Case Study: Vera Bradley Operations Center
Design an HVAC system that was energy efficient and would perform to maintain the office environment in accordance with IAQ guidelines.
The Solution, with a twist...
A geothermal heat pump system with a pond loop was selected. However, this type of system produces two challenges:
- Heat pumps are notorious for not maintaining space humidity at acceptable levels.
- Providing ventilation air to each space in accordance with ASHRAE 62.1 is not always done correctly.
How we made it work
Our solution was to use a dedicated outside air system with an energy recovery wheel and heat pump that would use the energy from the exhaust air leaving the building to pre-condition the incoming outside ventilation air by extracting heat in the winter and transferring the heat and humidity in the summer. This system delivers conditioned outside air directly to every room in the office complex and uses very little energy to do so.
One additional step that was taken was the use of the ‘Climadry’ option from Climatemaster, the heat pump manufacturer. This new feature allows a heat pump to switch to a dehumidification mode by using the heat from the compressors to remove the moisture and then reheat the supply air allowing the system to maintain space temperatures within 2 deg F of setpoint and maintain space humidity within 5% of setpoint, even on a cold and rainy day.