Adding a heat pump to a steam setup

1peterpan1

Hello everyone,

I'm exploring the possibility of integrating a heat pump into my home's heating system and would appreciate any advice or experiences you might share. Here are the key details:

• Home Details: Our home is a 2,000 sqft, two-story single-family house built around 1943, located in New England.
  
• Current Heating System: We currently use a one-pipe steam heating system powered by a natural gas furnace that's about 15 years old. While we're generally satisfied with the heating performance, the annual cost for natural gas is approximately $3,000, which is quite high.
  
• Existing HVAC System: A few years ago, I installed a ducted HVAC system for cooling, with the main unit in the attic and ducts extending to the ceilings of both floors.
  
• Interest in Heat Pumps: With the availability of massive rebates, I'm considering the feasibility of installing a heat pump to utilize the existing AC ductwork during winter. The goal would be to primarily rely on the heat pump, reserving the steam system for backup during particularly cold spells.
  

Concerns & Considerations:

• Efficiency of Ceiling Outlets for Heating: I'm aware that having outlets in the ceiling might not be ideal for heat distribution, given that heat rises.
  Climate: Our region experiences significant cold in the winter, which raises questions about the heat pump's effectiveness and the need for supplemental heating.
  

Questions for the Community:

1. Has anyone successfully integrated a heat pump with existing AC ductwork in a similar climate? What was your experience like?
   
2. Are there specific models or systems you would recommend that are effective in colder climates?
   
3. Any suggestions on how to address potential issues with ceiling ducts for heating purposes?
   
4. For those who've navigated the rebate process for such an upgrade, any tips or advice?
   

GW

Hello New Englander

are you discussing whole home rebate $10.000 or partial home rebate 1250/ton? The word “integrated” is specific language in the masssave program. Too confusing not knowing what topic we are on

technically, the steam system will need to be disabled, or removed.(whole home rebate). MassSave contractors have to follow the rules (rules changes several times in 2023). The electrification movement is still at its infancy. 

Duct layout, you need to get some HVAC people there to give you some opinion and commentary. The layout of the duct system is key, to how comfortable you’ll be when it’s single digits outside. Bathrooms— you’ll need some electric 

Clearly, you have an older home (steam), seems unlikely ducting sized for AC is going to heat your home well. (Whole home rebate). Currently, natural gas is the least costly means to heat a home. Electric rates in MA are very high. (Unless you’re current heating system is running poorly- your heating wills will certainly be higher)

We have worked with Bosch heat pumps and Bryant extreme heat pumps.

if we’re talking, partial home rebate, yes, good move.
whole home—- better have a really good hvac guy to properly set the table (expectations) 

Gary 

Hot_water_fan

This is a common situation. To compare fuel costs:

gas: $/therm x 10 / COP
heat pump: $/kwh x 293 /COP

If it makes sense, then look into a cold climate heat pump. I have a ducted Mitsubishi that does great in the single digits, and here, is substantially cheaper than gas. 

Jamie Hall

We have a Carrier four head mini-split for my wife's apartment (don't ask...) which supplements Cedric in her area -- she likes it a lot warmer. The Carrier works well down to about 0, but pretty well quits below that. It is NOT cheaper to run than Cedric, but is cheaper than electric space heaters. She likes it, and it is a very good arragement.

If you need to rip out the steam to get your hands in the taxpayers' pockets (which is what the rebate is), don't do it. You won't be happy with the results -- either in terms of usual day comfort or when it gets genuinely cold out.

If, on the other hand, you plan to use it on warmer days -- say 20 and up -- while you won't save money in Connecticut, nor saving on fossil fuel, you will have the satisfaction of having it.

Hot_water_fan

@Jamie Hall no politics please. 

ethicalpaul

It will work fine. And it is cheaper to operate than Cedric, within its operating range. At -20F Cedric wins for sure.

hot_rod

Start with the fuel cost calculation first. As you can see energy costs can vary quite a bit. Be sure to use delivered cost from the bottom line if your bill.

In areas of Maine  power costs go as low a 1 cent per kwh for off peak rates

a heatloss calc and energy audit with a blower door test might show ways to lower you energy use

Jamie Hall

Yes. As @hot_rod says, the energy cost calculation is critical in evaluating this sort of thing. Start there.

GW

Jamie the rebates in MA are Utility. To call it 'tax payer' is semi OK but not exactly correct.

bombaloo

What is your homes thermal envelope like. Did you do air sealing and insulation? R60 roof? Exterior insulation? Spray foaming rim joists? These types of improvements could lower your gas bill. 

Steamhead

@1peterpan1 , do NOT rip out the steam system. Get the heat pump if you want, but keep the steam. Don't abandon something that works well for something that doesn't.

Get a pro to look at your steam system to make it work as well as it can. If you're near Boston, call @New England SteamWorks . If you're on the other end of the state, call @Charlie from wmass . They're two of the best.

New England SteamWorks

And then there is this:

ethicalpaul

Yes ever since fracking, natural gas has been very cheap. Even in my CT house that I talk about all the time, I only just broke even against natural gas with my ground source heat pump, but that wasn't an option for me, I only had oil available, and the article conveys that vs oil it still a clear winner (as I found)

Charlie from wmass

Nj and MA are different climates. We are tundra compared to NJ.

ethicalpaul

Who said anything about NJ?

The article that I screenshotted above and was linked higher above was written in MA

Jamie Hall

Charlie from wmass said:

Nj and MA are different climates. We are tundra compared to NJ.

Not only that, but there's MA and MA. Boston metro is pretty balmy compared to the Berkshires...

Charlie from wmass

Your signature says nj and ct is also 2 growing zones warmer

ethicalpaul

I have lived in different places, it's true The article, though, as I said, is from MA.

I even lived in Michigan which will give MA a run for its money, but let's be honest, neither of those states can hold a candle to the plains.