Fresh air all year around.
OpenERV Energy Recovery Ventilators transfer clean air inside and move polluted air out, while retaining 91% of the heat energy. It is under development, for a few more months.
The OpenERV:
Provides fresh air during very hot or very cold weather, without the addition or loss of heat to the dwelling.
Provides a reliable, regulated supply of fresh air. Never too much or not enough - better than an open window.
Is easy and inexpensive to retrofit into any area of any building, even buildings with no ventilation system, or electric heat. No ducting needed.
Features these core aspects:
Ultra high real-world energy efficiency - 91% sensible, 45% average latent heat recovery.
High fresh air flow rate capability - 35 CFM net actual fresh air.
Absolutely whisper quiet - 0.2 Sone (~15 dBA, @8 CFM).
Excellent long term maintainability, due to it's Open Source nature, and the use of standard components. No planned obsolescence.
Provides a return on financial investment superior to photovoltaic panels in many climates.
Also works to prevent the intrusion of heat during hot weather, while providing fresh air.
Effectively reduces CO2 levels, reduces transmission of airborne pathogens and improves IAQ, but without heating or cooling related problems of a fan or open window.