Geo Thermal
- Thread starter Cruxin
- Start date
jumpingryan
Well-known member
Several of my neighbours have geo thermal in their houses.... think of geothermal as a method that gets you 80% to your target heat.... the rest of the way is done through other heating methods (fuels like electricity, wood, propane, oil, natural gas, etc).
In all cases, the efficiency of heating is mostly based on stopping heat loss.... the better quality your insulation material and install, the better your system will perform. The cheapest system is one that doesn't turn on often!
I would say pex infloor is your best option for heat transfer, however the advantages of using ductwork is that you have a geothermal heating AND cooling system.
Since you are from a northern climate, and it is a detached garage, I say go pex for the garage....
However, for your house.... go infloor heat AND ductwork... to get all the advantages of heating and cooling.
Good luck!
R
In all cases, the efficiency of heating is mostly based on stopping heat loss.... the better quality your insulation material and install, the better your system will perform. The cheapest system is one that doesn't turn on often!
I would say pex infloor is your best option for heat transfer, however the advantages of using ductwork is that you have a geothermal heating AND cooling system.
Since you are from a northern climate, and it is a detached garage, I say go pex for the garage....
However, for your house.... go infloor heat AND ductwork... to get all the advantages of heating and cooling.
Good luck!
R
theoldwizard1
Well-known member
From what little research I have one, the combination of a geothermal heat pump and in floor radiant heat is not very popular. I think a lot of this is because multi-zone heat pump systems have not been popular (too expensive ?) until recently.
The newer high efficiency, multi-zone, inverter heat pumps do a good job of heating even in cold climates. Of course adding geothermal means you get maximum efficiency regardless of the ambient air temp.
Mitsubishi sells multi-zone heat pump systems and they have a heat exchanger for in floor radiant heat.
The newer high efficiency, multi-zone, inverter heat pumps do a good job of heating even in cold climates. Of course adding geothermal means you get maximum efficiency regardless of the ambient air temp.
Mitsubishi sells multi-zone heat pump systems and they have a heat exchanger for in floor radiant heat.
This is incorrect.
We have a Geothermal system in our home utilizing pex in slab floor heat and it provides 100% of the heating & cooling needs without any backup sources.
How old are your neighbors systems and how well are they insulated?
jumpingryan
Well-known member
I doubt my statement is incorrect for every climate or local, and applies to the majority. Your local may be an exception in that with geothermal you get a perfect temperature.....
I am located in Ontario, Canada, 2 hours north of Ottawa. From below 0 F in winter to 90 F in summer is the range of temperature.
My one neighbor's house is built within 2 years.... It is a bungalow with walk out basement. Insulated concrete form bungalow top to bottom (R40 in the walls), underslab insulation, and min R 40 on the roof (possibly even R 60). Above the standard. He uses hot water tanks to raise the temperature to the final required temperature for heating. For cooling, there isn't much requirement other than a system to force the cooler energy through the house.
Are you stating that the ground temperature will somehow react and change to the temperature range of 0 F to 90 F???
Unless you live near a volcano, or hot springs (such as Iceland, or Radium Springs Alberta), it is HIGHLY unlikely the ground temperature is 72 F or above. And if it was the case, you would certainly be successful in heating, however, how would you use geothermal for cooling in that case?
Geothermal is based on a constant ground temperature, and the radioactive decay within the planet, and absorbed solar energy. The constant ground temperature of the earth is about 55 F anywhere from 6 to 10 feet down depending on local conditions.
In areas with wider ranges of air temperatures, you have to make up the difference either up or down unless you are happy with a temperature of 55 F.
I stand by my statement that for the vast majority of people in the world, Georthermal gets you from point A to point B. You will still need to expend some energy to get to point C (your desired building temperature)
R
And I still stand by my statement that your first statement was incorrect since you didn't mention anything about it being the majority. Your statement made it sound like this was the way it's going to be for everyone which is not true.
I also live in an area where winters can be below 0 F and over 90 F in the summer. And again, I have no problems heating our 3K sqft house in the winter without a backup source.
Highbeam
Well-known member
Whoa jumpingryan, you seem to have a profound misunderstanding of what geothermal energy is.
Yes, you have a constant temp in the earth. You use heat pump technology to steal or give heat to the ground in order to heat or cool your home. So you can boil water by using a heat pump to extract geothermal energy from that 55 degree ground. You can also use geothermal for your primary heat source but you do need to use electricity to move and concentrate the available energy.
Yes, you have a constant temp in the earth. You use heat pump technology to steal or give heat to the ground in order to heat or cool your home. So you can boil water by using a heat pump to extract geothermal energy from that 55 degree ground. You can also use geothermal for your primary heat source but you do need to use electricity to move and concentrate the available energy.
Rickcnc
Well-known member
I've been running Geo Thermal for 5+ years now with no backup source. (ground loop, forced Air)
During the winter months the incoming loop temperature is around 40F
Location Ontario.. approx 2 hours north west of Toronto
During the winter months the incoming loop temperature is around 40F
Location Ontario.. approx 2 hours north west of Toronto
jumpingryan
Well-known member
Highbeam,
The overall debate here isn't the efficiency of geothermal heat pumps.... they are outstanding. Nor is it the chemical and physical properties/dynamics of capturing heat from the ground and moving it inside the house. I do agree with your statement that you can concentrate heat from the ground, but you consume energy to do it (hence the 20% statement).
The debate started with the post from Zick in that he has no backup source. I encourage Zick to tell me what size breaker and voltage is on his heatpump at the panel..... and what energy he uses to get the say (a rough estimate)... final 20% of the required heat. Something gets him there.
This debate is about the perception that there is no back-up nor auxiliary, and the heat just comes from the ground, and that's it.... point B to C uses no energy, or perhaps very little (a pump and fan). There is definitely more going on inside of the geothermal unit than a movement of water to the earth and back to reach 40 F to 55 F, and a fan blowing on a pipe to somehow get you to 72 F. But what is going on inside isn't what this debate is about.....
There is a backup/auxiliary, and it is inside the unit, and yes, it uses energy to get you the final temperature you want. I am not arguing what goes on inside the unit (the process of extracting heat).
I would say it is HIGHLY likely that both Zick and Rickcnc have backups/auxiliary modes... and their unit does consume energy to go from point B to C.
The backup is inside the Unit.
We are not debating about the 80% of the ground energy that is somewhat "free", we are debating about where the remaining 20% comes from. I still stand by my statement that a rough average is 80% energy from the ground, and 20% from some other source during most heating cycles.
With cooling, it is likely a far more efficient process than with heating.
Just because you don't see a giant boiler tank doesn't mean there isn't a backup/auxiliary. Your heat comes from the ground, you don't need a giant boiler.... just a little extra push.
Yes, as you stated, electricity to move you from point B to Point C. Our overall goal is to move from point A (outside temperature) to point C (comfortable inside temperature). A post from Rickcnc came in at 40 F incoming.... similar climate to mine... That is a good start especially if you house unheated would be 0 F.
You need to move another minimum 30 F just to get to a room temperature. I hope we can agree on those numbers......
Energy will be used to make this move.... electricity or something else. Just alot less TOTAL energy as compared to other methods of heating. That is where the 20% comes in....
The backup or as it is sometimes termed, "auxiliary" is inside the Unit in what appears to be most cases (as per the posts).
That is probably why they unit is hooked up to 220 volt anywhere from 30 to 70 amp breaker. I encourage those with geothermal heat pumps to take a look at the size of the breaker feeding their unit. And please don't assume that you have 30 - 60amps (6600 - 13200 watts) of forced air fan and perhaps a compressor or two.
Other setups have heating backup/auxiliary ranging from natural gas, to solar, to wood boiler to electricity. Each method could exist inside or outside the unit and some are more suited as external backups than others.
If what you are suggesting, there is no backup or "auxiliary" either inside or outside the unit (in most cases, powered by electricity), then why is a geothermal heat pump generally hooked up to a 220 volt from 30 to 70 amp breaker? Why would a geothermal require that much electrical juice if there was no need to expend energy on electrical resistance or heat/compress anything?
Since, as you suggested, I don't know alot about geothermal.... please educate me the final move to heating temperature since your post was pretty short on details..... point B to C, how do you get there without expending energy?
Or as you suggested, how do you concentrate the energy to get up say... 15 to 30 degrees F? Chemical reaction of converting a gas to liquid back and forth without expending electricity or some other fuel source (similar to a fridge or AC)?
That would be free energy via a chemical reaction and a heat concentration.
And if there is no need to have a backup or auxiliary either inside or outside the unit, why is a geothermal heat unit hooked up to a 30 to 60 amp 220 volt breaker when likely the DC fan motor inside of it requires maybe 100 to 700 watts or so. What is the other say, 5000 to 13200 watts doing feeding the unit it doesn't have a backup/auxiliary?
My points are:
- There is a backup/auxiliary and it consumes energy along with the whole process of movement of heat.
- The 30 to 60 amp breaker in a 2 to 5 ton unit likely powers something more than just the fan motor and pump.... maybe that 20% of what I was referring to.... some heating days.
- I roughly estimate (as per my original post), using a baseline of spending 100% of your money on electricity to heat a house, you will spend only 20% of electricity to provide geothermal..... the other 80% is from "semi-free" energy from the ground.
- The 80%/20% numbers are variable each day, but I consider them a good average over a heating season. Some days will be more like 60/40.
- There is no free energy, and even the 80% isn't free.
- The backup/auxiliary may be built into the unit, or separate. But it is HIGHLY likely there is one, and that it does turn on with little user input.
- Movement from temperature (point) B to C requires energy, likely that 20% over a heating period.
- A backup/auxiliary isn't required every heating day. But over a heating season, the back WILL likely be used in most climates.
Anyways, I don't want to hijack the thread or put a damper on geothermal. The OP was asking about ductwork. I stand by my suggestion to go radiant infloor for heating, and consider ductwork for cooling if required. I doubt you will regret the decision..... and infloor radiant heating is far more difficult and expensive to retrofit as compared to retrofitting ductwork.
I would go geothermal for any new build, and some retrofits, especially if you don't have natural gas available.... However, depending on the costs of energy in your location, sometimes you have to wait years or decades to get your payback.
Good luck to the OP in his choices....
R
jumpingryan
Well-known member
In-floor and geothermal is getting more popular to have in new construction it seems. Retrofit is possible, but it is also expensive and not always cost effective when considering the cost of insulation and a re-pour with all the added labour costs. There are other methods (a raised subfloor with smaller tubing) but they can be expensive as well, and no matter what, raising the height of a basement plays hell with the height of everything from doors to stairs to ceiling.
In floor heat radiant (in concrete) has been around for awhile in terms of design, but it really only became popular and effective when pex hit the mainstream. Earlier systems were attempted with copper and other metals that didn't generally fare well over time.
All the insulation, pex, pumps, control system(s), heat sensors, thermostat(s) do add up in cost though.
Coupled with modern under slab insulation systems, and you really can't get a much better system than radiant hydronic in floor heating, especially when you consider that you can use a wide assortment of fuels to heat (not only just geothermal).
I say if you have a hard time stomaching the total cost of infloor.... install the insulation, pex, and runs for the heat sensors. Keep the tubing coming out of the concrete protected somehow and capped, and go with another method (forced air perhaps) of heating/cooling.
When you can afford the rest later on, do the final install and enjoy...
Or if you sell later, at least the hard part is done, and at a minimum, your house will sell faster than the exact one at the exact same price. I think it will be more likely that your house/garage will command a premium to a purchaser who understands the value of the already installed pex.
In floor heating is hard to retrofit.... ductwork, not as hard.
-----------
The Mitsubishi Zuba is what you are referring to for a heat pump, and it is reportedly by far the best out there, but the most expensive. There are more cost effective heat pumps such as the ones by Keep-Rite, but they don't seem to have the same reputation as the Zuba.
R
theoldwizard1
Well-known member
INCORRECT !
Heat pumps can easily "extract" heat from a 55°F infinite source (the earth) and provide plenty of heat, even in the coldest environment. That heat can be transferred to air (for forced air heating) or to water (heat exchanger) to heat a floor or other mass that has water piped through it.
Last edited:
Geothermal in Maine works if you use wells for your water but a local energy guru buried 1000ft of 1.25 black plastic and froze the ground by december. Not sure how deep he was but that small of a closed loop didn't work.
Highbeam
Well-known member
Ah jumpingryan, I see your problem. A combination of poor terminology and also you just don't know what happens inside a heat pump.
First, terminology, the terms backup or auxilliary both refer to a secondary source of heat. A secondary source of heat is not needed but some heating systems are designed to use one. Often it is cheaper to install a small primary heat source which would handle 90% of the load then on cold nights the system deploys the backup when the primary is unable to maintain temperature. If you choose to size your heat pump system to handle 100% of the load then you have no backup or auxilliary at all. You certainly don't need to have a backup.
Geothermal or air source, they both use large 240 volt power feeds to run the compressor. Make no mistake, these heaters are electric powered. They don't use the power to heat a resistance element. They use all of that power to run a large compressor. Yes, 30+ amps is not uncommon for just the compressor.
First, terminology, the terms backup or auxilliary both refer to a secondary source of heat. A secondary source of heat is not needed but some heating systems are designed to use one. Often it is cheaper to install a small primary heat source which would handle 90% of the load then on cold nights the system deploys the backup when the primary is unable to maintain temperature. If you choose to size your heat pump system to handle 100% of the load then you have no backup or auxilliary at all. You certainly don't need to have a backup.
Geothermal or air source, they both use large 240 volt power feeds to run the compressor. Make no mistake, these heaters are electric powered. They don't use the power to heat a resistance element. They use all of that power to run a large compressor. Yes, 30+ amps is not uncommon for just the compressor.
ratdoggy
Well-known member
My problem with the geothermal was that the payback time basically was when I had to buy a new system. I don't remember what the quote was but it was a pretty big number. How much does a basic system cost anyway these days?
Didn't have time to read all of jumingryan's posts, but I did catch were he still thinks I'm using a backup source to make my system work.
I will say this again, I do not use a backup source.
Yes my Geo (WF Synergy 3d) has a backup heater inside of it, but I've disabled it (turned off the separate breakers) so it doesn't go on without my knowledge.
I have been running this system for 4 years this way and I have a Brultech energy monitoring system so I can clearly see how much power it's using and there is a clear distinction when the backup heaters kick on.
Edit: clearly after reading some more of your posts, you don't fully understand how a heat pump works.
I will say this again, I do not use a backup source.
Yes my Geo (WF Synergy 3d) has a backup heater inside of it, but I've disabled it (turned off the separate breakers) so it doesn't go on without my knowledge.
I have been running this system for 4 years this way and I have a Brultech energy monitoring system so I can clearly see how much power it's using and there is a clear distinction when the backup heaters kick on.
Edit: clearly after reading some more of your posts, you don't fully understand how a heat pump works.
Last edited:
Highbeam
Well-known member
He defines "backup power" as the power used by a heat pump to extract heat from the ground, water, or air. This is causing him much confusion.
theoldwizard1
Well-known member
I can't answer your question, but people usually freak out when they find out the size, quantity and depth of the well(s) they need to drill !
Highbeam
Well-known member
Now that air source (minisplit) technology has evolved to a point of extracting large amounts of heat from very cold air, I expect a further decline in the feasability of geothermal.
Agreed, he knew it that december
. Trouble is he didn't have bigger footprint to put in more pipe. In Maine I would go with a mini split and propane backup for those days(approx 10) where the mini split won't handle the load. Much less money than drilling wells
Edit, we had a local school do geothermal, I think they drilled 20 wells, deep, real deep.
jumpingryan
Well-known member
$30,000 CDN was the quote I got for a bungalow 1500 square feet retro-fit forced air setup. My house was built in the 90's. This didn't include outbuilding(s). This was for a horizontal run.
Vertical runs are generally much more expensive.
The damage done to the field area would have been minimal so that quote doesn't include an remediation of lawn/landscaping that might have to be done.
I didn't go further than the quote as my return on investment wasn't apparent compared to the time I will be living in the house.
R
jumpingryan
Well-known member
Yes, and what gets used to extract this heat? What "fuel" is used to "compress" this heat to get you the 20% of the way there? I would say it is a good bet to be electricity, likely a decent amount of it based on the size of the breakers needed to run the compressors of it (30 amps of 220 volt compressors)
READ MY ORIGINAL POST... this isn't about the process of extracting heat, and I made no claims about the process inside the unit, from using chemicals with low boiling points at sea level, to the conversion of a gas and a solid.
My point in my original post was the 20% energy you need to use to process the heat from the ground at the Unit. The ground gets you approximately 80% there, and is your chief source of savings. The remaining 20% is an energy consuming process that occurs inside the unit unless your ground water comes up at like 85 F.
To get the final push over a heating season to target temperature. This part of the process exists, and involves compressor's, pumps, heat exchangers, and if required a form of backup.
There are various fuels & methods that provide this process for you including a backup.
Form that statement you made a claim that I essentially know nothing about geothermal, and that 20% is way off, and geothermal uses almost no energy and/or power.
Form our debate, we now have established that a geothermal unit has to the potential to use alot of power, starting at 30 amps 220 volt for the breakers for some heavy duty compressors....
5500 watts or so to start us off on a small unit. At $0.15 a kilowatt hour, about 83 cents a hour to run..... Just short of $20 a day to run. Likely not be as much as an oil heating setup however, and certainly not typical of a heating day..
My stats above are not typical, but they definitely show some of the power the unit is fed to start.
This assumes a heating day on your expected coldest day of the year to your maximum capacity... which is generally how a heating system should be sized to avoid oversizing.
This is a very rough suggestion, but that is what it can cost if it runs full time.... definitely not very free unless you wire it to the other side of the meter!
Now that Zick has established he has assorted breakers for his unit, and he disabled the backup ones (however, the backup system and breakers didn't exist in his previous post), we would have a good baseline of watts used without a backup if Zick is kind enough to tell us his respective breakers and what each is purposed for.
It was also implied there was no backup/auxillary (which are apparently different things totally in this forum despite a synonymous meaning) source required.
Well, it now appears that most systems have one built in, likely because the manufacturer says it is needed. Probably what Zicks extra breakers are for. The harsher the climate, the more likely it is used.
As to the requirement for a backup, read the last part of the post.
I never argued the process of extracting heat nor do I want to debate the boiling points of assorted chemicals and the storage of heat. Far too geeky for just about everyone here.
Through our debate however, it is starting to appear that process of extracting heat uses alot more energy than people generally expect.
A combo of an increased level of heat extraction (faster turning pumps), and if required electrical resistance is the likely backup inside of the unit unless configured differently.
As per my original post before I was verbally attacked in that I didn't know what I was talking about, both processes had always appeared to use that 20% of energy I talked about through the process of heat extraction, and any backups that may come into play should demand exceed unit abilities through a whole heating year.
The other 80%, is likely "somewhat free energy" from the ground.
As to the other poster that he has disabled the backup that he didn't have earlier..... I am happy you have the ability to turn it off. You likely have a stable climate & your heating system was well sized and setup for your climate and heat loss calculation of your house. I am also glad when you admitted you went from "no backup" to "disabled backup at homeowners action"
But more on the backups that don't exisit:
From Highbeam: "Ah jumpingryan, I see your problem. A combination of poor terminology and also you just don't know what happens inside a heat pump.
First, terminology, the terms backup or auxilliary both refer to a secondary source of heat. A secondary source of heat is not needed but some heating systems are designed to use one."
Ahhhh, well we went from no backup/secondary heat source to some systems being designed to use them in this post. Kinda what I said in my orginal post, that there IS a backup, and it uses a fuel source.
I also say this.... Auxiliary and backup are synonyms. Look it up.
In addition, here is an interesting link on backups from people that likely know more than you about Geothermal..... They talk abit about the backups that you said weren't needed:
The International Ground Source Heat Pump Association
http://www.igshpa.okstate.edu/geothermal/faq.htm
"Q- Does this mean that in extremely cold climates additional heat sources are necessary?
A- All systems require an emergency back up. Heat pumps can provide all the heat necessary even in the coldest weather. An economic analysis by your contractor should dictate what portion of the heat should be provided by the heat pump and what portion by auxiliary means."
Hmmmm. No backup/auxiliary required as per your statement..... Hmmm, must be that free energy out there, or a few posters got the perfectly balanced system that still can use 5500 watts of compressor to extract the heat.
I say it is highly likely that most systems have at least one backup and most systems are designed to use one (unless the breaker is shut down by Zick who has one of the best setups out there it seems; no insult/sarcasm intended).
I will also emphasize that the pre-backup compressor power demands are getting a little hefty from the almost no power requirements, now starting at a 30 amp 220 V service just to power compressors and fans.
Damn, I thought we might have been onto the free-energy geothermal machine here! Don't worry, I still love geothermal!
In reality with geothermal you just save 80% , and pay 20% give or take as compared to your previous method of heating!!!
R
Rickcnc
Well-known member
My system does not have an emergency backup. When the system was installed this was a option, (electric heating coil.) which I turned down because of the extra cost involved. (part of this cost would have been upgrading the electrical service to the home)
When installed I was worried the system may not be able to keep up on the coldest days of the winter, (we usually get a week or two and -27 deg C). Our decision was to try it for the first year and if it couldn't keep up install a propane stove or fireplace as the emergency backup
Five years later we're still running without an emergency backup installed, although last winter the house got damn cold when a circulation pump quite working.
I don't believe for a minute Geothermal is free heat. However I agree it is close to 1/3 of the cost of electric baseboard heat). You're better to look at cost per BTU.
I moved from a Wood / OIL system to Geo thermal. At the time we were burning 18 face cord of wood and 1 tank of oil per season. The government had huge incentives and I was tired of cutting and splitting 18-20 cord of wood ever year. (been doing it for 30+ years). If natural gas was available or the government incentive were not, I doubt I have a GEO system installed.
I'm currently looking at heating options for a new shop I put up last year. Would I go GEO... No.. to expensive . Minisplits look cool, however I would need an "emergency backup" for those really cold weeks. Right now with propane at 0.50 liter this appears to the most economical option.
sands35
Well-known member
Emergency backup = fire place or stove or some other alternative method to heat your house in the winter. (even just a generator to run your house heater is sometimes OK. Ice storms probably take down electrical service more often than the heat pump will go out).
Last edited:
Highbeam
Well-known member
I agree and stated that auxilliary and backup are the same thing. Not sure where you read differently. Your mistake, JR, was that the backup/auxilliary power is what runs the compressor. It would appear from your last post that you have learned the difference between the power demands of the compressor and the optional auxilliary/backup demand.
You are mistaken again about power demands of the compressor. Just because the pump is powered through a 30 amp breaker you cannot conclude that it uses 30 amps at all, or constantly. That is silly. You know, I have a 200 amp breaker that feeds my house all the time. I suppose in JR's world, I am consuming 200 amps all the time at a cost of 172.80 per day.
Try to revise your assumptions without making up numbers. Still, a 20% input of power to get four times that much energy in return is a good deal. I would be happy to get a 400% return on my investment.
You are mistaken again about power demands of the compressor. Just because the pump is powered through a 30 amp breaker you cannot conclude that it uses 30 amps at all, or constantly. That is silly. You know, I have a 200 amp breaker that feeds my house all the time. I suppose in JR's world, I am consuming 200 amps all the time at a cost of 172.80 per day.
Try to revise your assumptions without making up numbers. Still, a 20% input of power to get four times that much energy in return is a good deal. I would be happy to get a 400% return on my investment.
Highbeam
Well-known member
Wow, 30,000 dollars for a horizontal is really awful. Good thing that air source heat pumps are improving so much. Geothermal will be going away soon.
theoldwizard1
Well-known member
My in-laws house has 2 propane fireplaces as "backup". I'm pretty certain they have not been used in the 15 years they lived there !
jumpingryan
Well-known member
I agree that the demands are the complete unit working at full load, compressors, fans, electronics..... many of the systems run at assorted power levels that the control board (in sense a computer). Likely if it needs a 30 am breaker, the unit could potentially use up to 80% of it by the manufacturer tolerances, but that is not necessarily typical of every heating day nor a number set in stone.
A toughly worded 20% is an outstanding return on investment when the 80% is in effect almost free. When you crunching the numbers with the highly variable install cost, it can take a long time to pay back your investment.
Those who already have heavy machinery to do some of the work, the space to do horizontal installs, and a zero chance of ever getting natural gas generally fair best in the cost estimates and quickest return.
R
theoldwizard1
Well-known member
ABSOLUTELY 100% CORRECT !
When it comes to Thermodynamics there is no "free lunch" (First Law). As a matter of fact, just playing the game, you will lose (Second Law).
100% CORRECT AGAIN ! (Except maybe the backup part.)
But if you do not understand the basic vapor-compression refrigeration cycle then how can you state that what other are doing is not efficient when they have the data to show that it is ?
And now you have come to the crux of the discussion !
The amount of energy (in the form of electricity) required to extract "heat" from a 55°F "infinite source" (the ground at adequate depth) is less than other typical forms of heating (of course, sitting on top of a hot spring would be the cheapest).
Installation is high, but there is a payback. The payback is much quicker if you are also going to be using your heat pump as an air conditioner.
I don't understand their position. It gets cold in SE MI. If the electricity goes out, my natural gas forced air furnace won't work. I'm not worried enough that I have installed any kind of backup for it.
Having a backup for a heat pump, even it is just a propane fireplace or a wood burning stove, is a good idea as repairing these complex units might take more than 1 day.
I don't know if those numbers are accurate, but I sure would like to save 80% of my heating and cooling bill !
jumpingryan
Well-known member
I don't disagree with that statement either. Outside of those who have natural gas available, I think geothermal will stick around for those high end new builds that use infloor radiant hydronic setups.
Mid end retofits, and mid-range budget's that use forced air for heating and cooling will likely move to the air source heatpumps.
Lowest budget and retrofits will probably stick with conventional methods.
-----------
I was really impressed with the Zuba.... well almost everything but the cost. Even still, it does look like a great unit, although alternative brands available in my area include Keep-Rite which is apparently catching up in quality and value.
I am stretching out my oil heating and oil hot water setup before moving to something different in 2016 for my house (my garage will always remain on oil). I am strongly considering going air source heat pump.
I am try to decide on the source of much disagreement here.... LOL... my air source backup.... It is a requirement in thise area.
My choices from the installer include electric, hydronic, or mount a propane furnace to the heat pump.
I am leaning to propane backup or a propane heated hydronic setup (via one of those dual use tankless water heaters).
Propane means the most work for me to get the ugly tank out of sight and a line buried. I am also leaning towards propane for my domestic water heating to keep the electric load down, and have quick recovery.
But electric backup is the cheapest install, as it electric water heating.....
Choices, choices!
R
jumpingryan
Well-known member
wfopete
Well-known member
I had Water Furnace Geo Thermal installed in my 1200 sq ft Arkansas home in 2005 using vertical lines. Prior to the Geo install I had wood stove and a window A/C, no duct work or other previous HVAC. My total system cost $25K including duct work. I had 'em punch a extra line or two in case I decided to expand. Yup I put in for a tax credit in April. Conventional wisdom says Geo isn't cost effective unless you plan on hanging around in your home for 15+ years to get the payback. But where I live you go with electricity or propane & I had no real HVAC system so it didn't matter, I was going to get a system so I went with Geo.
Had a entry audit done by my electrical co-op. I questioned the electrical usage of my Geo system. We killed every breaker in the box except for the Geo Thermal then cranked up the Geo and took meter readings for 20 minutes. Power consumption wasn't squat and it took 20 minutes to get a decent amount of reading to calculate off of. Yeah, kinda crude but it proved the point; by far most of your money goes to all that other stuff that ***** on electricity (computers, TV, lighting, stoves, refers.). I don't remember the numbers but I do remember that once we crunched the numbers, even in the extreme hot and cold months I spend less than $50/month for cooling & heating.
I believe your best money is in insulation. BTW I still use my wood stove now and then, my wife likes the ambiance of flickering flames as opposed to a compressor kicking on. Go figure.
/
Had a entry audit done by my electrical co-op. I questioned the electrical usage of my Geo system. We killed every breaker in the box except for the Geo Thermal then cranked up the Geo and took meter readings for 20 minutes. Power consumption wasn't squat and it took 20 minutes to get a decent amount of reading to calculate off of. Yeah, kinda crude but it proved the point; by far most of your money goes to all that other stuff that ***** on electricity (computers, TV, lighting, stoves, refers.). I don't remember the numbers but I do remember that once we crunched the numbers, even in the extreme hot and cold months I spend less than $50/month for cooling & heating.
I believe your best money is in insulation. BTW I still use my wood stove now and then, my wife likes the ambiance of flickering flames as opposed to a compressor kicking on. Go figure.
/
OK, you have a total misunderstanding of how heat pumps, and how heat pumps referenced to a geothermal source, work.
I heat and cool my house 100% with geothermal. There is no other heating or cooling source available to the house. We're in a Zone 5, Cold climate, which is very similar to yours. Typical summer highs are in the high 90s with high 80s humidity and typical winter lows are around 0. In my lifetime at my location, it's gotten as cold as -35F and as hot as 109F. With no other source of heating or cooling, the open-loop geothermal system in my house copes just fine. So it's in no way correct to say that the geothermal system is only an 80% solution.
Now, here's where your understanding of a heat pump fails. Heat pumps use energy (typically supplied as electrical energy, but not always) to move thermal energy from one side to the other. To heat, the pump moves joules out of the reference and into your house. To cool, the pump moves joules out of your house and into the reference. That's it. All the thermal energy (heating/cooling) is from or to the reference, it's not from the electricity input into it. In an open-loop geothermal system like mine, the total efficiency can exceed 300%! That means for every 1kWh of electricity I spend to run the box I can move more than 3kWh of heat into or out of my house. None of the electrical energy ends up in my house, though. All the thermal energy is supplied by the geothermal reference.
I am pretty sure your misunderstanding comes from the fact that air-referenced heat pump systems often fail to be able to cool when it gets really hot out and fail to be able to heat when it gets really cold out. Every heat pump has a maximum delta-T. In other words, when the difference between the temperature you want your house to be and the temperature of your reference get too different, the heat pump stops working. So, in the summer, the air temp rises above the temp you want your house. At first, this is ok because the heat pump can pump thermal energy "uphill". As the temperature rises outside even more, the delta-T grows too large and the heat pump can no longer force more thermal energy into the outside air. At this point, your house stops being cold. The inverse situation happens in the winter. The heat pump can extract thermal energy from cold air and force it "uphill" into your house. However, as the outside temperature drops, the delta-T increases until the hill becomes "too steep" and the heat pump can't move the energy into the house anymore. At that point, the heat pump stops heating the house.
This is why geothermal, especially open-loop geothermal, systems are so efficient and reliable: the reference temperature never changes year round. The water coming out of my well is always 55F. 110F outside air temp and I want my house to be 70F? No problem, because the reference (geothermal water) is always 55F and it really doesn't have to do anything other than circulate cold water through the furnace. -25F outside and I want the house to be 70F inside? No problem, because the reference (geothermal water) is always 55F and the 15F "uphill" pumping of heat into the house is easy.
So, 100% of the heat into or out of my house comes from that well water. All the electricity does is to run the well pump and help the heat pump move thermal energy "uphill" when it has to.
theoldwizard1
Well-known member
Air source heat pumps, especially the multizone invereter heat pumps will give you a good return on your investment.
If you currently have forced air, a multizone setup may not be right for you, but consider it if there is a large portion of your house that you could run at a different temperature, even for only part of the day.
Being in Canada (or even where I live in MI), I would want some kind of a backup heating solution. Wood burning stove, propane fireplace, etc. I would not buy a generator to backup my heat pump. Electrical outages around here are short and infrequent. I see more of an issue with parts/service availability (easily more than 24 hours) if there is a system failure.
Last edited:
ratdoggy
Well-known member
How much can you save? My gas bill is approx $70 a month on a budget plan. ( heat, fireplace,drier and cooking) as far as I can tell the payback would be almost 40 years for me.How on earth could this be worth it??
JakeKohl
Well-known member
How much can you save? My gas bill is approx $70 a month on a budget plan. ( heat, fireplace,drier and cooking) as far as I can tell the payback would be almost 40 years for me.How on earth could this be worth it??
If your gas bill is significantly more than $70/month the math starts to offset. This works better particularly on a large scale (schools, office buildings, etc.). That said, there are different kinds of geo-thermal and some don't require expensive wells but still offer cost savings depending on local environment.
Highbeam
Well-known member
Geothermal is quickly becoming a dinosaur, there are better options now. With cheap current NG prices, you may never break even. Remember, the equipment has a life cycle as well.
Oh my god, you mean the price of natural gas will never rise and isn't subject to sometimes abrupt market price fluctuations???!?!?!?
Anyway, there's still nothing that rivals the efficiency of open loop geothermal and there's still nothing that comes even close to the cost predictability of geothermal. To me, I'd MUCH rather have a fixed cost for equipment that I can know and budget for up front than have a randomly changing payment to the utility company that's affected by the stupidity of the market.
Not to mention I can't get NG here, propane is an arm and a leg, and heating with electric is awfully expensive.
Highbeam
Well-known member
Oh my god, you mean the price of natural gas will never rise and isn't subject to sometimes abrupt market price fluctuations???!?!?!?
Anyway, there's still nothing that rivals the efficiency of open loop geothermal and there's still nothing that comes even close to the cost predictability of geothermal. To me, I'd MUCH rather have a fixed cost for equipment that I can know and budget for up front than have a randomly changing payment to the utility company that's affected by the stupidity of the market.
Not to mention I can't get NG here, propane is an arm and a leg, and heating with electric is awfully expensive.
I agree williaty. I was actually being specific that with current NG prices, and if you even have access to it, geo is a big fat loser. I know that energy prices will rise.