Heat Pump Water Heater - Coil in Tube - Page 3

vwhead77 · 10-18-14, 04:32 PM

I can definitely make this particular design out of all copper but I'm looking at an investment of almost 150.00 and that is just a bit much at this point for an 'experiment' I like the helpful hints like capping the center of the HP coil to force the water to wrap the coil (rather than shooting right up the middle) I believe this is something I would like to pursue but want ot make sure my money is spent well. I am offering this next design - as I have bits an pieces already lying around.

Mikesolar · 10-18-14, 04:42 PM

That will not help in this situation. Remember that the system will only move the water when it gets hot enough to rise. It needs the time to heat up so it becomes more buoyant. That is what will start the circulation, and the hotter the water delivered to the top of the tank the faster the flow. It is a self limiting system. Your coil is fine. It also needs to have very little resistance from bottom to top so a center blockage may be counter productive.

Mikesolar · 10-18-14, 04:56 PM

Try it out but you won't need to reduce anything. It needs very low resistance and the flow rate is self limiting so no need to restrict it.

BTW, I assume you are a VW nut (?). Check out my avatar. Very few in North America.

vwhead77 · 10-18-14, 05:20 PM

Thanks for the input - and yes, I have had over 60 VWs in my 55 years- including '72 Ghia 'Vert, '68 Ghia 'Vert, 2X'67 Vans, 2 Synchros, 1 Thing, 1 Fastback, 3 Squarebacks, a few Bugs (oldest was 63) , a few Rabbits, a few Jettas, two diesel pick-ups, a couple of Golfs - etc. - Plus, I used to find them for cheap- fix 'em up, drive them a while and then sell them. I love your Pick up man - had ONE chance to buy one and the guy backed out - I'm jealous

jeff5may · 10-18-14, 05:52 PM

Why insulate the center? The copper pipe will have a positive effect on the heat transfer. If you want to restrict the flow, just stuff the pipe with copper or stainless steel pot scrubbers.

Mikesolar · 10-18-14, 05:58 PM

The pipe needs to be somewhat clear bottom to top. LOW RESISTANCE to natural flow. It won't go fast anyway.

The LT is beast of a truck. Full 8'+ x almost 6' wide bed. It is now getting the a M-TDi from an 02 Jetta in it and then turned into a plug in hybrid.

vwhead77 · 10-18-14, 11:22 PM

Quote:

Originally Posted by Mikesolar

The pipe needs to be somewhat clear bottom to top. LOW RESISTANCE to natural flow. It won't go fast anyway.

The LT is beast of a truck. Full 8'+ x almost 6' wide bed. It is now getting the a M-TDi from an 02 Jetta in it and then turned into a plug in hybrid.

OOhhhhh...I'm really jealous
now .. man .. thas so cool

Ron342 · 10-23-14, 11:51 AM

First congratulations!
I'm dying to know how you did such nicely wound coils!
I tried salt filled 3/8 copper around the outside of 1 1/2 copper but had only marginal luck with it.
Nice thing about that 2" copper is that you can run some 3/4 copper up the center of it and connect it to a solar panel if you want to expand this to a 2 heat source system.

simenad · 10-23-14, 12:13 PM

what if you tapped into a nearby refrigerator. it would make the fridge much more efficient and direct the heat that would be released into the house into helping heat domestic hot water.

vwhead77 · 10-18-14, 05:58 PM

I'm insulating the PVC 'jacket'- the HW is still in the 2" pipe with the discharge from the compressor on the outside - but I like the advice about restricting the flow with SS

10-23-14, 11:51 AM	#8
Ron342 Apprentice EcoRenovator Join Date: Feb 2010 Location: Maryland Posts: 120 Thanks: 26 Thanked 12 Times in 8 Posts	Winding and winding First congratulations! I'm dying to know how you did such nicely wound coils! I tried salt filled 3/8 copper around the outside of 1 1/2 copper but had only marginal luck with it. Nice thing about that 2" copper is that you can run some 3/4 copper up the center of it and connect it to a solar panel if you want to expand this to a 2 heat source system.

10-23-14, 12:13 PM	#9
simenad Lurking Renovator Join Date: Jan 2014 Location: Ottawa Posts: 11 Thanks: 1 Thanked 0 Times in 0 Posts	fridge what if you tapped into a nearby refrigerator. it would make the fridge much more efficient and direct the heat that would be released into the house into helping heat domestic hot water.

10-18-14, 04:32 PM	#1
vwhead77 Helper EcoRenovator Join Date: Jan 2013 Location: Watkins Glen, NY Posts: 48 Thanks: 19 Thanked 5 Times in 5 Posts	I can definitely make this particular design out of all copper but I'm looking at an investment of almost 150.00 and that is just a bit much at this point for an 'experiment' I like the helpful hints like capping the center of the HP coil to force the water to wrap the coil (rather than shooting right up the middle) I believe this is something I would like to pursue but want ot make sure my money is spent well. I am offering this next design - as I have bits an pieces already lying around.

10-18-14, 04:42 PM	#2
Mikesolar Master EcoRenovator Join Date: Aug 2012 Location: Toronto Posts: 958 Thanks: 40 Thanked 158 Times in 150 Posts	That will not help in this situation. Remember that the system will only move the water when it gets hot enough to rise. It needs the time to heat up so it becomes more buoyant. That is what will start the circulation, and the hotter the water delivered to the top of the tank the faster the flow. It is a self limiting system. Your coil is fine. It also needs to have very little resistance from bottom to top so a center blockage may be counter productive.

10-18-14, 04:56 PM	#3
Mikesolar Master EcoRenovator Join Date: Aug 2012 Location: Toronto Posts: 958 Thanks: 40 Thanked 158 Times in 150 Posts	Try it out but you won't need to reduce anything. It needs very low resistance and the flow rate is self limiting so no need to restrict it. BTW, I assume you are a VW nut (?). Check out my avatar. Very few in North America.

10-18-14, 05:20 PM	#4
vwhead77 Helper EcoRenovator Join Date: Jan 2013 Location: Watkins Glen, NY Posts: 48 Thanks: 19 Thanked 5 Times in 5 Posts	Thanks for the input - and yes, I have had over 60 VWs in my 55 years- including '72 Ghia 'Vert, '68 Ghia 'Vert, 2X'67 Vans, 2 Synchros, 1 Thing, 1 Fastback, 3 Squarebacks, a few Bugs (oldest was 63) , a few Rabbits, a few Jettas, two diesel pick-ups, a couple of Golfs - etc. - Plus, I used to find them for cheap- fix 'em up, drive them a while and then sell them. I love your Pick up man - had ONE chance to buy one and the guy backed out - I'm jealous

10-18-14, 05:52 PM	#5
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	Why insulate the center? The copper pipe will have a positive effect on the heat transfer. If you want to restrict the flow, just stuff the pipe with copper or stainless steel pot scrubbers.

10-18-14, 05:58 PM	#6
Mikesolar Master EcoRenovator Join Date: Aug 2012 Location: Toronto Posts: 958 Thanks: 40 Thanked 158 Times in 150 Posts	The pipe needs to be somewhat clear bottom to top. LOW RESISTANCE to natural flow. It won't go fast anyway. The LT is beast of a truck. Full 8'+ x almost 6' wide bed. It is now getting the a M-TDi from an 02 Jetta in it and then turned into a plug in hybrid.