Heat Recovery Ventilator
From Swikipedia
Introduction
Heat recovery ventilators (HRVs) provide an energy efficient way to bring in fresh filtered air while removing stale air. It brings in fresh air from the outside, preheats the incoming air during the winter and pre-cools the incoming air during the summer. It can provide clean fresh air every day while helping to keep energy costs low. This results in high amounts of energy savings (almost 50-70%) as the heating and cooling requirements are reduced.
The heat recovery ventilators and energy recovery ventilators (ERVs), though closely related, the latter also transfers the humidity level of the exhaust air to the intake air.
Brief Description
Benefits:
While improving the building efficiency through insulation and weather stripping, the buildings become more air-tight and consequently less well ventilated and since all buildings require a source of fresh air, the need for HRVs has become obvious. Though opening a window does provide ventilation, the building's heat and humidity will then be lost in the winter and gained in the summer, both of which are undesirable for the indoor climate and for energy efficiency, since the building's HVAC systems must compensate. An HRV is designed to be energy efficient and exchange the air to bring in fresh air you want at a rate you choose; clean the incoming air; exhaust stale air, pollutants, and moisture, while recovering up to 85% of the heating or cooling energy.
References:
http://en.wikipedia.org/wiki/Heat_recovery_ventilation
