Functions: Heating and cooling
Integrated rooftop units provide conditioned air through direct contact between the condenser coils and outside air, eliminating hydronic piping from the air conditioning system. Many RTU models can also be equipped with a gas boiler to use the same air duct system for heating.
RTUs can be configured as constant volume (CV) or variable air volume (VAV) systems. However, the VAV configuration provides superior energy efficiency while minimizing drafts and noise. According to a study conducted by the U.S. Environmental Protection Agency, VAV installations provide energy savings ranging from 10 to 21 percent.
When using a VAV system, it is important to ensure that a minimum external airflow is maintained, even when total airflow decreases in response to a reduced cooling load. This feature is sometimes ignored, which has a negative effect on indoor air quality.
