Correctly Placing HVAC Units on Commercial Rooftops

Rooftop units are an extremely common setup in HVAC systems for commercial buildings due to their ease of installation, good energy efficiency and ability to provide heating and cooling in one unit.

Unfortunately, an improperly placed and installed packaged rooftop unit can lead to roof damage, including punctured membranes and sagging that could lead to ponding water and leaks. Correct HVAC placement along with support struts can help protect your new HVAC system and your building’s roof so that you get the maximum expected useful life from both systems.

Commercial HVAC Rooftop Installation Considerations

Commercial HVAC rooftop units require special considerations and calculations prior to being installed. This includes calculating the load the unit will place on the roof and determining the best location for the rooftop unit. In general, the heaviest part of the packaged HVAC system should be placed over a roofing beam to ensure the unit is adequately supported and to prevent unintentional damage to the roofing system, like sagging and tearing, which could result in roofing leaks. The commercial HVAC contractor must also become familiar with the type of commercial roofing system and the manufacturer’s specifications for installing roofing curbs and performing roofing penetrations. Failure to follow the manufacturer’s recommended guidelines could result in the warranty for the roof being voided. Likewise, it may not be advisable or possible to set the rooftop HVAC unit directly on the roof, especially if the building has a membrane roofing system. In these instances, the HVAC technician would want to oversee the installation of several optimally placed strut supports that can hold the support beams for the new packaged HVAC rooftop system while minimizing damage to the commercial roof.

KnuckleHead Strut Supports for Commercial HVAC Rooftop Units

Our KnuckleHead Strut Supports are ideal for raising and supporting commercial HVAC units, conduits, coolant lines, and air ducts. KnuckleHead Strut Supports are manufactured using a glass-reinforced nylon resin, which ensures it is weatherproof and resistant to the freeze/thaw cycles that can negatively impact other support strut materials, like wood and steel. Each KnuckleHead Strut can support up to 600 pounds, and they can be purchased in heights range from 2.75” to 18”. In addition to providing load support for the HVAC system, the Knucklehead Strut Supports also help prevent roofing system and equipment damage due to ponding water, high winds, shaking or quaking due to seismic events and wind damage from severe storms. For buildings with membrane roofs, the Universal Base ensures that the struts can be properly attached either with screws and adhesive or solely with adhesive. To help maintain roofing warranties, flashing can be installed around the Strut KnuckleHeads and either heat welded to the strut and roofing material or installed using a commercial roof-friendly adhesive.

To learn more about our strut supports and to request pricing, call us at 888-672-9897.