PHFA – Pennsylvania Housing Finance Authority

QUICK FACTS

COUNTRY

USA

CITY
Harrisburg

BUILDING YEAR
2019

ARCHITECT
MURRAY ASSOCIATES

END USER
PHFA

Project: Passive House & LEED Platinum Historical Renovation and Tower Expansion.

To accommodate growth, the Pennsylvania Housing Finance Authority (PHFA) renovated their headquarters and added a new 8-story tower. As a proponent for buildings constructed to the Passive House concept, it is fitting that PHFA chose to design the project to meet PHIUS Passive House requirements.

Need:

The Passive House consultant sought to provide ventilation meet local code requirements, using air handlers with energy recovery meeting Passive House Institute requirements for:

• high heat recovery effectiveness
• high electrical efficiency
• low casing leakage
• low cross-contamination
• self-balancing control

Solution:

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.

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.