The Homemade Heat Pump Manifesto - Page 163

AC_Hacker · 12-09-13, 02:19 PM

Quote:

Originally Posted by 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

Your estimate of 1 Ton per hole might be not be quite the correct number.

In the 'Manifesto' I use that number because it is the one that is commonly used in Western Oregon where I live, when the average ground temperature is taken into account. The map indicates my soil temperature would be 56 F, but my holes aren't as deep as you have been able to achieve, and when I measured the temp in the winter time, which is when I need it, it is 52F... still pretty close. The map indicates that your soil temperature is around 67F. I can testify that as far as geothermal goes, the difference between 52 and 67 is huge.

Also the typical soil characteristics...

For instance, sandy clay (where you live) is considered to be sort of 'average to poor' classification, regarding geothermal... but wet sandy clay is the best you can get. This is also a big deal.

For heating, I think that 1 Ton per hole is too low. I'm not sure how much higher your situation will be, but I would recommend that you find some people in your area, who you can ask regarding their estimates.

For heating, your higher ground temp is very favorable. For cooling, your higher ground temperature is not so favorable... so your cooling capability will be less.

But if it is wet sandy clay that you have there, it will be to your benefit, whether you are heating or cooling.

* * *

I'm a little confused here... You said that you have three holes and you're only going to use one of them? I think that it would be to your benefit to use all of them, especially if they are not too far apart.

It's one of those situations where bigger actually is better.

If they are all available, run pipe from each of them to your house and do the combining and plumbing there.

And you should run them all in parallel, it will greatly reduce the size and power consumption of your pump.

* * *

Also, as I recall, you already have a heat exchanger? That will be part of the total resistance that the pump will need to pump through.

So if it is true that you do have your heat exchanger, I'll need to know what is is you have there.

By the way, you are well on your way to constructing a high class geothermal system. Your system will very much be influenced by your heat exchanger. Don't even consider fooling around with a little radiator in an ice chest... that's for experiments, and for children. You need a serious heat exchanger, which you can buy or build.

But whatever it is, I need to know about it to calculate your pump size.

-AC

waterdigger2 · 12-09-13, 03:23 PM

We use the same . 240 ft per ton here . This is comein from geothermal installer we drill for. Only reason for the 250 ft . Not sure if its the same with the shallow holes . But that pipe as it goes down the mud that floats up the cuttings actually works against you . Reason we use a huge heavy metal cylinder to drop em down. The second you take that cylinder . You have to hold the loops down or they will literally shoot right back up out of the hole. The 10 ft extra is just to compensate (if) it was to shoot up loose grip or something. I wonder how accurate that map is on the temp. I have 2 wells here . One is shallow one deep. The deeper one is actually warmer than the 14 ft shallow one. Strangely enough.
What are you classifying as (wet sandy clay) Not sure what that is . Unless you are talking about like the water table clay under that that is pourus enough to have water?
For the soil . Yea we have sandy clay. About 85& sand the rest clay,gravel, dry sand . But for the most its sandy clay.
_____________________________

Yeah do have 3 holes dug each 250ft deep. Reason i was going to use only 1 loop is because i thought the more holes it had to go through it would make it not as efficient. In that case . I will go with a bigger 1 1/4 hdpe pipe to connect each hole to the 1 1/4 . Or 1 1/2 . I cant remember what size they use to connect them up .
But being th heat exchanger is 3/4 instead may be better to just run the 3/4 instead of the 1 1/4 ?
I will have to get out there and measure once the rain stops i believe their something like 10ft apart. Their all in a line from each other.
__________________________________________________ _________

On the Heat Exchanger. None yet . Have found one with all sweat fittings that i plan on getting. Only its 10 plate.

10 Plate Copper Brazed Heat Exchanger 5"x12" 3 4" Sweat | eBay

Yea. I dont plan on usin a cooler or nothing crazy like that. From what i under stand the heat exchanger is basically what switches the heat from the refridgerant and exchanges it with the loop water and makes it efficient .

NiHaoMike · 12-09-13, 05:27 PM

I recommend a coax heat exchanger like this one:
TURBOTEC | COILS, STEAM & WATER | 1.70 TON COAX COIL | Surplus City Liquidators
It's physically much bigger (about the size of a small car tire for the 1.7 ton after you account for insulation) but also much less restrictive, meaning that the pump uses less power. I highly recommend oversizing the heat exchanger as that improves efficiency.
While you're at it, also get the TXV (must match refrigerant type and tonnage, a R22 TXV will work with R290 or R433b/ES22a), filter drier (do not open until right before you're going to braze it in), and other accessories like sight glasses and pressure cutouts. That site does not automatically calculate shipping, but you can send them an Email to get the exact amount before accepting the order.

stevehull · 12-09-13, 06:38 PM

Mike,

I see a 3.5 ton coax coil for $113 on Surplus City. Do you feel increasing to that size is worth the small extra cost?

Steve

NiHaoMike · 12-09-13, 07:39 PM

How big is the A/C unit you're planning to modify? At some point like 1.5x-2x the rating, it gets to the point of diminishing returns. It certainly won't hurt except for making the unit bigger and heavier.

jeff5may · 12-09-13, 08:07 PM

Quote:

Originally Posted by AC_Hacker

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

You trying to keep this thing secret?

-AC

The pic is from the thread Mike linked a couple of posts up from me on the $45 chiller. Guy said in his post that he was 15 when he built it. Second hand 5000btu aircon repurposed into -30C PC watercooler. Still working a couple of years later.

Here is a more comprehensive build, roughly the same end product, by another teenager:
First Chiller - EXTREME Overclocking Forums

BeerGrylls · 12-12-13, 12:16 PM

Hi All,
first off, thanks for sharing your knowledge in here, had a long read but the info is very valuable. I might need a bit of help or opinions needed for my project, just in case I am missing some obvious things. What is going on:
I live on a small boat, 27ft sailboat, it's getting freaking cold out here on the Danube, I'm not paying for electricity but I am environmentally conscious and want to be self sufficient if possible, resistive heating is just ridiculous. I have been looking at various ways to heat a small boat and I dislike the majority of them, so I ended up with a plan:
-buy one of the highest efficiency ASHP and convert it to WSHP. I bought a Midea MSX07HRNF1QE4 heatpump (8000btu on heating) with a COP of 5.56 or something like that.
-I figured I will install it myself this winter and run it as ASHP simply because it is getting too cold to diy now and I don't have all the tools required to deal with refrigerant lines.
-when spring comes I plan to swap the outside air coil with a water to refrigerant HX, open loop, add an efficient pump for the loop.
-keep all electronics and everything else intact, hopefully everything just works with the coil swap. And voila, happiness...

Well, what I have to figure out is - what HX to get, capacity of HX, what pumping volume and how to fill in refrigerant after the swap (quantity). The Danube gets close to 0 degrees in winter (mostly around 4degC), but outside air can get to -15 -20, I understand that occasionally this harbour can freeze sometimes (once a couple years).

I looked at my heatpump and made a few observations: it seems everything is as big as the 1 ton units in the same series of the product, the higher btu series seem to have identical hardware but their COPs go from 5.56(8000btu) to about 4.2 (12000btu). I believe but not yet confirmed even the dc compressor is the same in all units from 8000 to 12000btu. The compressor I have is DA110S1C-30FZ, the unit has a cap tube setup, no txv, not sure if I should be sad about it, as I read the TXV's are better as they offer adjustments.

I would be curious on your opinions on the HX and if in general my idea is not completely bonkers. It seems like the unit is pretty much the 1 ton unit, but "underclocked" for a higher COP, the label even says it goes from 2600-12500BTU in heating. So should I get a 1 ton HX or lower ? Also it is a R410A unit, not planning in changing refrg. type.

Before spring comes I assume I will have time to collect some tools to do the hacking, and more knowledge hopefully. I'm thinking of going with BPHE just because they are getting so cheap, and flush out the foulants every once in a while, and provide a decent filter on the river water inlet. Have no idea though what pumping capacity should I push through the loop. Ideally I will be running it on solar power once I finish making my panels, the dc compressor looks to draw very little after start. The interior volume is also very low, but the boat is old and there's not much hope to add more insulation now. I have added mineral wool blankets on the deck and some polysterene boards where possible. Also - an important factor is humidity, gets pretty humid inside, hope the interior unit can get rid of the humidity, it seems to have a separate dehumidification program.

It looks to be hard to get a coax HX around here, but BPHX pretty easy, I know they can foul quicker, but also read cleaning instructions from some manufacturers and they don't seem to really turn into hopeless junk that you can't do anything with if your water source is not clean enough, they can be flushed with some cleaning agents etc. Do you think I should avoid BPHX at all costs ? Also - now I'm on the Danube, but I might get into salt water at some point.

Look forward to hear some feedback on my hacking intentions.
Cheers from the cold-ish boat !
Florin

stevehull · 12-12-13, 02:43 PM

Florin,

All good ideas. I bet 1 ton (12,000 BTU) would be sufficient heat so long as you can blow warm air around the inside of the boat.

The gallons per minute is not large ~ 2 (or about 8 liters/min) of water flow will be sufficient. That said, you don't need a large pump as the only thing you have to overcome is the pipe resistance. A small 12 V DC water pump should work very well.

Freezing water is not a big issue as you can put overboard a hose that goes about a yard (meter) underneath the ice where the water is not freezing. The COP will get hit as it is hard to extract a lot of heat without freezing the outlet line.

I use an open loop water based heat pumps here and I have about a 10 degree F difference from inlet to outlet. Obviously, if your inlet water is 35 F then a 10 degree drop will not work (as in freezing the outlet line with open loop).

It is important to note that the water flow may have to be higher than stated above to deep your outlet line from freezing.

All that said, I would consider using a large truck radiator as a submerged river water heat exchanger and then use an antifreeze mixture in a closed loop configuration. First, a used large truck radiator is cheap and it has a LOT of surface area. Does the channel where you are have any water flow current? That will also help.

Lastly, your area gets wicked hot and steamy in the summer and you can easily have a reversing value in the heat pump guts to allow summer AC to get rid of the humidity you spoke of.

The salty water will eventually corrode the old radiator, so you may want to think of a large coil of HDPE pipe, but I do know that the radiator idea works. Just don't put it flat on the river bottom . . . . best if it can be put down there "upright" so that water can flow around it.

Another thought is to use isopropyl alcohol (10-15%) in the closed loop as this is "less" toxic when (not if) there are coolant leaks. Many in the EC get very fastidious about certain chemicals being dumped into rivers (the Danube formally being one of the most polluted rivers in the world . . . ). But I understand that fish are coming back (but would you eat them?)!

If $ is little object, you can buy open loop geothermal heater/AC for boats and they are not very big.

Keep us posted and we look forward to this interesting problem and how you solve it.

Steve

BeerGrylls · 12-12-13, 04:10 PM

Steve,
many thanks for the ideas. $ is an issue, I also want to keep the hack as simple as possible. Regarding low temps - I am thinking of having a split in my river water intake system, with routing valves, very easy to make in HDPE. The reasons is that in the winter I want to draw water from the bottom of the river, as it is warmer there, for that I will simply use an insulated hose with a strainer at the end, just drop it on the bottom (about 3m deep water in the harbour). Also in the winter I don't move the boat so I don't care about a hose going overboard, however in the summer I will take water from the through hull fitting, but I would avoid that in winter as water at the surface is colder than the bottom.
The large radiator idea is interesting, are you saying the radiator is submerged outside the hull and is a antifreeze/refrg HX ? Or it is a primary HX with river<>antifreeze and then an antifreeze<>refrg. HX inside the boat ? I assume the latter. I will avoid this kind of setup due to complexity, more pumps, more controls, more worries etc. Initially was thinking to have a closed loop system running antifreeze in a bunch of hose rolls dumped on the bottom of the river (under the boat) , but again, this is not a very elegant setup.

I assume, in order to avoid the above, the only thing remaining is to closely monitor the river temp and water coming out of the HX and oversize the pump capacity to avoid freezing the HX. But the pump capacity would have to be guesstimated somehow.

The heatpump comes with a reversing valve from factory, so it works both ways (cooling).

Fish are coming back, but I am vegan... This area is particularly clean, I sailed the whole Danube from end to start and I've seen some really nasty polluted areas. Here it is pretty good, there is fish and the Otters are my night neighbours which I love, great area.

I have looked a the marine units too. The option was discarded because: too expensive, low COP's (1.8-2.8). Normally they are really compact so there is little performance to squeeze out of them, sure there are better ones but the prices are ridiculous.

I bought this ASHP unit because I figured it will be an easy hack to WSHP (remains to be seen) and it is really high performance, and I actually bought it as it was on a ridiculous sale, the reason probably being the size. It is about 50kg for 8000btu, the marine units weigh less than half for that capacity.

Anyone has experience with BPHE cleaning of performance decrease in open loops ?
So the current plan is - 1 ton water to refrg HX (coax or BP), variable speed water pump (capacity to be determined, the air coil fan is rated 30W, would be nice if the pump is the same power rating because I could even use motor wiring for the pump, fan is BLDC) and to figure out refrg. filling after the hack is mechanically done.

BTW - AC hacker, was thinking of how you brazed the copper tubing to the BPHE, the wet rag - why not submerging the BPHE in water instead (in a shallow bucket etc), of course lower than the inlet. Would that work ?

Cheers,
F

waterdigger2 · 12-12-13, 04:23 PM

BeerGryllis. Dont know how much budget you have If you are like me at the moment without a job . You can get a few pieces of wood build a partial box kinda like a solar pannel put in some garbage bags in with some clear food wrapping paper . Doesnt look great . But does keep things a little warmer and also wont break the bank or turn the electric meter into a extremely fast merry go round.

12-09-13, 05:27 PM	#1623
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	I recommend a coax heat exchanger like this one: TURBOTEC \| COILS, STEAM & WATER \| 1.70 TON COAX COIL \| Surplus City Liquidators It's physically much bigger (about the size of a small car tire for the 1.7 ton after you account for insulation) but also much less restrictive, meaning that the pump uses less power. I highly recommend oversizing the heat exchanger as that improves efficiency. While you're at it, also get the TXV (must match refrigerant type and tonnage, a R22 TXV will work with R290 or R433b/ES22a), filter drier (do not open until right before you're going to braze it in), and other accessories like sight glasses and pressure cutouts. That site does not automatically calculate shipping, but you can send them an Email to get the exact amount before accepting the order. __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

12-09-13, 06:38 PM	#1624
stevehull Steve Hull Join Date: Dec 2012 Location: hilly, tree covered Arcadia, OK USA Posts: 826 Thanks: 241 Thanked 165 Times in 123 Posts	Mike, I see a 3.5 ton coax coil for $113 on Surplus City. Do you feel increasing to that size is worth the small extra cost? Steve __________________ consulting on geothermal heating/cooling & rational energy use since 1990

12-09-13, 07:39 PM	#1625
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	How big is the A/C unit you're planning to modify? At some point like 1.5x-2x the rating, it gets to the point of diminishing returns. It certainly won't hurt except for making the unit bigger and heavier. __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

12-12-13, 02:43 PM	#1628
stevehull Steve Hull Join Date: Dec 2012 Location: hilly, tree covered Arcadia, OK USA Posts: 826 Thanks: 241 Thanked 165 Times in 123 Posts	Florin, All good ideas. I bet 1 ton (12,000 BTU) would be sufficient heat so long as you can blow warm air around the inside of the boat. The gallons per minute is not large ~ 2 (or about 8 liters/min) of water flow will be sufficient. That said, you don't need a large pump as the only thing you have to overcome is the pipe resistance. A small 12 V DC water pump should work very well. Freezing water is not a big issue as you can put overboard a hose that goes about a yard (meter) underneath the ice where the water is not freezing. The COP will get hit as it is hard to extract a lot of heat without freezing the outlet line. I use an open loop water based heat pumps here and I have about a 10 degree F difference from inlet to outlet. Obviously, if your inlet water is 35 F then a 10 degree drop will not work (as in freezing the outlet line with open loop). It is important to note that the water flow may have to be higher than stated above to deep your outlet line from freezing. All that said, I would consider using a large truck radiator as a submerged river water heat exchanger and then use an antifreeze mixture in a closed loop configuration. First, a used large truck radiator is cheap and it has a LOT of surface area. Does the channel where you are have any water flow current? That will also help. Lastly, your area gets wicked hot and steamy in the summer and you can easily have a reversing value in the heat pump guts to allow summer AC to get rid of the humidity you spoke of. The salty water will eventually corrode the old radiator, so you may want to think of a large coil of HDPE pipe, but I do know that the radiator idea works. Just don't put it flat on the river bottom . . . . best if it can be put down there "upright" so that water can flow around it. Another thought is to use isopropyl alcohol (10-15%) in the closed loop as this is "less" toxic when (not if) there are coolant leaks. Many in the EC get very fastidious about certain chemicals being dumped into rivers (the Danube formally being one of the most polluted rivers in the world . . . ). But I understand that fish are coming back (but would you eat them?)! If $ is little object, you can buy open loop geothermal heater/AC for boats and they are not very big. Keep us posted and we look forward to this interesting problem and how you solve it. Steve __________________ consulting on geothermal heating/cooling & rational energy use since 1990

12-09-13, 03:23 PM	#1622
waterdigger2 Helper EcoRenovator Join Date: Dec 2013 Location: mississippi Posts: 36 Thanks: 9 Thanked 0 Times in 0 Posts	We use the same . 240 ft per ton here . This is comein from geothermal installer we drill for. Only reason for the 250 ft . Not sure if its the same with the shallow holes . But that pipe as it goes down the mud that floats up the cuttings actually works against you . Reason we use a huge heavy metal cylinder to drop em down. The second you take that cylinder . You have to hold the loops down or they will literally shoot right back up out of the hole. The 10 ft extra is just to compensate (if) it was to shoot up loose grip or something. I wonder how accurate that map is on the temp. I have 2 wells here . One is shallow one deep. The deeper one is actually warmer than the 14 ft shallow one. Strangely enough. What are you classifying as (wet sandy clay) Not sure what that is . Unless you are talking about like the water table clay under that that is pourus enough to have water? For the soil . Yea we have sandy clay. About 85& sand the rest clay,gravel, dry sand . But for the most its sandy clay. _____________________________ Yeah do have 3 holes dug each 250ft deep. Reason i was going to use only 1 loop is because i thought the more holes it had to go through it would make it not as efficient. In that case . I will go with a bigger 1 1/4 hdpe pipe to connect each hole to the 1 1/4 . Or 1 1/2 . I cant remember what size they use to connect them up . But being th heat exchanger is 3/4 instead may be better to just run the 3/4 instead of the 1 1/4 ? I will have to get out there and measure once the rain stops i believe their something like 10ft apart. Their all in a line from each other. __________________________________________________ _________ On the Heat Exchanger. None yet . Have found one with all sweat fittings that i plan on getting. Only its 10 plate. 10 Plate Copper Brazed Heat Exchanger 5"x12" 3 4" Sweat \| eBay Yea. I dont plan on usin a cooler or nothing crazy like that. From what i under stand the heat exchanger is basically what switches the heat from the refridgerant and exchanges it with the loop water and makes it efficient .

12-12-13, 12:16 PM	#1627
BeerGrylls Lurking Renovator Join Date: Dec 2013 Location: Austria Posts: 25 Thanks: 1 Thanked 1 Time in 1 Post	Hi All, first off, thanks for sharing your knowledge in here, had a long read but the info is very valuable. I might need a bit of help or opinions needed for my project, just in case I am missing some obvious things. What is going on: I live on a small boat, 27ft sailboat, it's getting freaking cold out here on the Danube, I'm not paying for electricity but I am environmentally conscious and want to be self sufficient if possible, resistive heating is just ridiculous. I have been looking at various ways to heat a small boat and I dislike the majority of them, so I ended up with a plan: -buy one of the highest efficiency ASHP and convert it to WSHP. I bought a Midea MSX07HRNF1QE4 heatpump (8000btu on heating) with a COP of 5.56 or something like that. -I figured I will install it myself this winter and run it as ASHP simply because it is getting too cold to diy now and I don't have all the tools required to deal with refrigerant lines. -when spring comes I plan to swap the outside air coil with a water to refrigerant HX, open loop, add an efficient pump for the loop. -keep all electronics and everything else intact, hopefully everything just works with the coil swap. And voila, happiness... Well, what I have to figure out is - what HX to get, capacity of HX, what pumping volume and how to fill in refrigerant after the swap (quantity). The Danube gets close to 0 degrees in winter (mostly around 4degC), but outside air can get to -15 -20, I understand that occasionally this harbour can freeze sometimes (once a couple years). I looked at my heatpump and made a few observations: it seems everything is as big as the 1 ton units in the same series of the product, the higher btu series seem to have identical hardware but their COPs go from 5.56(8000btu) to about 4.2 (12000btu). I believe but not yet confirmed even the dc compressor is the same in all units from 8000 to 12000btu. The compressor I have is DA110S1C-30FZ, the unit has a cap tube setup, no txv, not sure if I should be sad about it, as I read the TXV's are better as they offer adjustments. I would be curious on your opinions on the HX and if in general my idea is not completely bonkers. It seems like the unit is pretty much the 1 ton unit, but "underclocked" for a higher COP, the label even says it goes from 2600-12500BTU in heating. So should I get a 1 ton HX or lower ? Also it is a R410A unit, not planning in changing refrg. type. Before spring comes I assume I will have time to collect some tools to do the hacking, and more knowledge hopefully. I'm thinking of going with BPHE just because they are getting so cheap, and flush out the foulants every once in a while, and provide a decent filter on the river water inlet. Have no idea though what pumping capacity should I push through the loop. Ideally I will be running it on solar power once I finish making my panels, the dc compressor looks to draw very little after start. The interior volume is also very low, but the boat is old and there's not much hope to add more insulation now. I have added mineral wool blankets on the deck and some polysterene boards where possible. Also - an important factor is humidity, gets pretty humid inside, hope the interior unit can get rid of the humidity, it seems to have a separate dehumidification program. It looks to be hard to get a coax HX around here, but BPHX pretty easy, I know they can foul quicker, but also read cleaning instructions from some manufacturers and they don't seem to really turn into hopeless junk that you can't do anything with if your water source is not clean enough, they can be flushed with some cleaning agents etc. Do you think I should avoid BPHX at all costs ? Also - now I'm on the Danube, but I might get into salt water at some point. Look forward to hear some feedback on my hacking intentions. Cheers from the cold-ish boat ! Florin

12-12-13, 04:10 PM	#1629
BeerGrylls Lurking Renovator Join Date: Dec 2013 Location: Austria Posts: 25 Thanks: 1 Thanked 1 Time in 1 Post	Steve, many thanks for the ideas. $ is an issue, I also want to keep the hack as simple as possible. Regarding low temps - I am thinking of having a split in my river water intake system, with routing valves, very easy to make in HDPE. The reasons is that in the winter I want to draw water from the bottom of the river, as it is warmer there, for that I will simply use an insulated hose with a strainer at the end, just drop it on the bottom (about 3m deep water in the harbour). Also in the winter I don't move the boat so I don't care about a hose going overboard, however in the summer I will take water from the through hull fitting, but I would avoid that in winter as water at the surface is colder than the bottom. The large radiator idea is interesting, are you saying the radiator is submerged outside the hull and is a antifreeze/refrg HX ? Or it is a primary HX with river<>antifreeze and then an antifreeze<>refrg. HX inside the boat ? I assume the latter. I will avoid this kind of setup due to complexity, more pumps, more controls, more worries etc. Initially was thinking to have a closed loop system running antifreeze in a bunch of hose rolls dumped on the bottom of the river (under the boat) , but again, this is not a very elegant setup. I assume, in order to avoid the above, the only thing remaining is to closely monitor the river temp and water coming out of the HX and oversize the pump capacity to avoid freezing the HX. But the pump capacity would have to be guesstimated somehow. The heatpump comes with a reversing valve from factory, so it works both ways (cooling). Fish are coming back, but I am vegan... This area is particularly clean, I sailed the whole Danube from end to start and I've seen some really nasty polluted areas. Here it is pretty good, there is fish and the Otters are my night neighbours which I love, great area. I have looked a the marine units too. The option was discarded because: too expensive, low COP's (1.8-2.8). Normally they are really compact so there is little performance to squeeze out of them, sure there are better ones but the prices are ridiculous. I bought this ASHP unit because I figured it will be an easy hack to WSHP (remains to be seen) and it is really high performance, and I actually bought it as it was on a ridiculous sale, the reason probably being the size. It is about 50kg for 8000btu, the marine units weigh less than half for that capacity. Anyone has experience with BPHE cleaning of performance decrease in open loops ? So the current plan is - 1 ton water to refrg HX (coax or BP), variable speed water pump (capacity to be determined, the air coil fan is rated 30W, would be nice if the pump is the same power rating because I could even use motor wiring for the pump, fan is BLDC) and to figure out refrg. filling after the hack is mechanically done. BTW - AC hacker, was thinking of how you brazed the copper tubing to the BPHE, the wet rag - why not submerging the BPHE in water instead (in a shallow bucket etc), of course lower than the inlet. Would that work ? Cheers, F

12-12-13, 04:23 PM	#1630
waterdigger2 Helper EcoRenovator Join Date: Dec 2013 Location: mississippi Posts: 36 Thanks: 9 Thanked 0 Times in 0 Posts	BeerGryllis. Dont know how much budget you have If you are like me at the moment without a job . You can get a few pieces of wood build a partial box kinda like a solar pannel put in some garbage bags in with some clear food wrapping paper . Doesnt look great . But does keep things a little warmer and also wont break the bank or turn the electric meter into a extremely fast merry go round.