HVAC in New Construction in 2024

54% of new homes the primary fuel is electric, resistance or heat pumps.

All I can is get ready for brown outs as the electrical grid isn't going to hack this.

Seems steam and oil are not popular LOL

The only problem with studies like that — and it's a sort of minor irritation — is that they are, geographically, so coarse. It's inevitable — going finer grained would be very difficult. But it does tend to bias — inevitably, no criticism — towards suburban type areas, and overlook relatively sparsely populated areas (such as where I live!) where LP is wildly expensive, electricity is eye-watering, and so… more oil.

As to system type the emphasis nowadays is on having air conditioning available, so it is quite natural that correspondingly heat pumps will be popular, and forced air is cheap.

If I was building a new home, I would absolutely be in the small minority of people installing forced hot water heating through modern radiators (or rescued ones) because I know how much better heating that is in my opinion. I hate forced air heating.

I would still install ductwork for central air. Take me back to the days when radiator heat and the concept of air conditioning was sold as a matching pair.

In the second section from top of the article they show that they are differentiating "forced air systems" and "air/ground source " by specifically saying "forced air systems without a heat pump" It's definitely not very clear and even as I'm re-reading it and typing it I'm not 100% sure thats the way its supposed to be read lol. I'm pretty sure it is though because then almost immediately after defining the two systems thats when the stats for systems with "air or ground source heat pump as the primary means of providing heat" and "forced air systems" still seems a bit weird they wouldn't just specify "forced air systems where a heat pump is NOT the primary source of heat" or "forced air systems where gas/oil/solid fuel is the primary source of heat"

This is also made even more confusing as that whole first section is not supposed to be about the fuel source at all, just the heating system, the section that follows is the part that covers fuel type. SO yeah it really makes no sense why they would differentiate the 2 fuel types in the section devoted to heating system type, and also kind of cuts out a bunch of relevant info like how many duct free split systems? how many water/steam systems? how many fully ducted systems? The words Water Steam and hydronic do not even appear in the article… I need someone else to take the raw data and do a more thorough write up lol

This.

@Roger If you look at the NREL report the Seasonal average efficiency of the heat pumps was closer to 3 (some outliers there though):

The issue is most (all?) units ran the backup heater during defrost instead of doing fan off. This significantly increases the energy use without improving comfort. On most units, this can be programmed.

With properly sized and set up unit, a seasonal average of 3 is not an issue.

$0.3 electricity with 3 COP heat pump is equivalent to $3.1/gal oil in 75% boiler or $2.5/therm natural gas. Around me gas connection fees also add up to about 1 month of free winter time heating cost so heat pump is cheaper than gas.

Older gen heat pumps did blow cold air when temperature dropped, modern EVI heat pumps provide 100F+ air even down to 0F.

That table is full system COP including outdoor and indoor unit loads. A bad install can definitely hurt efficiency, but that is the case with any setup regardless of furnace/boiler/heat pump.

Anything duel fuel only makes sense if you already have the equipment. When you do the math on cost, the savings are in the order tens of dollars per year, so ROI of installing any extra equipment is never.

The table you referenced is not seasonal efficiency. Cold climate hybrid savings are in the range of $500 to $1000 per year for a typical house for the fuel prices noted. Even greater if it’s a natural gas boiler or furnace.

Please show me the calculation of $1000 hybrid fuel energy savings. Short of firing a wood boiler on self harvested wood, I don't see that.

I think it’s completely possible with 1. Expensive electric 2. Cheap gas 3. Large heat loss and 4. Cold climate.

But my entire heating needs are about $800, so no use for me.

@Hot_water_fan If gas was that much cheaper, you would not install a heat pump as a hybrid system would make no sense as gas would always be cheaper.

@Roger wrote
» Bosch recommends mini splits with boilers, not just heat pumps alone. 

That makes a lot of sense to me.

And in an old house, with an existing hot-water or steam heating system, going to mini splits for air conditioning and for milder days like we're having now (60s with 30s at night), that's the way to go. Anyway it's my plan.

If I were building new, I'd install radiant floor heat + mini splits, and choose the energy source to heat the water based on efficiency and price. I'd miss the utility of hot radiators but I'd get over it.

cheers -m

@Hot_water_fan

He wasn't blaming the customer, he was blaming the builder.
I also believe he is correct.

I don't know enough to disagree. I do know that price pressure is a serious concern when building a development. I'm not interested in ever buying new construction, but if I were going that route, I'd want a serious say in what goes in it.

A friend of mine bought a house for a little over $300k after the mortgage crisis, in 2013. It's now worth not much less than 600, which around here is getting up there. Mid-Michigan is still somewhat affordable. He has copper plumbing throughout, two water heaters, and the house seems well constructed and insulated, with outside walls built with 2x6s. It's an affluent neighborhood.

But the vinyl windows are not something I'd want in my house. My retrofitted Andersen's are far better, and I'd gladly pay more to have them. But the builder had his plan for where the money made sense for him, and where it didn't.

If you're a builder, you can't go upscale everywhere, and not everyone will appreciate — or be able to buy — amenities that are extra, even if they save money in the long run. So that's how I see the "electric heat pumps everywhere" trend. The step up in price for a hybrid system, which will pay for itself in colder climates, is quite the risk for the builder.

In Europe, they just mandate all that stuff, and pretty soon houses are a luxury good. It's a hard circle to square.

My dad (he’s in the trade) replaced his furnace and a/c last year and went with the latest and greatest like he always does. Modulating communicating natural gas Trane furnace with a XV20i heat pump. Our electric rate is $0.11/kwh and natural gas is $.88 /therm. I went to calculate the balance point and there isn’t one, but I will say the system is extremely comfortable and quiet. And who knows what energy prices will be tomorrow.

@Roger

" $1,080 with a high efficiency oil boiler vs cold climate heat pump. Here’s the backup: 696 gal oil at 87% efficiency and 11,723 kWh at 2.1 COP. $3,516 electric bill at $0.30/kWh and $2,436 with oil heat at $3.50/gal."

I haven't seen any recent studies on non-condensing units, but last I saw of in field monitoring of these, the real world efficiency was between 50% to 75%. Add in that most are 3x oversized and tend to short cycle, the efficiency drops even more. Better controls does help a bit but you are still not hitting nameplate.

Most hydronic systems also have about 3 pumps in the system. Running those is not free. Let optimistically say we use 200W for pumps and boiler for 5 months, that adds 720kWh or ~$200 to heating cost.

Add in there yearly maintaince calls and you are in the red even assuming 2COP heat pump.

A heat pump will hit manufacturer rating if sized and installed properly, a COP near 3 is not hard. If your power is that expensive, PV is a no brainer so electricity costs also drop significantly.

This discussion is also moot as this thread is about heating system for new builds. Nobody is installing boilers, never mind oil boilers in a new build (except maybe in Alaska).

For a new build, you need something to meet code and provide what buyers want which is AC. Heat pump is currently the lowest cost option to do that, thus that is what builders will install. Currently there is a mix of hybrid gas/heat pump furnace systems in colder climate but that will slowly fade away as cost pressure increases.

@Kaos , top efficiency heat and hot water boilers are 87% field efficiency - it makes sense to compare top heat pumps with top boilers. COP of 3 does not happen during freezing temperatures when looking at field performance. Today’s circulators use about 30 W of power and many systems have zone valves which are a small fraction of that power. In total, the electric cost to operate a boiler (the burner is the highest consumer) is in the range of $60 to $90 per year at $0.30/kWh.

If you want to look at annual maintenance costs (consider expensive refrigerants and typical leak rates), you should also look at the much more frequent replacement costs of heat pumps versus boilers as well.

Roger

@Roger

If you want to look at annual maintenance costs (consider expensive refrigerants and typical leak rates), you should also look at the much more frequent replacement costs of heat pumps versus boilers as well.

how is this relevant to your point above about the appeal of dual fuel systems? Or just AC in general? You’d be replacing an AC/HP either way correct?

@Roger sounds like you expect different reliability for AC only vs heat pump if I’m understanding correctly?

@Roger gotcha. I agree it doesn’t seem well supported, as we’d see an AC in NY last 10x as long as one in AZ probably :).

I’m still unsure why the disparity between AC/HP and a boiler lifespan matter? The boiler doesn’t cool. If you want AC, then the lifespan different isn’t relevant right? You may as well compare a fridge to a boiler.

@Roger yup we agree on that!