After my successful post on How to select Air conditioner, Air-cooler or Fan for home cooling … I got queries from blog readers about more Eco friendly ways to keep their home cool .. and hence my research went on this subject …
Option 1 : Solar Heat Reflective Roof coating / Painting
This option is always helpful for people staying at the top floor. Simply paint the roof top with white heat reflective paint, which helps bringing down house temperatures during day time.
Here are options available in market for Solar Heat Reflective Roof coating
- EXCEL CoolCoat (20 liters for @ pack)
- OzoProtect KR – 100% acrylic polymer based concrete roof/terrace coating
- StarShield Solar Reflective & Insulating – Certified by GRIHA Council, US Green Building Council & Indian Green Building Council
- Allied Koolmax
Highest SRI value thus reflect maximum amount of the solar infra-red and UV rays
Reduce the inside temperature by 15-20% in summer
Option 2 : Use Exhaust Fans
Exhaust fans can be used for home cooling during night times … For better results you must locate them near the roof top and shall have window opening on the opposite side .. This will create draft of cool air through night time (Here my suggestion is mainly for India, where summer nights are mostly cool)
How do I know exhaust fan will work for me ?
Now here is simple check if ur exhaust fan will help u keeping cool during nights ..
At night time say ~10 pm measure temperature in balcony of your flat / house, if get temperature difference of around 2 Degrees to the inside bedroom temperature, then surely exhaust fan will work for you..
Logic behind this is that human body cold / hot sensation is subjective, so 2 degrees also make remarkable difference in comfort level. All that you spend sleepless night is due to this small difference in temperature and roof fan will never be able to make temperature low. So here exhaust fan will help equalizing outside to inside temperature driving hot air out and naturally sucking cold & fresh air in …
It will make your bedroom breathe happily …
Tip : Locate exhaust fan at the top most point of house / room since that removed hot air which is stagnant & creates cold flow inlet in house
- No fan can cool your home like Air conditioner can !! in terms of speed of cooling ! however the DELTA temperature difference makes your nights happier 🙂
- This is the most cost effective way, A/C will eat up to 2 KW load as against an exhaust fan which pulls mere 50 Watt (40 times less) so most eco-friendly way !
- Exhaust fans will cool house in night time than day time
- Due to low power consumption this works even in power cuts on Inverter ( Now here is simple guide helping you out to select inverter for your home )
- A/C can keep only one room cool, as against POWERFUL exhaust fan located at say terrace door keeps entire house cool by expelling naturally accumulated warm out & drawing cool air thro’ all windows in house
- Bathroom exhaust fan helps in cooling down + main work is to reduce unpleasant smells & helps in reducing the fungus formations due to moisture
- Compare to A/c unit window fan circulates lot of fresh air in house, however this may not work in polluted area where air filters in A/c may help preventing entry of outside air
- Fresh air circulation and delta difference in temperature throughout home makes u feel cozy, which may not be the case for an A/c in single room
Option 3 – Cheap air conditioners from reused Plastic Bottles
Inventor Ashis Paul from Bangladesh
Concept : As the hot air passes through the bottle neck, if gets compressed and cooled !
Here is an interesting video on invention, you may like to try at home, it uses simple air compression method
more reading …