The Homemade Heat Pump Manifesto

[Geo NR Gee]

Rhino 660, way to go. Perfect. Now, I could have turned them on the lathe, had them coated, drilled and well, sometimes its faster to buy them.

[AC_Hacker]

Originally Posted by rhino 660

look here,
you guys had said something about making your own socket fusion ends these are replacement faces.

Excellent contribution rhino, thanks for the link, this really opens up a lot of possibilities.

Many thanks!

-AC_Hacker

[charlesfl]

[URL="http://www.campbellmfg.com/brady/documents/wellinstallation.pdf"]

Here is the URL for the information on how some people drill wells in Florida. No rocks here, we have to buy them.

Charlesfl

[charlesfl]

[url=http://www.campbellmfg.com/brady

That one didn't work. This one should work under, instruction sheet, well installation instructions.

Charlesfl

[Geo NR Gee]

New hacker question.......... When shopping for a vac pump, what level of HG should the pump be required to pull the system down to? I will be using it for R290, R134a, R22.

[AC_Hacker]

Originally Posted by Geo NR Gee

New hacker question.......... When shopping for a vac pump, what level of HG should the pump be required to pull the system down to? I will be using it for R290, R134a, R22.

The pump should have a spec designating the maximum vacuum, and the unit for the spec is usually in microns.

For instance, the cheapo ($140) twin rotor Harbor Freight pump I got was rated at 60 microns, as I recall. I measured it with a micron gauge at 80 microns, and that was good enough for me.

A friend loaned me some well-worn vac pumps which only went down to about 500 microns, not good enough. He didn't have a micron gauge, he had a manifold set, and his vacuum gauge read 29.9 Hg, so he thought the vacuum pumps were perfect.

But at low vacuum, the manifold gauge will only read the really huge errors in vacuum.

And as I said before, you need to use fresh oil every time you evacuate your HVAC equipment... the oil is actually part of the process.

I think it's better for experimenter, amateur and hobby users to buy the oil in one or two use sealed containers. Only get the giant economy size oil if you are doing continuous production work, day after day.

Hope this helps.

-AC_Hacker

[Geo NR Gee]

I found one that has the following features....
Dual voltage design vacuum pump operates on 115 VAC or 230 VAC (50 or 60Hz). Single Stage design pulls vacuums fast.
•Fan cooled motors for high ambient temperature operation.
•High torque motors.
•Inlet port: 1/4" and 3/8" SAE and 1/2" ACME male ports
•Large oil slight glass with background for easy viewing.
•Motor thermal overload protection.

Specifications
Dimensions:
13.7" x 5.3" x 10"

Free Air Displacement:

4 CFM @ 60 Hz

Horse Power :
1/4 HP

Inlet Ports (male flare):
1/4", 3/8" SAE Male & 1/2" ACME Male

Oil Capacity:
13 oz.

Product Weight:
19.44 lbs.

RPM (50/60Hz):
1440/1720

Ultimate Vacuum:
100 microns

Should I keep looking?

[AC_Hacker]

Originally Posted by Geo NR Gee

Should I keep looking?

Well, you didn't mention the price...

Like I said, I got my two-stage pump at HF for about ($140).

I'd use that as a benchmark, if I were you.

All things being equal, the two-stage will pull a deeper vacuum.

The dual voltage thing isn't so important.

Just about all the other items are pretty much standard.

And another thing... the micron gauge I mentioned before is a tool that will allow you to actually test a used pump to see if it is worth buying.

You said your brother is in the HVAC trade, maybe he can loan you a pump and/or a micron gauge.

If I were you and had a bit of time, I would haunt ebay for a modern working micron gauge. The modern ones are pretty small and electronic, there were some older ones that were the size of a school lunch box and looked like they were Heath Kits... don't go there.

I got my micron gauge for $130... I really gulped when I did, but I had no other way of knowing if my vacuum pumps were working correctly. It turned out that they were not working correctly. That micron gauge also told me that the cheapo HF pump, that I took home as a trial, was working much better than the old pumps I had borrowed. Now, the HF vacuum pump will probably not have as long a life as the used American madeb pumps I borrowed, but I'm just not going to build that many heat pumps.

My friend that loaned me the vacuum pumps, bid a micron gauge for $60 on ebay. Petty good deal.

But getting back to the vacuum pump, if it can actually pull a vacuum of 100 microns, that should be good enough. Is it new? Is it used? How much?

If it's new and under $100, it's probably a pretty good deal.

If it's not used much and under $60, it's still a pretty good deal.

But I think that if you're going to use a vacuum pump, you should also have a micron gauge.

You should see what people who are in the trade think about this stuff, check on some off the HVAC blogs, see what they think...

That's what I did before I got my micron gauge.

I can tell you that the HVAC blogs have nothing good to say about HF vacuum pumps, but they use their equipment far harder than you or I ever will.

You might even be able to DIY a couple of refrigerator compressors in series and get some reasonable vacuum (maybe) but you wouldn't know if it's good enough without a micron gauge.

That's what I think.

-AC_Hacker

[charlesfl]

I found some sites for R290

http://www.gasco.nl/documents/logp-h...ram%20R290.pdf
http://www.elyenergy.com/media/SNG/D...0Data/CO37.pdf

charlesfl

[charlesfl]

Here is some good application guides from McQuay

Application Guides/Technical Bulletins