India is a tropical country and its Northern parts face extreme weather conditions. People living in this part keep looking for solutions that will keep their houses cooler in summers and warm in winters. Air conditioners, blowers and water heaters consume substantial energy. To tackle the issue, LEC systems are being invented and popularised by companies believing in sustainable development. LEC systems mean Low Energy Consumption Systems. These systems insulate a building and customised packages are available to treat the roofs, walls and terrace gardens. Here’s how the LEC cover can work for your home:
The roofs are given water and heat-proofing treatment. This involves a layered application of different kinds of membranes and materials. First of all, a foam shield is applied to the concrete slab of the roof. This is followed by the application of two coats of elastomeric material. These coats ensure waterproofing of the roof slab. Thereafter, a 3 inch thick plain concrete screed is deposited over elastomeric coatings with proper slope given to concrete surface towards the rain water pipes embedded in the walls. The sloping surface of the screed is then provided with a geotextile layer. This is finally covered with white elastomeric acrylic and UV stabled coatings. White colour is good for heat reflection. It is ensured that the elastomeric coatings have good solar reflectance index (SRI) value. These layers act as thermal insulation layers.
Saving through walls
The walls are treated with coatings of elastomeric materials that possess waterproofing properties and have low thermal conductivity. These coatings have high solar reflectance index (SRI) and high total solar reflectivity (TSR). Sometimes, the coatings applied on the walls trap air and ensure excellent heat insulation. The overall result is a complete waterproofing of walls, low heat gain by them and cooler internal surfaces of the buildings.
Try it on terrace garden
Many people prefer to lay terrace gardens in their houses. But while opting for terrace gardens the issue of dampness and seepage remains a key concern. In such cases, when terrace garden is to be developed, the roof slab is, first of all, sprayed with a waterproofing material that sets instantly to produce a breathable and rubberised membrane. It is ensured that this material has good adhesion with the concrete surface. This is followed by a foam shield and elastomeric material coatings as is done in roof treatment. Next, the concrete screed is laid to required slope towards the drain pipe. The concrete screed is now covered with a membrane that is root resistant and waterproof. Over this layer, the drain board is laid followed by a geo textile layer. Now, the soil is laid over the geo textile layer and grass is grown in the earth layer.
LEC Systems are considered successful only if these result in saving power consumption by 50 per cent, reduce internal temperatures by 8 to 10 degree and reduce the use of ACs to minimal.
Mere assurances by a company providing LEC systems may not build its credibility in the eyes of a customer. The solutions provided by the company should comply with the provisions of Energy Conservation Building Code (ECBC) of Bureau of Energy Efficiency (BEE). The company should hold LEED certification for low energy consumption and sustainable construction. The customer should handover the building to the company for application of LEC systems. After the inspection of the building, the service provider should first prepare the blueprint of the work to be carried out by him and discuss it with the building owner along with the cost involved in it.
The writer is former HoD and engineer-in-chief, Civil Engineering Department in a Punjab PSU