Solar homes is a great way in which tapping of solar energy is done through the solar radiations entering the house. Solar home helps in containing those radiations and converts them into the solar power required. Therefore apart from attracting the maximum amount of sunlight to the house, it is also equally important to store the radiations hitting the surfaces. Thus as a passive mean of generating solar power, solar homes are needed to have proper solar insulation of maximum benefits.
Heat from the house can escape through 3 major processes- conduction, convection and radiation. Air infiltration is the primary reason which causes convection form of heat loss. Air infiltration can occur through cracks, more than necessary open windows and vents. Therefore for proper tapping of solar energy it is primarily important to have compact structure avoiding uncontrolled heat loss.
Importance of Air Infiltration in Solar Homes
Air infiltration is an important aspect that should be taken care of while the designing of the solar home. Therefore it is important to know about air infiltration as a prerequisite for building the solar homes. Some of the important consequences of air filtration are:
- Reduction in Efficiency – Air infiltration is an important way of deescalating the amount of solar radiations escaping from the solar home resulting in below optimum power generation. Air infiltration accounts for around 5 to 40 % of total heat loss.
- Can be Controlled – While the heat loss through Air infiltration can be avoided, the heat loss due to conduction through windows and radiation loss are hard to prevent.
- Insulation loss – The insulation added to the house is also disrupted by the air infiltration. Even the smallest hole can allow the heat to pass out condemning the efficiency of the solar technology to be low.
- Moisture Growth – Air infiltration can also lead to growth of moisture in the walls and surfaces having the problem. This may lead to weakening of the structure.
- Rodent problem – Air infiltration also causes rodents and vermin to enter the house. This can be easily prevented by building compact structures.
Factors solving Air infiltration
Air infiltration is measured in terms of Air Exchanges per hour (ACH). ACH is recommended to be between 0.35 and 0.50. Below that is also not recommended for ventilation purposes.
For preventing air infiltration, proper detection of leaks is an important part. There have been various easy methods and sophisticated processes devised for detecting such processes. Proper maintenance can also lead to prior prevention of such holes. After detection the cracks can be further treated easily.
Some of the important measures that can be taken to reduce the air infiltration are listed below:
Controlled ventilation – Controlled ventilation is an important factor which leads to decrease in air infiltration. At the time of designing itself, controlled ventilation can be implemented. Ventilation through windows should be measured to an extent so that extra ventilation does not lead to heat loss.
Improved windows – The window quality as well as quantity should be developed such that the windows offer ample but controlled amount of air circulation. Low air circulation results in increase in the amount of carbon dioxide which can be poisonous. Therefore there is an essential requirement of limiting the level of air circulation to around 0.5 ACH is required.
Air barriers – Air barriers are an alternate method to reducing the problem of air infiltration. Air barriers not only reduce the infiltration levels but they also help in reducing the speed with which the air hits the house walls.
Sealing the solar home – Sealing and proper insulation of the house are important measures for air infiltrations’ reduction. Sealing helps in reducing the cracks which may have been leading to air infiltration.
Summing it all up ..
Solar home is an innovative idea towards sustainability, which helps in solar power generation through passive means. It soaks up the heat that the sun provides and then uses it for important purposes. Therefore for keeping up the heat supply, it is important to limit the heat losses. Limiting Air infiltration plays a major role in limiting heat losses
Air infiltration is an important measure which should be taken care of before designing solar homes. Using simple precautions and flexible architecture, Air infiltration can easily be reduced. Making homes compact is a basic method of solving the infiltration problem.
However it is also advisable to measure the amount of air infiltration in the house, as there is a range in which air infiltration should lie for most favorable benefits.