Dehumidifier conversion question

comlink · 07-30-2002, 06:34 AM

Hi, I'm new, you can probably tell

I have an old dehumidifier out in the garage that still runs like a champ (not been used in 14 years), and I had this crazy idea of somehow soldering copper flex-pipe onto the evaporator tubing, then running water through the flex-pipe to cool various things around my room. Apparently others had the same idea, as I see posts on here about "phase change cooling". Now, here's my question: can you solder copper to the evaporator while the system is pressurized? The only reason I didn't do this two years ago was I don't want to rupture a refridgerant system while flame soldering on it (compressor lube and flame apparently create great gobs of fire that can kill by merely seeing them

)

Update: Darn this thing's weedy. Takes about 10 minutes for frost to form on the evap. and that's without any airflow over it! Hope it can get the job done.

bigben2k · 07-30-2002, 09:15 AM

I'm not sure it would be a good idea, but the problem would be that it's not the most efficient way to transfer the heat: you'd have a gap between a copper to copper interface, that's filled with lead (bad heat conductor).

You probably want to consider an exchanger type setup, like Punisher's: wrap the evaporator coils in PVC, and run your coolant through it. (much more efficient)

_Mike_ · 07-30-2002, 12:23 PM

That would also require a recharge of refrigerant, running an extra 25' (or so) of tubing.

bigben2k · 07-30-2002, 01:04 PM

Quote:

Originally posted by _Mike_
That would also require a recharge of refrigerant, running an extra 25' (or so) of tubing.

I think he meant soldering a different pipe along the evaporators', so that he can fill it with some coolant: it would allow him to have a dry cooling exchange.

comlink · 07-30-2002, 03:11 PM

I was actually going to use silver solder, it's the only type of solder I can get at Home Depot

Well, I found rotor's site and looked at what he had done, and then looked at mine and realized that mine was almost the same as his. So I just unbent the tubing and stuck the evap core into a basin of water. Worked great! I'm suprised.

airspirit · 07-31-2002, 04:31 PM

Bad idea. You won't get good xfer, since the heat will bleed to all sides of the evap. coils, not just the side soldered to the new coils. Just submerge the evaporator coils in a bucket of your favorite coolant and go nuts. Your other option is to (this sounds totally looney) take flex tubing and surround the evap coils with it (a tube in tube setup) and find a way to pump your coolant in one end and out the other without leaks. That would work pretty good, but would be a PITA. Naw, just dunk it in a bucket.

#Rotor · 08-01-2002, 10:22 PM

Suprised at it working so well?

or maybe suprised at how easy it was?....

Glad to have been able to help ya there...

what kinda temps are you getting with it?

comlink · 08-08-2002, 06:20 AM

Thanks Rotor, you opened my eyes

I haven't finished milling up my new block yet (have to wait until I can get a mill-vise) and until then I'm not going to bother drilling my wall up and all. But just with the evap core in a vat of antifreeze/water with a simulated 50W load provided by a peltier, the water freezes solid. Mwa hahahahaha!

07-30-2002, 06:34 AM	#1
comlink Cooling Neophyte Join Date: Jul 2002 Location: Sacramento, CA, USA Posts: 14	Dehumidifier conversion question Hi, I'm new, you can probably tell I have an old dehumidifier out in the garage that still runs like a champ (not been used in 14 years), and I had this crazy idea of somehow soldering copper flex-pipe onto the evaporator tubing, then running water through the flex-pipe to cool various things around my room. Apparently others had the same idea, as I see posts on here about "phase change cooling". Now, here's my question: can you solder copper to the evaporator while the system is pressurized? The only reason I didn't do this two years ago was I don't want to rupture a refridgerant system while flame soldering on it (compressor lube and flame apparently create great gobs of fire that can kill by merely seeing them) Update: Darn this thing's weedy. Takes about 10 minutes for frost to form on the evap. and that's without any airflow over it! Hope it can get the job done. Last edited by comlink; 07-30-2002 at 07:57 AM.

07-30-2002, 09:15 AM	#2
bigben2k Responsible for 2% of all the posts here. Join Date: May 2002 Location: Texas, U.S.A. Posts: 8,302	I'm not sure it would be a good idea, but the problem would be that it's not the most efficient way to transfer the heat: you'd have a gap between a copper to copper interface, that's filled with lead (bad heat conductor). You probably want to consider an exchanger type setup, like Punisher's: wrap the evaporator coils in PVC, and run your coolant through it. (much more efficient) __________________ WBTA (Water Block Testing Alliance) Nordic Hardware WC 101

08-01-2002, 10:22 PM	#7
#Rotor Cooling Savant Join Date: Feb 2002 Location: Dione, sector 4s1256 Posts: 852	Suprised at it working so well? or maybe suprised at how easy it was?.... Glad to have been able to help ya there... what kinda temps are you getting with it? __________________ There is no Spoon....

07-30-2002, 12:23 PM	#3
_Mike_ Cooling Neophyte Join Date: Apr 2002 Posts: 29	That would also require a recharge of refrigerant, running an extra 25' (or so) of tubing.

07-30-2002, 03:11 PM	#5
comlink Cooling Neophyte Join Date: Jul 2002 Location: Sacramento, CA, USA Posts: 14	I was actually going to use silver solder, it's the only type of solder I can get at Home Depot Well, I found rotor's site and looked at what he had done, and then looked at mine and realized that mine was almost the same as his. So I just unbent the tubing and stuck the evap core into a basin of water. Worked great! I'm suprised.

07-31-2002, 04:31 PM	#6
airspirit Been /.'d... have you? Join Date: Jul 2002 Location: Moscow, ID Posts: 1,986	Bad idea. You won't get good xfer, since the heat will bleed to all sides of the evap. coils, not just the side soldered to the new coils. Just submerge the evaporator coils in a bucket of your favorite coolant and go nuts. Your other option is to (this sounds totally looney) take flex tubing and surround the evap coils with it (a tube in tube setup) and find a way to pump your coolant in one end and out the other without leaks. That would work pretty good, but would be a PITA. Naw, just dunk it in a bucket.

08-08-2002, 06:20 AM	#8
comlink Cooling Neophyte Join Date: Jul 2002 Location: Sacramento, CA, USA Posts: 14	Thanks Rotor, you opened my eyes I haven't finished milling up my new block yet (have to wait until I can get a mill-vise) and until then I'm not going to bother drilling my wall up and all. But just with the evap core in a vat of antifreeze/water with a simulated 50W load provided by a peltier, the water freezes solid. Mwa hahahahaha!

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