29 ENERGY USE AND CONSERVATION IN BUILDING CONSTRUCTION – NEED AND SCOPE

P.G. Padma Gowri

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Introduction:

 

In the design of energy efficient buildings, it is necessary to optimize building construction and energy utilisation in buildings. If we plan to design a new home or do extensive remodel on an existing house, optimizing home energy efficiency requires a whole-house systems approach to ensure that optimum use of energy and conservation of energy.

 

The energy efficiency is based on the home’s structure and efficient heating, cooling, and hot water systems. Information in the existing home provides details about the current structure and systems. In that some recommendation is added to improve the efficiency of the buildings.

 

Objectives:

  • Impart knowledge energy efficient building construction.
  • Explanation about of concepts of green building.
  • Design of energy efficient buildings in various aspects.

Energy conservation:

 

Energy conservation refers to reducing the energy consumption by using required amount of energy sources. In the construction we are using minimum required construction materials. In all the places safety and security is ensured. In the electrical energy conservation refers to use of maximum amount of renewable energy.

 

Energy conservation is different from efficient energy use, which refers to using less energy for a constant service. For example driving less is energy conservation. Driving the same amount with a higher mileage vehicle is called as energy efficiency. Energy conservation and efficiency are both energy reduction techniques.

Green Building:

 

Energy efficient building or the green buildings are the structural construction processes respect the environment and make efficient use of resources. A green building is a clean, sustainable building, designed with natural materials, uses little energy and renewableones    at that,  is easy tomaintain with cost effective.

 

They consider that a building must above all adapt to humans, the well-being of its occupants being capital. Green building not supports use of toxic substances in the industrial manufacture of construction materials. In any form hazards are eliminated. It also provides natural efficient design of building construction.

 

Eco-construction, also referred to as energy efficient construction, proposes various possibilities of reducing the environmental impact of buildings. Green building is not a specific construction method, but it brings together a set of techniques, materials and technologies which is integrated in a construction project, contribute to enhancing itsenvironmental    performance.

 

A green building is designed to reduce the overall impact of the built-up environment on human health and the natural environment, by the following:

  • The efficient use of energy, water, air and other resources.
  • Protecting good health and improving working productivity.
  •   Reducing  waste,  pollution  and  harm  which  will  make  to  the  environment.

Types of energy conservation:

 

1)  Existing building energy conservation planning.

2)  New building energy efficient planning.

 

Existing building energy conservation planning:

 

In an existing house, the first step is to conduct a home energy assessment also called as energy audit to calculate how much the home uses energy and determine the best ways to cut energy use and costs.

  •  Data collection: first we start collecting some preliminary information on the energy consumption of the facilities and some technical details such as connections, drawings and equipment inventory.
  • Field work: In the buildings energy consumptions, details of the consuming equipment such as brand, model, power and hours of operation are collected .
  •  Analysis of energy consumption and performance of energy accounting: In that all the operations of the organization must be analyzed, including equipment’s consuming higher energy.
  • Analysis and development of energy saving measures: once all the data collected has been analyzed, energy saving measures can be identified using various techniques.
  • Energy audit report: After performing all the above steps in the energy audit, an energy audit report must be issued.

This should include at least the following information:

  • Technical scope: this point includes facilities, services and included areas and level of depth in the analysis and other details are mentioned.
  • Methodology: this point includes the analysis of the state of art of the facilities that is energy inputs, technologies and services, measurement results.
  • Suggested energy saving measures: this point includes a details of each energy saving measure, including potential energy savings, economic savings, investment needed and payback is mentioned.
  • Conclusions: the recommended measures, total energy savings, total economic savings, total investment and payback period of the devices are given in detail

Energy Efficient Planning for New Building:

 

The planning process is to look into a renewable energy system that can provide electricity, water heating, and space heating and cooling. It may also provide an option for financing an energy-efficient home.

 

To design a new building, in addition to occupant behaviour, site conditions, and climate, the following factors also included,

Ultra-Efficient Homes

 

Theultra-efficient homes combine state-of-the-art energy-efficient construction, appliances, and lighting with commercially available renewable energy systems, such as solar water heating and solar electricity. For the local climate and site conditions, designers can often also incorporate passive solar heating and cooling and energy-efficient landscaping strategies.

 

Advanced House Framing

 

If we build a new house or adding on to an existing one, consider using advanced house framing also known as optimum value engineering, which reduces lumber use and waste and improves energy efficiency in a wood-framed house.

 

Cool Roof

 

In the hot temperature region Cool roofs are used. It is highly reflective materials to reflect more light and absorb less heat from sunlight, which keeps homes cooler during hot weather.

 

Energy savings

 

By energy savings, we mean all economically interesting actions undertaken to reduce energy consumption, by for instance installing suitable equipment in electrical installations. The aim is also to consume energy in an optimal manner e.g. recuperate heat lost in combustion gases or produce clean energy from waste. We should be aware that energy savings do not concern just electricity. Adopting some simple daily habits along with a judicious choice of equipments also enables us to control consumption of all other forms of energy example gas, heating fuel, etc. In a building, the main priority is to identify energy savings.

 

Energy Conservation:

 

Home automation system:

 

Energy efficiency can be materialised in a home through the use of occupancy detectors and full home automation systems. All these solutions help to manage and programme lighting, heating and other uses to optimise their use at a lower cost.

 

In commercial buildings, solutions are multiplied to reduce energy use and contribute to reducing greenhouse gases, both in lighting, office equipment management, safety lighting, infrastructure measurement and surveillance.

 

Electrical Panel:

 

Automatic on and off Electrical panels can improve energy performance in a home and thereby contribute to sustainable development and the energy efficient building approach.

 

Reactive energy will created when we use many number of motor and coil related electrical components. It will affect energy quality. New innovative solutions are available to compensate reactive energy and measure building consumption. Using capacitor banks in buildings increase the efficiency of the installation and network analysers make it possible to measure the consumption and quality of the energy.

 

Energy savings in cooling system:

 

Very large quantity of energy was saved by proper usage of cooling equipment’s in buildings. Air-conditioning systems and reversible heat pumps with a rated cooling power above 12 kW are equipment for home comfort. Their energy use is not in proportion to actual needs, either because they are incorrectly dimensioned, or that they are not correctly maintained or serviced.

Some  of  the important    measures that   enable   energy  savings are:

  • Good thermal insulation of all exterior components for walls, windows, roof, etc. Eliminate thermal bridges and other energy leakages and take measures to avoid.
  • Good airtight seal on the exterior building envelope are used.
  • Reduction of thermal losses through ventilation.
  • Optimised electricity management .reduction of installed power ratings, central management, use of lighting control equipment, etc.c.

Energy conservation by Heating and temperature control:

 

Water heating consumes main part of the electricity bill of homes in India. Domestic heating is therefore the expenditure item to be considered in highest priority in the search to identify solutions for reducing electricity and natural gas bills.

 

Energy efficient heaters and some simple energy solutions that encourage energy efficiency and therefore energy conservation in building. Boiler maintenance is very example, avoids deregulations that can lead to energy over-consumption.

 

Using air conditions also important energy consumption in home. It is also recommended to adapt the opening/closure of shutters and curtains according to the outside temperature and to the sunlight on glass separations. Use automatic controller for energy conservation in buildings.

 

Doors and windows for green buildings

 

Doors and windows seal the buildings and therefore must respect very strict criteria. Entrance the doors must protect against humidity, heat and noise. They must provide safety, durability and energy efficiency.

 

The conventional doors made of wood are replaced by using aluminium and PVC for the structure,  with   low-quality  insulating     foam   fillers.

 

Today there is a wide range of durable and efficient solutions made of plastic materials for doors that are easy to maintain. They are low weight, plastic doors are extremely durable. In fact, the spreading use of plastic door products has validated their strength, their energy efficiency  and  their  acoustic  value. Vinyl windows and glass doors enables less electricity to be used for heating and cooling a house or larger building.A low maintenance needs of vinyl windows and glass doors eliminate the need for paint, tinting, thinners and paint removers, which harm the air quality.

Renewable energy:

 

The various forms of renewable energy are solar power, wind power, biomass power, geothermal power, hydraulic power, etc.

 

Renewable energy sources have the advantage of being available plenty like solar, wind and biomass. Their use is a way of satisfying our energy needs and conserving the environment.

 

The energy produced by photovoltaic panels is an important component of renewable energy production, used in the form of automation and optimum use of energy.

 

Investment on various clean energy technology projects around the world have been undertaken to improve the efficiency of renewable energies, to reinforce the economy, protect the environment and reduce our dependence on oil products.

 

Solar power systems:

 

An energy efficient buildings balances all aspects of energy use in building-lighting, space conditioning and ventilation by providing optimizing mix of passive solar design strategies ,energy efficient equipment and renewable sources of energy.

 

Solar heating systems:

 

Solar heating systems installed in all types of buildings for energy conservation. Using solar power to pre-heat outside air before it is allowed to enter a building can be reduce heating costs both in residential buildings and commercial constructions. Solar heating systems are more efficient for large buildings such as hospitals, hangars, school and gyms, as well as multi-storey residential buildings.

 

Bio mass:

 

Biogas is a product from biomass. .Biogas typically refers to a mixture of different gases produced by the breakdown of organic waste in the absence of oxygen. Biogas can be produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste or food waste.

 

Biogas is a renewable energy source. It is an alternative source production by using home waste products. From a carbon perspective, as much carbon dioxide is absorbed from the atmosphere in the growth of the primary bio-resource as is released when the material is ultimately converted to energy The by-product of bio gas also used as manure .It is used for agriculture purpose. than absolute zero emit thermal radiation. We can use solar and conventional radiant heating system. It is called as hybrid heating system.

 

The Hybrid solar radiant heating system is a solar heating kit that works with any in floor heating loop or radiant floor system. The system is to be used as the primary heating source for any radiant floor system, replacing the need for an expensive boiler.The hybrid solar radiant heating system includes a primary solar heating loop with both a top and bottom heat exchanger.

 

Rain water harvesting:

 

Rain water is an inexhaustible natural in the green building. Rain water is collected by channels as it runs off a roof and is stored in a tank. In the construction we can made provision for rain water storage. Due to the presents of carbon monoxide, carbon dioxide and other pollutants present in the air rain water is slightly acidic (pH from 5 to 6).

 

For domestic use, we store the rain water in concrete or limestone tank that neutralises the natural acidity in it. By storage of rain water or rain water harvesting we can effectively increase  the    ground    water   level.

 

Reduction of waste and toxic substances:

 

A good building design helps the occupants to reduce the quantity of waste generated. It also offers solutions such as composting organic waste, to reduce the volume of matter going to landfills. The main aim of green architect is to reduce waste in terms of energy, water and materials used for the construction.

 

Green buildings avoid the systematic burial of materials retrieved from buildings at the end of their life by recycling and reuse them. The organic manure is properly composed and used for garden plants.

 

Toxic substances:

 

During design and construction, the construction materials and interior finishing products are selected to reduce the amount of toxic substances in the building. Many construction materials and cleaning products emit toxic gases such as Volatile organic compounds and formaldehyde. Volatile organic compounds are chemicals used to construct and maintain building materials, interior furnishing, cleaning products and personal care products. VOCs as evaporate into the air from products. These gases can have a negative impact on good health. By avoiding these products, we can increase the quality of the interior environment in a building.

 

Energy Conservation in Buildings by Heat Insulation:

 

Heat insulation:

 

Thermal insulation is an efficient technology to reduce energy consumption in buildings by preventing heat gain or loss through the building envelope.

 

Thermal insulation uses a construction material with low thermal conductivity; it is less than 0.1 watts per meter-kelvin. The materials used for heat insulation is a purpose to save energy and protect and provide comfort to occupants. Verities of shapes and applications of thermal insulation, this section focuses on those that are commonly used for building envelopes– i.e., floor, walls and roof. For insulation the materials like Polyethylene foam , Cementations foam, Perlite loose –fill ,Vacuum insulated panel , brick, Glass, poured concrete , etc. are used.

Types of Thermal Insulation:

 

1)   Opaque constructional elements

 

In Opaque constructions can consist of evacuated or non-evacuated insulating elements. A vacuum space was created between insulator (radiators) and wall, the heat transfer mechanisms are restricted to the transport of energy through radiation. It has high production cost so evacuated panels used are very limited. Heat gain within the buildings is low so it is used in hot places.

 

In the region of radiators, exterior walls can be coated with reflective paints to enhance the reflection of the long wave radiation of the radiator into the room and to reduce the heat absorption on the exterior wall. In fig the energy pathways in insulation constructions are shown in a qualitative manner.

 

2) Transparent constructional elements:

 

Transparent thermal insulation enhances the passive use of solar energy on exterior walls. The solar radiation passes through the transparent insulation material and reaches the wall partition behind and heats it up room.

 

The long wave radiation emitted from the partition cannot pass through the insulation layer, because the transparent insulation layer is opaque for infra-red radiation. Heat gain within the buildings is high so it is used in cold places.

Advantages of Thermal Insulation in a Building:

  1. The buildings are thermally insulated remain warmer in winter and cooler in summer. A thermally insulated building provides great comfort both in summer and winter.
  2. A building provided with thermal-insulation requires less power to maintain the desired temperature conditions within the building. This saves energy and extra costs.
  3. Less usages of Air conditioner cooler, heater etc.
  4. Thermal-insulation prevents the roof deck from cracking and leakages.
  5. The materials that are used in thermal-insulation are lightweight than conventional concrete which reduces the weight on the roof slab.
  6. Usually thermal insulating materials are manufactured from recycled materials.
  7. Installation of materials is quite easy.
  8. Fire resistance will be provided by insulation.
  9. Very Less Maintenance.
  10. Environment-friendly materials used.

Electrical  And  Fire Safety Materials:

 

Electrical safety and fire safety is important issues in any buildings. The durability of the plastic parts of electrical components enables such products to have a long useable lifetime and ensure fire safety.

 

Conclusion:

 

Electrical energy minimisation which is carried out in existing building was discussed .the other methods like green building, heat insulation, plumbing, elimination on toxic waste are carried out for new buildings. Thus various forms of energy used and the methods to conservation of energy were discussed. Above motioned Green building concepts is need of the hour.

 

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