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Geothermal Heat Pump for Radiant Floor Heating

mknmike
mknmike Member Posts: 80
We get 10 degree days here, and with my current home, my mod-con curve is:

outdoor temp + radiator water temp = 150 F.

Nice and simple.

I've read a little about heat pump water heaters.
I assume there are heat pumps that can heat house boiler water too then.
I assume radiant floor heat is the lowest temperature water you'd need (assuming enough heating tubing/elements in the flooring.

I'd done some previous research over ten years ago about Geothermal and think I discovered we are on a run of granite on my property. So no go. But in searching my email, I found this from 2016. I'd enjoy the opportunity to learn what was covered in this webinar now that I'm researching options for a newly purchased house:
------------------------------------------------
Webinar
The Art of Hydronics & Geothermal

Presented by:

Mark Eatherton, Executive Director, Radiant Professionals Alliance


Jeff Persons, President, Geo Source One Inc.


Dennis Bellanti, Hydronics Manager, Ferguson

Join three industry experts, an instructor, contractor and distributor and find out the benefits of adding hydronics to your business. Yes, this is a specialty in the HVACR trade, but some contractors have already taken the leap and have added this to their business offerings, thus, growing their businesses. If you are new to hydronics and geothermal this webinar is perfect for you! Learn the basics and see if this is a specialty you would like to learn more about and add to your business.

Jeff Persons will discuss the basics of and efficient hydronic system, including a brief introduction to radiant cooling, focusing on how this can be utilized 365 days per year. Persons will also give piping/installation examples during the presentation. Dennis Bellanti will then discuss the importance of a good heat loss design upfront, along with a discussion about the importance of marketing presentations during the bidding process. With a good presentation a contractor can standout! And Mark Eatherton will discuss controls and how, what to do and what not to do, when integrating them into existing and new systems.

Register for Comfortech 365!
---------------------------------------


Comments

  • hot_rod
    hot_rod Member Posts: 16,320
    Ground source or air source heat pumps will work fine when properly sized and applied. Idronics 27 and 30 may help explain the concepts involved
    https://www.caleffi.com/sites/default/files/file/idronics_27_na.pdf
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    ayetchvackerRich_L
  • ayetchvacker
    ayetchvacker Member Posts: 55
    I’ve been researching air to water for about a year now. Nordic, a Canadian company, makes some very nice looking equipment. https://www.nordicghp.com/product/nordic-products/air-source-heat-pump/air-to-water/
    If you have a well for your domestic water that may also be a heat source. Here in Pennsylvania I service several water to air systems and one or two water to water heat pumps. The Caleffi article mentioned above are excellent on the subject. The case study they did in Boston was very interesting.
    Fixer of things 
    Lead Service Technician
    HVAC/R
    ‘09Moto Guzzi V7
    ‘72CB350
    ’83Porsche944
  • ethicalpaul
    ethicalpaul Member Posts: 3,739
    Granite does not stop you from trying ground source heating. My driller in CT hit granite after 20 feet (and expected to), no problem
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
    wmgeorgeHot_water_fan
  • Hot_water_fan
    Hot_water_fan Member Posts: 537
    edited February 4
    @mknmike Geothermal makes sense if you can recoup the cost of the hole. Air to water heat pumps don't have to pay for drilling, which is why they're expected to pay a larger role. The hole cost (and associated hardware) can buy a lot of electricity. It fits best where heating degree days are high, heat loss is high, and electricity is expensive. The headwinds include increasing air source efficiency, better constructed homes and decreasing solar costs.
    mknmikeRich_L
  • mknmike
    mknmike Member Posts: 80
    Thanks guys! I am in Wilmington, Delaware, and the plot is 80x140, and I would imagine that due to the heavy equipment required for the drilling, my driveway would be the best location. I guess my concern is whether this concept would be worth it or not for my application. I guess a proper heat load calculation is going to be really important for this. I think for the last time I started looking into this for my 2500 square foot house, Calvert Heating and Plumbing said they'd drill two holes. I can't remember the details from 10 years ago, but believe government incentives were bigger back then, and popularity of the conversation has waned.

    This video was encouraging. Sounds like it was in the state of New York. They mention “preheating” DHW, which makes me wonder if it simply doesn’t make heating water hot enough for an old radiator system, which is the reason radiant floor heat would be proposed.





  • Hot_water_fan
    Hot_water_fan Member Posts: 537
    Delaware doesn’t have cold enough winters or high enough energy costs for geothermal. If you want to use radiant floors, use air source and pocket the (huge) cost difference.
  • mknmike
    mknmike Member Posts: 80
    Delaware doesn’t have cold enough winters or high enough energy costs for geothermal. If you want to use radiant floors, use air source and pocket the (huge) cost difference.
    I will agree based on the fact that I think we pay more for cooling now than we do for natural gas heat.  But the geothermal also helps save with air conditioning too.  Right?
  • Hot_water_fan
    Hot_water_fan Member Posts: 537
    Yes you would. Still, air source will probably come out decades ahead compared to ground source in that climate. It’s just really difficult to recoup the drilling and associated work without checking all four: 1. Cold climate 2. No natural gas 3. High electricity rates and 4. High heat load. I’m not sure about your heat load yet, but you’re 0/3  so far :smile:
    STEVEusaPA
  • hot_rod
    hot_rod Member Posts: 16,320
    Consider the air to water, you need an analysis of your loads and heat emitters

    Here is where you can find incentive programs

    https://programs.dsireusa.org/system/program/de
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • wmgeorge
    wmgeorge Member Posts: 222
    A ground source geothermal since all is inside in a nice warm basement or other has 2x the service life of an outside air source unit. Yes I have worked on both, geo to radiant floor very common out here. Loops or wells are a one time expense. You need to compare costs of fuel vs electric. The COP of a geo is stable 3 or 4 perhaps even 5, whereas air source varies as to the OSA temp. Yes you can cool with a geo, it just involves switching the water to an AHU coil.
    Old retired Commercial HVAC/R guy in Iowa. Master electrician.
  • Jamie Hall
    Jamie Hall Member Posts: 18,953
    Permit me to throw a very minor monkey wrench into the gears. Check and make sure exactly what your specific jurisdiction (town/city, county, state) requires or even permits in terms of drill holes or wells. Some don't care -- drill all you want. Some prohibit anything except domestic water supply on parcels not served by municipal water. Most are in between...

    Also be quite sure you are using a really competent driller. The last thing you want is to find, ten years down the road, that your well is a potential ground water contamination source -- proving it isn't doesn't come cheap, unless the driller was competent and documented doing the job correctly (and, of course, if it is, may I recommend a nice retirement community in Belize?)
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    Rich_L
  • wmgeorge
    wmgeorge Member Posts: 222
    edited February 8
    Most Geo installers know the dance, drillers seal the well, there is zero pipe on the surface all underground. Some folks with the room just put in ground loops.

    In this town, the stupid school board people took out working boilers some not very old and chiller systems and put in geothermal! So they went from one or two AHUs with filters to hundreds of Geo fan units all with filters and coils to clean. Sure they saved money in operating costs but when will and who will change all the filters!! When those fan motors burn out who will change them out and all put in within 5 years!
    Old retired Commercial HVAC/R guy in Iowa. Master electrician.
  • hot_rod
    hot_rod Member Posts: 16,320
    Some of  the systems going in cities use directional boring. I would guess that is cheaper and less mess compared to a well drilling rig
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • psb75
    psb75 Member Posts: 570
    The video shows them boring the deep hole then putting the twin pipes in and grouting the entire bore hole immediately. So in the end, it is not a bore hole with a stored column of water like a typical deep-well borehole would be.
  • mknmike
    mknmike Member Posts: 80
    psb75 said:
    The video shows them boring the deep hole then putting the twin pipes in and grouting the entire bore hole immediately. So in the end, it is not a bore hole with a stored column of water like a typical deep-well borehole would be.
    I assume you are talking about the ~7:20 video I posted above from this old house / futurehouse, which shows the loop going into the hole at 6 minutes and at 6:21 says grouting is done.  I didn’t see how they did that.  I guess I am missing where they are stating that they are grouting the entire bore hole.  My assumption was that it was just the top of it somehow, but I can’t imagine they’d fill the entire hole.  I would think they’d want groundwater to move heat as much as possible.  So I’m just confused and would need to educate myself more.
  • psb75
    psb75 Member Posts: 570
    They are in fact grouting the ENTIRE bore hole column. You'll notice that they insert THREE pipes: two of them are "the loop" and the third pipe/hose is for grouting the entire bore hole as it is extracted. There is no reason to have the hole filled with water. It's all about heat transfer from deep in the earth. The grouting material can do it almost as well as water--due to heat stored in its mass.
    ethicalpaul
  • Jamie Hall
    Jamie Hall Member Posts: 18,953
    If the entire bore hole is grouted from the bottom up there shouldn't be any problem. Where drillers sometimes cut corners is if the hole is to be open for groundwater extraction -- like a domestic well -- there must be a casing What is supposed to happen is that the hole is supposed to be drilled big enough to accept the casing down at least 20 feet, or an absolute minimum of 10 feet into bedrock if the water source is in the bedrock. Then the casing is lowered -- never pounded -- into the hole and the outside of the casing to the earth grouted from the bottom up. The two shortcuts -- both evil -- are to grout from the top down (the grout will not fill and seal the casing to the borehole) or to pound the casing into the borehole, which will almost guarantee that the casing will split on the longitudinal seam -- not up where you can see it, but partway down. Either error will almost guarantee that surface or shallow ground water will get into the well.

    For a closed circuit geothermal well one could get away without the casing (if the well will stand without it -- not all will) provided, again, that the grout is emplaced from the bottom up, withdrawing the grout pipe as one goes.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • ethicalpaul
    ethicalpaul Member Posts: 3,739
    psb75 said:

    They are in fact grouting the ENTIRE bore hole column. You'll notice that they insert THREE pipes: two of them are "the loop" and the third pipe/hose is for grouting the entire bore hole as it is extracted. There is no reason to have the hole filled with water. It's all about heat transfer from deep in the earth. The grouting material can do it almost as well as water--due to heat stored in its mass.

    This is exactly how my well was done in CT. They mix the grout on site and inject it into the hole, lifting the grout tube as the well fills. The grout is engineered to maximize thermal conduction. My engineer even tested the conductivity on site to ensure it was mixed to spec.
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
  • mknmike
    mknmike Member Posts: 80
    hot_rod said:

    Consider the air to water, you need an analysis of your loads and heat emitters

    Here is where you can find incentive programs

    https://programs.dsireusa.org/system/program/de

    Thank you!

    I saw a site that listed federal incentive heat pumps and would like to link that here too.

    https://www.energystar.gov/about/federal_tax_credits

    It looks like the incentives might be limited for primary homes:
    https://www.energystar.gov/about/federal_tax_credits/non_business_energy_property_tax_credits
    My place is currently a rental, and I see it looks really complicated for commercial buildings.

    Ahh... I was in the wrong section. Renewable energy credits here:
    https://www.energystar.gov/about/federal_tax_credits/renewable_energy_tax_credits
    That says Rentals DO NOT qualify.
    So I may be "out" unless I move into this property.

    Mention of Water-to-Water heat pumps on that page:
    https://energystar-mesa.force.com/ENERGYSTAR/s/article/Is-there-a-tax-credit-for-water-to-water-geothermal-heat-pumps-1600088473860


  • mknmike
    mknmike Member Posts: 80
    Not giving up on this quite yet.  Still haven’t gotten a. Heat load Calc done as I plan to do that when my tenant is out of the house in a few weeks.

    So I finally got a copy of the bills on the subject property, and my tenant had been running the AC and Heat at the same time for a few days resulting in a $637.09 electric and gas bill (1089 KWh of electricity for $162.13 and 447 CCF of natural gas for $474.96). I guess that’s a problem with separate thermostats.  It’s not obvious when the AC was switched on, but it’s possible it could have been a LONG time as I recalled hearing the AC running before in the shoulder season and thought maybe the older lady was just having hot flashes.  So now I’m a bit concerned that my usage info is all garbage.  

    But let’s Assume it’s not, or that the heat needs to be sized to fight the AC.  Stupid assumptions I know, but it appears that on average, the 447 CCF is an average of 64,380 BTU/hr (assuming 103,700 BTU/CCF).  

    Maybe the 447 CCF is not all that bad bc my house that is about half the house took 187 CCF for the same period, but we also have 5 people in the house instead of 1 and also use gas for the dryer and stove every day.  The prior month, my home was 182 CCF and the subject property was 358 CCF (almost exactly double).  My home seems to have a max CCF/day of about 10 CCF.  It looks like a day the subject property was fighting the AC on a 22 degree day about 28 CCF were used another 19 degree day, it appears 20 CCF were used.  

    It seems that it might be reasonable to design the system for about 24 CCF or about 1 CCF per hour, or about 103,700 BTU/hour.  That makes sense to me since the house currently has a 175k BTU boiler.

    I PERSONALLY, have no trouble augmenting heat on cold days with the fireplace insert.  In fact, I only run the fireplace insert when the high is below 40 F, and see significant drops on our CCF usage on those days.  The problem is that I can’t gaurantee I personally will be around. 

    Now to translate these BTUs into Tons of heat pump action.  

    And IS IT EVEN POSSIBLE to get the required radiator / baseboard temperatures from a heat pump, or will radiant floor heating be the only option.  Will I need to switch to all radiant floor heating immediately?  Or could I migrate it all over time.  That’s the question.

  • mknmike
    mknmike Member Posts: 80
    edited February 15
    So it seems that 103,700 BTU/hr converts to roughly a 9 Ton (or let’s just say 10 Ton for about 120,000 BTU/Hr) or about 30 KW 

    This unit looks like it’s more for commercial applications, and it’s minimum would be about the same as my maximum requirement. 



    Edit: This thing sounds like its minimum size would be about right for the subject property and says it’s ideal for lots of things I assume I’d want to possibly do, like maybe heat a swimming pool. 

  • Hot_water_fan
    Hot_water_fan Member Posts: 537
    And IS IT EVEN POSSIBLE to get the required radiator / baseboard temperatures from a heat pump, or will radiant floor heating be the only option. Will I need to switch to all radiant floor heating immediately? Or could I migrate it all over time. That’s the question.


    We won't know that now as it depends on the to be determined heat loss and the existing radiation. You might be able to meet the load using radiators and 90 degree water or maybe you'll need 180 degree water. A R410A heat pump can get you to about 120 and if needed, a R134A heat pump can be added and take you to about 160, so there are many levers here. Plus you have existing ductwork.

    If you used 20 CCF on a 19 degree day, the heat loss is not 103,700 BTU/hour, probably closer to 80,000 using an oversize factor, as about 20% of those CCF were wasted.

    The radiant floor decision is somewhat separate as you can use lower temperatures with a variety of delivery methods and use different types of backup for the coldest days. Do not assume you need to retrofit radiant floors.

    Did you read the Idronics that were mentioned above?
    mknmike
  • mknmike
    mknmike Member Posts: 80
    And IS IT EVEN POSSIBLE to get the required radiator / baseboard temperatures from a heat pump, or will radiant floor heating be the only option. Will I need to switch to all radiant floor heating immediately? Or could I migrate it all over time. That’s the question.
    We won't know that now as it depends on the to be determined heat loss and the existing radiation. You might be able to meet the load using radiators and 90 degree water or maybe you'll need 180 degree water. A R410A heat pump can get you to about 120 and if needed, a R134A heat pump can be added and take you to about 160, so there are many levers here. Plus you have existing ductwork. If you used 20 CCF on a 19 degree day, the heat loss is not 103,700 BTU/hour, probably closer to 80,000 using an oversize factor, as about 20% of those CCF were wasted. The radiant floor decision is somewhat separate as you can use lower temperatures with a variety of delivery methods and use different types of backup for the coldest days. Do not assume you need to retrofit radiant floors. Did you read the Idronics that were mentioned above?
    I’m sorry I didn’t read the full 84 page report from idronics mentioned above.  This one, right?  https://www.caleffi.com/sites/default/files/file/idronics_27_na.pdf

    My assumption is that it’s going to say that new heat pumps are better at extracting heat from colder air.  

    I got excited when I saw that Bosch has the WW products and saw that it appears a WW122 or WW180 might be ideal. I love the idea of possibly also being able to heat a swimming pool with geothermal heat.  Page 5 here: https://issuu.com/boschthermotechnology/docs/bosch_wt_ww?fr=sNGRhYzM0OTMzMQ

    Some more here: https://www.bosch-thermotechnology.us/us/media/country_pool/documents/engineering-submittal-sheets/water-to-water-water-source-heat-pumps/btc761408103b_wwwt_ess_06.2021_us_1.pdf

    Main page here: 

    The mod-con curve in my current home is 150 F = radiator temp + outdoor temp.  Usually that makes the radiator temp in my house 120 F or less, but of course there are times it needs to be 140 F on a 10 F degree day.  Based on the fact that I was in the subject property on a 30 degree day and saw it had a boiler temp in the cast iron boiler of ~120 F, I’m assuming the curve in this house could possibly be similar.  

     It’s good to know the refrigerant used may affect the max water temp.  Thanks for that.  I wasn’t aware of that being a concern.  

  • mknmike
    mknmike Member Posts: 80
    edited February 15
    …If you used 20 CCF on a 19 degree day, the heat loss is not 103,700 BTU/hour, probably closer to 80,000 using an oversize factor, as about 20% of those CCF were wasted.



    GOOD CATCH, Wise man!  
    :-)


    Well, we do occasionally have 10 degree F days, even if just a few hours, I think it would be wise to size for that rare event, especially knowing this unit would probably be used for other things like hot water, and maybe pool heating.  
    It seems that if oversizing a hydronic unit, it’s smart to have storage tanks to store excess energy to extend cycle times.  That would be more practical in warmer times when the load is lower, and might not apply to the coldest days when it would ideally be sized for constant running.



    I had kind of thought maybe I better just burn fossil fuels because the heat load/loss is greater than I expected, but on the other hand, that might also be reason to get the most efficient possible system.

  • mknmike
    mknmike Member Posts: 80
    These water-to-water systems certainly don’t appear to be for the average home DIY job.  LOL.  I don’t even know where in the world one would find 460 Volts laying around.  https://www.ebay.com/itm/CARRIER-5-TON-460V-3PH-GEOTHERMAL-WATER-TO-WATER-HEAT-PUMP-/264647352188?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l6249&mkrid=711-127632-2357-0
  • mknmike
    mknmike Member Posts: 80
    I didn’t think I was going to be able to find pricing on the Bosch ww122 and ww180, but it’s nice to see this popped up on eBay.  $14,000 plus the cost of drilling.  Yeah.  Ain’t never getting that money back.  
  • Hot_water_fan
    Hot_water_fan Member Posts: 537
    I’m sorry I didn’t read the full 84 page report from idronics mentioned above. This one, right? https://www.caleffi.com/sites/default/files/file/idronics_27_na.pdf

    My assumption is that it’s going to say that new heat pumps are better at extracting heat from colder air.


    That's a good one for you, also 25. Really you can't go wrong with them, it'll surprisingly be quicker just to read them then wait for responses here and it'll answer questions you didn't even know you had. 84 pages say a lot more than that air-source is better than before, you'll want to pay attention to lowering water temperature requirements as well as the assortment of hybrid and backup systems.

    Well, we do occasionally have 10 degree F days, even if just a few hours, I think it would be wise to size for that rare event, especially knowing this unit would probably be used for other things like hot water, and maybe pool heating.


    That 80k is with 20% padding, you'll be fine.

    Lots of ways for you to proceed with no real technological barriers here, it'll just come down to many decisions (like air vs. ground source, water vs. air distribution, in-floor tubing vs. other options (or combination), hybrid vs. full heat pump, etc.).

  • Rich_L
    Rich_L Member Posts: 77
    I have a W-W GSHP with in-floor radiant in our home. We use the chilled water in a fan coil to cool our home in the summer. It doesn't seem as efficient as a DX system. My GSHP is 16 years old, same as our house, and 2 years ago I replaced a failed compressor. Our outdoor design temp in Iowa is -10F. I designed my system to need a max water temp of 115 degree supply water temp and use outdoor reset for temp control. It's a very comfortable system.
    One of the things often overlooked when determining the COP of a W-W GSHP is the energy required to run the solution through the ground loops. That is normally (in our area) done with a couple of substantial sized pumps.
    When it's time to replace ours, it will most likely be with an air to water system. I would love to see Fujitsu or one of the similar manufactures bring their air to water systems to the US market. From what I've read, they're very popular in Europe and Asia.
    On a side note, you don't necessarily need to size your system to cover the entire load. You can consider a hybrid system with a small gas boiler or electric heater to augment the load at the extreme - coldest temps. You also then have that as a back-up for if (when) you have a system failure.
    ethicalpaulHot_water_fanayetchvackermknmike
  • ethicalpaul
    ethicalpaul Member Posts: 3,739
    Respectfully I don’t know how you can be looking at 9 or 10 ton. The house I mentioned before was a 2100 foot cape from 1930 by no means tight and I installed a 3.5 ton which kept up fine (but was admittedly chosen on the small side). I had a wood stove for additional heat but I never needed it— I liked to use it to save electricity and for the nice fire.

    Do your heat loss before you start looking at 10 ton commercial rigs! I had my geothermal engineer run mine. He had me at between 3.5 and 4 ton and I told him “let’s give me some incentive to tighten this place up”
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
  • mcc
    mcc Member Posts: 1
    I have a Bosch W-W GSHP 2 stage 3 ton ramps to 4 ton. 6 zones in floor heat. 3 zones cooling chilled water fan coils. House is 2400sqft of shop and storage downstairs. 1000sqft of living space upstairs. All heated and cooled at all times. I installed everything myself.... I drive a forklift for a living.  Have Warmboard 3 zones upstairs. 3 zones inslab downstairs. I have solar on the roof. Been running for 4 years now. Entire house is electric. Is currently 7f outside. Have had 0 bills since start up. Since I did it all myself. Cost less than the 2 estimates I received to have someone install conventional heating and cooling. Had the loops in the yard installed by THE  loop guy in this area. Installed the lines into the slab before it got poued came back and filled system once I got it hooked up. $5000 4 loops 4 tons. In one end of my 1 acre lot. Included in my total for my system. 
    ethicalpaulayetchvacker
  • mknmike
    mknmike Member Posts: 80
    Great info hereethicalpaul said:
    Respectfully I don’t know how you can be looking at 9 or 10 ton. The house I mentioned before was a 2100 foot cape from 1930 by no means tight and I installed a 3.5 ton which kept up fine (but was admittedly chosen on the small side). I had a wood stove for additional heat but I never needed it— I liked to use it to save electricity and for the nice fire.

    Do your heat loss before you start looking at 10 ton commercial rigs! I had my geothermal engineer run mine. He had me at between 3.5 and 4 ton and I told him “let’s give me some incentive to tighten this place up”
    The subject property is a 1919 built 4200 sq ft of currently finished space and the basement that might get finished and is currently heated by the uninsulated hydronic heating pipes (currently warmer than the rest of the house as a result) is another 1200 sq ft.  That means the house could be 5400 sq ft.  Also, the garage is going to get finished which is another 1100 sq ft.  The house when listed for sale was erroneously listed as 6200 sq ft.  I currently can’t afford to live there, so I rent it out with $2000/mo positive cash flow. LOL.  :)

    The house I currently live in is in the same neighborhood, similar building techniques, all designed by DuPont around 1919, but it’s only half a house in comparison to the one we just bought and can’t afford to live in.  That was all the comparison I had at the time, and is also a sanity check.

    Based on the house being ~twice the size of some 3-4 ton systems and having windows from 1919 with storms in most, straight signal pane in others, I think 6-9 tons might be realistic.

    Since this would be an obvious improvement in the property, and tax incentives are not available for rental properties for geothermal, not to mention that someone above Mentioned that even though they currently have Water to Water system, they plan to switch to air to water.  That’s a telling experience.   I guess there’s just too much resistance for the flow rate.  I also have to wonder with both sides of the loop going into the ground in the same hole if you end up with less efficiency.  

    Geothermal does SOUND great, but it is sounding like something I’m definitely not jumping into at the moment.  This has been very educational.

    I think a smarter move for me would be to perhaps implement in that big basement a energy/heat storage tank which could be fed by various sources.  That way I could keep the 83% efficient cast iron boiler for now, and add more efficient systems over time to feed that storage tank.  I can add a modcon/combi, and a DHW storage tank, perhaps after that remove the low efficiency heater and water heaters freeing up the chimney access in the basement.  That could allow me to maybe put a biomass furnace or even just a wood stove to augment the storage tank.  I could maybe convert to heat pump technology. 

    I wonder if maybe running a heating water loop to the detached garage might be a good idea while I’m trenching to the garage in the next few weeks.  

    Lots to think about, and this site has given me lots of great ideas.  

    I’m dropping the geothermal for now, and resolving myself to continue burning natural gas as I try to tighten up the house.  I think our grid is only 10% renewables right now anyway.  So it might just be greener for now to continue on with natural gas and take the money that geothermal might cost to invest in community solar instead where the most efficient solar panels could be added to our grid. We have lots of mature trees in our neighborhood which is on the national historic register, and nobody wants to see bolt on solar panels.  My 6 KW $34,000 (after supposed tax rebates, $42,000 before) Tesla Solar Roof design claims it will generate 3138 KWh/year, <$500/year in electricity I calculate.  So that’s not going to work out financially, not to mention it still won’t look right.  

    So as for heating:
    - investigate costs and plan for storage tanks for heating water and DHW.
    - modcon / combi
    - tighten up seal up the house
    - continue to monitor heat pump technology

    Cooling:
    - maintain and research the TWO Unico cooling systems in the house, and see if perhaps it would make sense to change them in any way.
    - research heat pump technology to perhaps be prepared for that if any parts of the existing systems were to fail.

    H the good thing is that nothing NEEDS to be done right now, but I’m far more educated to my options.  Learning is fun, and I appreciate everyone’s help.  THANK YOU!  :-)
  • ethicalpaul
    ethicalpaul Member Posts: 3,739
    Ahh, sorry about that, I saw you mentioned 2500 sq ft in an early post but I think you must have been talking about a former house of yours. Good luck with your home no matter how you heat it!
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
  • mknmike
    mknmike Member Posts: 80
    Ahh, sorry about that, I saw you mentioned 2500 sq ft in an early post but I think you must have been talking about a former house of yours. Good luck with your home no matter how you heat it!
    Thank you!

    The situation is confusing because we aren’t living in the most recent purchase, rather renting it out.  We sold two rentals and bought one mildly neglected dream home.  We didn’t move, and the dream home became a high-end rental, high end to me anyway.  I prefer the idea of being the pool boy or handyman to  someone rich, as opposed to kids that mess up my houses.  I like the idea of fixing up a house that can be my pride and joy as opposed to something I’d never want to live in again.  So far this all seems to be working out really well financially, providing me with the funds to buy whatever systems make the most sense.  I’m still in the h first 9 months trying to come up with the grand plans.  

    I really appreciate everyone helping me come up with the grand plans.  The education has been a lot of fun!

    ethicalpaul
  • GEO80
    GEO80 Member Posts: 11
    Much as not rich researching GeoThermal htp for 42 years, and even 48 boreholes/ 27 net ton system, etc... it is well : gas + A HP, and my customers are very happy.

    Minisplits sometimes mentioned and other working AHP down to -10, -15, ???!

    Ask Jeff Persons about that.
    Shared about fall-off of AHP down to +5f, then before todays 'properly' sized air coil heat exchangers..., Jeff, who taught my company in 1980 about Hydro-Geologics and everything- well-water, piping, and Water:Water GT
    --- all as he learned about Air-Solar making Dom Hot Water by flowing through fancoil box, and a three-way air-diverter to Space Heating.

    Same air-Solar can add to any boiler where an 8x3ft collector can function for 3000 BTUh , normal- perpendicular to Solar Radiation.
  • GEO80
    GEO80 Member Posts: 11
    'my company' was where I worked , but others owned it...