Comments by "eDoc2020" (@eDoc2020) on "Why Heat Pumps are Immensely Important Right Now" video.

@andymerrett A battery-powered ignitor would need battery replacement and a physical or piezo ignitor is is much more annoying. As almost every stove has an electric (or electronic) clock built in there's no reason not to use the same electricity for lighting the stove.
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Central air conditioning US homes with gas heat is installed in exactly the same way. For plenty of people with this setup a conversion to hybrid heat pump should be fairly cheap with only a few valves and a new controller.
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@criticalevent You're right that most electric vehicles can't be used for vehicle to grid but hopefully that gets improved over time. You're right that when you leave home your car can't power your home but that's literally what the grid is for. Other people's storage systems would help power your house during that time and if you plug in at your destination you could power your house using the grid as an interconnect. As for inverter gear, it's not $20000. A Sol-ark is $7000 and there are plenty of cheaper options. The permits needed aren't that special, they are the same as you'd need for grid-tie solar. Even if they don't let you feed back to the grid you can still use the energy to power your own house. I agree an EV with a discharged battery goes 0km. That's why you set discharge limits so you still maintain enough range for what you need to do.
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@criticalevent First of all I don't like Elon Musk bullshit either. But saying you can't grid-tie storage systems anywhere in the US is simply false. I live in Massachusetts where you definitely can, and there are incentive programs (ConnectedSolutions) for doing so. In times of grid overload they do pay more for kWh then you paid to charge the battery. They can afford to do this because wholesale electricity prices are highly variable. Today (3/26/2022) in New England wholesale electricity was $49.43 at 12:00 and $91.28 at 1:00. As for getting a permit for a 100kWh grid tie storage unit on an extension cord in a driveway does sound a bit ridiculous. 30 years ago you would think the same of people saying anybody could create home videos and anybody anywhere in the world could watch them without the creator or the viewer needing to pay for the service. Today it's obviously feasible as anybody who watches YouTube would know. The 100kWh storage unit in the driveway looks more sane when you consider that the energy capacity probably wouldn't matter, only the actual power. Saying you have a portable 5kW inverter seems much more reasonable.
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There's one brand (Mr. Cool) which produces DIY-capable mini-split heat pumps which don't require special tools. If they're legal in your area it's definitely worth checking out.
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I feel much the same. Gas engines are generally 35% efficient at the high end so whole house generators are going to be fairly worse, totally tanking at lower load levels. And most of the time they will run at these lower load levels. I'd guesstimate the generator would be running at around 20% efficiency, meaning you'd need a heat pump COP of 5 to be a more efficient use of gas. Directing the hot air coming off the generator into the cold air intake of the heat pump would probably work reasonably well to boost the system efficiency. AFAIK most whole house generators are air cooled so it would be hard to use their waste heat directly. If you have a water-cooled generator it would theoretically be easier as you could use the engine as a boiler in a hydronic heating system. This is such a good idea automakers have been using this for cabin heating in ICE cars for ages.
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@weetwteqtwtwwt The inability to heat without electricity is already a problem with 99% of existing gas heat installations. Relying on heat pumps won't change that at all.
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@paulhaynes8045 The systems being discussed here heat air directly instead of using water and radiators. However, there are similar systems which work for water-based heating systems. They would be installed in the same loop as the existing boiler. Danish YouTuber Morten Hjorth has such a system and has some videos discussing it on his channel My Playhouse.
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@Sha.ll0w A stove ignitor normally using grid power but having batteries for backup ends up being a terrible solution. When you have power the batteries sit and sit, likely leaking and causing damage. Then when the power's out it's still no good. It would work if you regularly check the batteries but nobody will do that. If somebody is willing and able to change the backup batteries chances are they can handle some matches. Also the circuitry needed to seamlessly support both is much more complicated than only dealing with a single power source.
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@KyouTGD Furnaces need fans but basic gas fireplaces do not. There are also some very old gas room heaters still in use which don't use fans.
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@markm0000 Thermostats for (whole-house) heat-pump systems have built-in support for backup heat systems. It will work automatically and will maintain constant living temperature. As a plus smart thermostats can use other data to help make their decision, such as weather forecasts and realtime energy prices.
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In a practical sense, if everybody keeps their existing heating system as a backup it shouldn't make a difference in peak grid usage. Worst case draw would remain what it is now. Note that doesn't mean it's not an issue, in some places it obviously is already an issue.
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It's good to know that this actually exists. In another comment thread we were discussing the possibility of running a heat pump from a gas generator.
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@EebstertheGreat Presumably you'd have something else. I have gas forced air heating and a separate gas water heater. If you don't have gas you'd probably have an electric water heater. They do make heat pump water heaters but I think there's much less value in them.
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How much of your system they can reuse probably depends on the pressures involved as well as material compatibility. I believe older systems run at lower pressures which might not be compatible but if you have a modern central air conditioner most of it can probably be reused. I'm not an HVAC expert but I'd expect the lines and the evaporator would certainly be reusable if they use similar refrigerants. It should be possible to convert just by adding extra valves in the existing outside unit but installers may be unwilling to do that and you may want a new variable-speed compressor for added efficiency.
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Something I think would help push heat pump adoption is if they were readily available in the same form factor as window and (two-hose) portable air conditioners. If you could get one for $300 and set it up yourself there would be such a lower barrier to entry. Not only that but it would boost visibility. If somebody is out buying an air conditioner and one of the boxes in the store says "also heats, 5x as efficient as traditional electric heat" they might want to check it out.
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I believe geothermal systems run with (more-or-less) water. If there aren't any harmful additives used then I'd say just don't worry about leaks.
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@Guysm1l3y I agree you shouldn't replace a working furnace for funsies. Most furnace setups in my area are paired with an air conditioner where the condenser goes above the furnace's air output. In such a setup the heat pump would replace the air conditioning unit, or the AC can be converted with some valves.
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@michaelsexton1107 If there's sufficient coupling of the generator's waste heat into the heat pump it will be a more efficient use of energy than a furnace. The question would come down to how much coupling is needed and whether or not that much coupling is feasible. Putting the generator and heat pump outside unit in a sealed box would provide good coupling but this isn't an option because the generator needs fresh air intake and exhaust. Adding tubes for intake and exhaust would be feasible but might not meet safety standards, plus you'd need to make sure you don't overheat anything.
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I just heard of the York Triathlon heat pump which was a natural gas engine driving a heat pump. It seems when they worked they worked well, but unfortunately they weren't very reliable.
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