Cement or plastic pad for Condensor

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drewdin

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I am in the process of getting a condenser installed, the HVAC guy recommended a pre-cast plastic pad for the condenser to sit on.

I would rather use a concrete slab than a plastic pad, some friends told me that had issues where the pad moved, bent, collected water, etc...

My question is, which is the preferred method? If concrete is preferred, how big of a base should I make? 4'x4'? How far from the house should it be located? Thanks
 
Have seen both. Plastic is light weight, easier to move. But, the edges or corners get brittle and can chip. You can pour your own pad or get a precast ... I prefer poured because you can get a perfectly level base that will never move. Size it 6" larger than the equipment footprint all around.

AC.jpg
 
Thanks, how far from the house should i keep it? is 18" enough or does it depend on the size of the unit? Thanks
 
The proximity is more for servicing than anything. The 18" gap is a workable minimum. Putting it closer makes future servicing a pain.

Getting ready for the hot Summer?
 
I am, its been muggy here and the only thing I have left to get the AC going is to install the condenser. The area where i plan on putting the condenser is on a corner of the house just like the picture above. I might just fill the whole corner with cement and not just a 4' square, so just 2" thick with some gravel underneath will be sufficient?

Thanks again
 
Form up with 2x4s, so you will get 3.5" ... pre-level the area with light shovel work to minimize ground disruption. Use RediCrete which has gravel in it and you will be fine ... a gravel bed is an added bonus. Just do your best to get the forms level. (Unlike the pic below) I have heard debates that the condenser MUST be perfectly level versus "Aw, BS, it can be anything close to level." I prefer the former because the unit lubricates best when level. :D

Another note ... set up your condensate drain so it does not undermine the pad. It can wash out and the unit will start to sink right where the condensate line drips off. Run the line away from the pad a bit.

Compressor1.jpg
 
I would go with a little slope maybe 1/8 per foot away from the house and shim the unit level and give it a broom finish.

nealtw makes a good point, add a slope to keep water from sitting on the pad.
 

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