Geo thermal for a shop?

[longroof]

Am planning a new shop now to hopefully start within the next year. Does anyone have geo thermal in their shop? I have heard of some farmers up here that use it in their shop and like it and claiming outrageously low utility bills. I am also looking into possibly solar heat in addition. I need to keep the shop 50 degrees and warmer year round. I live in northern Iowa. Thoughts, comments?
Thanks!
Jerry

 

[mattmankow]

Just the geothermal will keep it that temp year round.

 

[kb2tha]

How big is the shop and will this be the only building heated with it? Will you be heating a residence as well? Will the current energy credits work if you are not heating a residence?

My wife and I expect to be building this summer and are planning geothermal. Have been quoted an operational cost of an additional $800 in electrical costs to heat for a year. Even if they are off by 50% and it runs me $1200. I will be thrilled with that. Geothermal makes best sense with new construction as you would be spending $xxxxx dollars on a conventional system to begin with. Put that money towards your geo system, add the allowable credits and if necessary finance the difference with the anticipated fuel savings.......or just pay cash.

In my case, using their estimate for electrical costs, I will spend about $3400 less per year on my new home vs. the old on energy costs. If needed, that would finance $40k (well over what I will need before credits, etc.) for my new system. I am planning a 15 yr. partial mortgage at today's rates sub 3%. Will probably borrow around $12k for the geo system and still realize a $200 per month energy savings over present expenses.

I agree with mattmankow. Your decision will be based on payback time and initial expense. Good luck.

Oh, and welcome to the forum.

 

[jkeyser14]

We put geothermal in our house and love it. Our heating and cooling costs are much lower than they used to be. As long as the installers properly size the system for your shop it will have no trouble. The tax credits do not limit where the system can be installed.

You should read the forums on geoexchange.org for more info.

 

[jvitez]

We built our house in 2006 with geothermal. We're seeing about a 40% saving over our previous house which wasn't as well insulated (built in 1995) but used NG for everything, so our actual energy use is about 60% less. With cheap NG now the saving is less, but we built for the long haul.

Our system is rather complicated and has had several repairs. It's an open loop 4 zone water to water system. A shop system should be really simple: one zone, water to air for forced air or water to water for in-floor radiant. Insulation and air sealing are still key.

 

[kbs2244]

The only problem with geo thermal is the initial installation cost.
After that it is virtually free.
If you can swing it for the long run advantage, go for it.

 

[longroof]

The shop will is going to be 40x60 hopefully I have a carpet cleaning business so I need to keep things warm, plus I want to work on cars, etc. in my down time, etc. Maybe I wont even need the solar? I am going to read up on geotherm. Some friends of ours are building a new home that will have geotherm and I thought hey, maybe that would be great in a shop/garage as long as I am starting from scratch. Thanks for the replies! Love the forum! Great ideas for sure!
Jerry

 

[jvitez]

The only problem with geo thermal is the initial installation cost.
After that it is virtually free.
If you can swing it for the long run advantage, go for it.

Sorry, but I only wish it was virtually free. We have two heat pumps and each uses 7000 watts while running. It doesn't run for long, but its still 14kw together.

 

[Sureshot]

No experience myself other than hearsay from two. One said the power bill and the other couldn't justify the upfront cost and expected life as compared to NG.

I have looked into solar and I think that I will go that way with my next shop. Infloor heat and solar would seem to go hand in hand. I have infloor currently with no thermostat I have my mixing valve set manually and except for spring and fall I leave the system run. It can be down for days and the thermal mass of the floor carries it well. I would convert my current shop but we plan to move in the next few years.

 

[HoosierBuddy]

If it was me, and natural gas was not an option I would price both the geothermal and an air source heat pump, do a comparison of the payback at current energy prices and then decide.

Data is always useful in making decisions!

What would I just guess (with no data)?

I'd guess that a well insulated shop that is only heated to 50-degrees in the winter and cooled to 80 or so in the summer will not use enough electricity to cost-justify the additional cost of a ground source (geothermal) heat pump over a good air source heat pump to payback during the lifetime (say 12-years) of the unit.

That's a guess. Without data I wouldn't act on just a guess.

Phil

 

[BadgerBoilerMN]

If you do the math, there is no ROI, like solar space heating, if you really need it you can't afford it. Look to insulation, radiant floors and condensing or wood boilers depending on the local fuel rates of course.

Air source heat pumps are perfect for most climates with high humidity, such as Iowa, but you will not have warm floors.

 

[sparky1562]

I would absolutely disagree with the "No ROI" statement. Yes, geothermal costs more due mainly to the cost of the wells. The equipment in general will last much longer than the 12 years stated as well. No equipment sitting outside in the enviroment. Equipment life is in the 20 year range.
I have three heat pumps for the house, 4 wells feeding a common header. Payback was around 9 years.
I wish I had planned for my shop, but didnt.
I was going to say if your only heating it on weekends, then it would take a long time to payback, but if your going to heat it 24/7, (and cool it), I dont see how you could loose.
I am involved in two large commercial projects using all geothermal heating cooling, one is a hospital, one is a medical office building, so I am a fan!

 

[BadgerBoilerMN]

ROI is based on the heat load and the cost on fuel. In cold climates, more heating than cooling small shops and residences do not merit ground source heat pumps "savings".

 

[theoldwizard1]

Just so that we are all on the same page, we are talking about a geothermal heat pump (a.k.a. ground source heat pump). The heat pump can then generate hot or cold air for a forced air system, or heat for in floor radiant heat.

Sadly, I think Mr Badger is correct especially when comparing the installation and operation costs against a natural gas fired, forced air system. If the only energy sources are electricity and propane, the equation changes.

 

[jkeyser14]

ROI is based on the heat load and the cost on fuel.

You are correct here.

In cold climates, more heating than cooling small shops and residences do not merit ground source heat pumps "savings".

You are completely wrong with this statement though.

In my neighborhood we only have electric or propane/oil. The savings are tremendous when compared to oil or propane. Geothermal hands down outperforming air to air systems in terms of longevity, cost to run, and efficiency when used on extremely hot or cold days. We also generate our hot water with geothermal.

Remember in cold climates an air to air heat pump won't work well below freezing. Where they may have a seemingly high COP at mild temperatures that COP drops by an insane amount when you get below freezing. The geothermal system will have a nearly constant SEER/COP independent of outdoor air temperature as long as the loops were sized correctly.

 

[jvitez]

Yes, it's all in the numbers: fuel costs, actual heat loss of the building, need for summer cooling, length you're planning to live there for operating cost, then cost of equipment as capital cost.

Geothermal can be installed and be an excellent heating/cooling source anywhere, anytime, it's simply the capital cost vs ROI that's the deciding factor.

 

[tomroblee]

A heating contractor once told me that heat pumps are perfect for folks who want to save money no matter how much it costs them.

If you are wanting to keep a very well insulated and air tight building at a constant temperature you won't use a great deal of energy. You can get by with a small HVAC system and the fuel/electric costs should be fairly modest. Heat pumps work very well for this kind of heat load.

It's a whole different game if you want to keep a poorly insulated shop at 50 degrees during the night when it's shut up, then crank the temperature up to 70 degrees during the day when you are frequently opening and closing large overhead doors or operating a big exhaust fan for ventilation purposes. You would need a huge HVAC system for this application and the fuel/electric costs would be pretty high. Heat pumps don't function all that well for this kind of heat load.

 

[BadgerBoilerMN]

Air-to-air heat pumps are the future for most of us. Mine will exceed a COP of 2 well below freezing air temperatures and exceeds 3 in warm weather.

For the typical residence the initial investment would be better spent on insulation in most cold climates. Once the heating and cooling loads reach equal parts the ground source and air-to-air heat pumps start to make more sense. There is no empirical evidence to substantiate claims of longer equipment life, since ground source heat pumps are extremely installation sensitive.

We do all types of heating and cooling systems but always do the math first.

 

[HoosierBuddy]

A heating contractor once told me that heat pumps are perfect for folks who want to save money no matter how much it costs them.

If you are wanting to keep a very well insulated and air tight building at a constant temperature you won't use a great deal of energy. You can get by with a small HVAC system and the fuel/electric costs should be fairly modest. Heat pumps work very well for this kind of heat load.

It's a whole different game if you want to keep a poorly insulated shop at 50 degrees during the night when it's shut up, then crank the temperature up to 70 degrees during the day when you are frequently opening and closing large overhead doors or operating a big exhaust fan for ventilation purposes. You would need a huge HVAC system for this application and the fuel/electric costs would be pretty high. Heat pumps don't function all that well for this kind of heat load.

It's worth noting (again) that heat pumps are equipped with backup electrical resistance heaters for this situation where someone sets down the t-stat and then "cranks it up" to get the temperature back up when they want to use the building.

I was helping a pastor with his churches (air source heat pumps) heating and he was explaining how they were setting the t-stats back to 48 when no one was around and cranking them to 70 a couple of hours before each service and their electric bill was eating them alive.

In that situation, it would likely be much cheaper to leave the t-stat alone. Once the unit reverts to resistance heat, it will use 3 to 4 times as much power per BTU delivered to the structure.

I go back to my original point though...decisions like this take data. Also, regarding the equipment lifespan issue...most ROI decisions in the real-world are looking for paybacks of 1 year, 5 years, maybe even 8 years. My point regarding 12-years is that even if you go out that long it may not show a savings. But without data, I wouldn't care to speculate.

How much longer will one unit last compared to another? That's crystal ball stuff. Who knows? Comparing the warranty might be a place to start...but the best thing would be to talk to people that have use the equipment.

We've done multiple gas installs to replace ground source heat pumps. Those people weren't happy...but obviously that isn't a valid sample. If they had been happy, I wouldn't have heard about it.

Phil

 

[longroof]

I talked to a lumber yard manager yesterday about GEo therm for a shop and he had said that there were several farmers in the area that have it and really like it so far. I will talk to them before we get to far involved in the project to look at there shops. I know it can be all over the map, but what do you think the cost for a geo therm be?

 

[jkeyser14]

Sending you a PM with what we paid.

 

[theoldwizard1]

Air-to-air heat pumps are the future for most of us. Mine will exceed a COP of 2 well below freezing air temperatures and exceeds 3 in warm weather.

So what are the breakthroughs that allow this kind of performance ?

Got any website links ?

 

[nirion]

I have an existing 30x48x12 pole barn with concrete floor, and no current heat. We are planning on building a new home on the property with geothermal in the next year or two.

Is it possible to use the same geothermal well/system for both the house and shop?

Thanks

 

[BadgerBoilerMN]

http://heating.danfoss.com/Content/12f5c1de-5801-463f-8ba9-6335f152ab8b.html

http://www.mitsubishipro.com/en/pro...zone/m-series-heat-pump-systems/msz-gemuz-ge?

The second link is a copy of the specs for my own air-to-air. The bottom line is the bottom line.

You have to keep in mind that design condition in this climate are rare. A few days below zero and a few day in the 90's.

PS. The new "Hyper" series is even more impressive and will go in my new shop, since my customers can't have all the fun...

http://www.mitsubishipro.com/en/pro...-zone/m-series-heat-pump-systems/msz-femuz-fe

 

[2005UltraClassic]

Not sure how far you have gone into your research, nor where you are located.
You might plan a visit to this site: http://www.tthermgeo.com/geothermal.php

 

[BadgerBoilerMN]

I have an existing 30x48x12 pole barn with concrete floor, and no current heat. We are planning on building a new home on the property with geothermal in the next year or two.

Is it possible to use the same geothermal well/system for both the house and shop?

Thanks

Only your designer can tell, after doing the heat loads. When I lived in OH we suffered some power outages, all those ice storms. I would want some backup, which is easy if you have hydronic radiant floors. An air to water or GSHP to water will do it. You can have cooling as well.

 

[jvitez]

Is it possible to use the same geothermal well/system for both the house and shop?

Thanks

Yes, but it depends on the numbers as does everything in HVAC, hence Badgers post above. If you have enough flow from one well, and have a well pump that can supply both shop and residence and potable water, then yes it will work. This is only known with the heat loss/gain of both shop and house, and a flow test from an already drilled well. More insulation and excellent air sealing will make a big difference. Case in point, our house build.

The initial iteration called for R60 ceiling, R20 batts in walls, R24 batts in basement. This exceeded the capacity of two ground source heat pumps, so our design called for the smallest forced air furnace they could find for the full basement, and the two heat pumps for the main and second story. We'd were holding off on an AC unit for the basement until we spent a couple of summers there.

Then we changed the R20 walls to high density spray foam. It gave about R33, though there still is conductive loss through 2x6's 16 inch OC. I looked at 1.5 inches of Styrofoam cladding on the outside, but it was cost prohibitive in addition to spray foam and didn't reduce heat loss very much. Simply by changing to spray foam we reduced the heat loss enough to be able to use the heat pumps alone. So we spend quite a bit more on insulation costs but partially recouped it by not needing one furnace and its installation costs. Plus, we save monthly heating costs. Win/win overall.

This is the type of discussion you should have with any competent HVAC contractor.

 

[Cougfan]

This may be a dumb question, but if the OP only wants to heat his floor to 50°F, and ground water typically is 55°F, why couldn't he just insulate the floor well, and circulate ground water through his in-floor tubing? It may take a really long time to heat up the floor initially, but once it reached steady state, it seems like it might work. The energey bill would certainly be cheap .

 

[BadgerBoilerMN]

If he just wants the floor at 50. The heat load will determine what the water temperature needs to be. My designs run from 2btu to 120btu (snow melting) but only the computer can tell. Typically a couple of degrees above target ambient in a super-insulated building. For all else you have to think higher.

 

[6inarow]

Boy I really hesitated about jumping into this conversation but this sort of stuff makes my blood boil.

Dont take this personal Mr BadgerBoilerMN, I am only going to give facts. Your comments irritate me because after I read your profile I realized you had something to gain by your posts. I dont. The first thing is that I am not a heating A/C guy, so I am not a professional in that regard, I am a rank amateur. You are the professional. But my experiences count for something.

Here is what happened to me in the last 15 years with our Geothermal: We remodeled a 100 year old house top to bottom. 2500 Sq ft, 2 story victorian. We re-did everything. It isnt the most effecective construction to begin with, but its how it worked out. We had no incentives. Nada, Zero. We did geothermal. We calculated the cost of conventional heating and cooling systems from the manufacturers and the contractor. We installed the geothermal system anyhow. Guess what? It was paid for in savings after 4 years 11 months compared to what the conventional guys promised their efficient line would cost us. That means free heating and cooing for us for the past 8 years.

We built a new office 9 years ago. 3000 sq ft. The lender would not allow geothermal without a huge up-front escrow account to change back to conventional heating and cooling claiming that geothermal was "unproven". So we installed the conventional heating and cooling. 18 months later we took it out, donated the system to habitat for humanity and installed the geothermal. I could compare apples to apples and guess what? We SAVED $400 per month on heating and cooling. We tracked it and i have the invoices to show. It cost me $30 grand to put the system in. You calculate the payback. I was happy to throw the conventional system away. If you get ANY incentives in tax relief, energy rate cuts or rebates it is an even greater return. The thing that irritated me most is that all the so called experts and financial guys had their head up their *** on this one.

With the cost of fossil fuel and energy in general, these thing pay for themselves even faster than when we built. We are moving to the Black Hills of South Dakota and guess how my shop and house will be heated and cooled....

Sorry to rain on your parade BadgerBoilerMN, but this is my experience. As a side note, and correct me if I am wrong, but I believe Williams Arena at the U of M used this inefficient geothermal technology to heat and cool that building when my father was there in 1950???

 

[tomroblee]

I don't think that there is any argument that geothermal is a more energy efficient way to heat and cool than many other alternatives. The arguments always seem to end up debating the amount of any cost savings.

I'll toss in my experience. Until about 18 months ago I lived in a drafty poorly insulated house that was built in the 1920's. It had a 1250 sq. ft. footprint with two stories above ground and a basement. It was heated by a gas fired steam boiler (about 220,000 btu input) that was nearly 50 years old. Our central air conditioner was 30 years old when we moved. It was definitely not an energy efficient situation. Our temperature preferences are for mid 60's in the heating season and low 70's in the air conditioning season. I think that our annual gas bill maxed out at about $2500 (including cooking and hot water heating) and our annual electric bill maxed out at about $1000. (A steam system doesn't have a blower motor or a circulating pump. Our electric bills never got above $50 per month except in the air conditioning season.)

Would a geothermal system have been cheaper to operate? The answer is obviously yes. How much could we have saved? Darned if I know, but the savingings couldn't have exceeded our total utility bills (which also included water heating, cooking, refrigerator, freezer, lights, TV etc. as well as about $20 per month in flat charges.)

About 8 years ago we built a home 2200 sq. ft. vacation home in the country. It is extremely well insulated and fairly air tight. It is 100% electric and has two air to air heat pumps (13 or 14 seer). When we are away from the home we leave the electric water heater on and set the thermostat at about 60 in heating season and 80 in cooling season. Our total annual electric bills over the past four years have ranged from a little over $1000 to a little under $1200. This includes a flat charge of about $30 per month in addition to the kwh rate.

Would a geothermal system have been cheaper to operate? The answer is probably yes. How much could we have saved? Darned if I know, but the savings couldn't exceeded the variable portion of our electric bill which was $600 to $800 per year. The lowest monthly electric bill we have had in the past four years was about $60--- it was in a month when neither the heat nor the air conditioning was running. This suggests that we have been spending $300 to $450 per year on heating and cooling.

A year and half ago we moved to a newer home in the city. It is 3500+ sq. ft on one floor with 10' ceilings. It has geothermal heating and cooling and a tankless gas water heater. It is well insulated, but is built on a slab with the entire HVAC system in the attic. Our 2012 electric bills totaled $1028.

Would a gas furnace or air to air heat pumps have been more expensive to operate? The answer is yes. How much more expensive would they have been? Darned if I know, but I doubt that the difference would have been huge. The manufacturer's literature says that our geothermal system puts out about 50,000 btu per hour heating (under ideal conditions). A gas furnace could put out 50,000 btu per hour for less than $400 per month even if it's running 24 hours a day, 7 days a week.

My experiences have been in Indiana where utility rates are fairly reasonable.

 

[BadgerBoilerMN]

I am happy for you 6in., but your example is anecdotal at best.

Truth is, in a good part of N.America there is no greater potential for low fuel consumption for space heating than a slab-on-grade radiant floor heating system driven by a properly designed water-to-water ground-source heat pump (GSHP); often mistakenly referred to as geo-thermal. Think "Old Faithful".

I don't know if I have a vested interest or not. I do consult about all kinds of HVAC systems with lots of people across the US and Canada including GSHPs. The results are mixed, and efficiency anything but guaranteed. This is understandable since all HVAC systems must be custom designed and installed to specifications. Since Geo-thermal systems are more technically challenging than most, e.g. soil, compressor, low air/water temperature requirements to meet design COP, pumps, air handlers, trenching, well drilling. So the margin for error is much higher than with more conventional systems.

I spoke to residential applications--small garages included--where payback can take a decade or two, or three depending naturally on the load of the building, the cost of fuel and installed equipment. This is true even it "we" chip in, i.e. tax incentives.

As I tell all of my clients in areas where natural gas is available; insulate and condensate.

The only place I have really "vested my interest" has been in radiant panel design. Since the panels don't care where the hot water comes from, neither do I. The beauty of the whole thing is we can use true-Geo-thermal, GSHP, coal, wood, waste oil, #2 oil, bio-diesel, propane, corn, bio-mass and yes, even electricity to heat the water depending on our particular circumstances. And if we install any type of hydronic radiation, we can changer our minds!

One of my buildings is heated with a direct resistance electric boiler, even though I have been promoting condensing boilers for 25 years, the numbers did not work. The cost of electricity is so low, in this particular case, that the material costs and 4 extra days of labor, did not make economic sense. Yes, it would be more efficient--cost less to operate--a water to water ground source heat pump, but my fuel bill, all told, was $200.00 last month including the operation of a 4x60ft snow melting system (two snow events) in the sidewalk.

We also use an air to air heat pump in milder months (though is operates into the single digits with great efficiency) and the total electric bills are well under $150.00 for 2200sf.

Had I installed a condensing propane boiler the fuel bill would have doubled this number, at the going rates.

Your challenge is timely, and welcome, since the subject just came up in another venue:
http://en.allexperts.com/q/Radiant-Floor-Heating-3710/2013/1/geo-radiant-floor-high.htm

 

[6inarow]

Badger, thanks for the link and the edumikation.

The guy that bought our office doubled his heating bills compared to what we had in the same building the month before. Maybe there is something to do with operator error. He keeps telling me that I lied to him and fudged the numbers. What actually happened is that he reprogrammed the thermostat to the most inefficient way to operate the heat pumps. But since he is a know it all he can figure it out on his own. Meanwhile he will badmouth the efficiency of the geothermal system too.

The only question I have Badger: how is my experience anecdotal?

 

[BadgerBoilerMN]

A small sample, from limited experience. I did not say you were wrong, just that not all outcomes are good. I think GSHP are great if they fit the application and the pocket book.

The most conservative investment is in insulation, which is not energy dependent nor prone to maintenance. Still a good part of the energy load a residence is domestic hot water and this is not always considered. The right heat pump can also cover DHW.

 

[Jackfre]

So what are the breakthroughs that allow this kind of performance ?

Got any website links ?

In about '07 the first of the 410A refrigerant variable speed (inverter) mini-split heat pumps came out. Prior to that they were single speed and R-22 supplied. The performance difference was simply incredible. You have a variable speed compressor with a variable speed condenser fan. The interior evaporator has a variable speed fan. Living in New England I told anyone who bought one of the R22 heat pumps they were crazy. Today with the 410A and inverter operation you are crazy if you do not buy the heat pump. 410A runs at significantly higher temperatures and pressures. In selecting these mshp you have to be sure you understand your temperature range and carefully select the right model for your application. I have a dual system in the house that says it will heat down to 32. It being in the bedrooms I hardly ever run it in heating but it does well in cooling for the summer. The downstairs system will operate down to 5*. Fujitsu & Mitsubishi now have hp that will operate down to -15*.

Check out www.fujitsugeneral.com for info, as well as mitus's site

 

[jkeyser14]

In about '07 the first of the 410A refrigerant variable speed (inverter) mini-split heat pumps came out. Prior to that they were single speed and R-22 supplied. The performance difference was simply incredible. You have a variable speed compressor with a variable speed condenser fan. The interior evaporator has a variable speed fan. Living in New England I told anyone who bought one of the R22 heat pumps they were crazy. Today with the 410A and inverter operation you are crazy if you do not buy the heat pump. 410A runs at significantly higher temperatures and pressures. In selecting these mshp you have to be sure you understand your temperature range and carefully select the right model for your application. I have a dual system in the house that says it will heat down to 32. It being in the bedrooms I hardly ever run it in heating but it does well in cooling for the summer. The downstairs system will operate down to 5*. Fujitsu & Mitsubishi now have hp that will operate down to -15*.

Check out www.fujitsugeneral.com for info, as well as mitus's site

Inverter systems are also now available with geothermal. New inverter tech = EER of 41 and COP of 5.3. They also greatly extend the compressor life because you have a lot fewer start stop cycles. You can look at the datasheets for the Waterfurnace 7 Series to verify those numbers.

Compare that to the fujitsu's peak 27.2 EER rating, which drops drastically with outdoor weather conditions unlike geothermal. It's easy to see why those who have geothermal systems love them.