Dxgshpwh (ground source heat pump water heater) - Page 16

AC_Hacker · 06-24-15, 09:24 AM

Quote:

Originally Posted by jeff5may

...Most of them can change capacity by changing orifices...

Yes, I found that out. After months of searching, I ended up finding on ebay, a reasonably-priced, rare (for ebay), small Danfoss TXV tailored for R290, that could be fitted with various orifices. And yes, these orifices would cover various ranges. One of the orifices mapped exactly onto the requirements for my project. So, I was able to use the smallest orifice for my project.

However, I found that when I had to work with such specific parts, the orifice, I could only find from a conventional, commercial trade-outlet, and the cost of that one part equaled the cost of the rest of the project.

So here is my point: the largest part of the overall advantage of hacking discarded equipment is, if you keep within the boundary of used, commodity parts (especially when you maximize use of the parts on the donor unit), you can easily realize amazing advantages of efficiency at very little cost and effort.

In that light, you dodged my question, which was that you are recommending that MEMPHIS91 use an unusual specialty valve for an unusually small compressor.

Are you sending him on an expensive, time consuming, wild goose chase?

-AC

jeff5may · 06-24-15, 10:50 AM

Oh no... is this a trick question?

You read the disclaimer, right? I'm not a salesman, nor an HVAC parts guy. I am not recommending anything, just provoking the imagination. Jake is planning on a larger build someday. For anything under about 10000 btu per hour, a cap tube is best.

Edit: upon further consideration, what I would do given the circumstances is dismantle the valve, braze the original orifice shut, and drill a new hole in it. Upon reassembly, it would operate like I bought the other orifice. I'm not you, though.

MEMPHIS91 · 07-11-15, 05:33 PM

I am planning on a much larger build and will need a txv. If I happen to find a small one in the mean time I will look into putting it on this set up. Today is one month of running. It had used 66.05 kWh. That's less than $7!!

randen · 07-12-15, 07:41 AM

MEMPHIS91

That is an impressive result 66 kwh $7.00 The HPWH I had built for my parents is gobbling up about 114 kwh /month which is about $23.00 Can. You have some serious bragging rights there!!!! Good work.!!

I'm going to phone the parents and tell them they need to start taking cold showers!!! Their using way too much hot water.

Randen

jeff5may · 07-12-15, 09:25 AM

Nononono! Don't ruin it, man. Run what you brung and get some good data for posterity. This configuration is relatively easy to rig, and is predictable and highly reliable. Your numbers seem too good to be true to the architects of the way it should be done. More time, temp, pressure and power readings without a system tweak add credibility to what you are doing right now. Save lots of money on hot water, log what you want to share, and let those eyebrows flutter every time they read. Some may come around.

Meanwhile, gear up for another monster machine build. Start another thread, and move to the next module in wizard apprentice training: taming the superheat with expansion valves.

AC_Hacker · 07-12-15, 09:53 AM

I completely agree with jeff5may.

You have created a very interesting unit here, with several innovative features, and you have stayed within the envelope of parts at hand.

As you may recall, your early impulse, when you weren't getting the results you wanted, was to start ripping and rending new parts (bigger compressor, etc.), but you stuck with it, and did system tuning to get respectable performance.

There are several important lessons here.

Leave this one alone for a while, enjoy what you've done. Allow others take a good look at it too.

And yes, start a new thread and another new project...

Best,

-AC_Hacker

P.S.: In my opinion, further hardware hacks on this unit will only give you marginal improvements. If you want to do another DX unit with significantly improved performance, you should scale your ground loop larger (2x or better). My previous analysis suggests that your ground loop capacity is on the edge with this build. Don't forget, the heat has to come from somewhere.

MEMPHIS91 · 07-12-15, 11:02 AM

Randen, thanks man it does seem to good to be true. We use a lot of hot water. The compressor runs twice a day. Once for dishes and things in the morning and then from the time I get home and get a shower till about midnight after we have gone to bed. That's heating to 120F. Which I plan to change once the in laws come and go. (9 extra people in the house). That will be the true test.

Jeff, yes you are very tight sir I shall leave it be and start a new project, already have the basic idea. It's gonna be big. I'll be posting the hour water heater data every month .

Ac, yes I like that it's a simple build too. And DX this next monster will be.

Redmohawk · 07-12-15, 12:48 PM

Forgive my initial Intrusion , Most impressive MEMPHIS91. I will attempt to replicate your construction down here In Victoria Australia in the not to distant future. This will be my first attempt at such a construction . A new farm/house without water heating ATM has motivated me to do so.

MEMPHIS91 · 07-12-15, 01:12 PM

Welcome to the forums redmohawk. I hope the info here is useful in getting started. The people here are very helpful. Do you know what type of compressor you intend to use? How are your soil conditions, rocky, clay, sand ?? Please feel free to ask any questions.

Redmohawk · 07-12-15, 01:53 PM

I've spent approx 12 hours over the last two days skimming info from this forum. I'm very DIY orientated, with a strong fabrication background , I'm familiar with a rudimentary understanding of Gas dynamics in this sort of environment.

Have a electronics background , I'll muse over the info for a day or two before deciding on the eventual initial design. I was initially thinking something very similar to your own design but I see the long term heat transference of a single bore to be an issue for large water heating use.

So I'm leaning more to a water loop purely on a cost to benefit ratio, The entire unit will be 100% solar powered. And need to supply enough water for a 5 person household and medium water consumption levels for around here. Being on rain water alone limits our consumption a little but not that I can convince the females of the house so far.

I would factor around 50 to 60L per person per day, Here in Aust a hot water storage unit MUST heat stored water to 60 deg c every heating cycle , unless the water is NOT in circulation (IE sealed heat bank).

Obviously without going to a CO2 based system this is not feasible , and Though I believe I could source the correct components to achieve this it would be at close to commercial off the shelf units anyway . Negation the whole point of DIY for me (Lower COST).

Desired consumed water temp would not exceed 45 deg c as all clothes washing is done in cold water and dishes will be washed in a dishwasher that heats the water to correct operating temp with electricity. So I'm thinking a extremely well insulated 600L heat bank with a copper coil inside as a heat exchanger for consumed water.

Heated by window mount type unit in a compressor sized to consume around 1.5kw would be about right I hope. Removing the fan completely. Now that I think about it , its probably quicker to fabricate water boxes around the existing air con condenser and evap avoiding opening up the sealed system at all.

Ground is a sand/clay type with a water table around the 5m mark average year round ground temp below 1m is 15.5 deg c . Climate is Mediterranean like , summers are 25 deg nights 36 deg days with peaks of 8 to 10 days over 40 deg c 44 deg 2 to 3 times a year. Winters -8 early mornings frosts day temps around 12 to 13 deg c but ground temp remains 15 deg c below 1m.

I will rummage through my dwindling brain cells for a day or to and nut out a idea. For now I'll get out of your thread and stop this diversion. If all Goes well I'll start a thread and post up some constructions of my own.

06-24-15, 10:50 AM	#152
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	Oh no... is this a trick question? You read the disclaimer, right? I'm not a salesman, nor an HVAC parts guy. I am not recommending anything, just provoking the imagination. Jake is planning on a larger build someday. For anything under about 10000 btu per hour, a cap tube is best. Edit: upon further consideration, what I would do given the circumstances is dismantle the valve, braze the original orifice shut, and drill a new hole in it. Upon reassembly, it would operate like I bought the other orifice. I'm not you, though. Last edited by jeff5may; 06-24-15 at 03:40 PM..

07-12-15, 09:53 AM	#156
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 723 Times in 534 Posts	I completely agree with jeff5may. You have created a very interesting unit here, with several innovative features, and you have stayed within the envelope of parts at hand. As you may recall, your early impulse, when you weren't getting the results you wanted, was to start ripping and rending new parts (bigger compressor, etc.), but you stuck with it, and did system tuning to get respectable performance. There are several important lessons here. Leave this one alone for a while, enjoy what you've done. Allow others take a good look at it too. And yes, start a new thread and another new project... Best, -AC_Hacker P.S.: In my opinion, further hardware hacks on this unit will only give you marginal improvements. If you want to do another DX unit with significantly improved performance, you should scale your ground loop larger (2x or better). My previous analysis suggests that your ground loop capacity is on the edge with this build. Don't forget, the heat has to come from somewhere. __________________ I'm not an HVAC technician. In fact, I'm barely even a hacker...

07-11-15, 05:33 PM	#153
MEMPHIS91 Journeyman EcoRenovator Join Date: Apr 2015 Location: Oxford, MS USA Posts: 496 Thanks: 69 Thanked 87 Times in 61 Posts	I am planning on a much larger build and will need a txv. If I happen to find a small one in the mean time I will look into putting it on this set up. Today is one month of running. It had used 66.05 kWh. That's less than $7!!

07-12-15, 07:41 AM	#154
randen Uber EcoRenovator Join Date: Apr 2011 Location: Strathroy Ontario Canada Posts: 657 Thanks: 9 Thanked 191 Times in 129 Posts	MEMPHIS91 That is an impressive result 66 kwh $7.00 The HPWH I had built for my parents is gobbling up about 114 kwh /month which is about $23.00 Can. You have some serious bragging rights there!!!! Good work.!! I'm going to phone the parents and tell them they need to start taking cold showers!!! Their using way too much hot water. Randen

07-12-15, 09:25 AM	#155
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	Nononono! Don't ruin it, man. Run what you brung and get some good data for posterity. This configuration is relatively easy to rig, and is predictable and highly reliable. Your numbers seem too good to be true to the architects of the way it should be done. More time, temp, pressure and power readings without a system tweak add credibility to what you are doing right now. Save lots of money on hot water, log what you want to share, and let those eyebrows flutter every time they read. Some may come around. Meanwhile, gear up for another monster machine build. Start another thread, and move to the next module in wizard apprentice training: taming the superheat with expansion valves.

07-12-15, 11:02 AM	#157
MEMPHIS91 Journeyman EcoRenovator Join Date: Apr 2015 Location: Oxford, MS USA Posts: 496 Thanks: 69 Thanked 87 Times in 61 Posts	Randen, thanks man it does seem to good to be true. We use a lot of hot water. The compressor runs twice a day. Once for dishes and things in the morning and then from the time I get home and get a shower till about midnight after we have gone to bed. That's heating to 120F. Which I plan to change once the in laws come and go. (9 extra people in the house). That will be the true test. Jeff, yes you are very tight sir I shall leave it be and start a new project, already have the basic idea. It's gonna be big. I'll be posting the hour water heater data every month . Ac, yes I like that it's a simple build too. And DX this next monster will be.

07-12-15, 12:48 PM	#158
Redmohawk Lurking Renovator Join Date: Jul 2015 Location: Victoria , Australia Posts: 27 Thanks: 0 Thanked 1 Time in 1 Post	Forgive my initial Intrusion , Most impressive MEMPHIS91. I will attempt to replicate your construction down here In Victoria Australia in the not to distant future. This will be my first attempt at such a construction . A new farm/house without water heating ATM has motivated me to do so.

07-12-15, 01:12 PM	#159
MEMPHIS91 Journeyman EcoRenovator Join Date: Apr 2015 Location: Oxford, MS USA Posts: 496 Thanks: 69 Thanked 87 Times in 61 Posts	Welcome to the forums redmohawk. I hope the info here is useful in getting started. The people here are very helpful. Do you know what type of compressor you intend to use? How are your soil conditions, rocky, clay, sand ?? Please feel free to ask any questions.

07-12-15, 01:53 PM	#160
Redmohawk Lurking Renovator Join Date: Jul 2015 Location: Victoria , Australia Posts: 27 Thanks: 0 Thanked 1 Time in 1 Post	I've spent approx 12 hours over the last two days skimming info from this forum. I'm very DIY orientated, with a strong fabrication background , I'm familiar with a rudimentary understanding of Gas dynamics in this sort of environment. Have a electronics background , I'll muse over the info for a day or two before deciding on the eventual initial design. I was initially thinking something very similar to your own design but I see the long term heat transference of a single bore to be an issue for large water heating use. So I'm leaning more to a water loop purely on a cost to benefit ratio, The entire unit will be 100% solar powered. And need to supply enough water for a 5 person household and medium water consumption levels for around here. Being on rain water alone limits our consumption a little but not that I can convince the females of the house so far. I would factor around 50 to 60L per person per day, Here in Aust a hot water storage unit MUST heat stored water to 60 deg c every heating cycle , unless the water is NOT in circulation (IE sealed heat bank). Obviously without going to a CO2 based system this is not feasible , and Though I believe I could source the correct components to achieve this it would be at close to commercial off the shelf units anyway . Negation the whole point of DIY for me (Lower COST). Desired consumed water temp would not exceed 45 deg c as all clothes washing is done in cold water and dishes will be washed in a dishwasher that heats the water to correct operating temp with electricity. So I'm thinking a extremely well insulated 600L heat bank with a copper coil inside as a heat exchanger for consumed water. Heated by window mount type unit in a compressor sized to consume around 1.5kw would be about right I hope. Removing the fan completely. Now that I think about it , its probably quicker to fabricate water boxes around the existing air con condenser and evap avoiding opening up the sealed system at all. Ground is a sand/clay type with a water table around the 5m mark average year round ground temp below 1m is 15.5 deg c . Climate is Mediterranean like , summers are 25 deg nights 36 deg days with peaks of 8 to 10 days over 40 deg c 44 deg 2 to 3 times a year. Winters -8 early mornings frosts day temps around 12 to 13 deg c but ground temp remains 15 deg c below 1m. I will rummage through my dwindling brain cells for a day or to and nut out a idea. For now I'll get out of your thread and stop this diversion. If all Goes well I'll start a thread and post up some constructions of my own.