Dick in Wisconsin
Well-known member
How much do you pay for electricity? If your electricity is expensive, then the propane route be the way to go. If your electricity costs are low, that makes a better case for geothermal.
Geothermal heating for House
- Thread starter woodzy
- Start date
How much do you pay for electricity? If your electricity is expensive, then the propane route be the way to go. If your electricity costs are low, that makes a better case for geothermal.
theoldwizard1
Well-known member
Geothermal is still the way to go, but in your climate, vertical wells are THE ONLY REASONABLE SOLUTION. I suspect you have a dozer and or excavator, but you really need a deep well drilling rig ! Depending on the size of your house, you are going to need 2 - 4 wells OVER 100' deep. Yes, this is a LOT OF $$$$, but geothermal heat pump will have the lowest cost of heating and cooling REGARDLESS of what you are paying for electricity. The only thing that can come close to geothermal operating cost is natural gas or wood.
With deep wells, your inlet water temp should be ABOVE 50F. You will have to run anti-freeze in these loops because the lines from the wells to the house will be close to your deep frost line.
Check this spreadsheet.
Check this document Geothermal Heat Pump Design Manual
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Bib Overalls
Well-known member
When we built 15 years ago we had Hydro-Temp, a local manufacturer of ground source heat pumps do our system. They also insulated our house as well. They offer insulation services because they want to control the envelope to ensure the heat pump meets expectations.
Our area is electric only and our total heating bills bills are much cheaper than our neighbors who use propane.
Are we happy? You bet.
If you are considering a ground source heat pump Hydro-Temp has dealer/installers nationwide. Not as well known as Water Furnace but highly regarded in the trade.
http://hydro-temp.com/Studies/study_res.htm
Our area is electric only and our total heating bills bills are much cheaper than our neighbors who use propane.
Are we happy? You bet.
If you are considering a ground source heat pump Hydro-Temp has dealer/installers nationwide. Not as well known as Water Furnace but highly regarded in the trade.
http://hydro-temp.com/Studies/study_res.htm
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backintheday
Well-known member
Now that you all have smashed my hopes and dreams of being the only kid on the block with geothermal I'm thinking a propane boiler with maybe a wood stove or solar hot water assist might be the way to go. Anybody have any info on solar hot water radiant systems they would like to share? Building is 40 X 64 X 16.
Sorry about jacking the thread.
Sorry about jacking the thread.
backintheday
Well-known member
Now that you all have smashed my hopes and dreams of being the only kid on the block with geothermal I'm thinking a propane boiler with maybe a wood stove or solar hot water assist might be the way to go. Anybody have any info on solar hot water radiant systems they would like to share? Building is 40 X 64 X 16.
Sorry about jacking the thread.
Sorry about jacking the thread.
theoldwizard1
Well-known member
theoldwizard1
Well-known member
I hope you are young, strong and healthy, because you will be burning a lot of wood so that you don't go broke from your propane bills.
Consider wood pellets or corn. Easier to handle and close to the cost of wood (unless you have your own forest to cut down).
If you are serious about solar and have the money to get over the initial costs, consider going photo-electric and then using an electric boiler. During sunny days a "grid tie" inverter will feed your excess electricity into the grid (and you will get paid for it). At night and on cloudy/very cold days when you are not making sufficient electricity, you buy it from the POCO.
Those solar panels aren't cheap, but this IS a viable solution.
backintheday
Well-known member
I only have my water well, 220' deep. I have a few acres I could use for a ground loop. I don't own a excavator but I can rent one for a few hundred for the weekend. I do own a 35 horse tractor I can use for black filling. I'm an automation tech by trade, I set up natural gas wells so I have a good understanding of the systems and liquids processessing.
theoldwizard1
Well-known member
Your frost level is too deep for a ground loop. Period. End of discussion.
Water welss can not be used as geothermal heat inks/sources. You would have to have 1 or 2 additional wells drill for your geothermal.
mires
Well-known member
I have an all electric 1,700 sq. ft. home with a geothermal system. It is just the lady and I but our highest winter bill since we have had the system was $145. That is keeping the temp at 74 degrees all day every day. The thermostat literally has not been touched in over 3 months.
We live in North Texas where cooling is a bigger issue than heating, and am on my third geothermal system in nineteen years. The first was a closed loop, four well, four-ton attic-mounted Trane, in a 2800 sq ft, all electric home, that was well insulated by 1996 standards. Compared to the similar, but conventionally cooled and heated house we had before, the geothermal paid for itself in four years. Clean, quiet, efficient, and not one service call in ten years.
We moved to East Texas and built a 3,000 sq ft house, all electric and more energy efficient than the first. It had a four-ton Water Furnace. Four wells, closed loop. In seven years, it required three service calls, with one occurring after the labor warranty had expired. The installer complained about Chinese made parts being the only ones available to replace the failed parts, but what can you do? Electric bills averaged a little over $250 a month for those seven years.
We moved back to North Texas two years ago and built a very energy efficient 2,500 sq ft, all electric house with a three well, three-ton Bosch system. It has already had a couple of failures due to Chinese made parts, but so far they have been covered by warranty.
Natural gas has not been available at any of the locations where we built, so it was never a consideration. And propane prices are too inconsistent for my tastes, though I now have a 500 gallon propane tank to feed my emergency generator and dual-fuel fireplace.
With a wife who likes the house meat locker cold in summer, and my arthritic joints liking long showers and warm rooms in winter, we are not typical energy users, so perhaps are not the ones to quote when it comes to HVAC comments. But, after nearly twenty years of experience I would never have any other system than geothermal. The degree of efficiency can be debated, and the payback time arguable, but it’s perfect for this part of the country…at least for us. And while my neighbors are serenaded by one or two howling AC units every time they step into the back yard in summer, I can sit on the patio and listen to the birds sing while the unit hums quietly in the garage.
We moved to East Texas and built a 3,000 sq ft house, all electric and more energy efficient than the first. It had a four-ton Water Furnace. Four wells, closed loop. In seven years, it required three service calls, with one occurring after the labor warranty had expired. The installer complained about Chinese made parts being the only ones available to replace the failed parts, but what can you do? Electric bills averaged a little over $250 a month for those seven years.
We moved back to North Texas two years ago and built a very energy efficient 2,500 sq ft, all electric house with a three well, three-ton Bosch system. It has already had a couple of failures due to Chinese made parts, but so far they have been covered by warranty.
Natural gas has not been available at any of the locations where we built, so it was never a consideration. And propane prices are too inconsistent for my tastes, though I now have a 500 gallon propane tank to feed my emergency generator and dual-fuel fireplace.
With a wife who likes the house meat locker cold in summer, and my arthritic joints liking long showers and warm rooms in winter, we are not typical energy users, so perhaps are not the ones to quote when it comes to HVAC comments. But, after nearly twenty years of experience I would never have any other system than geothermal. The degree of efficiency can be debated, and the payback time arguable, but it’s perfect for this part of the country…at least for us. And while my neighbors are serenaded by one or two howling AC units every time they step into the back yard in summer, I can sit on the patio and listen to the birds sing while the unit hums quietly in the garage.
backintheday
Well-known member
I think geo makes a lot of sense. I'm not writing it off 100 percent, there are a few installers in the WY, UT AND Montana area that I'll speak with and see what they have to say.
theoldwizard1
Well-known member
Not relevant unless we know where you live !
theoldwizard1
Well-known member
4 year pay back ? IMPRESSIVE ! Thanks for you input.
Geothermal is excellent for areas with high cooling loads. Air cooled heat exchanger efficiency really drops off after 90F !
Glad to hear you have a back up. Some areas of the country can goes days with no electricity after a natural disaster.
Are you using the propane for anything else (cooking, hot waster, clothes drying) ? If you already owned electric appliances it is understandable. When they die, consider switching to propane.
Another bonus !
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mires
Well-known member
True. I live in mid Missouri. We have cold winters. Not like Michigan though
It's not uncommon to get real close to or below zero. Sure makes me miss Texas sometimes.Dick in Wisconsin
Well-known member
Don't you mean high cooling loads?
theoldwizard1
Well-known member
Fixed ! Thanks.
volleyball
Well-known member
Almost, you spelled coling
sms1974
Well-known member
Your not going to get a 50 degree temp on a closed loop in mid winter, sorry not going to happen... open loop maybe, but not on a closed loop. I service a development with aprox 75 homes all geo all 1 loop per ton at 225' per loop. right now my customers average loops tems are incoming at 32-24 deg.
I'm not nocking the geo idea it is a fantastic way to heat and cool a home or shop but lets give honest and correct information.
theoldwizard1
Well-known member
Inlet temperatures below 40F indicate the engineer who designed that system didn't know what he was doing. PERIOD !! The whole point of geothermal is to TRANSFER HEAT TO/FROM A CONSTANT TEMPERATURE SOURCE ! If the inlet water changes more than 5-10F over a 12 month period, you have a problem !
Are they horizontal or vertical ?
If horizontal, the loop is not buried deep enough.
If vertical, they need a second (or third) well.
volleyball
Well-known member
Depends on whether the loop is coiled or vertical. Also how quickly the heat in the ground flows. If you run a lot of water through a loop, it may be more than the ground can transfer and stay at temp. Longer loop or lower inlet temp is a trade off.
sms1974
Well-known member
I'm certainly not going to make a ******* match out of this thread but your wrong. you like many people think that since the ground temperature 50+ degrees you loop temps are going to be the same, they will not be. Do you even know what or how to figure a Reynolds Number?
we service several hundred geo systems, I have a very competent loop enginer and installer.
theoldwizard1
Well-known member
Water furnace does spec a minimum EWT of 25F, but not ALL manufactures will operate at that temp.
I would like to see Water Furnace's COP numbers versus EWT and what trips the resistance heater.
sms1974
Well-known member
I'm a Water Furnace dealer what unit would you like to see them for?
pseudorealityx
Well-known member
Your loops should be pretty close to the same. The pipe is a big heat exchanger. You should design the loop to get a much closer approach than you're getting if you've got 32 degree LWT.
And yes, I can figure out a Reynolds number. But that's only half of it. You need to take into account the geology you're working with to determine your heat transfer coefficients.
sms1974: Is the colder temp with the horizontal coils? or does this happen with wells also?
I know my neighbor has problems with his due to cold water -- I asked him and he does not know what he has .. but I think I saw a well driller .. so I think a well.
I'm pricing one out (well) .. because I get hit with the AMT, the ability to use the tax credit is questionable. Without that I don't think it will pay.
Another neighbor who installed a new high end HP has had great results .. and this winter was cold.
I know my neighbor has problems with his due to cold water -- I asked him and he does not know what he has .. but I think I saw a well driller .. so I think a well.
I'm pricing one out (well) .. because I get hit with the AMT, the ability to use the tax credit is questionable. Without that I don't think it will pay.
Another neighbor who installed a new high end HP has had great results .. and this winter was cold.
theoldwizard1
Well-known member
Pick 2. One designed for EWT of 25F, another designed for an EWT of close to 40 or above.
COP is all about ΔT (EWT vs LWT). You can get much as much ΔT with EWT at 25F as you can with EWT at 40F or 50F.
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theoldwizard1
Well-known member
50F may be a high target, depending on what area of the country you live in. What do your engineers target as their desired EWT ?
EWT is directly proportional to the length of the pipe and the depth it is buried at. EWT from wells deeper than 50' experience almost no change seasonal change in temperature assuming they are sufficiently deep (long). High water flow rate will reduce heat transfer.
If Water Furnace is telling you to design for an EWT of below freezing in winter, I think they are doing a dis-service to their customers.
theoldwizard1
Well-known member
Your neighbor needs to chart his EWT across an entire heating season. While not cheap, drilling a second (or possibly third) well will likely mean a big reduction in his operational costs.
Geothermal Heat Pump will beat all other fuels in cost of operation except solid (wood, corn, pellet, coal) fuels. Against natural gas, the pay back time may be so long as to not be worth the additional cost of installation unless you factor in the cost of savings for cooling.
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It has to do with the amount of rock in our area and the streams -- we don't get 55 degree water in the winter. I don't know what the average water temp that a typical system works with .. but if it is in the 30's when it gets real cold out that would explain why the air to air are catching up.
The wells around me are extremely expensive for geothermal -- without a tax rebate they never come close. I think the rebate goes away in 2016
theoldwizard1
Well-known member
Wells aren't cheap or DIY anywhere. Add in rock and the price really goes up.
If my EWT was below 32F in mid winter, I would be saving for another well !
Dick in Wisconsin
Well-known member
What do EWT, LWT, and COP stand for?
pseudorealityx
Well-known member
EWT = entering water temperature
LWT = leaving water temperature
COP = Coefficient of Performance
Dick in Wisconsin
Well-known member
Thanks! I thought those were the definitions, but wasn't sure.
I looked up "Reynolds number" in Wikipedia and got a headache reading the explanation. Reminded me why I left the engineering school at Wisconsin and hiked up Bascom Hill to the Business School instead!
For a geothermal heat pump, is it possible to pump water out of a well and (1) dump the discharge water on the surface in say the woods or a low area or (2) dump the discharge water into a lake, stream, river, creek, swamp, or marsh? The water should be clean.
pseudorealityx
Well-known member
Modern geothermal pumps like very clean treated water. Typically you either have a single closed loop where the same fluid that goes through the heat pump(s) is the same fluid that goes through the geothermal loop, be it wells, trenches, loop in a lake, whatever.
The other option is to have 2 separate loops with a clean closed loop that hits all your heat pumps, and then goes through a heat exchanger to a second loop that is just doing the ground/water. This would allow a 'dirtier' ground loop if you choose a heat exchanger than can deal with some particulate, etc.
In theory, what you're saying is true, however, in many places, it's against code.
meathooker
Well-known member
It's common, and in my opinion a very prudent feature to add.
meathooker
Well-known member
I have a system like this in my house. We call them "pump and dump". Hopefully I can convert it to a closed loop,system in the future.