The Homemade Heat Pump Manifesto - Page 126

Vlad · 06-23-12, 03:25 AM

Theprof,

I guess Klimaire is a mini split AC unit that uses R410a. If it is I think propane is not the best option.

1. Capacity will change. From 12k BTU you will get only 9k or 10k who knows?

2. All your safety devices are for much higher pressure range. Just as an example your high pressure switch is hard to trigger with R290.

If you want more "help" we need more info.

Thepprof · 06-23-12, 07:32 AM

This unit Klimaire KSWM12H113 (MINISPLIT HEATPUMP) I installed 2 of these units in January 12, 1 is working just fine the other locked up. I removed the unit and brought it home to scrap (New toshiba compressor cost 75% of what the entire unit cost. A few weeks later I decided to bring the unit in the shop and play with it. I took the compressor unit and bypassed all of the computer stuff added a hard start cap. and the unit ran and sounded fine. I went online to price some R410a and found several articles regarding R290 as a substitute and figured this would be a cheap way to test the unit to the unit.

I have ran it in the shop several times now and the numbers are nuts. Yesterday local temperature was 94 degrees, wet bulb temp 72 degrees
At the compessor liquid line 75 psi 60 degrees, gas line 86 deg. 80 psi. temperature at the evaporator 50 deg on the liquid line and 87 deg on the gas line. Delta T on the evap was 10 deg with 12 deg on the compressor. If you use these numbers with a very simple BTU calculation I'm getting 10K btu out of the evap and 12K out of the compressor. ????

Vlad · 06-23-12, 02:56 PM

Quote:

Originally Posted by Thepprof

This unit Klimaire KSWM12H113 (MINISPLIT HEATPUMP) I installed 2 of these units in January 12, 1 is working just fine the other locked up. I removed the unit and brought it home to scrap (New toshiba compressor cost 75% of what the entire unit cost. A few weeks later I decided to bring the unit in the shop and play with it. I took the compressor unit and bypassed all of the computer stuff added a hard start cap. and the unit ran and sounded fine. I went online to price some R410a and found several articles regarding R290 as a substitute and figured this would be a cheap way to test the unit to the unit.

I have ran it in the shop several times now and the numbers are nuts. Yesterday local temperature was 94 degrees, wet bulb temp 72 degrees
At the compessor liquid line 75 psi 60 degrees, gas line 86 deg. 80 psi. temperature at the evaporator 50 deg on the liquid line and 87 deg on the gas line. Delta T on the evap was 10 deg with 12 deg on the compressor. If you use these numbers with a very simple BTU calculation I'm getting 10K btu out of the evap and 12K out of the compressor. ????

My guess about R410a was right.

R290 or just propane is very close to R22 but really different from R410a. AC or HP is a system and not just system but closed balanced system. Every component affects the other and the rest of the system.

Refrigerant is a component and the part of the system and you can't just ignore this fact.

If this is a "play" unit you can play with it but you have to follow rules. So lets assume you want to build your system from scratch.

1. You start with your compressor. You have R410a compressor.
a) Make sure (Google it) compressor oil will be OK with R290. If not forget it.
b) Its capacity with R290 will be lower then original R410a. Lets assume somewhere 9k BTU

2. Your condenser/evaporator will be somewhere OK.

3. Your metering device. Here is the problem. MD is refrigerant specific. I would put R22 TXV 3/4 -1 ton capacity. Just eBay one. They are 20-30$ there. Make sure it is R22 one(bulb charge especially). You can use cap tube but again follow R22 9k-12k capacity table and not R410a.

4. Make sure your safety switches are R22 switches. R410a pressure switches won't be activated by R290.

At this point we can talk about numbers and pressures and charge size here and there. Without this minimum your system will never run properly.

I might missed something. Please correct me if I did.

Just noticed that it is HP. You will need HP txv or 2 txv's with check-valves.

Thepprof · 06-28-12, 04:13 PM

I'm guessing here but the device that meters the liquid in the compressor unit appears to be a check valve and orifice combination. The compressor was locked up initially and hence I pulled the unit to scrap. Later bypassed all of the computer controls and with the addition of a hard start cap. the compressor sounded fine. Mainly I wanted to test the compressor prior to hiring a competent professional to correctly vac,purg,and resupply the unit and put it back in service. My hvac training was in the military 45 years ago and home study in the meantime. I know enough to be dangerous to myself. I really do not plan to make any modifications to this unit. If the compressor is bad mechanically then I will keep the good pieces for parts and scrap the rest. I'm thinking of making and adapter for the liquid line direct to a gage and connecting the propane to the low side and once again bypassing all of the electronic stuff to see if the compressor will build up a couple of hundred pounds. I will then shut the whole thing down and look at internal leakdown (just as we used to check the bores on my racing kart engines) good pressure minimal leak down internally the compressor should be good to go. BUT I cannot find any supporting information in this regard. I played with the unit again this PM 90 deg, anbient, 66 deg wet bulb. Delta t at the evap 14 deg. 86.6 deg gas line 44.6 deg liquid line 72 psi gas line 85 psi liq line Delta T at the compressor 7.6 deg. any thoughts. I'm thinking about cleaning the system and going back to R410a. thanks again Owen.

Vlad · 06-28-12, 06:49 PM

Quote:

Originally Posted by Thepprof

I'm guessing here but the device that meters the liquid in the compressor unit appears to be a check valve and orifice combination. The compressor was locked up initially and hence I pulled the unit to scrap. Later bypassed all of the computer controls and with the addition of a hard start cap. the compressor sounded fine. Mainly I wanted to test the compressor prior to hiring a competent professional to correctly vac,purg,and resupply the unit and put it back in service. My hvac training was in the military 45 years ago and home study in the meantime. I know enough to be dangerous to myself. I really do not plan to make any modifications to this unit. If the compressor is bad mechanically then I will keep the good pieces for parts and scrap the rest. I'm thinking of making and adapter for the liquid line direct to a gage and connecting the propane to the low side and once again bypassing all of the electronic stuff to see if the compressor will build up a couple of hundred pounds. I will then shut the whole thing down and look at internal leakdown (just as we used to check the bores on my racing kart engines) good pressure minimal leak down internally the compressor should be good to go. BUT I cannot find any supporting information in this regard. I played with the unit again this PM 90 deg, anbient, 66 deg wet bulb. Delta t at the evap 14 deg. 86.6 deg gas line 44.6 deg liquid line 72 psi gas line 85 psi liq line Delta T at the compressor 7.6 deg. any thoughts. I'm thinking about cleaning the system and going back to R410a. thanks again Owen.

Because this is HP (I kinda missed this part at the beginning) and it is split you have couple of options for MD.

1. you have 2 MD one is in inside unit(air coil) second is in outside unit (condensing unit)

2. your MDs are fixed orifice with piston (check valve). This is cheap option but it works.

3. like any(or almost) MD they are refrigerant specific and will not work properly with other refrigerant (really different one).

Your compressor probably was not wired right (you mentioned you had some electronics problem). Because of this it couldn't start. Now when you bypassed all and added hard start kit it starts.

It is not easy to do the compressor test you want to do without proper tools and knowledge.

Be careful playing with propane.

randen · 07-04-12, 01:50 PM

The 3 ton GSHP I had made for the shop is in cooling mode today. The outside air temp is a very humid 34 Deg C with a humidex of 42 Deg C. This morning was raining hard and the water flowed under the garage doors and the floor is wet therfore the air within the shop is very humid. I had started the GSHP at 9:00 this morn. and at 1:00 the shop is cooled to 21 Deg C and the floor is drying. The condensate line is running alot. Not bad for homemade. All learned here.

Randen

AC_Hacker · 07-05-12, 10:50 AM

Quote:

Originally Posted by randen

The 3 ton GSHP I had made for the shop is in cooling mode today... I had started the GSHP at 9:00 this morn. and at 1:00 the shop is cooled to 21 Deg C and the floor is drying. The condensate line is running alot. Not bad for homemade. All learned here.

Great report... and you know how it all works, too!

-AC

RB855 · 07-13-12, 11:10 PM

Finally finished reading all 127 pages of this string, what a read. I came upon it while looking for ways to improve upon a very similar project. Iv built a heatpump waterheater from a 12k btu window a/c. Funny enough, the concept is nearly identical to a GSHP, so I thought I would share what Iv found along the way. The unit is a 12k Amana Heatpump r-410a unit that came from the factory with DOA electronics, was given to me from a friend in the PTAC industry. The unit was very easy to take apart as he had already recovered the 410. The Evap brazed off easily with only a few additional screws. I proceeded to dissect the 2 way drier/orifice tube asym and decided it wasn't useful for my application. I picked up a 1ton TXV intended for 12 or 22, Iv forgotten at this point. The gas Im working with is r-134a, as Im a auto mechanic and have a automotive R-134a recovery/charging machine at my disposal. Got a little discouraged while hunting down a condenser, as the coaxials were usually expensive or undersized. Then I had a thought. I had replaced my home heatpump a few months prior and had 15' of 7/8 and 3/8 lineset that got replaced. I attempted soldering the two together as a bonded exchanger, it failed quite terribly. Simply was not enough heat exchange, should have attempted making my own coax instead. The unit has progressed into using twinned BPHE's that were intended for R410, rated up to 600psi! The drawback was the coolant circuit was very restrictive. I placed the units in a balanced parallel setup to improve water flow, and increase transfer surface. I tried to oversize the condenser since my water entering temp will likly see 120*F, so every bit I can get out/ less Delta T is gained COP. The unit has not gone into service but has had a lot of test and tune time. I have even used a garden hose and used it as a watercooled a/c in one of the bays @ work! lol. There is a clear loss of pumping capacity using a r-410 compressor with 134, about 3k loss if my calcs are close. The unit, in my intended operating range gets between 4 and 6 COP, which is a whole lot better than resistance heating! Im going to try to include a link, not sure if Im allowed on my first ever post. I have new pictures I have not added to the album, but thought yall would like to see it. FYI the unit still has a operating rev valve for defrost mode, using a Chinese hpwh thermostat control (The instructions required a lot of trial and error to solve typos btw), and there are 8 passes of extra condenser under the evaporator to burn off waste heat that the BPHE did not dissipate to water, to keep the head down, and improve liquid quality to the txv.

(edit, I'm not allowed to post links, see yall in 4 more posts!)

AC_Hacker · 07-14-12, 01:44 AM

Quote:

Originally Posted by RB855

Finally finished reading all 127 pages of this string, what a read. I came upon it while looking for ways to improve upon a very similar project. Iv built a heatpump waterheater from a 12k btu window a/c.

Welcome to the conversation!

Congratulations for making it through the whole manifesto, and thanks for your great post on the water heater project... I'm really looking forward to seeing your pics.

I think the minimum character count to qualify as a post is something less than 20 characters, so it shouldn't be too burdensome.

My guess as to compressor size for a water heater project was about 1/3 Ton (4,000 BTU), but then I live by myself and don't have to supply DHW to a family. So it sounds like your project used around 9,000 BTU, in the final analysis.

I'd really like to know what your recovery curve looks like... If you could measure water temp at regular intervals, we could do that.

So what capacity is your DWH tank? Also, how big were your HX's (length, width, height, # of plates). I'm curious what kind of fittings your HX's had, and the diameter... also tell us about what pump you settled on, and what gpm you figure you have.

Also, what did you do for a controller?

Thanks again,

-AC_Hacker

RB855 · 07-14-12, 08:01 AM

Hello again,
The unit has not gone into service yet, but the intended storage tank will be a 55gallon waterheater that has had the lower element disabled. The pump is still a work in progress. Iv made 2 attempts at buying used grundfos and taco pumps from ebay, one got lost in the mail, the second looks undersized and requires a rebuild kit. As it sits Im using a free plastic grundfos spa recirc pump of unknown rating (missing tag). I suspect I'm circulating 2-5gpm. A problem I have run into is the unit runs on 220v, and almost all hydronic circs are 115v, which will require a stepdown trans or running a new 4 wire branch to the unit. The BPHE I'm using are 16plate 8x3" brazed fitting, designed for 5kw on r22 which seems a little high (ebay #370568522689). All of my measurements have been done with a 12 gallon bucket and not a single piece of insulation anywhere, so the curves are estimates at best. If memory serves, I guessed the unit could recover a 55gal tank from 90f to 130f in about an hour in 80f+ ambient. I have a whole spreadsheet at work of the data, so that will come soon. The evaporator on the system is the condenser re purposed. Built a distribution manifold which splits the evap into 3 circuits of 12, 12, and 14 passes. It is very oversized for cooling as I hope to get decent ratings out of it in cooler weather, as the unit will be placed outside. The controller, has actually surprised me. It is a cheapy but feature packed. (ebay #160794073510). It only comes in C* which my mind is still getting used to. It allows you to configure discharge temp lockout, evap temp for defrost, water temp for setpoint, compressor delay, min and max settable temps, time scheduled, input for pressure lockouts, settings for how long and how many times it can recover from lockout before it shuts down, and can control 3 different types of defrost inclu 2 types rev valve, and resistive. If you use one of these they are intended for heated water only, and the instructions sheet has many critical errors, of which I can supply a corrected sheet (by my own experimentation). Off to work with me, tc!

06-23-12, 07:32 AM	#1252
Thepprof Lurking Renovator Join Date: Jun 2012 Location: Virginia Posts: 28 Thanks: 0 Thanked 4 Times in 3 Posts	Klimaire This unit Klimaire KSWM12H113 (MINISPLIT HEATPUMP) I installed 2 of these units in January 12, 1 is working just fine the other locked up. I removed the unit and brought it home to scrap (New toshiba compressor cost 75% of what the entire unit cost. A few weeks later I decided to bring the unit in the shop and play with it. I took the compressor unit and bypassed all of the computer stuff added a hard start cap. and the unit ran and sounded fine. I went online to price some R410a and found several articles regarding R290 as a substitute and figured this would be a cheap way to test the unit to the unit. I have ran it in the shop several times now and the numbers are nuts. Yesterday local temperature was 94 degrees, wet bulb temp 72 degrees At the compessor liquid line 75 psi 60 degrees, gas line 86 deg. 80 psi. temperature at the evaporator 50 deg on the liquid line and 87 deg on the gas line. Delta T on the evap was 10 deg with 12 deg on the compressor. If you use these numbers with a very simple BTU calculation I'm getting 10K btu out of the evap and 12K out of the compressor. ????

06-28-12, 04:13 PM	#1254
Thepprof Lurking Renovator Join Date: Jun 2012 Location: Virginia Posts: 28 Thanks: 0 Thanked 4 Times in 3 Posts	thanks. I'm guessing here but the device that meters the liquid in the compressor unit appears to be a check valve and orifice combination. The compressor was locked up initially and hence I pulled the unit to scrap. Later bypassed all of the computer controls and with the addition of a hard start cap. the compressor sounded fine. Mainly I wanted to test the compressor prior to hiring a competent professional to correctly vac,purg,and resupply the unit and put it back in service. My hvac training was in the military 45 years ago and home study in the meantime. I know enough to be dangerous to myself. I really do not plan to make any modifications to this unit. If the compressor is bad mechanically then I will keep the good pieces for parts and scrap the rest. I'm thinking of making and adapter for the liquid line direct to a gage and connecting the propane to the low side and once again bypassing all of the electronic stuff to see if the compressor will build up a couple of hundred pounds. I will then shut the whole thing down and look at internal leakdown (just as we used to check the bores on my racing kart engines) good pressure minimal leak down internally the compressor should be good to go. BUT I cannot find any supporting information in this regard. I played with the unit again this PM 90 deg, anbient, 66 deg wet bulb. Delta t at the evap 14 deg. 86.6 deg gas line 44.6 deg liquid line 72 psi gas line 85 psi liq line Delta T at the compressor 7.6 deg. any thoughts. I'm thinking about cleaning the system and going back to R410a. thanks again Owen.

07-04-12, 01:50 PM	#1256
randen Uber EcoRenovator Join Date: Apr 2011 Location: Strathroy Ontario Canada Posts: 657 Thanks: 9 Thanked 191 Times in 129 Posts	Update for homemade GSHP For the shop The 3 ton GSHP I had made for the shop is in cooling mode today. The outside air temp is a very humid 34 Deg C with a humidex of 42 Deg C. This morning was raining hard and the water flowed under the garage doors and the floor is wet therfore the air within the shop is very humid. I had started the GSHP at 9:00 this morn. and at 1:00 the shop is cooled to 21 Deg C and the floor is drying. The condensate line is running alot. Not bad for homemade. All learned here. Randen

07-13-12, 11:10 PM	#1258
RB855 Helper EcoRenovator Join Date: Jul 2012 Location: Jacksonville, fl Posts: 48 Thanks: 3 Thanked 14 Times in 10 Posts	1st post! Finally finished reading all 127 pages of this string, what a read. I came upon it while looking for ways to improve upon a very similar project. Iv built a heatpump waterheater from a 12k btu window a/c. Funny enough, the concept is nearly identical to a GSHP, so I thought I would share what Iv found along the way. The unit is a 12k Amana Heatpump r-410a unit that came from the factory with DOA electronics, was given to me from a friend in the PTAC industry. The unit was very easy to take apart as he had already recovered the 410. The Evap brazed off easily with only a few additional screws. I proceeded to dissect the 2 way drier/orifice tube asym and decided it wasn't useful for my application. I picked up a 1ton TXV intended for 12 or 22, Iv forgotten at this point. The gas Im working with is r-134a, as Im a auto mechanic and have a automotive R-134a recovery/charging machine at my disposal. Got a little discouraged while hunting down a condenser, as the coaxials were usually expensive or undersized. Then I had a thought. I had replaced my home heatpump a few months prior and had 15' of 7/8 and 3/8 lineset that got replaced. I attempted soldering the two together as a bonded exchanger, it failed quite terribly. Simply was not enough heat exchange, should have attempted making my own coax instead. The unit has progressed into using twinned BPHE's that were intended for R410, rated up to 600psi! The drawback was the coolant circuit was very restrictive. I placed the units in a balanced parallel setup to improve water flow, and increase transfer surface. I tried to oversize the condenser since my water entering temp will likly see 120*F, so every bit I can get out/ less Delta T is gained COP. The unit has not gone into service but has had a lot of test and tune time. I have even used a garden hose and used it as a watercooled a/c in one of the bays @ work! lol. There is a clear loss of pumping capacity using a r-410 compressor with 134, about 3k loss if my calcs are close. The unit, in my intended operating range gets between 4 and 6 COP, which is a whole lot better than resistance heating! Im going to try to include a link, not sure if Im allowed on my first ever post. I have new pictures I have not added to the album, but thought yall would like to see it. FYI the unit still has a operating rev valve for defrost mode, using a Chinese hpwh thermostat control (The instructions required a lot of trial and error to solve typos btw), and there are 8 passes of extra condenser under the evaporator to burn off waste heat that the BPHE did not dissipate to water, to keep the head down, and improve liquid quality to the txv. (edit, I'm not allowed to post links, see yall in 4 more posts!)

06-23-12, 03:25 AM	#1251
Vlad Apprentice EcoRenovator Join Date: Aug 2010 Location: Windsor ON Canada Posts: 229 Thanks: 4 Thanked 30 Times in 22 Posts	Theprof, I guess Klimaire is a mini split AC unit that uses R410a. If it is I think propane is not the best option. 1. Capacity will change. From 12k BTU you will get only 9k or 10k who knows? 2. All your safety devices are for much higher pressure range. Just as an example your high pressure switch is hard to trigger with R290. If you want more "help" we need more info.

07-14-12, 08:01 AM	#1260
RB855 Helper EcoRenovator Join Date: Jul 2012 Location: Jacksonville, fl Posts: 48 Thanks: 3 Thanked 14 Times in 10 Posts	Hello again, The unit has not gone into service yet, but the intended storage tank will be a 55gallon waterheater that has had the lower element disabled. The pump is still a work in progress. Iv made 2 attempts at buying used grundfos and taco pumps from ebay, one got lost in the mail, the second looks undersized and requires a rebuild kit. As it sits Im using a free plastic grundfos spa recirc pump of unknown rating (missing tag). I suspect I'm circulating 2-5gpm. A problem I have run into is the unit runs on 220v, and almost all hydronic circs are 115v, which will require a stepdown trans or running a new 4 wire branch to the unit. The BPHE I'm using are 16plate 8x3" brazed fitting, designed for 5kw on r22 which seems a little high (ebay #370568522689). All of my measurements have been done with a 12 gallon bucket and not a single piece of insulation anywhere, so the curves are estimates at best. If memory serves, I guessed the unit could recover a 55gal tank from 90f to 130f in about an hour in 80f+ ambient. I have a whole spreadsheet at work of the data, so that will come soon. The evaporator on the system is the condenser re purposed. Built a distribution manifold which splits the evap into 3 circuits of 12, 12, and 14 passes. It is very oversized for cooling as I hope to get decent ratings out of it in cooler weather, as the unit will be placed outside. The controller, has actually surprised me. It is a cheapy but feature packed. (ebay #160794073510). It only comes in C* which my mind is still getting used to. It allows you to configure discharge temp lockout, evap temp for defrost, water temp for setpoint, compressor delay, min and max settable temps, time scheduled, input for pressure lockouts, settings for how long and how many times it can recover from lockout before it shuts down, and can control 3 different types of defrost inclu 2 types rev valve, and resistive. If you use one of these they are intended for heated water only, and the instructions sheet has many critical errors, of which I can supply a corrected sheet (by my own experimentation). Off to work with me, tc!