AC Condenser Pad Design Tips

[Acemas99]

Hello All,

I have used Eng-Tips throughout my college career, but this is my first time posting a thread.

I am designing a concrete AC condenser pad. The pad will likely be 42" x 42" x 4" and will contain a foam core to reduce the overall weight. The current target weight is 265 lbs, which is driven by the Florida Hurricane requirements.

I am wondering what basic design features I can incorporate to reduce the risk of cracking. I'd like to keep the cost as low as possible, so I am trying to avoid re-bar. I'm looking more for tips on the shape / geometry of the foam, wall thicknesses of the concrete, etc.

 

[bimr]

You can buy prefabricated concrete pads or slabs can be purchased in a wide range of sizes. Go with the gravel and plastic grey pad.....it will last longer than your condenser.

http://www.grainger.com/Grainger/a-c-mounting-pads/central-equipment/hvacr/ecatalog/N-8ti

 

[MiketheEngineer]

YEP!!

 

[Ron]

Agree with bimr and Mike...if you must have a concrete slab, look in the Florida Building Code....it gives a prescriptive method.

Don't worry about cracking....your slab is small, so shrinkage cracks, assuming a thickness of 4 inches, shouldn't be an issue.

I would thicken the edges to reduce scour/undermining potential.

 

[JedClampett]

Check your design vs these guys. They post excel spreadsheets for exactly what you're proposing.

http://www.diversitech.com/