, LED bulbs hold up well to jarring and bumping.
These bulbs do not cause heat build-up; LEDs produce 3.4 btu’s/hour, compared to 85 for incandescent bulbs. Common incandescent bulbs get hot and contribute to heat build-up in a room. LEDs prevent this heat build-up, thereby helping to reduce air conditioning costs in the home.
No mercury is used in the manufacturing of LEDs.
LED light bulbs use only 2-17 watts of electricity (1/3rd to 1/30th of Incandescent or CFL). LED bulbs used in fixtures inside the home save electricity, remain cool, and save money on replacement costs since LED bulbs last so long. Small LED flashlight bulbs will extend battery life 10 to 15 times longer than incandescent bulbs.
The cost of new LED bulbs has gone down considerably in the last few years and is continuing to go down.
Light for Remote Areas and Portable Generators
Because of the low power requirement for LEDs, using solar panels becomes more practical and less expensive than running an electric line or using a generator for lighting in remote or off-grid areas. LED light bulbs are also ideal for use with small portable generators which homeowners use for backup power in emergencies.
Choosing an LED Light Bulb
Many different models and styles of LED bulbs are emerging in today’s marketplace. When choosing a bulb, keep in mind the following:
Estimate Desired Brightness
Read the package to choose desired brightness level. You can use wattage to compare bulb illumination. For example, a 9 watt (W) LED is equivalent in output to a 45 W incandescent. However, wattage measures energy used, not the light output. The new method for comparing bulbs is lumens. ‘Lumens’ is the measure of perceived brightness, and the higher the lumens, the brighter the bulb. Bulbs with similar wattage may vary in lumens.
Do You Need a 3-Way Bulb?
New LED bulbs are available as combination three-way bulbs. These replace 30, 60 and 75-watt incandescent bulbs, while consuming 80% less power than an incandescent bulb.
Choose Between Warm and Cool Light
New LED bulbs are available in ‘cool’ white light, which is ideal for task lighting, and ‘warm’ light commonly used for accent or small area lighting.
Choose Between Standard and Dimmable Bulbs
Some LED bulbs are now available as dimmable bulbs. They will work with any standard dimmer switch.
Choose High Quality Bulbs or They Will Die Prematurely
Don’t buy cheap bulbs from eBay or discounters. They are inexpensive because the bulbs use a low-quality chip, which fails easily. Many cheaper varieties also don’t work inside enclosed light fixtures (see below) and will burn out within a year or less as they heat up.
Enclosed Light Fixtures Require Special LED Bulbs
LEDs have mechanisms to dissipate heat build-up, but these require more airflow than many common light fixtures permit. Bulbs designed for enclosed fixtures will last longer than standard LEDs. Look for explicit statements saying that a bulb works inside enclosed light fixtures.
Recessed, ‘Pot’ and Can Light Fixtures
Be sure to check the diameter of the bulb you’re considering against that of the can you’re filling. Your existing bulbs should say whether they are R20, BR30, or BR40. Look for these same numbers on the LEDs you’re purchasing. Because heat can also be an issue with recessed lighting, look for a description that indicates its suitability for recessed fixtures.
Floodlights, Spotlights, and Accent Lighting
If you’re replacing floodlights, spotlights, or accent lighting, be sure to consider whether you want the light to be diffused or focused. Omnidirectional bulbs will cast light over a wide area, while spotlights and floodlights will have a narrower band of illumination.
Buildings and construction are responsible for 39% of global energy-related carbon emissions & contribute in more than 75 % Energy Consumption in India. With the need to save & preserve the energy and understand different practices to conserve the energy. The National Energy Conservation Day is being celebrated every year on December 14 since 1991. The Bureau of Energy Efficiency (BEE), under the Ministry of Power spearheads the celebrations every year. ECONAUR is Celebrating the Energy Conservation Week week and the campaigns for the week with a specific day wise themes.
Heating, powering, and cooling buildings (in-use) contributes 28% to global energy-related carbon emissions, while 11% of these emissions refer to carbon released during the construction process and material manufacturing (embodied emissions). Themed #BuildingLife this year, World Green Building Week is seeking to explore how to create a green, healthy, and climate-resilient built environment for all.
To date, the building and construction industry’s focus has been on operational emissions and how buildings actually perform in-use.
However, in order to fully decarbonize by 2050 to keep global warming to below 1.5 degrees, the building and construction sector must also tackle embodied emissions from the entire building lifecycle, according to the World Green Building Council (World GBC), Econaur being India’s First Integrated Platform for Green Building Solutions working to promote the Sustainable Solutions for making a Green Building and also showcasing the New technology available.
Themes for the week:
Every Day we have a Theme depicted to our Environment and Buildings where we will be Highlighting some stories, Case studies of some projects Offers and Discounts for Sustainable Products and also some exciting offers in which anyone can participate.
Do Visit and share your projects, stories or any new technology related to buildings and start writing here – https://econaur.com/sign-up/. Do visit Econaur for other updates related to Sustainable Buildings.
If you want to know more about Energy Conservation Day, Check here.