long time no chat - Questions about heat pumps

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jharkin

Minister of Fire
Oct 21, 2009
3,890
Holliston, MA USA
Hi guys-

Feels like its been forever since I sold the old antique and said goodbye to the VC... miss this place ;em

Anyway Ive been busy... New contemporary house sadly only has an open fireplace, but it does have much more modern system in general including 2 zones of central air (1st and 2nd floor) and a Veissman condensing boiler w/ 4 zones of hot water baseboard for heat.

Which brings me to my questions - ones I expect this crowd could answer better than anywhere else.

So the Veismann, while efficient is running on propane . The first floor AC is on its last legs (vintage '93) and the great Commonwealth offers a lot of incentives to put in heat pumps. So you know where this is going... I got 2 proposals to replace our first floor SEER10 ducted 2.5ton AC with a central heat pump.
  • Vendor A proposes 19k before rebates to put in a Mitsu hyper heat light commercial (PUZ-HA36NHA5) - 3ton SEER 17/HPSF11
  • Vendor B proposes 9.8k before rebates to put in a Mitsu SUZ-KA30NA - 2.5ton SEER 18/HPSF13.4

First off - I think vendor A is gouging me on pricing, but putting that aside I have some questions on what options to go with.

Question 1 - Is hyper heat worth it?

I did some math with calculating the BTU delivered per dollar delivered over various heat ranges from my condensing boiler, the hyper heat and the standard heat pump. The thing is, while the hyper heat will heat well below our design temp of 8F, its COP drops off much steeper than the standard unit. Based on my numbers it looks like its probably far more cost effective to just buy the basic unit which can heat down to 14F, and switch to propane whenever the temp drops under 20F or so - which around here means basically just overnights in Jan/Feb.

Thoughts?

heatcurves.JPG
Notes:
  1. my price of propane averages $2.90 a gallon and the boiler eff ranges 88-95%
  2. my price of electricity is 23c/kWh all up
  3. the Hyper heat option has a COP of 3.66@47F going down to 2.06@17F but it can heat to -5
  4. the standard heat pump has a COP of 4.27@47F and 3.22@17F. It can only heat down to 14F
  5. Our design temp around here is 8F afaik
  6. Reverse engineering my annual propane usage and HDD, i calculate a design day heat load for the whole house of about 45-50k btu/hr. probably 25k for the first floor.

Question 2 - Has anyone done the "integrated controls" and had sucess?

MA will rebate $250/ton for heat pumps, but will do $1250 a ton if you install "integrated controls" (ie dual fuel thermostats) that automatically switch systems at the ideal outside temp. I love this idea in theory but it seems the only system you can use with the Mitsu and preserve all its modulating capabilities is their own Kumo Cloud/Kumo Station controller. Vendor A seemed happy to do whatever I wanted to pay for. Vendor B is strongly warning me off these - he says when his techs went to the Mitsu training course the instructor couldn't even get the system to connect reliably in the classroom and that it has all kinds of problems with wifi (which it requires to communicate with the room and outdoor sensors, apparently no wired option). Looking online I see lots of horror stories and abysmal reviews for the Kumo cloud app. Vendor B says that the cost will basically be a wash adding the Kumo vs the extra rebates and a lot of his customers that installed it for the rebates later called them back to take it out due to problems. He suggested Id be better off doing this old school, running the heat pump until christams and then firing up the boiler in Jan/feb, and then back to heat pump.

This is disappointing as I really liked the idea of setting something like this up and later adding Ecobee or Nest for our other heat zones and integrate the entire house.

---------------------

Other notes-
Q: Why am I just doing one zone?
A: The upstairs already has a SEER16 AC, and all hte registers are ceiling mounted up on catherdral ceilings. We struggle to keep the heat even up there as it is and probably wouldnt be good use of heat pump/forced air heat.

Q: With all this heat pump talk have you considered solar?
A: Yes!! 7.6kW of REC Alpha panels and enphase microinverters (at $2.90/watt before credits) are going up in Sep. This is litterally the max that will fit.
 
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Hey hey, Jeremy. Welcome back. I hear your dilemma. We went through something similar in 2006 when deciding on a heat pump for our house. Fortunately, there are a lot more excellent choices to consider. We got 4 bids, all which were in a couple thousand of each other and then one bid for double the price for a Trane vs American Std. system that on paper was not much different. Based on what you have described I would lean toward the standard system also. The advice that dealer is giving you is helpful. Field experience is important. I would also get more bids. See if you can locate a Daikin and maybe a Carrier dealer. And it is at least worth considering the Mr. Cool (Midea?) option as a third choice. There are several write-ups on their offerings.

Out of curiosity, does the new house cost less than the old to heat?
PS: I would have an insert in the fireplace. :cool:
 
Hey BeGreen!! missed you guys.

more info-
Vendor A also quoted me a Trane system and it was even more than the Mitsu light commercial.
Vendor B carries Carrier as well. He priced out an "AC only replacement" if I wanted to save a few buck but its only about $1k cheaper than the heat pump option beofre rebates and a wash after rebates. He said he looked at the Carrier heat pumps but cant beat the pricing he can offer on the Mitsu.

I can look around for some more vendors. Vendor B was used by my neighbor and they are very happy with them, said that bid was the lowest of 3 they got. Its a big outfit that also does commercial work.


Oh another wrinkle - Mass renews the incentive programs every 3 years and 2022 is a reset year. There is some talk that heat pump rebates may be further increased so I maybe should wait for the announcement of next years program before making a final decision?

Out of curiosity, does the new house cost less than the old to heat?
PS: I would have an insert in the fireplace. :cool:


Question 1 - No, unfortunately. New house is 200 years newer and has 2x6 R19 walls/R38 roof and double pane windows, however its also 2x the square footage of the old antique and we don't have natural gas on the street. I'm paying 2-3x as much for heat

Question 2 - I would in a heatbeat but it was vetoed by the better half. She has to have at least one open hearth in the househould and unlike the old antique there is only one hearth in this place. No good spot to put in a freestander and pipe either.
 
Can't say where Mass incentives are heading though I think if the infrastructure bill passes we may see more incentives for increased efficiencies nationwide.
I would in a heatbeat but it was vetoed by the better half. She has to have at least one open hearth in the househould and unlike the old antique there is only one hearth in this place. No good spot to put in a freestander and pipe either.
In a big place, there's always room for a new hearth, or maybe a basement stove?
 
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Can't say where Mass incentives are heading though I think if the infrastructure bill passes we may see more incentives for increased efficiencies nationwide.

It would be nice, but the way the political winds are blowing I suspect they will end up having to give up a lot of that to get the overall bill to pass. And the administration is very focused on targeting incentives and tax breaks to low/middle income families (which I think is a good thing) so no guarantee we would qualify for any new programs.

But there is a public push here in MA to drop all the existing incentives for high efficiency gas and oil retrofits and double down on heat pump incentives starting next year. So it probably makes sense for me to wait until the fall when that would be announced and then decide if I should do something before January or wait.



In a big place, there's always room for a new hearth, or maybe a basement stove?

This place is all windows, high ceilings and open plan first floor. Great for natural light and ventilation, but not so great for wall space with clearance for a stove pipe access to place a hearth :(
 
I agree that Mass is going towards more incentives to electrify heating and cooling and the incentives are going to follow. There is a problem that building owners are not seeing the real world efficiency gains that the COPs of their air source equipment would indicate. Geothermal also has its issues of lower real world than nameplate efficiency. Air source units have a tough time with low outside temps and backup systems are kicking in a lot more often than modeled. Most industry seminars I attend are really stressing that there has to be backup heat and 20 F is the normal temp they recommend despite equipment companies claims to the contrary. Building controls are complex and building occupants have an annoying tendency to do what they are told not to. The combination of the two can mean that windows are left open in some areas of a building in winter to deal with poorly operating controls.
 
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Question 1 - Is hyper heat worth it?
I only think it is if you don’t have a second heat source.

really all heatpump systems need a secondary heat source. The design temp probably covers all but the the 100 coldest hours a an average year. Get a near record cold snap and you’ll survive but be cold.
A quality hvac system has a 20+ year lifespan. Makes sense to pay a little more up front for efficiency and quality if you plan on staying in the house a long time. Cheaper systems can be had. My personal opinion is that incentives will continue and or increase if you are in a solid blue state.
Evan
 
Fellow Masshole here - had my own similar thread recently.

I think I’m with you on waiting a bit. I don’t think the incentives will be going away any time soon either -at least until heat pumps are accepted generally as primary heaters around here. There’s still supply issues to deal with as well. I think it would be optimistic to see costs go down in the next year, but I doubt they will be going up more from where they are today. I’m still keeping feelers out with some contractors and will pounce when the time is right and the budget allows. Though I may end up electrifying my transportation before my heating - we’ll see.
 
This place is all windows, high ceilings and open plan first floor. Great for natural light and ventilation, but not so great for wall space with clearance for a stove pipe access to place a hearth :(
Can be done. We have excess windows too. The stove with rear heat shield and double-wall stovepipe can be in front of glass if necessary.
 
Wow those prices ($2.90 per gallon proplane and 23c/kWh are extremely high. I live in Woodstock, NY where I paid $1,45 per gallon of propane (800 gallons/year and own my tank) and average 15c/kWh electric plus $19.50 basic monthly charge. I know the price of propane is going up next year. I will have to see what I can lock in at. I joined Nexamp solar farm that reduces my electric bill. This month my electric cost was 12.3c/kWh with Nexamp solar farm discount. It would have been 13.9c/kWh without Nexamp discount.

I installed multi-split with two 24K heat pumps August 2020 with 5 heads. With the cheap cost of propane I use the heat pump for heat when its is above 30F outside. The main reasons I don't use the heat pumps below 30F is because the hot water baseboard propane boiler is cheaper and does a better job circulating heat near the floor. You won't have that problem of heat circulation. Anyway you have two options for heat depending on price, which obviously will not be getting cheaper 10 years from now. Good luck. Think more long term in your decission process.

At 23c/kWh I would be considering putting solar on your property, which could affect your heat pump choices.
 
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Propane prices are fixed in some areas. Propane has not been below $3/gal in this area for a long time. Yet 90 miles north they are under $2.
 
Propane prices are fixed in some areas. Propane has not been below $3/gal in this area for a long time. Yet 90 miles north they are under $2.

East too, 1.99$ per gallons for years now once you leave the city.
 
Fellow Masshole here - had my own similar thread recently.

I think I’m with you on waiting a bit. I don’t think the incentives will be going away any time soon either -at least until heat pumps are accepted generally as primary heaters around here. There’s still supply issues to deal with as well. I think it would be optimistic to see costs go down in the next year, but I doubt they will be going up more from where they are today. I’m still keeping feelers out with some contractors and will pounce when the time is right and the budget allows. Though I may end up electrifying my transportation before my heating - we’ll see.

I think the incentives are only going to get better. I believe most of the New England states have legislation to be carbon neutral by 2050. They are aggressively putting money out there to reach that goal. CT has some awesome incentives that get better every year and the amount of money they are throwing out there is nuts. In my town you can get almost $5k in insulation for practically free and a $10k heat pump is $4300 after incentives.


I have had solar for 5 years and put in 2 cold climate mini splits that carry probably 90% of my winter heating load. My electric bill is $9 every month. Its a great setup.