Build "refrigerated" walk-in beer cellar cheap

Requirements: central AC, a basement below ground, wood, nails, common building know-how

We finished our basement and had a closet installed. I noticed that the heat / AC Duct ran right above closet. Since I live in the Northeast: I insulated the inner walls but left the outside foundation wall uninsulated and bare. Ground temp is always @55, if you live in Arizona: insulate the outside wall. Weather strip and insulated the door ( I taped on aluminized bubble wrap type)

I put a well sealing vent in the AC DUCT: in winter when ground is cold . Close the vent ( the heat is on).

In summer, open the vent when AC is on. You now have an actively cooled, insulated closet that remains @ 50 degrees all year. You could do the same by building or getting a large cabinet , and running a medium diameter duct off your AC into the cabinet. My AC puts air @ 45F and is able to cool a 6x10ft closet to 50 when it's 85 outside-and 70 in the basement. The hotter it is , the more the AC runs, the better. My only problem month is September when the ground is warm , but the AC isn't needed

To solve this problem I ran a dryer sized vent hose to a dryer type vent outside : on cold evenings, I open the vent and let the cold night air into the closet: free cooling. It really does maintain a temp range 55-50F with very slow gradual changes seasonally

 

I forgot one IMPORTANT factor. The insulated closet needs to be on the North side of the foundation.

After 3 seasons it goes like this: November through May, the cool concrete ground foundation wall and floor maintains the temp ( vent closed) . June- August the Air Condition vent is open , blowing cold air. September, October- the outside air vent is open daylight highs 60's but nights at 45 equal it out.

Regarding the fall months : I have checked air flow using a candle flame. Warm air always rises, so when the outside vent is open : air only travels down the pipe into the cellar when it is cooler than the cellar. In the daytime, the warm air above your head in the closet escapes via the vent while the cooler air sinks into the closet.

The more bottles, the steadier the temp because it takes a lot of energy to change the temp of 300 bottles x 750 ml of beer.

Lowest ABV beers on bottom shelf ( floor) , > 12% on second shelf up, old ales & higher than 14% ABV (120, Samael's , BCBS ) on highest shelf. I drink all the beer at cellar temp except sours, which I chill

 

I wish I knew how to post pictures. If anyone can lead me to a link , I will figure it out

 

Billy, the top of the closet is vented, ( it's under the dining room, and there is a register there)so I am relying on the warm air rising out of the room, while the cool air falls ( the AC duct crosses top of closet) Slow convection plus the radiant "coolness" of the exposed cinder block back wall 10 feet below grade. The upper 2/3 of that wall has fiberglass insulation. I'm sure my outside vent line leaks too. I think it's crucial that the closet be on north side of foundation.

That said: I've robbed the dining room of its AC which has a good and bad point. The main house thermostat is in there, so it reads higher without AC. Not terrible @ 2 degrees warmer. This makes the AC run more and I have to pay for the electricity. We only use the dining room for the kids homework area. I Leave the ceiling fans on to keep the AC from other outlets distributed though house.

In have gone on vacation and left the AC on for the cat, come back and it's 49f in there. I have a remote thermometer upstairs. It is hard to keep it cool if the door gets opened a lot, not enough power for that. I try to slide in through a cracked door 1-2 x per week.

It is labor intensive: we had a cold front go through last night and it went from 85 to 45. The AC won't be on for a week, so I will have to open the outside air vent at night, and close it in the morning