Proper ventilation is essential for maintaining good indoor air quality, yet it places an additional burden on heating and cooling equipment, which must condition air that will soon be exhausted from the building. Fortunately, energy recovery ventilation systems can help ameliorate this problem.

After a decade of development, ice storage for small unitary air conditioners is still expensive but has the potential to be competitive with several utility-scale electricity storage technologies. It remains to be seen if the latest generation of equipment can live up to manufacturer projections.