The Homemade Heat Pump Manifesto

[AC_Hacker]

Originally Posted by NiHaoMike

Not as good as a proper heat exchanger but it does work pretty well. Good solution while you either build up a proper unit or wait until spring to do it right. Use distilled water and RV antifreeze (propylene glycol, safer than car antifreeze) as the fluid.

I think he already has a HX.

-AC

[waterdigger2]

Originally Posted by NiHaoMike

If it's above freezing, you can easily turn a window A/C into a heat pump by turning it around.

It Rarely gets down to freezing here. The past few days it was in the 80s. Then the cold wave hit . Dropped down to the 30s. Had ac on Friday night. Last night. The heater was on. And had to wrap the jet pump scared it would freeze. But this is once and a blue moon weather for us .

[waterdigger2]

Originally Posted by AC_Hacker

The part of your A/C that is warm is called the condenser, and the part that the cold air comes out of is called the evaporator.

There is a tiny tube that is called the cap tube that might get frosty when your A/C is running. This tube is matched to your compressor, so you will want to take care not to bend, break or damage it.

You have some choices here...

You can put the whole A/C unit in a window backwards, sort of what was previously mentioned, or you can remove the condenser from the unit and braze some copper lines from the A/C to the evaporator. If you do it this way, you will still need some kind of fan (probablly not real big) to blow air through it to warm the room or house or whatever. The advantage to this is that your finished project will be really quite in the house. The disadvantage is it will require more work.

The part of your A/C that has the cold part (the evaporator) will need to be removed and you will instead, braze in the heat exchanger in it's place, but you precious little cap tube will be brazed in just ahead of your new evaporator/Heat Exchanger.

When you do all of this, notice that the tiny cap tube has larger diameter tube connected to it on both ends. You DO NOT want to cut into the tiny cap tube itself, because you will change its length, and its length is very important.

So, are you going to do this stuff, or is your relative who is a HVAC tech?

When you open up the refrigerant lines, the refrigerant gas can escape into the atmosphere, which is against the law. Your HVAC tech relative will have the equipment and knowledge to do this legally.

You are also going to need some kind of circulator pump to circulate water through your bore hole tube and heat exchanger.

So, don't go wildly cutting tubing until you have a plan for how this is all going to come apart, and more importantly, go back together.

And go borrow, or go to a thrift store and get a cheap digital camera and take photos... and show us what you are doing.

If you can afford a 6-pack of beer, you can afford a camera.

-AC

He will be doing the brazing and the hvac for exchange that i help him dig a water well .Being i know how to do that stuff and he knows how to do that stuff. On the 6 pack beer. I dont drink or nothin like that that waste money. No offence to the ones who drink . But its waist of money. But he said that he had a camera when he gets back down he would take me some pics. one less thing to spend 5 or what ever bucks on. Youd have to know me to get the my way of thinkin.
What kind of pump did you decide on. I seen you had went with a small aquarium pump for one ya test but that flow was to small. I think that an open loop geothermal takes 1.5 to 2gpm per ton. I havent given much thought on the water circulation.

On the groutin The main purpose for the grout is contact with the pipe so they can transfer the heat to the soil.If their formation is hard (clay,rock, limestone ,etc) forms like that they will benifit from grout. If it is sandy . They dont . The sand will cave back in on the loops only the top to the water table needs to be bentonited,grouted or cemented.

[waterdigger2]

Originally Posted by AC_Hacker

NiHaoMike,

Are you aware that this guy has ALREADY drilled 300' deep boreholes and has the grouted pipe in place and wants to make a GSHP?

-AC

No grouting required here. We have sandy ground. I wouldnt be able to dig a dry hole like you did 17ft. At 9 ft you hit good ice cold water.

Their 250ft deep. Sand collaspes around it The top part your required to bentonite . Protect the water from the rain and etc.

Weve don some i believe they were 420ft deepest ones weve done here. They was for govt buildings though. There loop field was Huge compaired to all of ours

[waterdigger2]

Originally Posted by NiHaoMike

He was thinking about buying a window heat pump, which is of no extra value in a heating only geothermal build. Geothermal doesn't need defrosting.

sub $45 Homemade chiller
Not as good as a proper heat exchanger but it does work pretty well. Good solution while you either build up a proper unit or wait until spring to do it right. Use distilled water and RV antifreeze (propylene glycol, safer than car antifreeze) as the fluid.

You'll probably want to swap the cap tube for a TXV once you put in a proper heat exchanger since TXVs are cheap on the surplus market and they improve efficiency. Don't forget to replace the filter drier as well.

We wouldnt know what to do if it got below freezing for very long. It is usuallly pretty mild winters butas far as waiting until spring. Im guessing reason ya say that is because snow maybe ? We dont get that here very much thankfully. Although white christmases are nice. Good link though

[jeff5may]

I especially love this one:



If a teenager can do it, you can do it. Water is an awesome secondary refrigerant.

EDIT: Here are the original threads:

http://www.xtremesystems.org/forums/...memade-chiller

http://forums.extremeoverclocking.co...hlight=chiller

[AC_Hacker]

Originally Posted by waterdigger2

What kind of pump did you decide on. I seen you had went with a small aquarium pump for one ya test but that flow was to small. I think that an open loop geothermal takes 1.5 to 2gpm per ton. I havent given much thought on the water circulation.

I did use the aquarium pump, but I soon realized that it was way too small. I experimented with other pumps until I got a reasonable GPM (3/4 HP). So I ran it at that rate. I then realized that the pump that it took to push water through my loops was consuming too much power... it was too big, So then, I did some digging and broke my loop field into two parallel fluid paths, which allowed me to use a pump of about 25% the previous power. I think that a 140 watt pump ought to do it (somewhere around 1/8 HP).

I think that I can calculate your pump size for you. I need to know:

• how many bore holes are you going to work with?
• how deep is each one?
• how much (total) pipe will you run horizontally?
• what size pipe did you put in? (I seem to recall it is 3/4", am I right?)
• how many BTUs do you want to get out of the whole loop field?

-AC

[AC_Hacker]

Originally Posted by jeff5may

I especially love this one:



If a teenager can do it, you can do it. Water is an awesome secondary refrigerant.

So what's with a photo with no explanation and no link?

You trying to keep this thing secret?

-AC

[waterdigger2]

It is 3 holes dug 250 deep. Loops set right close to 250 may be 248 or 249. But lets round it 250 still 3 ton thats for the whole house well pump house and the shop. (never had money for unit or ductwork yet) And we sized it for the additions i will be doin also

Bein their just sittin taped waitin to be hooked up. I will just use 1 hole at the 250ft. Thats 1 ton. I understand that a ton will do 600-700sq ft But That should be plenty to heat and cool the 450sq ft . 8ft celins. Unless you think thats overkill on the depth. I do know how to dig em my self by hand around 40 to 60ft.

Horzontal i will run 10ft lenght to that closest hole still use the 3/4. so all togather 530ft of 3/4 pipe

[waterdigger2]

O and im tryin to get 6000btu right now out of that 240ft to a ton here we dig em 250 to compensate it floatin back up when you remove the hole loader . But when i get th other unit i will try pull the whole ton out of that hole.