will my 20x20 heating coil freeze?

[daveh12]

My 20x20 heating coil is mounted about 12 inches above my A coil.

I'm running water only (no antifreeze) through the coil.

Can it get cold enough to freeze when AC is on?

If so, I guess i need to drain the coil in the summer months?

Thanks

 

[habanero]

I bet it could potentially get cold enough to freeze, but I highly doubt it would get cold enough to burst the pipes. Would certainly suck if it did, though, so you might want to drain it just in case.

 

[tawilson]

I think you'd see your A coil frosting up before that happened. But it might be a good idea to drain it anyways. I'm just wild guessing here, but if your heating coil was higher than your owb, you could get a circulation going where you'd be sending cold water to your boiler.

 

[daveh12]

Using Greenwood in detached garage

Thanks for the replies guys.

I don't anticipate reverse flow to OWB. I'm using a Greenwood in my detached. It has a flat plate heat exchange at the furnace. The pump to the house will only activate when I have useful heat or if water is getting cold enuf at the Greenwood to possibly freeze.

I think to be safe, I'll have a shutoff / drain valve at the heating coil entry / exit. When heating season is over, I'll drain the heat exchanger.

Being able to isolate the heat exchanger like this will also allow a yearly leak check.

Cheers!