Help! Cold room problems

Hello,
Over this summer at my parents house my father and I built a cold room. He had an old wine cellar in the basement so we ripped its guts out and re-did the insulation. We lined the walls and celling with roll insulation then put board insulation over it.
Unfortunately I had to leave to go back to school ( oregon state fermentation science!) before it was finished so He had to go through and finish by himself. Fortunately my dad just happened to have some professionals over working on insulation for the rest of our house and they offered to professionally seal it up for him.

Heres the problem, we had installed an analog ac where i threaded the copper wire back through the unit and hooked it up to a ranco. My dad said he tested everything out today and despite having the ranco set to 45F the room never went below 56 after four hours. Plus he said the unit never shut off. The ac is sealed into the wall pretty well so taking it out is the last resort. I asked, and no the coils did not freeze so something else must be wrong.

Any suggestions? Thanks

Capacity mismatch? How many cubic feet is the room, and what's the BTU rating for the AC unit?

Cheers!

If i remember correctly, the room is about 5 1/2 feet tall by 4 feet wide and maybe 6 or 8 feet long. The ac unit is only 8,000 but i figured that if the ac could cool an average sized living room this small room wouldnt have been a problem

BrewWein said:

If i remember correctly, the room is about 5 1/2 feet tall by 4 feet wide and maybe 6 or 8 feet long. The ac unit is only 8,000 but i figured that if the ac could cool an average sized living room this small room wouldnt have been a problem

Click to expand...

You could be right, but otoh, you're trying to drop the temperature way below what would be "normal" for a living space...

Cheers!

What's the temp of the air coming out of the AC unit? Maybe it's bad?

Sounds like you are not bypassing the controller and controlling the compressor directly, the controller low limit is usually 55 degrees. The fan will run continuously, but compressor will cycle off when temp drops below 55 degrees to prevent coil freeze up. When you get past that problem you will run into the next problem, cold surfaces will attract and hold moisture, which ends up as ice on the cooling coils. The greater the air infiltration and higher the ambient humidity, the faster things freeze up, and the faster moisture collection causes biological problems.

I can have my dad attach a couple fans onto the coils so it wont freeze, but i thought that by threading the copper wire back through the ac unit i was bybassing the compressor.

Also my dad got back to me with the specs....It contains 112 cubic feet (70 x 66 x 42 inches)

Generally the unit will freeze up if it goes that low. There could be a frost thermostat on the coils.