New Construction HVAC decisions. Geothermal vs. alternatives with upgraded envelope.

[Sigarms]

Yea, me too.

True life... in a 600k home and they had the cheapest non programable DICO t-stats on the wall you can find (back then, about $20 each). Asked the guy about it and he told me it's what came with the house. What was totally mind boggling was he was really proud of his $6,000 door, but he had some of the cheapest crap you could find to heat and cool his house. I get kitchen cabinets and countertops, but some of the stuff just blows me away as people have no clue what they're getting for good home comfort system (AKA HVAC system).

 

[MGH PA]

Isn't zoning between floors a given!? I have a ranch, so I'm not certain, but it sounds very strange that the contractors are not recommending it. I know my parents separated into basement, first floor, and bedrooms. You might also want to watch out for zoning a room with south facing windows with other rooms. My parents have one bedroom that is always MUCH warmer because it has South facing windows, but the thermostat is in another room.

That was my thought (regarding the basement), but none of them have specified it in their bids. Just a single zone with "some air in the basement." :confused2:

FWIW, my entire kitchen, living room, and master bedroom will be south facing.

 

[dodge man]

Our house originally had electric heat and a propane fired furnace and AC was added before we bought it. We then switched to GEO later on. We have only 1 zone, its a one story ranch with a full basement, and it actually works pretty good. I'm guessing they did a pretty good job of balancing the duct work when it was installed. I do wish the bedroom was cooler though.

 

[Sigarms]

I do wish the bedroom was cooler though.

Generally speaking, depending on the layout of the house, the one area that should always be zoned are the bedrooms, partiuclarly the master.

So many times the one t-stat in the house for the one system is in in the hallway or living room away from the bedroom, and the owner is stuck trying to heat or cool their master bedroom but get's "stuck" at a temperature they don't like in the bedroom because they don't want to heat or cool the entire home.

 

[Kubota L39]

Go radiant infloor heat, you'll be so happy you did. 110-120 water temp is ideal, you will be more comfortable at a lower thermometer setting - so you'll save money. Also, your heat is at floor level where you are - not rising to the ceiling. I can see it costing a little more, but $10000 is nuts - try a different contractor. We did our house with a NG modulating boiler and indirect water heater for under $3500 (DIY). 2 zones (up & down), you can fine tune each if you need with adjusting the flow on your loops. We did each loop the same length for balanced flow and have never needed to touch (5 loops).
For your AC needs I'd go mini-split heat pump. We have a Fujitsu 33 seer. One outside unit can supply multiple inside coils. It will do heat as well which helps in the "inbetween" seasons. Also as a backup.
We are planning a new home next summer, and won't have Natural Gas available - so I've been researching the best alternative & at our current local costs Propane is very close to Geo. With much lower upfront costs.
We have high co-op electric costs & Propane is currently cheap - which can change at any time. I followed your home plan thread with interest - it made me re-think our plans. So now I'm re-doing them - thanks
Good luck

 

[Sigarms]

Funny, just got back from a short 3 day trip up to Pennsylvania with my father.

First time in about 10 years since I spent time up at the old home around the winter time (normally I'm sweating like a pig because I'd go up in the summer and he doesn't have AC LOL). I replaced his old oil fired boiler around 94 (he bought the house around 78). Radiant infloor basement, baseboard on main floor and attic.

Came home Friday late afternoon, old T87 t-stat on first floor was set to 52, which you felt right away coming into the house. Turned it up to 72 to get some heat going and I completely forgot how great radiant heat was. Swear, it felt like it was actually 80 degrees in the house within 15 minutes:laughing: Just amazed and completely forgot during the last 3 days exactly how comfortable radiant heat is compared to forced air for heating.

 

[deezler]

We are planning a new home next summer, and won't have Natural Gas available - so I've been researching the best alternative & at our current local costs Propane is very close to Geo. With much lower upfront costs.
We have high co-op electric costs & Propane is currently cheap - which can change at any time. I followed your home plan thread with interest - it made me re-think our plans. So now I'm re-doing them - thanks
Good luck

Oof, yeah how do you plan for the future of propane prices though. I sold 6ac to my buddy who built next door to me. He also didn't want to pay to tap into the natural gas line at the road and run it 600' back to his house. Despite my pleas, he went propane also, due to the low upfront costs (free tank, only need a basic furnace, etc). 2 years later after spending THOUSANDS on propane refills and getting jerked around by the delivery company, he had to take out a home equity loan to get a woodstove (foolish, sure, but) and now they try to never use the furnace. That low upfront cost of propane actually turned out to be pretty expensive. Of course they still have to use it for water heating and the oven, and look out the window at a big ugly tank sitting there.

I'll say it here one more time before I shut up (haha), but a modest solar PV array can easily cover the consumption of a set of very-affordable mini-splits, especially if you supplement with wood heat. With solar payback times under 10 years for almost every location now, then you're looking at decades of free heat and free electricity.

 

[NorTracNY]

Actually, one item I forget and I haven't seen with others. If you do radiant floor heat you need to watch out what you do for flooring. Carpet is no issue and I don't believe tile was, but hardwood floors need to be chosen carefully. I believe they recommend 3 things...Quartersawn, narrower boards, and a type of wood with a smaller thermal expansion. We did two out of 3 and the floors have never had a problem.

 

[Kubota L39]

Oof, yeah how do you plan for the future of propane prices though. I sold 6ac to my buddy who built next door to me. He also didn't want to pay to tap into the natural gas line at the road and run it 600' back to his house. Despite my pleas, he went propane also, due to the low upfront costs (free tank, only need a basic furnace, etc). 2 years later after spending THOUSANDS on propane refills and getting jerked around by the delivery company, he had to take out a home equity loan to get a woodstove (foolish, sure, but) and now they try to never use the furnace. That low upfront cost of propane actually turned out to be pretty expensive. Of course they still have to use it for water heating and the oven, and look out the window at a big ugly tank sitting there.

I'll say it here one more time before I shut up (haha), but a modest solar PV array can easily cover the consumption of a set of very-affordable mini-splits, especially if you supplement with wood heat. With solar payback times under 10 years for almost every location now, then you're looking at decades of free heat and free electricity.

Our current home averages around 60 Mbtu of gas annually, which supplies heat, hot water, cooking, & clothes drying. New home is going to be smaller & better insulated, but even figured at the same BTU load it would equal 690 gallons of propane a year. Or about 1000 bucks. I'm all for looking at every alternative, but some just don't payback in my lifetime.
As a side note, how much heat can you get from your mini-split when it gets this cold 2 miles from our building site?
Cold, but no cigar: Cotton again hits 56 below, missing state record | Duluth News Tribune

 

[deezler]

Our current home averages around 60 Mbtu of gas annually, which supplies heat, hot water, cooking, & clothes drying. New home is going to be smaller & better insulated, but even figured at the same BTU load it would equal 690 gallons of propane a year. Or about 1000 bucks. I'm all for looking at every alternative, but some just don't payback in my lifetime.
As a side note, how much heat can you get from your mini-split when it gets this cold 2 miles from our building site?
Cold, but no cigar: Cotton again hits 56 below, missing state record | Duluth News Tribune

Um, probably zero heat whatsoever from a mini-split at -56 ambient temps. YIKES. But also, you know, don't live there? haha.

A woodstove, on the other hand, would have no problem keeping your house warm at -56 degrees.

 

[Kubota L39]

We currently have a wood Fireplace (zero clearance, outside air intake, can heat our home if the powers out), but my wife and I have decided we will have a gas fireplace in the new home. As much as we love the wood fire, we're tired of the mess & commitment required. Also, we're retired and plan more travel - we need something that can "do it's own thing".
Just looked at off-peak electric rates - if we can get by with a gas fireplace for back-up. A ground source heatpump might be back in play. Off peak rate is 1/2 our .14kwh regular rate. Or approx $615 annually vs $1230 at regular rate (and COP of 3).
But still have to consider lots more upfront costs.

I should add - we're going one level on a heated slab - that's non-negotiable, so it would mean a outdoor wood boiler if we went the wood route.

 

[Sigarms]

As a side note, how much heat can you get from your mini-split when it gets this cold 2 miles from our building site?
Cold, but no cigar: Cotton again hits 56 below, missing state record | Duluth News Tribune

Using a record low for a cold temp is kind of misleading when sizing for HVAC equipment.

Looks to be that Deluth does not average below 0 degrees Farenhiet duing the winter months. I know of some single zone mini split heat pump systems that could give you 33,000 BTU/h of heat at -15 degree F outside air temp while maintaining 70 inside.

Not as bad as you think I'm guessing.

 

[BitChin1]

I'm a little late to your post here (been following it over on GreenBuildingAdvisor though) - I have a Bosch Ground source system installed in late 2012 (new house build) - it has never worked quite like we expected but today the evaporator coil is being replaced (under warranty) due to having a coolant leak, so hopefully this will change shortly. I am located in central KS with ~ 4600HDD's (so a bit warmer than you). My house ~ 1900 sqft along with full walkout basement and a 600sqft loft with 28' vaulted ceilings. We are a total electric with ~ .13c/kwh electricity. My avg bill for last 6 years is $240/month with highest single bill of $337. Lowest bill was $186. My key to heating/cooling with a partially working Heatpump has been that we really rarely need it! (that also can help explain why it took so long for the HVAC contractor to figure out the issues). Along with being in a CZ4A area we also built our house very tight and moderate r-value (SIPs 24 walls 40 roof).

Would I use a ground source heatpump again? NO. The key reason being it was fairly expensive (open loop, 2 zone 3T system was ~ $22,000) and has been complex to operate and debug. I have had to replace the pump for the desuperheater and the valve that controls water flow along with R410 refills and now finally a coil.
Would I use SIP's again? NO - again expensive and too much foam, but I would focus on a solution that seals the house very tightly (including blower door to verify) and then go for a Whole wall r-value of 25+ in my area (probably a little more for yours).

As for you contractor doing the load calcs - I did my own and then argued (debated) for a couple rounds on my my #'s made sense - his initial approach/proposal was for a 6 T system and was a little concerned that it might not be enough! We went with 3T as it was the smallest they made at the time (I really only need 2T, but it has 2 speeds along with variable fan speed).

Anyway I suggest you focus on making the HVAC minimally necessary and look at other options before settling on Ground source - (that said your quotes don't seem out of line based on my experience but I think you could get a lower cost solution)

 

[Kubota L39]

Using a record low for a cold temp is kind of misleading when sizing for HVAC equipment.

Looks to be that Deluth does not average below 0 degrees Farenhiet duing the winter months. I know of some single zone mini split heat pump systems that could give you 33,000 BTU/h of heat at -15 degree F outside air temp while maintaining 70 inside.

Not as bad as you think I'm guessing.

I was making a joke but we did have 2 weeks with nightly lows around -30 or less. We have a Fujitsu Halcyon mini split heat pump - it's great for AC & a little heat spring and fall before turning on the floor heat. I wouldn't consider it for a main heat source in my climate, and our radiant floor rules it out in any case.

Done with my hijack- sorry...

 

[Sigarms]

I was making a joke but we did have 2 weeks with nightly lows around -30 or less. We have a Fujitsu Halcyon mini split heat pump - it's great for AC & a little heat spring and fall before turning on the floor heat. I wouldn't consider it for a main heat source in my climate, and our radiant floor rules it out in any case.

Fujitsu has 3 different models for single zone, one to one systems for example, and each system having a diffrent maximum heating capacity, some down to as low as -15 degree Farenhiet. Each model different model does have a different cost associated with it, primarily being the heating capacity. The issue IMO is that HVAC contractors do a crappy job of explaining what they're selling and why they're offering it. Numerous times I'll be asked to handle a phone call from a contractor with questions on mini splits only to be informed that the only thing the contractor is interested in is SEER rating. When it comes to a mini split system, SEER rating really the last thing you need to be looking at.

That said, would I rely on a mini split system only for heating if I lived in Minnesota? Heck NO! That said, would I ever live in Minnesota? HECK NO! :laughing:

Use to live in upstate Maine as well as upstate NY (around between Syracuse and Watertown), so I do speak from some good personal experience IMO LOL

With the OP being in PA, would feel more than comforatable with a mini split for heating only needs though.

 

[kenmac]

I have no idea what the temps are in Minnesota, but If the temps are no lower than -20 , I would have no issues with a mini VRF for heat.

 

[DKCDKC]

I put in a 1.5 ton Wood Furnace Geothermal in my 2,900 sq ft rancher in 2001. Never regretted it. Could have used a bit more capacity since we added windows after the calculations, but it generally does the job. We have an average $160 monthly power bill for this all-electric house and can't complain. We have a small Irish wood stove in the center of the house for use on really cold days or for ambience. Wood is free for me because I have an 80 acre woodlot and a couple guys who pay me in split firewood for wood they cut for themselves - 1 to 4 ratio. I imagine the compressor on this old heat pump will conk out in the next five years and I plan to replace it. One of the big things I really like about geo is not the lower cost - and it is a bit complicated - but it is totally quiet. Inside or out, I cannot tell when the system is running. I got so tired in other houses of that outside unit running all the time. Overall I remain a fan.

 

[Kubota L39]

I put in a 1.5 ton Wood Furnace Geothermal in my 2,900 sq ft rancher in 2001. Never regretted it. Could have used a bit more capacity since we added windows after the calculations, but it generally does the job. We have an average $160 monthly power bill for this all-electric house and can't complain. We have a small Irish wood stove in the center of the house for use on really cold days or for ambience. Wood is free for me because I have an 80 acre woodlot and a couple guys who pay me in split firewood for wood they cut for themselves - 1 to 4 ratio. I imagine the compressor on this old heat pump will conk out in the next five years and I plan to replace it. One of the big things I really like about geo is not the lower cost - and it is a bit complicated - but it is totally quiet. Inside or out, I cannot tell when the system is running. I got so tired in other houses of that outside unit running all the time. Overall I remain a fan.

I'm assuming Water Furnace Brand Geothermal - not Geothermal from a wood furnace:ashamed:

 

[DKCDKC]

I'm assuming Water Furnace Brand Geothermal - not Geothermal from a wood furnace:ashamed:

Yup. Freudian slip there. Do use wood, but it's a Water Furnace. And we now have multiple dealers around to shop for service - big change since 2000.

 

[MGH PA]

Thanks everyone. So much to digest. I'm still not sold on the up front investment. It also appears it's not recommended to zone individual rooms with the 5 series since it's not variable speed system.

Does anyone have a recommendation on a DIY load calc software?