Window Air Conditioner Freezing Up, Will Portable AC Do the Same?

Critical420

Critical420

Member
I have a window air conditioner in my grow room that has been working perfectly until the other night when the outdoor temp got down below 32F. The fan started making a loud noise (most likely froze with ice), so I shut it off and opened the window a little to cool the room off (fortunately the room is on the second story).

So, I am thinking about buying a portable air conditioner that has an intake hose and an exhaust hose. But I am concerned that I may run into the same problem when the temps drop to sub-zero over the winter. Does anyone here have any experience with using a portable AC unit in below-freezing temps? Or if you have any other ideas on how to keep the room cool, please post them. I have four LEC/CMH315 lights in the room.
 
chemphlegm

chemphlegm

Well-Known Member
pick up a small light bulb, a heat cable even and attach it to the bottom of the pan. avoid those shit portables imo, but no, they wont freeze because they sit on the floor of your room and exchange odors with the outside too
 
Lite

Lite

Well-Known Member
if the outside of the window unit (condensing coil) is 32 degrees, then the inside coil (evaporator) would be like 5. You cant run an airconditioner with it exhausting outside when it is that cold. It drives the pressure of refrigerant down too far and causes freezing.
 
Critical420

Critical420

Member
Lite said:
if the outside of the window unit (condensing coil) is 32 degrees, then the inside coil (evaporator) would be like 5. You cant run an airconditioner with it exhausting outside when it is that cold. It drives the pressure of refrigerant down too far and causes freezing.
Click to expand...
So what can you do? Just open the window? That makes it hard to regulate the temp. Will a mini-split freeze up also?

On my last few grows I didn't use AC in the winter, and the plants suffered due to high temps. I'm hoping to prevent that this winter.
 
Lite

Lite

Well-Known Member
can u have it exhausting into ur house outside of the grow area?

you need a head pressure control on an airconditioner to have it run in low ambient, but good luck installing one of those on a mini split, and window units are impossible.
 
Critical420

Critical420

Member
Lite said:
can u have it exhausting into ur house outside of the grow area?
Click to expand...
Actually, I could cut a hole in the wall and vent it into the attic, which would help keep the house warm. And since the hot air will be exhausting into the closed cool attic, it will never freeze. This will also keep my neighbors and other snoopers from wondering why I have a window AC running during the winter. Genius! Going to get my sawzall now.

Thanks!
 
Last edited:
chemphlegm

chemphlegm

Well-Known Member
I got lucky in Michigan winters. my first shaker had the blade freeze in the water and tripped a breaker after three years of running. My next window shaker I got no issues once I installed heat tape to the pan. I monitor the power draw year round with my phone app. seems good year long.
my buddy had some issue with his split freezing so he put a dog house over it with a small light inside, works like a charm now.
 
Lite

Lite

Well-Known Member
critical, an easy temporary fix could be to go throw a piece of plastic over half of the outside of the window unit. this will kill the unit tho
 
Critical420

Critical420

Member
Lite said:
critical, an easy temporary fix could be to go throw a piece of plastic over half of the outside of the window unit. this will kill the unit tho
Click to expand...
Good idea. The 5k window units are just over $100 which is a cheap fix compared to the problems that uncontrolled temps would cause.
 
Lite

Lite

Well-Known Member
covering half of the outdoor will cause the headpressure to rise because it wil have a harder time expelling the heat from the tent. the warmer it is outside the more u need to cover it. it will totally burn out the fan inside the unit tho so monitor amperage if you can.
 
whitebb2727

whitebb2727

Well-Known Member
Why not just hook an inline fan to a thermostat to draw cold air in? It would work about the same.

Exhaust outside if you can. If you vent to the attic watch humidity. I got mold from exhausting inside. Never again. I had to scrub the walls down and paint with kilz paint.
 
whitebb2727

whitebb2727

Well-Known Member
Lite said:
I will be making a guide here in the next week or so of rigging up a normal HVAC thermostat to power a damper and fan system (used when pulling fresh air from cold places)
Click to expand...
There is another thread with a guy asking how to do that.

I think it would be the easiest and possibly cheapest route for winter time.
 
chemphlegm

chemphlegm

Well-Known Member
Lite said:
where dis thread at?
Click to expand...
why my ac work so well in winter time year after year?
I understand what you say and have heard it before, but mine cycles flawlessly for some reason.
the water draining will freeze solid in a bucket underneath the pan, for an idea of temps.
 
Huckster79

Huckster79

Well-Known Member
Ive been thinking of building a thermostat controlled inlet fan to outside in winter. Kinda foolish to pay to cool air in winter... if others have ideas how to do this please share! I was just going to use the thermostat switch i have my window shaker
Plugged into (its not in window but into my basemen) and put a louvered vent w duct booster in it to pull outside air in when it reaches certain temp instead of ac unit in winter... i use a thermostat switch on my window unit so i can set different temps for day and night...instead of the controls on the ac unit which would be constant temp all the time. I got it for $40 at big box home improvement store. Then was going to attempt to difuse air up after it exits the louvers inside so that if its real cold out girls dont get a blast of bitter air on em... let the cool sink over the room. . On outside was just going to put a dryer vent with baffle out being air would be in reverse to normal operation, the downward facing not multi louvered type, just to prevent wind from blowing inside louvers open...

Seems like pretty cheap cool air just the electric cost of duct booster fan...
 
chemphlegm

chemphlegm

Well-Known Member
Lite said:
what is your indoor temp? and how cold os it outside for u chem?
Click to expand...
My room stays 70 lights off 78 lights on, temps outdoors between 25-89, water is frozen in the bucket if I catch the ac drainage during winter, (not today, its nice out right now)
 
You must log in or register to reply here.
Top