Don’t Trust What You Read. Measure.
It is common knowledge that manufacturers often over-inflate the efficiency ratings of their products. When making selections of HVAC and heating/cooling equipment, rather than base our decisions upon the marketing literature of products, we perform actual bench testing of proposed equipment under conditions that simulate field conditions to accurately determine both their effectiveness and operating costs in advance. Then, we specify products that have met our standards. Alternates are not accepted.
In lieu of traditional vertical shafts and large rooftop exhaust fan units, we favor the “unitized ventilation” approach. Each apartment is effectively air sealed and separated from the next unit. This not only helps provide for quieter living spaces, but also helps to reduce the transfer of smells and smoke in between units. It also hinders the movement of insects/vermin through the building.
From 2010 through 2017, small individual, energy efficient exhaust only fans were used to remove moist and smelly air from bathrooms and kitchens through the side walls of the buildings. This also helped to reduce the transfer of odors/smoke/sound from one unit to another.
As of 2017, all new buildings are equipped with energy recovery ventilation units (ERVs). These small individual units (one per apartment) exhaust from the kitchens and baths (as before), but use the heating/cooling energy of the exhausted air to pre-heat or pre-cool the apartments through 4 sets of ducts all terminating at the ERVs. The use of ERVs in buildings with very air tight envelopes helps to reduce space heating/cooling energy consumption by a factor of 40% – 50%, and also allows for a much more comfortable, draft-free living space.