Running Residential AC in Winter...AC keeps freezing

Hi,

RI grower here!

New to this forum (and commercial growing) and would really appreciate any help!

Running 24 bare vertical 1000-watt lights in the room...currently they are at 75%. So it's HOT. Using undercurrent system, btw.

The problem is, my AC keeps freezing up (live in the north with cold winters). I came to check on it the other day, the unit was frozen up and the temps in the room were above 90F

Just had a 5 ton AC on the roof installed but it's a residential unit...wish I had known that I needed a commercial unit, but I've spent plenty of money on this unit so I am trying to find a way to make it work.

I've put in a low ambient kit and am considering building shed housing over the condenser on the roof. But I'm hearing that those may or may not help and could be high maintenance?

Does anyone have experience with a similar situation? Thank you!!

-Ms. Caregiver

You need a functional low ambient "freeze kit" installed.

You could tent the condenser to cause recirculation. Next time shop for ductless mini split inverter type units rated for very low ambient. Or just vent in some of that cold fresh air

ok so maybe this is a stupid question but why use an ac if the outside temp is below 32? couldn't you do the same thing with a couple inlines? even if you are running a completely closed system, I would think it would be cheaper to set up a heat exchange system, like a couple trashcans full of water + antifreeze/salt, a pump and a drain line.
=/

We install ductless minisplits all the time to cool server rooms year round. Downside to venting is on days where temp fluxuates too much outdoors and room gets too hot. Requires user intervention to change from venting to aircon.

oic I thought it said 2 1k lights the first time I read it lol.

Did the five ton hold good temps in the summer? We generally size at 4kbtu/hr per bare 1kw thus 8 tons to handle lighting heat load (doesn't include summer solar radiation calcs)

SnapsProvolone said:

Did the five ton hold good temps in the summer? We generally size at 4kbtu/hr per bare 1kw thus 8 tons to handle lighting heat load (doesn't include summer solar radiation calcs)

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Thanks for your help! We used a wall unit too. What material would you use for the condenser tents?

I have never tented one intentionally, we always run mini splits and commercial buiding codes/ordinances would have an issue with the concept. I suppose you could simply put a tarp over a central tent pole and tie down the corners. Just be sure its wind proof and that there is no possibility of damaging the feeds to the condenser. Don't suffocate it, provide an ample volume of air around the unit.

The idea is keep most but not all of the heat that radiates from the condenser.

If the condenser fan is running and you have an electrician handy have them temporarily disconnect the condenser fan from the contactor (although freeze kit should keep fan from running on a cold coil).

1itsme said:

ok so maybe this is a stupid question but why use an ac if the outside temp is below 32? couldn't you do the same thing with a couple inlines? even if you are running a completely closed system, I would think it would be cheaper to set up a heat exchange system, like a couple trashcans full of water + antifreeze/salt, a pump and a drain line.
=/

Click to expand...

I live up north also, this is exactly my "air conditioning" as soon as the temps get below 10C/50F at night (when I run my lights). At those outside temps I bring in fresh air with an inline fan connected to a thermostat, free air conditioning, throw in a filter, make sure the vent is directed anywhere but directly at the plants so it can blend in with the rest of your indoor air, good to go...

Another thing to consider, if the a-coil is freezing and you do have the freeze kit check your filter or change it to a cheapo one. If return air flow is either designed with too few return cfm or your filter is restrictive it will make coil freeze ups common. Also try pulling down the humidity with a commercial dehu.