I am wondering if there would be a way for me to have water warmer than the air in winter pass across the coils of my heat pump? I have constant ground water under my basement that i pump out with a small pond pump and i am wondering if on say a 20 or 30 Degree F day if I passed warmer water over them or near them it could help the heat pump use less electricity? also considered a rocket stove heating water nearby to run past the coils. i really wish i could have a zone of coil to directly affect either by submerging in warm water or something? same would go for AC in summer. it would be cooler than the air outside. kind of making the system more like a ground source pump?
Has anyone tried adding heat to their heat pump with warm water or air to make it more efficient?
- Thread starter toadman03
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Hedges
I See Electromagnetic Fields!
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I don't think consuming fuel such as in the rocket stove to heat input of heat pump delivers any extra energy. Just use heat from that directly.
If you have earth temperature water to feed the heat pump, that should do well. one meant for ground source would have been the way to go. If you can run a refrigerant line through the water that ought to work. Not touching the heat pump system, maybe just pump water through a radiator on air intake side of heat pump.
If you have earth temperature water to feed the heat pump, that should do well. one meant for ground source would have been the way to go. If you can run a refrigerant line through the water that ought to work. Not touching the heat pump system, maybe just pump water through a radiator on air intake side of heat pump.
Zwy
Solar Wizard
There was some research done using earth tubes to increase incoming air temp for an air to air heat pump. https://diysolarforum.com/threads/senville-aura-24k-heating-results.72030/post-911845
This was the research paper I read and yes, it is practical. https://geothermal-energy-journal.springeropen.com/articles/10.1186/s40517-015-0036-2
Daddy Tanuki
Solar Wizard
if you have ground water that is warmer than ambient then the easiest would be to unsolder the condenser and submerge it in a tank and pump the water over it. this would require degassing, soldering vacuuming the lines out and a re-gas. this is basically what geothermal heat pumps do, most of them offer two version, one sunk in a well that is at least 400' deep (most usually 4 x 100' spaced about 20' apart, or a 400' long trench that is at least 6' down. the other option is to run the black hose into a pond and coil it across the bottom and then stake it down. as long as the pond is deep enough that it does not freeze it offers an advantage if your temps regularly go below 32f or 0c.
6' down the earth temp is pretty stable at about 55-60°f, 12-15°c so the simple fact that the medium is warmer in the winter uses the pond, or the buried black hose as a huge heat sump. air to air is trying to get heat from cold air, with a geo-thermal setup as described you are starting at 55-60 to begin with so its much more efficient. so its more efficient in the winter and the summer.
this is one of the long term projects i wanted to start in the next 3-4 years
6' down the earth temp is pretty stable at about 55-60°f, 12-15°c so the simple fact that the medium is warmer in the winter uses the pond, or the buried black hose as a huge heat sump. air to air is trying to get heat from cold air, with a geo-thermal setup as described you are starting at 55-60 to begin with so its much more efficient. so its more efficient in the winter and the summer.
this is one of the long term projects i wanted to start in the next 3-4 years
labeeman
Solar Enthusiast
It has been done and is out on the market
up to 70 EER Geothermal Inverter Heat Pumps
Daddy Tanuki
Solar Wizard
i know but the OP was talking about DIYing it. not to mention all of those prepackaged units are like 10x the cost they should be just for the heat exchanger and the basic compressor package.
labeeman
Solar Enthusiast
Not quite 10X the price but at least 3X the price and the smallest unit is 4 tons I only have found 2 inverter-driven units made for geosource.
He could run water in a water-to-air heat exchanger in the air intake of the mini-split and get some heat from that but in very cold weather would need to keep the water from freezing.
Daddy Tanuki
Solar Wizard
yeah I looked into it last about 12 or 15 years ago... cost turned me off as the ROI was too long and uncertain. now DIY yourself on the other hand, the ROI is definitely there. take a used one or two year old split pack and slice and dice. use the fan motor wiring to trigger a replay for the water pump and fill the black poly water pipe with a 50/50mix of coolant antifreeze. A couple of aluminum specific zincs in the tanks to keep the corrosion down on the condenser and you are in business.Not quite 10X the price but at least 3X the price and the smallest unit is 4 tons I only have found 2 inverter-driven units made for geosource.
He could run water in a water-to-air heat exchanger in the air intake of the mini-split and get some heat from that but in very cold weather would need to keep the water from freezing.
labeeman
Solar Enthusiast
I have been running a geosource heat pump system for over 25 years and am looking for an inverter-driven system to replace my unit the one I link to is brand new on the market. The heat exchanger is a coaxial unit (pipe in a pipe) with the water running in the inside pipe and the refrigerant on the outside of the inner pipe.
Daddy Tanuki
Solar Wizard
is yours forced air? one of the benefits of using a split pack is that if your house is small or pre-existing with no ducting, you can put one unit per room in a small cabin without ducting and all of the labor etc. required.
labeeman
Solar Enthusiast
It is water to air and is a one-piece unit not split I have a small house with ducting the water loop is 700' virtical 3 200' wells and one 100' well
Daddy Tanuki
Solar Wizard
nice bet that set you back a bit 25 years ago... I was originally looking at paying a company to drill me four or five hundred footers at my primary house, untill i saw the estimates.
in the past i used about 9 cubic meters of wood for the wood stove each winter, but that was for friday night through sunday afternoon each weekend. fine for a weekend getaway, but not so much for full timing it.
So my brain turned back to a geothermal setup. here at the cabin it is cheaper for me to buy the adjoining parcels of land and trench and lay the pipe myself. Just trying to see how big a plot i need to buy for heating my cabin... It is 800 square feet, and now that the outside remodel is done, I have double panes on all glass and all new insulation in all the walls and a double layer of insulation above the drop ceiling. So i use less wood know (this is first season since remodel) and i think that geothermal will work with my solar system and batteries, but no three phase, jsut split phase 240 here from my inverters. hence I am still looking at taking a split pack and breaking it down.
labeeman
Solar Enthusiast
Actually, it was cheaper than trenching only about 2k when I had it done. I have just started doing solar in the last two years and found out that inverter-driven window units keep the house comfier than the central unit I am in south Lousiana.
Daddy Tanuki
Solar Wizard
here it is about 10k usd per hundred feet. thats for a 10" bore for a water well. I can rent a bulldozer or backhoe and move the earth out of the way to a 6' -8' depth, lay out all the pipe in a grid pattern spike it down and then use the bulldozer to cover the pipe up to the expected 6' depth. so for me that or a combo backhoe with dozer blade would be cheapest, and would be 2-3 days for a skilled operator, or about a week for me.
We do not have window units here in japan, (inverter or otherwise.) and the US ones would not fit the japanese sized windows anyway. the normal high quality 1.5~2 ton split packs range from a low of 1000USD up to about 3000 USD for one with a lot of bells and whistles. you can buy that same 3k USD splitpack for about 1k when it is used and one year old. personally i would opt for a larger one without all the crazy options that will eventually go bad. the cheaper units run as low as 2-300 USD used when they are 1-2 years old. easy pickings to experiment with.
We do not have window units here in japan, (inverter or otherwise.) and the US ones would not fit the japanese sized windows anyway. the normal high quality 1.5~2 ton split packs range from a low of 1000USD up to about 3000 USD for one with a lot of bells and whistles. you can buy that same 3k USD splitpack for about 1k when it is used and one year old. personally i would opt for a larger one without all the crazy options that will eventually go bad. the cheaper units run as low as 2-300 USD used when they are 1-2 years old. easy pickings to experiment with.
Plum Crazy Rob
Solar Enthusiast
Same here, but 20yrs. DIY'd for $2800 less $600 rebate at the time. Replaced propane heat so paid off about 4 yrs. I saw the Geocool and thought about starting a topic see if anyone had experience with it yet. Interesting modular design to keep from having to make the usual assortment of configurations, yet creating potential leaks on a normally internal sealed refrigerant circuit.
Otherwise ClimateMaster Trilogy 45 is inverter driven?? More like money driven - saw list price up to $18k just for the unit. That is completely ridiculous. I know someone on this board said he was a retired geo dealer and thought geo was putting itself out of business with costs.
Partimewages
Solar Addict
I was in the geothermal business for 20 years and still get calls now.
Geothermal Considerations:
1. Don't buy the highest efficiency unit. It likely will push out ROI to far.
2. 2 speed equipment is tried and trusted.
3. You don't need to heat all of your hot water. The desuperheater is the best ROI.
4. Ground loop should be installed properly with heat fusion joints unless all joints are readily accessible.
5. You should size your backup heat appropriately, gas furnace, electric strip.
6. If you are in an area with good Ground water investigate using it. This is the #1 best ROI. Cost reduction and efficiency increases.
7. Do a heat load calculation and duct sizing.
8. Install a zoning system if you don't need to condition all of your areas.
I'm happy to answer questions or give opinions. They will be based on experience and what works. I worked with lots of people who wanted to experiment.
Geothermal Considerations:
1. Don't buy the highest efficiency unit. It likely will push out ROI to far.
2. 2 speed equipment is tried and trusted.
3. You don't need to heat all of your hot water. The desuperheater is the best ROI.
4. Ground loop should be installed properly with heat fusion joints unless all joints are readily accessible.
5. You should size your backup heat appropriately, gas furnace, electric strip.
6. If you are in an area with good Ground water investigate using it. This is the #1 best ROI. Cost reduction and efficiency increases.
7. Do a heat load calculation and duct sizing.
8. Install a zoning system if you don't need to condition all of your areas.
I'm happy to answer questions or give opinions. They will be based on experience and what works. I worked with lots of people who wanted to experiment.
Partimewages
Solar Addict
If you mean Ground water?
Great Lakes region is 46-56 depending on time of year and location.
45 does not seem worth the effort but possibly worth a try to satisfy the curiosity.
Pump the water through a radiator mounted next to the heat pump with a moderate enclosure so the air drawn in pulls through the radiator first.
Pump the water through a radiator mounted next to the heat pump with a moderate enclosure so the air drawn in pulls through the radiator first.
Plum Crazy Rob
Solar Enthusiast
You must be the dealer I thought of? Pump 'n dump (Open Loop for the uninitiated) here. Up well and dump to riverbottom, back property line 1/2 mile away IS the river. Use the same well as house supply, never been a problem. While the inexhaustible water supply increases geo efficiency, I assumed it's net lower with pumping wattage (?)
Edit: Would you look at the Geocool / Mr Cool modular and offer opinions on it?? They are around $6k.
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