Excessive ventilation in winter expels heat and increases heating costs. This can occur due to oversized fans and/or poor controllers. Energy to operate air inlets and exhaust fans varies significantly. Self adjusting air inlet baffles require no energy at all to operate. Every exhaust fan consumes between 1000 and 10000kWh of electricity per year based on continuous operation. Energy efficiency in terms of ventilation equipment is very important. Producers can determined the electrical energy demand of a fan by the following equation:
reference kWh x hr/day fan is running x #days/yr fan is used x current energy cost $/kWh