I encountered an air handler today that was suspended by metal straps. It appeared the straps were fastened directly to the cabinet, but I couldn’t confirm since I couldn’t see it. My thinking is vibrations from the unit will eventually wear out the screws and the unit will fall. Has anyone else seen this type of installation? Unfortunately I don’t have a shot farther back.
Go ahead and put it in your report. I don’t see any fatigue cracks in the strap or a broken screw. Predicting future defects that aren’t a defect. What about all those sheet metal screws installed in ducts? How old is the house? Has it been installed this way for the last 20 years?
I have seen them suspended in the crawl space, but suspended with Unistrut, all thread and plywood .
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Around here, they suspend AHU’s with proper kits to isolate the vibration and can also hold the safety drain pan. Typical kits have threaded rods with rubber bushings, and are quite robust.
But I’ve also seen all manner of improvised support systems, so if it’s working and not causing problems, use your best judgment on what you’re documenting.
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I wouldn’t worry about straps and screws that don’t show any evidence of stress or fatigue. You were worried about the screws and you missed this.
My thinking is the sheet metal screws may be connecting a couple of pounds of ductwork, not supporting a couple hundred pounds of air handler. As such, I can see the potential for the sheetmetal screws to fail as their not designed for the load. Of course, I’m not an engineer so I could be off base on this. It’s a Goodman air handler manufactured in 2017. Oddly enough, the house was built in 1917.
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Hey @dwigger I see the Unistrut as well. That’s what has me concerned about this installation is that I don’t believe it’s designed for the purposed. There’s also no way to dampen or isolate the vibrations.
I always managed to have at least one good friend in all the different trades (plumbing, HVAC, electrical, framing, etc.) and in this case I would send my HVAC guy a picture of that installation and get his opinion before deciding how to report it.
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Sound advice David, I need to broaden my network.
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Which should include researching the Manufacturers Installation Manual for their guidelines and preferences on how to install/mount/suspend.
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but that would make too much sense.
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If the Hvac system is vibrating so much that it will vibrate through a screw , you have other concerns to deal with.
Likely they used short self tapping sheet-metal screws, and those could work loose. Recommend pre-drilling metal strap and install two additional 1.5" wood screws, for peace of mind. After installing the wood screws, remove one of the existing screws to decide if you want to do the other 4(?) straps. (are they hard to get to?)