buckeyefarmer
Epic Contributor
I installed geo myself for around $7k per unit, including ductwork mods.
New Construction HVAC decisions. Geothermal vs. alternatives with upgraded envelope.
- Thread starter MGH PA
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I also installed geo units myself. Mine was $ 8500 in '05 for two geo systems (zones up and down stairs). A 2 ton for the first floor and a 1.5 ton on the second floor, sharing the same geo loop. Using horizontal trenches was the most cost effective.
paul
paul
/ New Construction HVAC decisions. Geothermal vs. alternatives with upgraded envelope.
#13
Sigarms
Super Member
Anyone who is giving you a "size" per your HVAC system, ask them to see their load calculation. Personally, for that kind of money on a Geo system, particularly per the fact that this is new construction, you shouldn't have to ask for one IMO.
When looking for a geothermal HVAC contractor, one standard I'd try to ensure they met is that they're a member of the International Ground Source Heat Pump Association, and verify that they took took training. Absolute worst case, ask the HVAC contractors for references on previous jobs they did and contact the homeowners yourself. A contractor who does good work and stand behind what they do generally has no problem giving out references and the people they do work for don't mind sharing their experience. Because of this, 28k for a new install for new construction isn't way out of wack depending on the quality of work IMO. However, what scares me is no one is willing to go over their load calculations with you.
Geo is genearally rated in EER for cooling and COP for heating (not SEER rating). a 20 SEER fully modulating forced air AC/heat pump system may have around a 13 EER rating. A mid tier geo unit generally starts out around 30 EER. World of difference per performance.
When looking for a geothermal HVAC contractor, one standard I'd try to ensure they met is that they're a member of the International Ground Source Heat Pump Association, and verify that they took took training. Absolute worst case, ask the HVAC contractors for references on previous jobs they did and contact the homeowners yourself. A contractor who does good work and stand behind what they do generally has no problem giving out references and the people they do work for don't mind sharing their experience. Because of this, 28k for a new install for new construction isn't way out of wack depending on the quality of work IMO. However, what scares me is no one is willing to go over their load calculations with you.
Geo is genearally rated in EER for cooling and COP for heating (not SEER rating). a 20 SEER fully modulating forced air AC/heat pump system may have around a 13 EER rating. A mid tier geo unit generally starts out around 30 EER. World of difference per performance.
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Heres a good quote for you
80 percent of a buildings costs are in the day to day operations over the buildings lifespan, not the initial build price.
I dont think you will lose money by paying more up front to over insulate and build using energy efficient components. It will be cheaper to operate in the long run and keep money in your pocket.
Also consider passive solar...take advantage of free energy available by simply orienting your home appropriately and using things like overhangs and porches to minimize solar gain in summer and maximize gain in winter.
80 percent of a buildings costs are in the day to day operations over the buildings lifespan, not the initial build price.
I dont think you will lose money by paying more up front to over insulate and build using energy efficient components. It will be cheaper to operate in the long run and keep money in your pocket.
Also consider passive solar...take advantage of free energy available by simply orienting your home appropriately and using things like overhangs and porches to minimize solar gain in summer and maximize gain in winter.
deezler
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Curveball: Skip the geothermal, and save thousands! Geothermal is great but dang, it's expensive. And you still suck down plenty of kW to keep it running.
You have a great floor plan with perfect position of the chimney in the exact center of the house. Get a high efficiency wood stove or fireplace insert, and try to heat primarily with wood! Your bedrooms will stay a few degrees cooler, but so what? Good sleeping temps back there, and nice and toasty in the main room. 25 acres should give you free firewood in perpetuity.
Agreed on the exterior rigid foam - do one inch of polyiso with taped seams and thermal bridging is all but conquered. Eddie is right on the window treatment advice, this is critical. You can also go nuts with caulk on framing seams before insulating. R50+ in the attic... minimize your can lights in the ceiling, they pour heat through.
For backup heat, since obviously you may have to leave home and can't let the house get cold, put a big ***** mini split in the main room, and one or two more in the bedrooms if you want. My house is similarly all electric, and we put in baseboard heaters in the bedrooms, but never use them. 65 degrees back there is just fine. We also did 2x6 walls with nu-wool. Our house stays warm for days! We also earth-sheltered our whole north house wall (kind of like one big walk-out basement) but I realize that's not for everyone nor compatible with many floor plan desires.
Is the house orientation on the lot already set? Don't forget about passive solar gain - free heat! Get that huge window wall in the kitchen aiming south and you won't even need heat on sunny winter days. Watch your glass coating on the south so that it does NOT block thermal gain (but do block it on the east and west sides).
Finally, if you don't have central ducting, you still need a ventilation system. A heat-recovery ventilator (HRV/ERV) system is very affordable and keep the house air fresh, with minimal energy loss.
Just food for thought. I think more people really ought to focus on minimizing their electrical demand up front - what will the energy and electricity situation be like in 30 or 40 years? The tree will always be there for firewood, but the grid might get pretty sketchy. Plus having a small electrical demand means you can install a PV array and get free electricity with a quick payback time.
You have a great floor plan with perfect position of the chimney in the exact center of the house. Get a high efficiency wood stove or fireplace insert, and try to heat primarily with wood! Your bedrooms will stay a few degrees cooler, but so what? Good sleeping temps back there, and nice and toasty in the main room. 25 acres should give you free firewood in perpetuity.
Agreed on the exterior rigid foam - do one inch of polyiso with taped seams and thermal bridging is all but conquered. Eddie is right on the window treatment advice, this is critical. You can also go nuts with caulk on framing seams before insulating. R50+ in the attic... minimize your can lights in the ceiling, they pour heat through.
For backup heat, since obviously you may have to leave home and can't let the house get cold, put a big ***** mini split in the main room, and one or two more in the bedrooms if you want. My house is similarly all electric, and we put in baseboard heaters in the bedrooms, but never use them. 65 degrees back there is just fine. We also did 2x6 walls with nu-wool. Our house stays warm for days! We also earth-sheltered our whole north house wall (kind of like one big walk-out basement) but I realize that's not for everyone nor compatible with many floor plan desires.
Is the house orientation on the lot already set? Don't forget about passive solar gain - free heat! Get that huge window wall in the kitchen aiming south and you won't even need heat on sunny winter days. Watch your glass coating on the south so that it does NOT block thermal gain (but do block it on the east and west sides).
Finally, if you don't have central ducting, you still need a ventilation system. A heat-recovery ventilator (HRV/ERV) system is very affordable and keep the house air fresh, with minimal energy loss.
Just food for thought. I think more people really ought to focus on minimizing their electrical demand up front - what will the energy and electricity situation be like in 30 or 40 years? The tree will always be there for firewood, but the grid might get pretty sketchy. Plus having a small electrical demand means you can install a PV array and get free electricity with a quick payback time.
dodge man
Super Star Member
At the time we did geo, some one on here had a really good spreadsheet for figuring energy costs. Gas, geo, electric, propane etc and you could put in actual numbers in it to see the cost. For example, propane at $1.50 per gallon. When I looked at it wood, natural gas and geo were pretty even, but I'm going by memory. Of course wood takes a lot of work and you may not have natural gas available. In our case the pay back for geo was about 5 years, but propane was the only other choice unless I wanted the work of wood.
The only drawback of geo that I can think of, other than the initial cost is you can't really screw with the temp. Turning it up and down a lot just doesn't work well.
The only drawback of geo that I can think of, other than the initial cost is you can't really screw with the temp. Turning it up and down a lot just doesn't work well.
/ New Construction HVAC decisions. Geothermal vs. alternatives with upgraded envelope.
#19
Our orientation can be anything we want. Right now, we're planning for SSE. We can have 150ish degree views from the back of the house.
I really don't want to deal with wood to be honest. I know it's great since it's accessible and all, but I have very little free time with two kids, and it's not really how I want to spend what little free time I have. I've been heating with wood for 10 years, and grew up with it as well. The dirt, allergens, etc. wouldn't be missed.
I do see your point, though.
Raspy
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MGH,
You mentioned Creatherm panels in the basement for hydronic radiant heat. Does that mean you'll be putting down a topping slab over the structural slab? If so, I'm wondering why? Why not put the tubing in the structural slab?
What about the main floor? Radiant there too? And again, if so, how will you do it?. The best way I've found is to staple the tubing directly to the subfloor, double plate all the walls, and pour a thin slab the thickness of the lower plate, typically 1 1/2". This gives you a radiant floor that will accept any flooring material and offers some mass for temperature stability. You can tile directly over it in the bath, or tile the whole house. So, you save money on the installation, you save putting in a tile mortar bed in the bathrooms, you get a stable heated floor everywhere and you can design the heat well because you are not locked into a defined tube spacing of the Creatherm panels.
You also mentioned the hydronic system would be later, but again, why? If you want tile, you'll need the hydronic floors or the tile will be very uncomfortable. I don't get why you would want to deliver the heat with blowing air, instead of with a radiant floor system that you are already planning anyway.
Have you done research to find the long term cost of maintenance and the reliability of GS systems? Maybe some others can chime in here too. I'm not saying one case is indicative, but my neighbor put a system in and it has not been reliable or cheap to operate. In other words, it has not lived up to its promise. If cost is a concern, a few service calls can certainly offset the savings you might get through a lower cost of operation. And each of those calls means a period without heat.
With all systems, you have to look beyond the theoretical efficiency and factor in reliability. This can vary wildly between different manufacturers as new products become available and contractors take them on. Manufacturer's reps, visit contractors and architects to promote new products, that then get spec'd in the plans, but have no track record. In my hydronic heating business I have been burned too many times by the newest, and seemingly greatest new products that did not prove to be reliable. All of those cases cost me dearly in warrantee repairs and somewhat in reputation. Be sure you understand the reliability and parts availability of any complicated system you choose.
You mentioned Creatherm panels in the basement for hydronic radiant heat. Does that mean you'll be putting down a topping slab over the structural slab? If so, I'm wondering why? Why not put the tubing in the structural slab?
What about the main floor? Radiant there too? And again, if so, how will you do it?. The best way I've found is to staple the tubing directly to the subfloor, double plate all the walls, and pour a thin slab the thickness of the lower plate, typically 1 1/2". This gives you a radiant floor that will accept any flooring material and offers some mass for temperature stability. You can tile directly over it in the bath, or tile the whole house. So, you save money on the installation, you save putting in a tile mortar bed in the bathrooms, you get a stable heated floor everywhere and you can design the heat well because you are not locked into a defined tube spacing of the Creatherm panels.
You also mentioned the hydronic system would be later, but again, why? If you want tile, you'll need the hydronic floors or the tile will be very uncomfortable. I don't get why you would want to deliver the heat with blowing air, instead of with a radiant floor system that you are already planning anyway.
Have you done research to find the long term cost of maintenance and the reliability of GS systems? Maybe some others can chime in here too. I'm not saying one case is indicative, but my neighbor put a system in and it has not been reliable or cheap to operate. In other words, it has not lived up to its promise. If cost is a concern, a few service calls can certainly offset the savings you might get through a lower cost of operation. And each of those calls means a period without heat.
With all systems, you have to look beyond the theoretical efficiency and factor in reliability. This can vary wildly between different manufacturers as new products become available and contractors take them on. Manufacturer's reps, visit contractors and architects to promote new products, that then get spec'd in the plans, but have no track record. In my hydronic heating business I have been burned too many times by the newest, and seemingly greatest new products that did not prove to be reliable. All of those cases cost me dearly in warrantee repairs and somewhat in reputation. Be sure you understand the reliability and parts availability of any complicated system you choose.