24000 BTU AC Unit conversion to geothermal well water source - Page 3

b420ady · 11-19-16, 04:03 AM

Thanks Jeff for your answer, another question I still did not found an answer is that I ve seen that all the pipes are cut so short .... is that normal to cut them so short ???Can they be blazed ? Do I need to flush it because as you see in the photos it looks like it could of got contaminated with moisture as it was stored in the yard

jeff5may · 11-19-16, 07:23 AM

Nope, not normal...the butcher got to it. Looks like the work of a carpenter and his helper. Person one suspended the unit close to the wall, person two hacked with a saw in one hand and a knife in the other. Maybe some wire cutters were involved, maybe not. I imagine all the copper got scrapped immediately with the rest of the demolition. I would just cut the pipes off square where they are not crushed and put flare nuts and unions on the ends. Less chance of burning something and easy to experiment with.

It's safe to say the unit has been exposed to atmosphere for quite a while. I would check the ends of the tubes for bugs or their remains after flaring the ends. Yes, you can still buy pipe cleaners cheaply at the smoke shop. For larger tubing, gun barrel cleaning tools do the trick. Then a double or triple wash with solvent and shop air or welding nitrogen or argon. I like acetone or brake cleaner. Finally, a double rinse and blowout with whatever oil your compressor likes. Any tiny residue of solvent or moisture will come out with a vacuum pump when the plumbing is sealed. Make sure installer uses a vacuum pump and micron vacuum gauge.

b420ady · 11-20-16, 08:49 AM

I ve got home the outdoor unit

More photos later

b420ady · 11-20-16, 05:15 PM

I was planning to show you the inside of the unit today but apparently some of the screws are to rusted and I could not get them out. I used sume WD40 but still I did not had any luck yet....
Anyway maybe there is someone here that can identify the real brand of this unit

b420ady · 11-20-16, 08:00 PM

I ve seen some interesting heat exchangers that I think I can replicate, please let me know what you think about them and if you have other ideas or which one do you think I should chose.
For sure I will have to buy a torch and begin building some skill with those pipes.

https://www.alibaba.com/product-deta...093599136.html

https://www.olx.ro/oferta/pahlen-ab-...tml#66f8c215e6

and there are other designs that use multiple pipes, smaller in diameter, but can someone here help me get the correct sizing for it and maybe some other tips.

b420ady · 11-20-16, 08:32 PM

I ve found a webstore from my country were I can get for 40 USD a 25 METERS roll of Cu pipe 6 mm diameter , 1 mm thick
What do you think ? this will do ?

How do I calculate how big my heat exchanger should be ??? or I just match the volume of the actual pipes in the air heat exchanger from the outdoor unit ???

I know the COP of a water source heat pump is greater than a air source water pump .... so my unit will pump more BTU/h than in the actual air feed setup .... do I have to oversize the final volume of the pipes in order to get more BTU/h ??

This might be a stupid question (sorry if so)

please if someone can explain me how much of it do I need for one heat exchanger that will suit my unit

Teava Cupru moale Ø 6 x 1,0mm, Colac de 25 m, Sanha / Diversi producatori

Some info on shell and tubes heat exchanger:
http://www.wermac.org/equipment/heat...ger_part2.html
http://www-unix.ecs.umass.edu/~rlaur.../exchanger.pdf
http://webserver.dmt.upm.es/~isidoro...exchangers.pdf
http://www.piping-engineering.com/he...gn-guide.html#
http://web2.clarkson.edu/projects/su.../shelltube.pdf
https://en.wikipedia.org/wiki/Shell_...heat_exchanger
http://www.hcheattransfer.com/shell_and_tube.html
http://homepages.wmich.edu/~leehs/ME..._corrected.pdf

I want to find a design that won t request to much skill out of my hand with the torch as I never did it befor , so I ll have to use somehow longer tubes lengths

PS: I have a huge archive of files and a lot of websites bookmarks that I should share with you that I ve gathered in my research about geothermal heat pumps ... but please let me know if any of you is interested in it because I have a slow 3g connection and takes a lot of time.

I ve found in the specs of a pool heat pump the next specs:
NTTP125-B1 12.5 KW 9 METERS of Φ12.7mm Cu tube inside a PVC pipe

) Φ200*500 50mm

here is the link: https://www.alibaba.com/product-deta...026150680.html

b420ady · 11-20-16, 09:25 PM

Ok, the outdoor unit has about 30 pipes in that radiator , so the total length will be pretty big so I think I sould buy Cu tube of the same dimension as the unit already have and make a nice shell and tube design...at first I was thinking to use tube smaller in diameter so I have a better heat transfer but I don t think I can do it as it will mean that I ll use a lot of meter ...

Prices of Cu tubes around here:
http://frigmania.ro/index.php?route=...h=64_65_91_139

The shared PDF files folder just became bigger

https://www.dropbox.com/sh/3owy0iq7o...jQSVmrC-a?dl=0

jeff5may · 11-21-16, 09:57 AM

Not that simple. The air source outdoor exchanger must have much more surface area, since air has less heat capacity and thermal conductivity than water. Unless your water flow rate is super high, the water source exchanger will be more compact. I already posted a few links to point you in the right direction. I recommended a coaxial exchanger with turbo tube inside for a reason.

Plate heat exchangers that will stand up to refrigeration pressure aren't the same as the common ones found on the used market. Most of these are rated for maybe 10 bar, you need better pressure rating. The common units are also rated at a higher temperature difference than a heat pump can provide. Depending on specs, you will need to oversize the hx by a large factor. Plus the fouling issue.

A coaxial exchanger made with smooth tubing will need more overall length than one with ribbed or corrugated center tubing, which will drive up the materials cost. The issues of pressure drops, turbulence and spacing between the tubes make more difference for the worse as well. If you have a cheap supply of smooth (inside and shell) tubing and don't mind the extra bulk, go for it. But the easily copied designs pretty much all use high performance inside tubing to save weight and bulk.

b420ady · 11-21-16, 08:11 PM

From were I can buy that ribbed or corrugated center pipe at a decent price ?

jeff5may · 11-22-16, 09:31 AM

That depends on what you call a decent price... In your location (Romania), finding a local metal supplier who will sell you small pieces will be the challenge. To mail order the material, international shipping comes into play. For the few meters of tubing you seek, shipping could cost more than the material. I live in the USA, so mail ordering the tubing would be much less expensive.

It may be worthwhile for you to make your own. If you can find inexpensive soft copper tubing, the process is not super difficult. You have to make a tool to do it, though. I'm always short on money, so if I was in your location, I could definitely justify the time and labor to do it myself. Knowing someone with a lathe would save lots of time, but with this type of tubing, you could do it by hand.

Here is a super industrial version of the method:

Straight off the top of my head, I would probably make something resembling a pipe threader head with wheels instead of thread dies in it:

11-20-16, 08:49 AM	#23
b420ady Helper EcoRenovator Join Date: Nov 2016 Location: Romania Posts: 47 Thanks: 19 Thanked 0 Times in 0 Posts	I ve got home the outdoor unit More photos later Attached Thumbnails

11-20-16, 05:15 PM	#24
b420ady Helper EcoRenovator Join Date: Nov 2016 Location: Romania Posts: 47 Thanks: 19 Thanked 0 Times in 0 Posts	I was planning to show you the inside of the unit today but apparently some of the screws are to rusted and I could not get them out. I used sume WD40 but still I did not had any luck yet.... Anyway maybe there is someone here that can identify the real brand of this unit Attached Thumbnails

11-20-16, 08:32 PM	#26
b420ady Helper EcoRenovator Join Date: Nov 2016 Location: Romania Posts: 47 Thanks: 19 Thanked 0 Times in 0 Posts	I ve found a webstore from my country were I can get for 40 USD a 25 METERS roll of Cu pipe 6 mm diameter , 1 mm thick What do you think ? this will do ? How do I calculate how big my heat exchanger should be ??? or I just match the volume of the actual pipes in the air heat exchanger from the outdoor unit ??? I know the COP of a water source heat pump is greater than a air source water pump .... so my unit will pump more BTU/h than in the actual air feed setup .... do I have to oversize the final volume of the pipes in order to get more BTU/h ?? This might be a stupid question (sorry if so) please if someone can explain me how much of it do I need for one heat exchanger that will suit my unit Teava Cupru moale Ø 6 x 1,0mm, Colac de 25 m, Sanha / Diversi producatori Some info on shell and tubes heat exchanger: http://www.wermac.org/equipment/heat...ger_part2.html http://www-unix.ecs.umass.edu/~rlaur.../exchanger.pdf http://webserver.dmt.upm.es/~isidoro...exchangers.pdf http://www.piping-engineering.com/he...gn-guide.html# http://web2.clarkson.edu/projects/su.../shelltube.pdf https://en.wikipedia.org/wiki/Shell_...heat_exchanger http://www.hcheattransfer.com/shell_and_tube.html http://homepages.wmich.edu/~leehs/ME..._corrected.pdf I want to find a design that won t request to much skill out of my hand with the torch as I never did it befor , so I ll have to use somehow longer tubes lengths PS: I have a huge archive of files and a lot of websites bookmarks that I should share with you that I ve gathered in my research about geothermal heat pumps ... but please let me know if any of you is interested in it because I have a slow 3g connection and takes a lot of time. I ve found in the specs of a pool heat pump the next specs: NTTP125-B1 12.5 KW 9 METERS of Φ12.7mm Cu tube inside a PVC pipe ) Φ200500 50mm here is the link: https://www.alibaba.com/product-deta...026150680.html Last edited by b420ady; 11-20-16 at 10:02 PM.. Reason: PS:*

11-19-16, 04:03 AM	#21
b420ady Helper EcoRenovator Join Date: Nov 2016 Location: Romania Posts: 47 Thanks: 19 Thanked 0 Times in 0 Posts	Thanks Jeff for your answer, another question I still did not found an answer is that I ve seen that all the pipes are cut so short .... is that normal to cut them so short ???Can they be blazed ? Do I need to flush it because as you see in the photos it looks like it could of got contaminated with moisture as it was stored in the yard

11-19-16, 07:23 AM	#22
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,431 Thanks: 431 Thanked 619 Times in 517 Posts	Nope, not normal...the butcher got to it. Looks like the work of a carpenter and his helper. Person one suspended the unit close to the wall, person two hacked with a saw in one hand and a knife in the other. Maybe some wire cutters were involved, maybe not. I imagine all the copper got scrapped immediately with the rest of the demolition. I would just cut the pipes off square where they are not crushed and put flare nuts and unions on the ends. Less chance of burning something and easy to experiment with. It's safe to say the unit has been exposed to atmosphere for quite a while. I would check the ends of the tubes for bugs or their remains after flaring the ends. Yes, you can still buy pipe cleaners cheaply at the smoke shop. For larger tubing, gun barrel cleaning tools do the trick. Then a double or triple wash with solvent and shop air or welding nitrogen or argon. I like acetone or brake cleaner. Finally, a double rinse and blowout with whatever oil your compressor likes. Any tiny residue of solvent or moisture will come out with a vacuum pump when the plumbing is sealed. Make sure installer uses a vacuum pump and micron vacuum gauge.

11-20-16, 08:00 PM	#25
b420ady Helper EcoRenovator Join Date: Nov 2016 Location: Romania Posts: 47 Thanks: 19 Thanked 0 Times in 0 Posts	I ve seen some interesting heat exchangers that I think I can replicate, please let me know what you think about them and if you have other ideas or which one do you think I should chose. For sure I will have to buy a torch and begin building some skill with those pipes. https://www.alibaba.com/product-deta...093599136.html https://www.olx.ro/oferta/pahlen-ab-...tml#66f8c215e6 and there are other designs that use multiple pipes, smaller in diameter, but can someone here help me get the correct sizing for it and maybe some other tips.

11-20-16, 09:25 PM	#27
b420ady Helper EcoRenovator Join Date: Nov 2016 Location: Romania Posts: 47 Thanks: 19 Thanked 0 Times in 0 Posts	Ok, the outdoor unit has about 30 pipes in that radiator , so the total length will be pretty big so I think I sould buy Cu tube of the same dimension as the unit already have and make a nice shell and tube design...at first I was thinking to use tube smaller in diameter so I have a better heat transfer but I don t think I can do it as it will mean that I ll use a lot of meter ... Prices of Cu tubes around here: http://frigmania.ro/index.php?route=...h=64_65_91_139 The shared PDF files folder just became bigger https://www.dropbox.com/sh/3owy0iq7o...jQSVmrC-a?dl=0

11-21-16, 09:57 AM	#28
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,431 Thanks: 431 Thanked 619 Times in 517 Posts	Not that simple. The air source outdoor exchanger must have much more surface area, since air has less heat capacity and thermal conductivity than water. Unless your water flow rate is super high, the water source exchanger will be more compact. I already posted a few links to point you in the right direction. I recommended a coaxial exchanger with turbo tube inside for a reason. Plate heat exchangers that will stand up to refrigeration pressure aren't the same as the common ones found on the used market. Most of these are rated for maybe 10 bar, you need better pressure rating. The common units are also rated at a higher temperature difference than a heat pump can provide. Depending on specs, you will need to oversize the hx by a large factor. Plus the fouling issue. A coaxial exchanger made with smooth tubing will need more overall length than one with ribbed or corrugated center tubing, which will drive up the materials cost. The issues of pressure drops, turbulence and spacing between the tubes make more difference for the worse as well. If you have a cheap supply of smooth (inside and shell) tubing and don't mind the extra bulk, go for it. But the easily copied designs pretty much all use high performance inside tubing to save weight and bulk.

11-21-16, 08:11 PM	#29
b420ady Helper EcoRenovator Join Date: Nov 2016 Location: Romania Posts: 47 Thanks: 19 Thanked 0 Times in 0 Posts	From were I can buy that ribbed or corrugated center pipe at a decent price ?

11-22-16, 09:31 AM	#30
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,431 Thanks: 431 Thanked 619 Times in 517 Posts	That depends on what you call a decent price... In your location (Romania), finding a local metal supplier who will sell you small pieces will be the challenge. To mail order the material, international shipping comes into play. For the few meters of tubing you seek, shipping could cost more than the material. I live in the USA, so mail ordering the tubing would be much less expensive. It may be worthwhile for you to make your own. If you can find inexpensive soft copper tubing, the process is not super difficult. You have to make a tool to do it, though. I'm always short on money, so if I was in your location, I could definitely justify the time and labor to do it myself. Knowing someone with a lathe would save lots of time, but with this type of tubing, you could do it by hand. Here is a super industrial version of the method: Straight off the top of my head, I would probably make something resembling a pipe threader head with wheels instead of thread dies in it: