Have you, would you consider hydronic in-floor radiant supplied by Geothermal Heat Pump?

SR

@User...so electric boiler are still less efficient than gas?

@fsq4cw Geothermal might work. It's a good suggestion. Even though the lot is atop a ridge there is still typical soil and rock below the house footprint. I suppose soil temperature 50 or 100 feet down would be similar to lower elevation areas? Good idea - will check into geothermal.

Our home is fully heated with hydronic in-floor radiant heat using an electric boiler. Gas was not an option for us, so we didn’t do any analysis of cost difference, but it’s an excellent home heating system.

@marilyncb Did you put hydronic in-floor on each floor? Such as, in the basement (if have one), on 1st floor, on second floor, etc. If in the basement slab do the tubes/coils rest on top of the slab or are they embedded into slab when concrete is wet?

What's approximate cost per month in coldest winter months for electric boiler??

Our house is built on a slab (no basement) and the tubes were embedded in the slab when it was poured. It’s a 1.5 storey house, so most of the living space is on the 1st floor. The upstairs rooms have hydronic baseboard heaters, also run through the electric boiler. I don’t have a good sense of the cost off the top of my head - everything in our house is electric, so all ends up on one bill. I could have a look at increase from summer months to winter months to try to give you a rough estimate. We’re in Nova Scotia, Canada, so electricity rates may be quite different from yours.

Re: JuneKnow

“Blasting through rock for geothermal could add more than 50K for a standard close to 80K geothermal HVAC.”

How do you know this, based on what?

You’re a ‘Pro’; in what, geothermal?

IMPO

SR

Our house in the Rocky Mountains (about the same elevation as yours will be) has in-floor radiant heating, and I would agree that it's an excellent home heating system. It keeps the house at a nice amount of humidity, and there are no cold spots. I recall our builder telling us that all new houses in our area are being built this way (I never confirmed that statement). Our house is built on an upward slope; on the ground level, the pipes were embedded in the slab when poured, I believe. Most of our flooring is hardwood, which we were told doesn't transmit heat as well as other surfaces. Our bathrooms and front entry are tile, and we can feel the heat on our feet better in those rooms. The only two down sides are that (i) we can't really turn down the heat at night in our bedroom, which I prefer because I sleep better when it's cooler, and (ii) we're currently using this as our second home, until we retire, and it's slower to heat up when we get here on the weekends. But we have a gas fireplace, so we use that to warm the place while the radiant heat gets going.

@lexma90 Great information, thanks. Glad to hear that most are building with radiant, at least in some places; this will probably help lower installation cost. When anything's new or different it costs more, usually. Yes, that's too bad heat can't be turned down - I may just open the window, in summer anyway. Gas fireplace is a great idea; they can give off a lot of heat, too. This is a reason to bring gas to the property - oh, and a gas barbecue grill, too. Wonder if heat could be controlled remotely and turned up like 5 hours in advance or something (from Internet and from another location)? Good luck & happy retirement!

My BIL has in-slab radiant heat with an electric boiler, in a house in North Dakota, and he is very happy with it. He chose electric because NG was not available, and he didn't want the hassle of keeping an infrequently used propane tank filled in a rural area.

I have been considering something similar, but I'm not sure I want it all embedded in the slab during the pour. I've had other houses where plumbing supply pipes were inside the slab, and it was not fun when something started to leak.

I wonder if you could pour a slab with high quality insulation under it, and then use more like a retrofit scheme where the hydronic lines are installed in a grid on top of the cement, and then flooring is installed over the heat grid. You would still have all the mass of the slab to provide constant, even heat, but if you needed to fix any of the hydronic lines they would be accessible by only pulling up the flooring.

Bruce

I have in floor water radiant fed off my boiler (oil) and LOVE it - trick is to keep it at a consistent temp and noted above its slower to heat up/down. I have exposed concrete floors (FLW usionian ) its dual zone so i keep the living area at a different temp than bedrooms (cooler for better sleeping). make sure you have good expansion joints in the floor. I have a wood stove in the house that provides fast heat and supplements the radiant - I run a fire almost every night in the winter - I live in NJ

Radiant in-floor heat is fabulous and agree with having a wood stove if you need a quick heat boost. Attention to conditioning the water before it reaches the boiler will help reduce scale build-up within the system.

I have almost exactly the same situation as the OP, for our new build in northern NY. My in-floor radiant heat is electrically heated. The walk-out basement had the Pex tubing imbedded in the floor during the original pour, and the main floor has it installed between the sub floor and the finished floor. We love it!

To reduce the power cost, we had solar panels installed, which supply about 3/4 of the power we use annually. The system has four zones on each floor, each with it's own thermostat. Two of the thermostats are connected to the internet, so we can turn them up remotely when we are coming up to this house, which started out as a vacation house. We have the same issue about bedroom heat as the OP, but since it's it's own zone, we just turn off that thermostat (enough heat leaks in from below and through the walls). The master bath is also it's own zone, and we keep that turned up - making a very nice, warm floor when visiting it at night!

The main downside of this system is that it's totally dependent on the grid-supplied power, which could fail, and a 30kW generator is very expensive!

We don't need to run the heat in the summer, and don't have A/C. Interesting factoid - we got a discount on something (city taxes perhaps?) because we put in fans in three rooms. I think we've run fan once in the 5 years we've had the place; it just doesn't get too warm here. We have zone heat, as well. On our ground level, where we have two extra bedrooms and an exercise area, we don't really turn that on at all. And then our master bed and bath are separate zones, as are the main living area. And we really like our fireplace, we use it more than we expected we would, because it makes our living area look and feel so cozy.

The buildings I designed in the mountains needed a quicker way to respond to the temperature drop when the sun dropped over the mountain ridge.

Fair point about the response time, that's a consequence of a large thermal mass which acts like a capacitor. A feed-forward control system or programmable timer would be one option for decreasing the response time and improving comfort.

@mtvhike....hmm, maybe a Tesla Powerwall or similar might work? So, have solar panels to charge PowerWall. Then if the grid goes down, if would be like what happened in Texas?? Just an idea...and the Powerwall would likely have to have massive capacity to heat a boiler? https://www.teslarati.com/tesla-saves-owners-texas-winter-power-outage/

Yes, Steve, I am considering that. Finding a Powerwall installer in my neighborhood is difficult (everyone wants to install a complete solar panel system!).

In response to RES2, my system has no problem keeping up with outdoor temperature changes. It's common for the daytime temperature to be 20° or more and the nighttime temperature to be -20°. And, to the OP, opening the window works fine but is unnecessary (in the winter). In the summer, we open the windows throughout the house at night. When it gets really hot in the summer (up to 100°!), it's still cool in the lowest level of the house where our entertainment center is located, and cools off quickly after sunset.

In floor hydronic is a great option if installed properly but it does take a while (days) to heat up so if you need its warmth at night you'll also have it during the day when you might not appreciate it so much.

I have never seen a geothermal system with a reasonable payback. Better to invest your money elsewhere like solar, insulation, better windows, etc.

In most parts of the U.S. the cost per resulting BTU of gas is much lower than electric so if you have gas available that will usually be a much lower operating cost. You need to compare your local rates.

If you can have enough solar to power your entire house plus an electric boiler then I'd certainly do that over gas. If you'll have to buy any electricity though then gas for your boiler might be the way to go.

Of course, burning gas and oil generate CO2; solar panels do not. Grid-connected electricity may also, depending on your utility's source; mine is mainly hydropower.

There is no question but that you should build as energy efficient an envelope as possible. That gets you to installing the smallest size system using the least amount of energy that will suffice.

The distribution side of the system remains essentially the same with the same costs almost regardless of what you install on the ‘Source’ side of the equation.

The real difference regarding geothermal is the cost differential between the heat pump and the ground loop installation from anything else that might be installed.

Regarding in-floor radiant, the lower the design for supply fluid temperature the more efficient the geothermal heat pump becomes. This is done primarily by close spacing of the piping.

Geothermal can also either preheat or supply virtually all DHW, dehumidification and air-conditioning at COPs as high as COP 5 (1/5th the cost of operating an electric boiler).

There is an absolute WAR on all energy now and for the foreseeable future - particularly Carbon based, such as Natural Gas & Propane. All the professional seminars I attend, there is nobody is talking about gas except as a ‘possible' backup or if it’s already there in residential installations and only if you really must.

The leading edge today is towards Cold Climate Air-Source Heat Pumps (Air-to-Liquid), Geothermal & Hydronics. We’re even moving away from central force air to Hydronics as rapidly as possible where possible.

The reason is simple economics:

"A given volume of water can absorb almost 3500 times a much heat as the same volume of air, when both undergo the same temperature change.”

3/4"tube = 20"x12" duct

3/4"tube = 18" ø duct

Water can be moved more efficiently than air

To the OP:

Particularly if you’re having a water well drilled in your property, you can contract with a well driller that also installs geothermal ground loops (Could be 1-loop of 450ft). You can plan to drill the geothermal borehole within the envelope of your home - right in the soon to be mechanical room - with no runouts, no trenches, no excavating, no backfilling & no foundation wall penetrations either - straight into a Flow Centre.

Those talking about $50k to $80k more for geothermal have no idea what they’re talking about - NONE! Neither do GC that discourage it and saying there’s no sensible payback. It’s not their thing & they don’t want it to be their thing - or yours either as long as you’re their client.

Separate all the HVAC from your GC, research and contract on your own. With interest rates being at historic lows, rebates, grants and tax credits, it might become a no brainer - especially the way we are and will continue be punished for using any energy.

You might find the incremental cost of geothermal a real bargain when amortized over the life of a mortgage especially since it has the longest life cycle of any active HVAC system you can install. Energy savings might even be equal to or greater than its incremental monthly cost.

I am a disinterested party; install whatever pleases you.

IMPO

SR

"I am a disinterested party.."

Have you often posted contributions that DIDN'T advocate for ground source heat pumps? If so, I missed them.

"There is an absolute WAR on all energy now and for the foreseeable future - particularly Carbon based, such as Natural Gas & Propane. All the professional seminars I attend, there is nobody is talking about gas"

Hmm, well while that war is raging in your colder location of Canada, with a much smaller population and relatively less expensive electricity, a large percentage of the US relies on natural gas and propane for residential energy.

"We’re even moving away from central force air to Hydronics as rapidly as possible where possible"

Maybe so in Canada but In much of the US, summer air conditioning is as essential as winter heating. I haven't heard of a movement to hydronics in my air conditioning dependent area because using that essentially requires the installation of two different HVAC systems no matter how the water is warmed, that's VERY expensive and unnecessary.

None of this is relevant to the OP, whose mountain top setting looks lovely. Good luck to you! Sorry but I wanted to speak up about some of the misdirection in the preceding comments.

He’s back! My biggest ‘Fan’ is back again. For those new to this site, this poster ‘Trolls’ me almost every single time he’s awake with no new technical content and little to offer.

The information I post here is technically accurate for both sides of the border. North America is one market. Technical Seminars almost always originate from the United States and are attended by and given by both American and Canadian leaders and innovators in this field.

Elmer J Fudd is stunningly uninformed and ignorant on this subject. Just because he hasn’t heard of it, it doesn’t exist!

How’s about we let the OP make up his own mind in the ‘Pursuit of Happiness’.

IMPO

SR

I'm as entitled to my opinions as you are to yours. I said I thought your comments were misleading and said why. Unlike what you said, my words were about your words and not about you personally. The majority of the participants here are homeowners and objective and balanced comments from those with more knowledge like you seem to have are of course most welcome.

There is no question but that you should build as energy efficient an envelope as possible.

Yes.

There is an absolute WAR on all energy now and for the foreseeable future - particularly Carbon based, such as Natural Gas & Propane. All the professional seminars I attend, there is nobody is talking about gas except as a ‘possible' backup or if it’s already there in residential installations and only if you really must.

The leading edge today is towards Cold Climate Air-Source Heat Pumps (Air-to-Liquid), Geothermal & Hydronics. We’re even moving away from central force air to Hydronics as rapidly as possible where possible.

The reason is simple economics:

...

You might find the incremental cost of geothermal a real bargain when amortized over the life of a mortgage especially since it has the longest life cycle of any active HVAC system you can install. Energy savings might even be equal to or greater than its incremental monthly cost.

And here's the problem with Geothermal. It does cost considerably more to install than traditional options including gas fired or electric forced air, gas fired or electric boiler, heat pump, etc. If there are no failures of the system then the payback of this extra cost is optimistically 15-30 years. Some systems never reach payback either due to higher install costs or maintenance costs.

That same money invested in a better envelope such better insulation, elimination of thermal bridging, better windows and better air infiltration sealing has a much shorter payback period of perhaps 1 to 3 years.

SO, if your house will have all exterior foam insulation (a PERSIST system) an ACH50 of below 1.0 (or below 0.8 Resnet ACH50), all high quality triple glazed windows and excellent ventilation with CO2 levels never above 500ppm - then a geothermal system might be a good consideration for the money you have left over. Otherwise geothermal is not a good investment.

Those talking about $50k to $80k more for geothermal have no idea what they’re talking about - NONE! Neither do GC that discourage it and saying there’s no sensible payback. It’s not their thing & they don’t want it to be their thing - or yours either as long as you’re their client.

This one is easy - get a binding bid and see what it is. Do some research.

Separate all the HVAC from your GC, research and contract on your own. With interest rates being at historic lows, rebates, grants and tax credits, it might become a no brainer - especially the way we are and will continue be punished for using any energy.

This is exceptionally bad advice. This will not be good for your relationship with your builder and will be a major PITA for you in trying to coordinate everything. Most builders will also, and rightly so, charge you extra for how much more of a PITA it will be for them.

@Elmer J Fudd and @fsq4cw Thanks for your comments. Recall that AC is not in the equation; just not needed at this site. I believe this is important because then no duct work is needed.

Good idea about geothermal with a simple drill (bore) straight down from mech. room. I'll look into that and see if we can reasonably, simply (and cost-wise) make it work. I know 2 people who have done geothermal and will check with them now that it's been installed for them for a few years.

Yes, there's a war on energy. A homeowner has to be careful to choose the right approach and not be emotional.

As a new home builder "exotic" bleeding edge technology is not desirable because one will likely pay more and have (probably) more install issues. E.g. PowerWalls have been around a while but solar shingles are still pretty new so I'd be hesitant to early adopt solar shingles.

Sure. Remember that one big factor with any kind of household equipment is availability of local expertise to provide services after the install phase has passed.

A major issue for a friend who installed a ground source system 10 years ago with the new build of a large house (in what I'll call a semi-remote setting in another state) is that while plenty of normal and capable contractors and tradesmen were available and inexpensive, there was only one HVAC contractor in the area that could provide what he decided on getting. They were happy to drive the distance required for the initial equipment sale and install but since then have been reluctant to come out for periodic maintenance and problem solving. My friend has decided he made a mistake and wasted a lot of money - he should have gone with air source heat pumps and propane furnaces for fast warmups and backup for colder days. He will be migrating to that when his equipment dies. It's already in the struggling to stay alive stage.