Pennsylvanie Housing Finance Authority
Quick Facts:
The Passive House consultant sought to provide ventilation meet local code requirements, using air handlers with energy recovery meeting Passive House Institute requirements for:
Continuous ventilation is provided by 2 Passive House Institute certified Swegon GOLD RX air handling units with rotary heat recovery exchangers. Heating season supply air is tempered by the rotors. Hot and humid outdoor air in the summertime is tempered first by the rotors, then cooled further by integral direct-expansion (DX) coils and wrap-around heat pipes. The DX coils are connected to the buildings Variable Refrigerant Flow (VRF) system, and provide a second stage of cooling. Swegon’s IQ Logic controllers activate this second stage of cooling only as required to meet the supply air temperature setpoint. This prevents unnecessary mechanical cooling when outdoor air conditions permit.
Location | Size | Airflow (CFM) | Electrical efficiency (W/CFM) | Heat recovery efficiency (%) |
Roof | 50 | 4400 | 0.49 | 84 |
Mechanical Room | 25 | 2400 | 0.51 | 84 |
Outdoors and on the roof, a size 50 delivers 4400 CFM using only 0.49 W/cfm – well below the threshold of Passive House applications.