Can I install a heat pump?

[StaggeringGoat]

I'd like to get some A/C sorted out for my shop (40x60) before summer comes. Here in the NW we only need A/C a couple months of the year, and it doesn't have to work that hard.

I've been seeing used heat pumps on craigslist in the $2-500 range. If I buy one of these units would I be able to install it myself? Obviously I'm no expert but I have an idea of how the system works. Maybe I could find a book on the subject? I would have to run the plumbing and charge the thing with refrigerant.

I also wonder what I would use inside as the evaporator portion for the heat pump. Do you think I could use an evaporator core from a car/truck in combination with a residential style heat pump?

The plan here is cheap A/C for a big shop...I don't care what it looks like and I know I'll have to jurry rig a few things....

 

[ghnl]

I installed a couple of 'ductless mini-split heat pumps' - one in the garage, the other for the room above. They cost more than $500 each though.

Another option is a PTAC unit like those used in hotel rooms. They require an opening framed to the right size and a 220V outlet.

 

[jayrush13]

you need an EPA license to buy refrigerant and some specialty gauges and equipment so if you had to buy that it would cancel out the savings you had

if you know anyone that does HVAC work you could do every thing but the brazing and charging and possible have them come over and do the hard stuff for a couple $$

 

[39portlander]

When someone talks about heat pumps and in the some paragragh is the word cheap, unhappy comes to mind. A 410A heat pump would be the ideal set up 40X 60 not a ptac, unless you wanna put in 3 or 4. Used stuff off craig's list or fleabay have no warranty

If your gonna go cheap, put a window shaker in your windows. Save up and invest you will be alot happier in the long run. With a heat pump you will have the best of both world

As jayrush stated, find someone who can help you out. Big Cash fan, love your avatar

 

[StaggeringGoat]

you need an EPA license to buy refrigerant and some specialty gauges and equipment

Supposedly you need an EPA license...but I've noticed refrigerant is freely available on ebay. Harbor freight sells a cheap A/C gauge kit and vacuum pump too.

Unfortunately I have no windows for a window unit...and I'm just flabbergasted at the prices of new heat pumps installed.

Does anyone think an automotive evaporator would work with a normal heat pump, if I had someone charge it for me?

 

[ghnl]

You don't 'need' a window. I put a casement style window A/C in our garage before we expanded it. The casement style A/C was 14.5" wide - thus it fit between the standard 16" OC studs - no need for headers or other fancy framing.

 

[pattenp]

The A/C gauges that Harborfreight sells are for R134A Freon (cars) only. Gauges for the newer 410A units are a lot higher pressure and are high $$.

 

[StaggeringGoat]

You don't 'need' a window. I put a casement style window A/C in our garage before we expanded it. The casement style A/C was 14.5" wide - thus it fit between the standard 16" OC studs - no need for headers or other fancy framing.

Unfortunately I lease the building and I don't think the owner would be very happy if I cut a hole in the wall. The heat pump could go on the roof and I already have a hole for the plumbing....

The A/C gauges that Harborfreight sells are for R134A Freon (cars) only. Gauges for the newer 410A units are a lot higher pressure and are high $$.

Thanks for pointing that out...it does look like I can find an R22 gauge/manifold for rather cheap on ebay. If I got a used heat pump it would probably be R22, not the newer 410 stuff.

 

[fastjohnny]

Just get an A coil, blower and plenum, probably easiest to get a complete gas furnace, even if you don't run gas to it. Brazing, evacuating, and charging not that difficult. If you buy new, the heat pump comes pre-charged, just evacuate, open the valve, and check pressures with gauge.

 

[StaggeringGoat]

Just get an A coil, blower and plenum, probably easiest to get a complete gas furnace, even if you don't run gas to it.

Problem with that is the A coils seem to be about $2-300 by themselves. I was hoping I could use an automotive evaporator, they only run about $30 new. I could simply put a fan behind that and blow cold air into the shop. I think automotive A/C systems are sized at a couple of tons just like a heat pump.

 

[BadgerBoilerMN]

You want a ductless mini-split, air-to-air heat pump installed by a professional.
He will do a proper heating and cooling load, size the AC unit properly for the best comfort, efficiency and reliability.

I am in the business and my shop and office are cooling with a Mitsubishi.

 

[StaggeringGoat]

You want a ductless mini-split, air-to-air heat pump installed by a professional.
He will do a proper heating and cooling load, size the AC unit properly for the best comfort, efficiency and reliability.

I am in the business and my shop and office are cooling with a Mitsubishi.

I am not spending multi-thousand dollars on this project.

 

[FXDawg]

You want a ductless mini-split, air-to-air heat pump installed by a professional.
He will do a proper heating and cooling load, size the AC unit properly for the best comfort, efficiency and reliability.

I am in the business and my shop and office are cooling with a Mitsubishi.

We just had one of these installed at work in our server room. The installed price was $5,500.00 for a 1-1/2 tons of cooliing

 

[Falcon67]

Why not just shop the local AC service companies for a take out - those usually go cheap.