Direct Replacement Specifications for Roof Top Units

Roof Top Unit Features

• A roof top unit houses the bulk of the HVAC system's components, from the condenser to the evaporator, within a paneled square or rectangular metal container. Each roof top unit is unique to the building it services, based on cooling and heating needs, as well as the structure's overall size. The roof top unit resides on a curb, or concrete support, that is customized to hold the unit securely. This protects both the roof and HVAC assembly's structural integrity.

Ducting

• The roof top unit supplies all the ducting within the building with cooled or heated air. A direct replacement roof top unit must be configured to match the existing duct work design. Once the direct replacement roof top unit is placed on the curb, the ducting should automatically fit snugly into all air outlets on the HVAC assembly. Any deviation from the duct work's design would require rerouting or additions of duct work for attachment to the roof top unit, creating a costly replacement situation.

Wiring

• A direct replacement roof top unit should have the same electrical wiring as the previous HVAC unit. Electrical rewiring requires adding and altering existing electrical configurations, generating a costly labor bill from an electrical contractor. A matching electrical system allows the roof top unit installers to simply plug into the existing wiring configuration and move forward with the final installation parameters. This electrical matching saves time and labor costs for overall direct replacement.

Curb

• The curb, or concrete support, must fit perfectly underneath the direct replacement roof top unit. As a result, the new roof top unit should be approximately the same size and shape as the previous unit. Any deviation in shape or size would require a new curb configuration or a curb adapter, costing more money for the building's owner.