Hot Topics: Covering an AC Compressor

an outside AC condenser with a cover on it

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Original Post: Covering the top of outdoor A/C condenser

BeingCareful88 - Member

Now that the summer has ended, I would like to cover up top of my outdoor AC condenser like below linked picture with a cloth cover until summer 2020 to reduce leaves, insects, rain moisture, and snow from getting into inside of the condenser unit. I have a split system, and heater runs on gas so when my heater is on, the condenser fan will not spin. It will only spin when I have AC on. Is this ok?

a covered AC condenser

Now when summer begins in 2020, can I cover the top of it with a mesh cover that allows ventilation during all summer? Even during the summer, bugs and leaves can fall into inside of the condenser unit. I would like to keep the inside of the AC condenser as clean as possible.

Since I've already invested in the cloth and mesh covers, I would like to use them. Your opinions are appreciated.

GregH - Super Moderator

I would not recommend cloth as a covering for the top.

It will hold moisture and encourage rusting.

You would be better off using waterproof cover so water runs off of it.

Also, you should not put anything over the air discharge as it will restrict airflow and cause it to slightly overheat.

You will also find that debris can enter from the bottom and would be trapped by additional screening.

manden - Member

All I use is a piece of plywood cut to the correct size and tied down with ropes over the winter.

In summer I do not recommend anything on the condenser unit as it will reduce air flow.

PJmax - Group Moderator

Your picture is showing a plastic tarp. That is good for the winter. Covering the top keeps debris from falling in yet allows air flow thru the unit to reduce rusting from condensation.

As the others have mentioned.... don't use any covering during operation.

BeingCareful88 - Thread Starter

Yes, you are correct. What I have in the picture is plastic tarp that is advertised as water proof and snow proof. So you're advising that I should use the plastic tarp only in WINTER? Right?

Now, would it be ok to put a mesh cover that allows air flows during SPRING, and FALL to reduce debris from getting in? It sounds like during summer, I should not put nothing on. Not even the mesh cover that allows air flows. I noticed that even that mesh lifts up a little when the fan in the condenser spins to blow out the air during the summer.

PJmax - Group Moderator

Don't use ANY covering when the unit is in operation and producing cold air.

BeingCareful88 - Thread Starter

Ok, then would it be ok and not cause any harm if I cover the top of the AC compressor with the black plastic tarp in fall, winter, and spring and remove it in summer when I turn on the AC? As of today on October 19th, I have the black plastic tarp on top of the AC compressor just like shown in the pic in this thread.

Or do I use the black plastic tarp ONLY in winter, and use plastic mesh cover that allows air flow in fall and spring to reduce debris getting into the AC compressor?

Norm201 - Member

All installers will recommend to only put a plywood top over the condenser in winter to protect and ice or snow from falling in from the top. Keep the side s open to the air flow. If a high amount of leaves or debris gets in from the sides then you can something like deer block netting to help prevent that. But in most cases that is not a concern. You don;t need any form fitting contraption. I use a 3 x 3 piece of ply wood with a 4x4 old post to prevent the wind from blowing off.

jannyrobert - Member

There is a reason to cover your air conditioner after the summer, and it's not just for the winter. As we said before, your unit is built to withstand the rain and snow, but it is not built to keep out leaves, seeds, or nuts.

Therefore, you will want to cover your system during the fall only. When leaves or seeds get into your air conditioner, they can create a place where moisture collects, which then causes corrosion. It can even block up any moisture drainage your system has built-in.