But with deregulation, most utility subsidies have dried up, Gotham said. We are optimistic that prices will continue to fall on the ERVs and the energy savings will make up for the initial cost anyway. We'd rather make our way in the marketplace without utility subsidies. Humidity Fighter Use of an ERV is even more important in hot, humid climates where bringing in outdoor air can also mean bringing in moisture. Adding moisture can not only make building occupants feel uncomfortable, and require additional cooling, it can actually damage building interiors and porous wall coverings, furnishings, and carpeting.
Moisture encourages mold growth and dust mite activity.
Greenheck offers a 50-page application manual, which begins by outlining the need for mechanical ventilation. School classrooms and auditoriums, with their varying occupancies, are a good application for ERVs. In Houston, five Greenheck rotary ERVs were specified to provide 20,215 cfm of outdoor air to the school, or approximately 20 cfm per student. Following the success at one school, Alexander Elementary, the district decided to add ERVs to three more schools. Greenheck recently expanded its product line to include a Mini-Vent 450 ERV that provides 300 to 500 cfm of outdoor air, with external static pressures up to 1 in.