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Inside a Pet Cool

PostPosted: Sun Aug 13, 2006 6:14 pm
by bdosborn
Here's some pics of the inner guts of a Pet Cool if anyone is curious about what's in there. The wires hanging loose on top go to the 300W heater that I was fixing at the time of the photo.
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Bruce

PostPosted: Sun Aug 13, 2006 11:12 pm
by asianflava
Thanks for the pics Bruce! I was wondering what the guts of a petcool looked like.

So it has separate fans for the condenser and evaporator?

I don't see why you can't make it a split unit. All you would need to do is extend the charge lines.

If I build another trailer, I want to experiment with making a split unit.

PostPosted: Mon Aug 14, 2006 10:43 am
by bdosborn
That's where I was going originally. I got as far as researching homebuilt computer A/C but lost interest after I got the Pet Cool. That would be a slick setup if everything but the evaporator was on the tongue or something. I wonder how hard it would be to recharge it if you cut and extended the refrigerant lines? I wonder if the compressor would pump the refrigerant very far or high?
Bruce

PostPosted: Mon Aug 14, 2006 12:40 pm
by asianflava
I figure if you are going to braze the extensions on, you can easily braze on some schrader valves.

I guessing that if you insulate the lines, the compressor should be able to pump the refirgerant. I'm thinking like an auto a/c the lines on my truck have to be about 6 feet long. As long as it doesn't evaporate in the lines before it gets to the evaporator you should be OK.

PostPosted: Mon Aug 14, 2006 1:11 pm
by Melvin
bdosborn wrote:That's where I was going originally. I got as far as researching homebuilt computer A/C but lost interest after I got the Pet Cool. That would be a slick setup if everything but the evaporator was on the tongue or something. I wonder how hard it would be to recharge it if you cut and extended the refrigerant lines? I wonder if the compressor would pump the refrigerant very far or high?
Bruce


Refrigeration isn't really sensitive to the length of tubing, at least for what would be required to split a pet cool in a tear drop. However you do need to know what you are doing and you need to be licenced (in Canada anyways) in order to buy the additional refrigerant you would need to compensate for the increase in volume from the additional piping.

Most any repair place could discharge the unit and then refill it once you have the unit in position. Refrigerant lines need to be Sil-Phosed (copper-copper) or silver solidered (copper-steel). If you want to do this yourself you'll need a hotter flame than provided by a propane torch. Plus you need practice keeping stuff clean.

What I'd do in your case is take the pet cool unit down to a independent shop that does both residential A/C and Automotive A/C. He can evacuate the system and supply you with two lengths of tubing appropriately sized. Once you have the evaporator and condesing unit mounted where you want them; and the tubing ran between the two (make sure to leave a good foot extra to give the tech something to work with) return to the shop. The shop can braze the joints up, pull a vacuum, check for leaks with nitrogen and finally charge the system.

This ain't going to be cheap by the way. There is at least a couple hours of labour + materials for 4 joints and the refrigerant grade copper tubing.

PostPosted: Mon Aug 14, 2006 1:15 pm
by tonyj
Old VW bugs had looong lines running from the compressor in back to the condenser in front mounted near the spare tire well. As I recall, the lines were high pressure hoses, barbed and hose clamp fittings.

Of course, the big problem today would be the environmental issues with opening the lines to make the unit. But I figure hoses and coils fail and vent that stuff all the time. You could probably take a window unit to a repair shop and have them remove the freon, build your split unit, and take it back to have it vacuumed and charged if you didn't have access to a vacuum pump and guages.

I think splitting the unit isn't the difficult part. The difficult part is engineering the intake and exhaust air so everything works properly.