The Homemade Heat Pump Manifesto

[mejunkhound]

Good posts Blauhng, keep'em coming.. great overview for folks here.

[AC_Hacker]

tweeker sent these pix & descriptions...
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>
I spend several months gathering/scrounging up all the pieces I MAY need to do a CHEAP & INEXPENSIVE A/C hack job, in order to turn it into a HP and hot water/hydronic heater.

First victim is a FEDDERS 5,000 BTU A/C unit that wasn't putting out enough cold air? AND shut off after about 15-20 minutes and would cycle on/off after that? So i took it to my shop and stored it, saved them the $20-$25 it would cost to recover the freon/refrigerant in order to dispose of it properly.

Problem I found with this one was that the inside of the condenser coil was packed full of mosquitos and gnats, I mean PACKED. (Not sure if you can see it in the photos). and it was over-heating. The air circulating past the compressor (HOT) couldn't get through the condenser (Becoming HOT) and was blowing backwards at the compressor (Becoming VERY HOT) and nothing was going through the condenser coil fins, the VERY HOT air was just swirling around inside the small Styrofoam insulated compartment ! Made it about 20 minutes at 70 degrees ambient Temp in my shop and shut down. BUT the evaporator was blowing out COOL air for about 5-10 minutes (NOT COLD AIR).

So now for the HACK, next I removed the cover/enclosure, cleaned out the mosquitos and gnats from the condenser (Had to douse the compressor and condenser with buckets of water to cool them down, UNPLUGGED of COURSE), removed the FANs, and bypassed the panel thermostat switch. I ran it again about an hour later after the compressor & Condensor cooled down and most of the vermin had been removed from the condenser fins, it made it about 30 minutes WITHOUT any FANS. I presume the thermal safety switch on the top of the compressor shut it down. BUT it was putting out the COLD AIR and FROSTING over on the evaporator like a normal 5,000 BTU A/C should.
WE NOW have a good candidate for the next HP HACK.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>

This is a different A/C Hack, it's a Quasar 5,000 BTU A/C Unit I picked up late last fall. I have access to a recycling center in town, they charge people to dispose of their freon/refrigerant containing units, something like $20-$25. The recycling center makes their money on separating the precious metals (All volunteers on Tuesday and Saturday) for a Greener Earth. I BUY stuff (A.K.A. Junk/Scrap) from them at scrap prices :-)

You gotta hear this one, the people that had it said it would not cool "All the TIME" ? So it is no good anymore and has finally kicked the bucket.
So I plugged it in at the recycling center, the fans ran O.K. but the compressor wasn't engaging ?? I had a hunch it was probably something simple/stupid, so I took it back to my shop and stored in a back corner.
When I do a hack, there is a time consuming task called gathering up all the necessary tools and laying them out so you can find them in a hurry. I also like to have at least 2-3 possible candidates available, since all the relevant tools are now very handy, and in case I need to scavenge parts/pieces, BUT I NEVER BREAK the REFRIGERANT SEAL on any of the units.
So when I hacked the previous Fredders A/C unit, I brought out this Quasar unit, plugged it in, fans ran but compressor did not engage, tinkered around with it, took the cover/enclosure off (Took Several HOURS, literally chipped/hacked small pieces of plastic off from it on the Condenser side), and low and behold, there was a service manual "Inside it" in a plastic zip-lock bag. (You can see it in the photo) Got the multi-meter out, checked the wiring, everything seemed O.K. ?
Read the manual a little further and came across a sentence in the "Trouble Shooting/Problem Solving" section that read:
UNIT WILL NOT COOL BELOW 65 DEGREES. HHmmmmm ???

NOTE: CAPACITORS ARE DANGEROUS just wanted to say "I Told you so!

So I bypassed the panel thermostat switch, rewired a few other connection
points (Actually CUT most of the wires) plugged it in, and BINGO.
It's Nice when things work out this way, because the bummer things are always around the next corner or next wire/shock/spark/stripped bolt/screw,busted knuckles, ETC. So I continued to Hack/Strip it down to the bare minimum components.
We NOW have another GOOD Candidate for an HP A/C Hack.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>>

Picture 003

KILL-A-WATT showing the watts the unit is using to make 5,000 BTU's of cooling (Unverified cooling capacity at the Moment)

I also test the WATTS/AMPS to make sure the START-UP SURGE is not over 1,200 WATTS or 10 AMPS, I can then plug it into my 600 WATT DC to AC power inverter and run the A/C unit off the 12V battery (Picture 004) that I can charge with my photovoltaic solar panels.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>>

...end of tweeker's post

-AC_Hacker

[tweeker]

Thanx AC for posting my stuff. I have more, and will follow up with them soon. Every A/C hack I have ever done (about 10+) always has the "Wild Card" issue, you never know how each unit is going to perform until "You Field/Shop Test It". I understand what the calculations tell you "On Paper", but my experience/calculations with my hack tests has not been in any papers I have read :-)

I just got back home from my A/C Hack experiments. I was able to get -10 C/14 F on the evaporator side in 3 gallons of 33% Anti-Freeze solution. Kept the Condenser @ 40 C/105 F using heat exchangers in 3 gallons of straight water, otherwise it shoots up past 120 F to 130 F and messes up the refrigerant heat transfer cycle. I wasn't using a heat exchanger on the evaporator, which is only about 50% submerged in the container. The Condensor is also about 50% submerged, but I put 2 smaller (in dimension) transmission oil coolers in the container, 1 on each side, and circulated @ 1 gallon a minute through them with my pump, coming from 2 five gallon buckets, 1 bucket had another tranny oil cooler in it. 400 Watts was the average reading to run the compressor over a 1 1/2 hour time period.

All for now, I should beable to get you some more stuff tomorrow.

BTW - Your e-mail file is full and kept returning my mail.

Regards,

Tweeker

[AC_Hacker]

Originally Posted by tweeker

Thanx AC for posting my stuff. I have more, and will follow up with them soon.

tweeker,

My mail should be ok now.

You should send me your phone # and I'll drop by and give you a quick tutorial on how to post pics on a blog.

You really need to know how to do it.

-AC_Hacker

[randen]

I had decided to start with the in-shop air handler. This device was originally a 3 ton air-conditioner (split) with an optional hot water coil. This was installed in our home and never worked correctly. Three service companies looked at it and turned out the compressor had been damaged. A new compressor had been installed under warrenty and 8 months later we had a comercial GSHP installed.The air handler was destine for the scrap heap until I had found you guys.
Since we will use this for the shop heating and cooling via GSHP the evaporator is going to change from refrigerant evaporator to water/glycol mix-air exchange. Our planned AC hacked GSHP unit on the evaporator HX side will cool a water/glycol mix that is to be pumped into the air-handler providing cooling. I'm not sure the air exchange unit would suffice for heating the shop during the deep winter months but for cooling the shop it will be more than enough as a 2T air to air unit had done the job prior. We will forge ahead later with plans for changing the concrete for in-floor heating.

The removal of the capillery tubes was acomplished and a fabricated 3/4" manifold is installed. The cap tubes simply where heated and pulled out. They had a 3/16"-3/8" copper bushings which made the switch easy. The 3/8 copper tubes on the 3/4 manifold incidentally where once the lines that carried fuel oil to the old boiler for the house. WASTE NOT WANT NOT. The unit was pressure tested re-assembled and painted.
The next order of business is to install the air-handler into location in the shop hung from the ceiling.

[AC_Hacker]

Originally Posted by randen

The air handler was destine for the scrap heap until I had found you guys...

Gumption really is contagious!

Nice donor unit you have to start with, lots of potential.

I like the manifold you built, nice job!

I share you question regarding heating... change of state (when it was refrigerant/air) really moves a lot of BTUs around, I'll be interested to know how the new incarnation works out.

Best of luck on your project!

-AC_Hacker

[Blauhung]

Run some drilling stuff by you.

slow motor but very high torque for price. Also really easy to power at 12V and DC so easily reversible. 10RPM might be slow, but i think the highest torque i could find for the price. Else i may want to look into doing the gearing myself on a bigger gearless motor.
6 RPM 12 VOLT DC HIGH TORQUE INLINE GEARMOTOR 5-1748 | eBay


and a sump pump that can handle solids to some extent for pumping drilling mud. This works on wall AC so also easy to run. 2000GPH sound like enough flow?
Solids Handling Direct Drive SUMP Pump - 2000GPH! | eBay

[AC_Hacker]

Originally Posted by Blauhung

10RPM might be slow, but i think the highest torque i could find for the price.

From my experience, 60 to 100 rpm seem about right.

My little drill rig only had 1/4 HP which was really way too small. But it was DC and reversible so that was very handy, especially when adding & removing drill pipe.

Even with my 1/4 HP I was able to do some good when soil conditions were favorable (no rocks). If I had sandy soil all the way down, I could have gone considerably deeper. I was also limited by my choice of 3/4" drill pipe. That small diameter has a lot of friction, especially when drilling with mud.

I think 1 or 2 HP at about 80 rpm would do some pretty good digging.

There is the issue of electricity and water... and there's gonna be water, it's dangerous. I had GFI between my motor and the mains and I'm really glad I did, literally a life saver.

There was a guy who posted previously named Vlad who built a drilling rig that used a 5 HP (240 VAC) motor that connected to a hydrolic pump and that connected to a hydrolic motor. I really think that is the right way to go. That gives you the possibility to reverse your hydrolic motor, and to have some degree of control of your motor. It also has the advantage of getting the electricity a little further from the working area. He even tried a higher HP gas motor, and went back to the electric because it was good enough and didn't disturb the neighbors.

Vlad was using pretty big drill pipe, around 2 inches as I recall. I think 1.5" might work out ok.

Vlad was in Vancouver BC, very similar to PDX soil conditions.

He said he had gotten down to 60 feet pretty fast, and had even gone through solid rock with a tri-cone bit.

Pretty serious rig. Maybe too much.

Originally Posted by Blauhung

...and a sump pump that can handle solids to some extent for pumping drilling mud. This works on wall AC so also easy to run. 2000GPH sound like enough flow?
Solids Handling Direct Drive SUMP Pump - 2000GPH! | eBay

Yeah, the mud pump is pretty important, it is what lifts the cuttings up out of the hole (and it does a whole lot more).

You might try haunting the Rebuilder's Center... They get in a constant stream of Jacuzzi type pumps and they sell them for cheap... They're not made for mud, but if you can get them cheap enough and get them to last for a day or two, that might do the trick.

And don't forget the shop vac trick. That was my best drill. I got a really big Ridgid shop vac at a thrift store for $15 and sucked about 11 tons of sand and small rocks out of the ground. I know that others have gotten down as deep as 30 feet with a shop vac, when conditions are right. 2" ABS pipe seemed to be the ticket. Ridgid shop vacs are the ver best.

I ended using my little 1/4 HP drill rig with non-recirculating city water to punch down through the initial clay layer, down to about 4 or 5 feet, then the shop vac to go deeper. Then I hit hard pan and very wet sand where I stopped.

Your mileage may vary.

-AC_Hacker

[tweeker]

Great info Blauhung, gave me a lot to ponder during my lataest A/C hack.

Until I figure out how to post pics, I will e-mail the info to AC Hacker.

As of right now:

My "Fredders 5K BTU" hack is the unit that gives me the biggest COP for heating.

My "Quasar 5K BTU" gives me the best EER/COP for cooling.

Scrap automobile electronic fuel pumps give me the best performance for fluid transfer to the heat exchangers. (I picked up 15 of them at a local junk yard, and lucky me, they all worked :-) Mostly because I run them off 12Vdc scrap car batteries charged by photovoltaic solar panels, and they don't use much more than 50-60 Watts but have anywhere from 40-80 PSI @ 1-2 gallons a minute. That is enough flow to get a good heat transfer/exchange.

[Blauhung]

Ok, for drilling starting to think about the possibility of finding a used treadmill. Motors in those are ~2HP and with the whole thing i've got a DC power supply and PWM speed controler in the package.