Can a Simple Rooftop Support Be “Engineered”?

A finished KnuckleHead installation supporting air conditioning units and pipelines is aesthetically pleasing.

Rooftop supports for pipes and HVAC equipment come in a variety of shapes and sizes, and, of course, prices.  Some feature a base made of recycled rubber and a metal top for supporting pipes or struts.  Some are simple one-piece units composed of molded plastic, some are metal components that have to be mechanically fastened piece by piece, and some are simply blocks of wood cut from treated lumber. None of these can be considered “engineered” in the truest sense.

To understand what an engineered support is, one should consider that engineered means “contrived” or “devised” and is related to the word ingenuity.  In the fullest sense, our modern understanding is that much thought and design go into creating a product by understanding its life cycle , from manufacture to  long-term field performance.

By this definition, the KnuckleHead rooftop support is truly an engineered product.  In its conception, design and making, every aspect of the role and performance of a rooftop support has been taken into consideration.

Original Design:  Base and Heads

The engineering of the KnuckleHead begins with the base.  The base has to be ample enough to provide stability while distributing weight evenly.  Most rooftop supports are rectangular or square in shape.  GreenLink chose a circular base because of its efficient radial symmetry. The diameter of the base is 7” which provides 38 square inches of surface area—a good balance between the size of the footprint and its stability.  Finally, the base is engineered to be universal, meaning that it will fit with any type of GreenLink head design.

The support heads are engineered as well.  Each head provides a nest, a snug compartment where the various rooftop components will be seated.  This again contributes to stability relative to other types of supports where the pipe or strut is set loosely on the surface.  KnuckleHeads are engineered for each specific application, whether it involve pipes, rectangular metal struts, solar arrays or pavers.

Easy Height Adjustability

A special feature has been engineered into all KnuckleHeads:  adjustability.  The typical support is static: it offers only a fixed height. In contrast, KnuckleHeads can be adjusted right at the point of installation simply by rotating the head.  The adjustability range is approximately 1” up or down.  Adjustment is critical to getting HVAC equipment perfectly level–especially on an uneven roof surface—since being level is critical to maximum long-term performance for chillers, air conditioning units, mini splits and heat pumps.  Much greater elevations can be achieved by simply using sections of PVC pipe:  the diameters of the base and head are compatible with standard pipe.

Material Selection:  High-Performance Nylon

A critical part of engineering a product includes the material itself.  In the making of the KnuckleHead, careful consideration was given to a material that would allow for intricate design, moldability, strength, and durability.  That material turned out to be a nylon polymer that could be reinforced with glass fiber.  The result was a support that could be shaped precisely to fit struts, pipes and pavers; was light in weight but could support 600 lbs. of weight; and could be efficiently molded.  KnuckleHeads can stand up to all types of weather: freeze/thaw cycles, continuous high heat, hail, vibration, intense sunlight, even impact.  Reinforced nylon is so strong and durable, it is substituted for zinc and aluminum in some military applications.

Nylon has another important property: certain types of adhesives will bond to it.  This leads to yet another engineered aspect of the KnuckleHead.  It can certainly be loose laid like any other type of support—its ample base was designed for that.  And it can be mechanically attached—the two holes in its center provide an avenue for mechanical fasteners.  But it can also be bonded to the roof membrane with adhesive.  GreenLink Adhesive/Sealant can be spread on the base which presses onto the roof surface to create a firm bond and a watertight seal.  The base features eights sets of holes through which adhesive can be squeezed out when pressed onto the roof membrane.  This allows the adhesive to access atmospheric moisture which accelerates the curing process. The combination of mechanical fasteners and adhesive/sealant makes an extremely secure installation.

Finishing Touches

Finally, KnuckleHeads feature a range of accessories that further enhance performance.  KnuckleStraps and KnuckleCaps are used to secure pipes in the head—important where equipment vibration, high winds or seismic events can threaten extensive pipeline installations.  In addition, KnucklePads are designed to fit the bottom of the base to prevent movement as well as to protect the roof membrane.  Straps, caps and pads are all molded from tough, weatherproof polyurethane and tinted safety yellow to add an aesthetic appeal to a finished project.

Every aspect of the role of rooftop support was taken into account when the KnuckleHead was designed: ease of installation, stability, suitability for specific use, aesthetic appeal, strength and durability.  A finished KnuckleHead installation supporting air conditioning units and pipelines is aesthetically pleasing.  It looks engineered.  Because it is.

GREEN LINK is committed to processes and products that cause no harm to the environment or human life. Visit them at www.greenlinkengineering.com.