Rooftop Packaged Unit with Integral Heat Recovery

Rooftop Packaged Unit with Integral Heat Recovery  - This large rooftop packaged unit also has a heat recovery wheel integrated inside the AHU itself. The all in one AHU and heat recovery unit saves energy by recovering heat that would otherwise be vented outside in the winter time and in the summer removing heat from the air that is used for economizer and minimum outside air.

In the winter the outside air dampers will open to bring fresh air into the building and vent stale air out of the building. The air inside the building contains heat. As the air is passing through the duct to be vented outside it encounters a heat recovery wheel. The air hits the heat recovery wheel and keeps moving past the heat recovery wheel but it leaves some of the heat is contained in the heat recovery wheel.

The desiccant wheel is turning and this heat contained in this wheel (from the old stale air) turns to the duct where the fresh outside air is entering the building. This cold air hits the wheel and absorbs some of the heat that was left there by the old exhaust air that was vented outside.

This saves energy by capturing waste heat in the air that is vented outside and exchanging it to the air coming inside via the heat recovery wheel. In the summer time the sequence works in a reverse manner as above except the wheel is absorbing more humidity and heat from the outside air so the load from the outside air is lessened in both sensible heating load and latent heating load.