Another heat pump food dryer

[mechanic]

So I added some piercing valves and topped up the refridgerant a bit. The compressor runs slightly cooler, enough to keep it from kicking out, and the evaporator gets way colder. With the fan and everything running it stabilizes at 360 watts. I found a timer setting of 1.5 hrs on/ .5 hrs off seemed to work well to keep the evaporator defrosted. Made up a batch of 6 lb of bison jerky and gave it a try, worked very well! Let it run for 24hrs, kill o watt said it used $0.73 of power total. Not too bad, cost less to process it than the spices! Made 12 medium ziplock bags, although I put it in the oven for a bit to get it up to safe temp the drying was complete.

[mechanic]

[mechanic]

[jeff5may]

Superb! Good to see you got the bugs worked out of the unit. I hope it lasts you a long time.

I was not so lucky. I modded the fridge and got it running. It does its job really well. Unfortunately, whoever had this unit before me let some food spoil in it and let it sit for an extended period of time. There is a lingering funk inside that appears with a putrid vengeance every time it gets warmed up. No matter how much I clean, it keeps coming back. This odor would certainly taint the food I put inside it to dehydrate.

Does anyone have any good ideas as to how I could go about deodorizing the interior spaces inside this unit? It would be a shame to have to scrap it.

[NiHaoMike]

If you have a small high voltage power supply like a flyback transformer, build a small Jacob's ladder inside and run it for some time. The ozone will zap the smell.

[Daox]

How are these things working out for you guys? Do they work well? Any draw backs?

[mechanic]

Only issue I ran into was its not hot enough to bring meat to a safe temp

[jeff5may]

I tried to get the stench out of mine a few different ways. Spraying and fumigating the inside didn't work well. Trying to burn out the odor by placing a space heater inside the unit did a little better. As a last resort, I built a liner out of greenhouse film around the fridge and filled the whole thing with a box of cascade and water. I rigged up a small pool pump and a hot tub heater element and slowcooked the whole cabinet at 150 degrees overnight.

After the unit was given a pressure washing and allowed to dry, I reassembled the phase change rig and ran trials on some herbs and peppers from the garden. While there was no longer any stench coming from the unit, the dried product still had a faint tainted odor. I threw in the towel and scrapped the shell.

I saved the phase change parts for future use. A growing number of friends and family have shown interest in these little projects I have been brewing up. My collection of spare parts is growing out of its boundaries, so I plan on assembling some custom rigs as gifts.

[stevehull]

Jeff - you get an A+ for effort!

As you know, sometimes the dragon wins . . . . .


Steve