Flat roofing offers additional space to those buildings with little interior storage and space. The flat surfacing makes it ideal for storage of heavier equipment when ground space is limited. It is also a more convenient location for your HVAC unit. While you can put many things up on your roof surface, HVAC units are the most commonly placed item on flat roof structures. There are pros and cons to having the HVAC unit on your roof.

HVAC Units on Flat Roofs: The Pros and Cons


One of the most important benefits is that by having the HVAC unit on the roof, it is not an obstruction for your customers or clients. It also keeps any loud sounds the unit takes away from the public. During the winter months, these units can turn on and off frequently, but when the noise is on the roof, it is not a disturbance to people. When HVAC units are on the ground floor, that means maintenance and upkeep is also performed right there too. This can cause major obstructions and disturbances. When up on the roof, maintenance crews can tend to the unit without getting in anyone’s way. HVAC units create a large amount of condensation, which will need to be frequently drained. When it is on the ground next to your building, it can leak and cause potential accidents as well as an unsightly mess. When up on the roof, any condensation can flow into the gutters and drain away from the roof in a much more orderly fashion.


The weight of the HVAC unit can cause damage to your roofing membrane. If you have foot traffic around the unit, this causes additional wear and tear. During routine maintenance and installation, the membrane becomes damaged which may lead to leaks inside the building. When installing an HVAC unit of the roof always ensure it is done properly and not rushed. If it is done in a hurry, you can end up with low spots on the roof surface which can lead to pooling, especially after rain. If there is pooling around the unit that is allowed to sit for days the interior material of your roof can begin to deteriorate. Always fill in low spots to avoid this potential damage. When the unit is on the roof and out of sight, it can be easy to forget about its upkeep and maintenance. The condensation line from the unit can cause malfunctions if not checked regularly and puddles can begin to form across your roof. Pooling water can cause mold and rot as well as leaks.

Final Thoughts

Understanding the pros and cons of having your HVAC unit on the roof is essential so you can make the best decision for your building. While it is more practical to have these units on the roof, it is essential that you don’t forget they are up there. So long as they are regularly maintained, your rooftop HVAC unit and your roof will be just fine.



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