It's official, New York State almost banned gas heating in new construction

[Marco]

The cost for retrofit a single home are far higher than a flat or renovation of a whole street any way. The costs of drilling increase highly sub-linearly. The future for new homes assuming widespread technological civilization survives for much longer, is district heating/cooling with ground source heat pumps (running airconditioning from the same system can go a long way to net zero heat exchange for the borehole). Hydrogen might be competitive for retrofits but I doubt it will ever be for large scale new homes.

In 3 decades there is supposed to be no natural gas, no propane, no fuel oil, no nothing ... hydrogen and GSHP are the only scalable renewable ways with significant technological readiness to heat homes. Worrying about increased bills is somewhat silly with only 3 decades to work with.

Status quo will die, with this time schedule defossilization has to be treated like a war, a long war.

[SilverSolder]

So I hear reverse cycle is more expensive over there? more than 20% extra? (common cost premium elsewhere in the world) An additional appliance just for heating is a huge expense if its a whole box similar in price, or even half the price (before installation, services, etc).

If you want to see the sort of equipment that is available in the US and the prices, a good place to look is https://hvacdirect.com/
I've bought a few systems from them, they mark it up over wholesale of course but it's still typically less than a HVAC company will mark it up. The whole industry here is full of protectionism and BS. Most HVAC trade counters will flat out refuse to sell to an individual and the HVAC message boards absolutely prohibit discussing prices or giving DIY advice, unlike pretty much any other trade.

I would have thought the US would be far more "capitalistic" than that...   but it is actually not.   Don't get me started on the whole road resurfacing industry, where companies are paid lots of money to repair roads every year instead of using higher quality materials and techniques to make it less necessary to do that...

[NiHaoMike]

Most HVAC trade counters will flat out refuse to sell to an individual and the HVAC message boards absolutely prohibit discussing prices or giving DIY advice, unlike pretty much any other trade.

Thank the EPA for that, they required a license to handle ozone depleting gases such as refrigerants. That then got phased out but HVAC supply stores found that not selling to unlicensed individuals cut down a lot on hassle (customers guessing what they needed and then returning a part that wasn't the problem, for example) so that practice stayed. Not sure if things have changed with the common availability of HVAC parts online, those online places usually sell for cheaper so the supply stores are more for getting a replacement part the same day.

[David Hess]

Would it be feasible to heat with propane?

In the past propane heating was common in any area where piped natural gas service is not available but electrical service is available.  I do not know about now.

There was a time when air-conditioner units were cool-only, is that still the case in the US?

I would say that cooling only air conditioning, with a separate furnace for heating, is still more common than a heat pump where natural gas is available.  Back in the 1960s when "electricity too cheap to meter" was right around the corner, some "all electric" homes were built with heat pumps and no natural gas service.

[nctnico]

Most HVAC trade counters will flat out refuse to sell to an individual and the HVAC message boards absolutely prohibit discussing prices or giving DIY advice, unlike pretty much any other trade.

Thank the EPA for that, they required a license to handle ozone depleting gases such as refrigerants. That then got phased out but HVAC supply stores found that not selling to unlicensed individuals cut down a lot on hassle (customers guessing what they needed and then returning a part that wasn't the problem, for example) so that practice stayed. Not sure if things have changed with the common availability of HVAC parts online, those online places usually sell for cheaper so the supply stores are more for getting a replacement part the same day.

Over here there is a healthy competition and many companies will sell HVAC equipment to consumers. Last year I bought a multi-split unit (pre-filled) and installed it myself. It is not really difficult if you have some affinity with doing pipe work. A vacuum pump is cheap from Aliexpress and based on recommendations from a refrigeration service / repair forum, I used a sealant on the connections to avoid leaks.

[Marco]

We have to do that illegally, but AFAIK Americans can do online F-gas exams for like 50$ and allowed to do it legally.

[NiHaoMike]

Perhaps a more gradual approach would be that rather than outright banning natural gas in new construction, just require that natural gas heating is allowed only if there's also a heat pump installed with an outdoor thermostat to select which gets used?

[rfeecs]

Berkeley (California) did it years ago:
https://www.theguardian.com/environment/2019/jul/23/berkeley-natural-gas-ban-environment

Of course they are also a nuclear free zone.

[BrokenYugo]

My question is how does this work in a freezing climate prone to extended power outages? You won't be running a heat pump, nevermind with resistive backup, off some cheap little 3-5kW one lung genset that runs a gas furnace easily with power to spare for a fridge and the TV. So I just don't see it working on a household level without gas backup, unless we're all expected to buy a 10+kW multi cylinder generator.

[james_s]

Thank the EPA for that, they required a license to handle ozone depleting gases such as refrigerants. That then got phased out but HVAC supply stores found that not selling to unlicensed individuals cut down a lot on hassle (customers guessing what they needed and then returning a part that wasn't the problem, for example) so that practice stayed. Not sure if things have changed with the common availability of HVAC parts online, those online places usually sell for cheaper so the supply stores are more for getting a replacement part the same day.

No, that's not it at all. I have an EPA license, HVAC trade counters won't sell to me because I'm not a professional with a contractor license, nothing to do with the EPA or refrigerants.

It may cut down on hassle, but the same would be true of any trade counter. I can buy a gas water heater at a plumbing supply house but I can't buy a gas furnace at a HVAC supply house. It's protectionism, nothing more.

[james_s]

My question is how does this work in a freezing climate prone to extended power outages? You won't be running a heat pump, nevermind with resistive backup, off some cheap little 3-5kW one lung genset that runs a gas furnace easily with power to spare for a fridge and the TV. So I just don't see it working on a household level without gas backup, unless we're all expected to buy a 10+kW multi cylinder generator.

That's precisely why I have a dual fuel system with a gas furnace paired with a heat pump. I can easily run the furnace off my little 2kW generator. I only use the heat pump when it's relatively warm outside, the furnace is quieter and I'd rather save wear on the heat pump for cooling. I have multiple heat sources but only one way to cool.

[james_s]

Berkeley (California) did it years ago:
https://www.theguardian.com/environment/2019/jul/23/berkeley-natural-gas-ban-environment

Of course they are also a nuclear free zone.

Berkeley is also a sanity-free zone, it's pretty well known as one of the most nutty corners of the whole nation.

[David Hess]

Perhaps a more gradual approach would be that rather than outright banning natural gas in new construction, just require that natural gas heating is allowed only if there's also a heat pump installed with an outdoor thermostat to select which gets used?

If the natural gas furnace is not regularly tested, by for instance being used, then it will fail when it is needed.

There is a much simpler and fairer solution.  If natural gas has negative externalities, then account for them:

https://en.wikipedia.org/wiki/Pigovian_tax

But of course they will not because politically powerful users will be subsidized.

My question is how does this work in a freezing climate prone to extended power outages? You won't be running a heat pump, nevermind with resistive backup, off some cheap little 3-5kW one lung genset that runs a gas furnace easily with power to spare for a fridge and the TV. So I just don't see it working on a household level without gas backup, unless we're all expected to buy a 10+kW multi cylinder generator.

I faced that in the 2007 North American ice storm.  The solutions are either sufficient backup power to operate the heating system, or a backup heating system like propane, kerosene, or wood.

[Marco]

At net zero the only scalable way to account for the externalities would be enough taxes to pay for direct air carbon capture (burying trees deep enough they won't decompose back into the carbon cycle is not scalable) since capture at the source is unlikely to be feasible.

I don't think there will be any takers for taxes that high, slowly growing taxes up to that point will just create a huge bottleneck in the future where everyone wants to transition at the exact same time.

[NiHaoMike]

My question is how does this work in a freezing climate prone to extended power outages? You won't be running a heat pump, nevermind with resistive backup, off some cheap little 3-5kW one lung genset that runs a gas furnace easily with power to spare for a fridge and the TV. So I just don't see it working on a household level without gas backup, unless we're all expected to buy a 10+kW multi cylinder generator.

No need to run the heating to prevent the pipes from freezing. Instead, a hot water recirculation pump can run for a very long time on batteries.

burying trees deep enough they won't decompose back into the carbon cycle is not scalable

Just make products out of the wood.

[David Hess]

At net zero the only scalable way to account for the externalities would be enough taxes to pay for direct air carbon capture (burying trees deep enough they won't decompose back into the carbon cycle is not scalable) since capture at the source is unlikely to be feasible.

But they do not apply *any* externalities, and even subsidize it which is the opposite.

I don't think there will be any takers for taxes that high, slowly growing taxes up to that point will just create a huge bottleneck in the future where everyone wants to transition at the exact same time.

Do you mean like that massive switch to electric vehicles happening right now, which is not happening?

The bottleneck in production requires capitol expansion, which would be paid for by higher prices anyway.  Politicians are solving the problem by ignoring it, creating a future crisis which conveniently will require more expansion of government.  Now you know why I assume all politicians are lying when they discuss global climate change, so far they are.

[uer166]

Even in the colder states (let alone Florida) it is beneficial to burn the natural gas at an electric powerplant, and use a heat pump for heating with reasonable CoPs. You'd need less gas to do the same work, and emissions would improve as the grid slowly shifts to renewables. There is maybe 1-5 days a year where the heatpump would be less efficient than a gas furnace, but who gives a crap? It still works just fine, and 99% of the time it is way, WAY more efficient.

It is so infuriating when people parrot the same old "heat pumps don't work in the cold", when that is verifiably false. I'm glad some states simply just force you to do the right thing, since the goals would never be achieved otherwise.

Some touch on the reliability of the heat pumps, and, well, it's no different than dealing with a broken furnace if you don't have backups such as electric space heaters or something redundant. Technology Connections goes into great detail with the math in a way that is accessible to anyone, so there is no excuse for ignorance anymore: . There seem to be some major issues with the HVAC industry based on some comments here, but that is something to be solved, and nothing to do with any engineering or technology issues.

[NiHaoMike]

Even in the colder states (let alone Florida) it is beneficial to burn the natural gas at an electric powerplant, and use a heat pump for heating with reasonable CoPs. You'd need less gas to do the same work, and emissions would improve as the grid slowly shifts to renewables. There is maybe 1-5 days a year where the heatpump would be less efficient than a gas furnace, but who gives a crap? It still works just fine, and 99% of the time it is way, WAY more efficient.

Even better to run the heat pump with a CHP generator if you're dead set on burning gas. It would be reasonable that in any place that needs heating for a significant part of the year, require new gas heating to be CHP, with or without a heat pump in addition. The generators and heat pumps could even be spread across separate buildings.

[nctnico]

It is so infuriating when people parrot the same old "heat pumps don't work in the cold", when that is verifiably false.

It is not false. Again, whether a heat pump is good enough on cold days highly depends on how well your home is insulated. Older houses are typically not insulated well enough to be heated by a heat pump throughout the year. Over here in the NL people install hybrid heating systems for that reason. These hybrid heaters combine a gas burner and heat pump in one system.

What even works better is burning gas in a power plant and use the residual heat for warm water and heating in a district heating system.

[Marco]

whether a heat pump is good enough on cold days highly depends on how well your home is insulated.

Poor insulation in and of itself is just a question of power, buy a bigger heatpump (and maybe increase total waterflow to the radiators). The fundamental problem is the thermal resistance between the water and the room air, if the radiators can't work on 40-45 degree water during worst case cold the radiators should be swapped or fan boosted.

Running the heatpump at high watertemperature is what makes them fail at cold temperature (cold for the Netherlands at any rate). The home insulation is a related issue but does not need to be a bottleneck.

Installing high water temperature district heating now based on natural gas generators when they have to be turned off in 30 years would probably be wasteful. Any new large scale systems have to be designed for the net zero future, unless the projected cost of electricity (or hydrogen) is so low that COP 1 heating is viable in 30 years that means low water temperature heating.

[Monkeh]

whether a heat pump is good enough on cold days highly depends on how well your home is insulated.

Poor insulation in and of itself is just a question of power, buy a bigger heatpump (and maybe increase total waterflow to the radiators).

.. no, that's exactly the wrong way to go about it.

Also, low flow temperatures are why hydronics need to be going the way of the dodo.

[Marco]

Also, low flow temperatures are why hydronics need to be going the way of the dodo.

For truly modern housing hydronic floor/ceiling heating can put enough power into the room even at 35 degrees water temperature ... forced air won't be able to win much COP wise.

[Monkeh]

Also, low flow temperatures are why hydronics need to be going the way of the dodo.

For truly modern housing hydronic floor/ceiling heating can put enough power into the room even at 35 degrees water temperature ... forced air won't be able to win much COP wise.

Underfloor heating is a serviceability nightmare. Leave it to bathrooms. Bonus of forced air: You get cooling! For once, the Americans are on to something.

[Marco]

The inside of ducts has its own serviceability problem when used for cooling, if warm air diffuses back into cold ducts after air conditioning turns off you have a problem which eventually will require servicing. Also not really suitable for retrofit for radiator heated homes.

Hydronics can do forced air heating and cooling too, just needs fan coil units.

[Nauris]

   Yes, to a very large degree most AC systems in the US are still cool-only units. New construction in the last ten years or so has started installing heat pumps but they're much more expensive than cool-only systems and in most parts of the US, heat pump simply DO NOT work in the coolest parts of the year so heat pumps are not economically justified.  In addition most US made AC systems (with or without heat pumps) in the US are not very efficient to start with.

   I just installed a Mitsubishi mini-split AC in a house in Florida this past summer and I elected not to buy the version with the heat pump.  It's reliability was lower than a non-heat pump version and it used more power even when you weren't using the heat pump and the cost was considerably more. So even though the house was in Florida which is just about a perfect climate for using a heat pump, I decided not to. 

   From everything that I have read, and I did a LOT of research, heat pumps are only practical when the outside air temperature is above about 30F. They will work somewhat down to about 20F but that's it. I have personally seen the temperature in central Florida get down to 17 degrees twice and down to 13F once. Everywhere north of there gets colder!  Note that most if not ALL, heat pump systems also include electrical resistance (I^2 R)strip heaters so the sellers CLAIM that the system works at colder temperatures and the strip heater will but not the heat pump so there is no efficiency to be gained. And I don't see any point in putting a $12,000 heat pump with a strip heater to replace a $49 heat dish.

   All of that said, I'm extremely pleased with the Mitsubishi mini-split AC system!

    For a couple of data points; the AC only Mitsubishi minisplit cost about $4,400 US installed. The same version with heat pump and strip heater was about $6,500 US.  This past winter the coldest temperature that we saw was about 30F but only for about three days and only at night. We never turned on the main heat and we used one heat dish (about 700 Watts) for a few hours per day in the main part of the house to take the chill off in the mornings for about a week.

Those Mitsubishi mini-splits are very good and our house actually has two of them. But them not working below 30F I think that is pretty outdated information from a time before modern japanese mini-splits. Mitsubishi has models for example the MSZ-RW that work reasonably down to -13 F and somewhat down to -30F. It is quite new model did not find any test report for it but here is graph for the older MSZ-LN. As you can see it puts out twice heat compared to it electrical consumption still at -22F. Problem is output is quite small only 2 kW (input is 1kW) at these temps. Newer MSZ-RW is better in this regard because of it's bigger compressor but unfortunately I did not find any actual grahps.

The strip heater thing it is market specific if it is fitted or not. For the units intended for colder markets (eg nordics) there is no strip heater normally but for units intended for warmer climates I think it is usually fitted. But you can unplug it on the indoor unit control pcb when it starts to annoy you too much.

Cost for the MSZ-RW25 is typically 2300€ installed

Generator operation - We have tested that and they work fine with small 3 kW gasoline generator. Input is just bridge rectifier with passive PFC it is quite tolerant and the compressor is ramped up slowly so not much inrush.

Lifetime - that is a bit open question still but typically more than 15 years in normal use (nordic region). Maybe longer but there is no data on that. Some units die earlier but rarely before 10 years old that is what we are seeing.