A heat pump follow-up with nuance!

Perfecto

Thank you

I'm in the similar boat. In Socal as well and spent a metric ass load on a new ac/furnace summer 2019. Could have gotten a heat pump and since it almost never even gets to freezing here and still never significantly below it sounds like it should just be standard here. WTF

Daniel Pritchard

The underground system is great - anything we can do to take heat out of the tunnels is a huge positive. The build up of residual heat in the ground around the tunnels over the years is huge - it used to be 'cool' underground - not so anymore!

zephyrmo

My understanding of district heating systems is that they don't feed radiators directly - there's a heat exchanger to keep the two parts of the system separate, I guess for safety reasons. And billing. Our work is not only heated by the local CHP plant, it also supplies chilled water for the air conditioning. (We're a TV studio. We need a lot of it.) You might also be interested in this new district system which uses waste heat from London Underground tunnels: https://www.newcivilengineer.com/latest/waste-heat-from-tube-used-to-heat-london-homes-09-03-2020/

Martin Deutsch

So what you're saying is we get more heat by using propane in the refrigerant loop of a heat pump than exothermically oxidizing it? Looking at propane from another angle - propane engines - advice varies from compression ratios of below 10:1 (~150 psi) to above 15:1 (~225 psi). - before it autoignites and causes "engine ping". "There is Propane and Propane. If it is not pure and contains reasonable amounts of Butane the octane will suffer. Also I have been told there are different isomers with different octane ratings. 11:1 will be safe with any commercial Propane and any camshaft." https://www.eng-tips.com/viewthread.cfm?qid=159998 How much does an A/C system pressurize? "If you are using a low pressure gauge when the low pressure reading is between 25 psi and 40 psi, the system is fully charged. For a high pressure gauge when the high pressure reading is 200 to 225 psi for R12 or 225 to 250 psi for 134a, the system is fully charged." https://itstillruns.com/much-should-cars-ac-unit-7239896.html So it would have to be a low-pressure system. And then there is the question of the purity and sourcing of the propane, to ensure there are no impurities like butane which reduce the octane rating (aka autoignition temp/pressure). Or maybe benzene could be added to increase the propane's octane rating, like is done in the compressable soup of flammable solvents we call gasoline.

Stephen Gillie

Depends on the contractor too! Most in my area charge 30-75% more than they should specifically due to the tax credit making consumers view it as more stomachable

Seth Hensinger

Haven’t watched fully yet, but was the geothermal tax credit of 26% mentioned?

Seth Hensinger

a) I love the cabin chime *adds* b) My family changed from a natural gas furnace to a groundwater heat pump at our farmstead in Nebraska in...I think 2002?...and simply reused the existing well we had for our farm, so I suspect that is still an option for those that don't have a city water line to connect to, which is exactly who will not benefit from economies of scale anyway and would most likely be using gas/oil-fired furnaces currently

RE the landlord dumping the cost of inefficient temperature control on the tenant. I get a nice warm feeling for having replaced the oil fired heating (we don't usually have air-con cooling in Scotland) I put in an air source using an all new system for £13k and didn't raise the rent. Obviously the tenant was pleased, but part of the reason I could do it was the renewable heat incentive (RHI) from the government (taxes) which means the system is largely paid for by the RHI payments over 7 years. In my own house I was able to put a ground source heat pump and the RHI will actually pay more than the cost.

Jim Hewlett

The Brits are probably talking about fuel-fired heat pumps like those by Robur. They use fire to drive a heat pump rather than electricity. This gets you better than 100% efficiency, but they're never as good as electric heat pumps. On the other hand, they use existing infrastructure that people understand and have built in fall-back to provide heat from combustion. These systems are very rare in the U.S. and usually used in industrial settings. For context though, look at propane air conditioners for RVs.

Jerrad Pierce

Re: Refrigerants and patent abuse. Your views in regards to refrigerant patent abuse got me saying "Yes! #&$&% chemical companies!", but it's a much worse situation than you seem to know. Remember back a few years when R-22 phase out started getting really expensive, forcing huge numbers of people to buy new, non R-22 equipment? Well, there was a perfectly good substitute for R-22 that would have let them keep running, although at slightly lower capacity (about 5% according to sources I could find), that is dirt cheap, has zero ozone depletion, and has extremely low greenhouse effect. Let me introduce you to R-290, a refrigerant that is illegal to use in most applications because of paranoia fueled by refrigerant makers. You know all about it, since you probably keep over 200 gallons of it on hand. R-290 is also known as Propane.. The only thing that they could find to prevent its use is that it's FLAMMABLE! So you can use it only in non air conditioning applications, and the total charge cannot exceed 150 grams. How do we stop the paranoia regarding hydrocarbon refrigerants, and get the chemical company mafia out of the decisions? Who do I send my letters to to stop the "it has to be non-flammable" idiocy?

HarveyB

A ground based system doesn't cost that much extra especially if you install it when you build the house. Watch https://youtu.be/GiLns7OFpiY

If I'd discovered your channel two summers ago, and you'd done this video before I replaced my AC that summer, I would have absolutely purchased a heat pump. I simply didn't know they were a thing in the summer of 2019. >_< Amusingly enough, because of how my condo complex is set up, my *only* natural gas usage is for my furnace (my hot water is shared with the rest of the condo, and I have an electric stove). If I had gotten rid of that when replacing my busted AC, I could have kicked SoCalGas to the curb *entirely*, and shut down their $15/mo interconnect fees throughout the not-winter when I literally use 0 BTUs of gas the whole time.

coredumperror

Seems like getting a heat pump for a home that *doesn't* already have AC is a completely different thing than what our inestimable host is talking about, though.

coredumperror

In my area of Atlantic Canada, heat pumps sound good but inevitably end up with an overall higher cost than just electric heat. You see, it *does* get hot in the summer, but not hot enough for A/C to be standard. Have a heat pump? All of a sudden you have available A/C and want to use it on those warm days! Well, there goes your savings on heat...

Michael Steeves

I'm on the board of a low-income housing building. A number of the tenants are refugees from north-east Africa and equatorial South America. While utilities are included, we are paying more for heat than on the mortgage! We are offloading the power cost to the tenants so they have some control over power cost! We've been talking about "renting" heat pumps from the utility, but I don't think they would really end up saving too much money.

Michael Steeves

Oil furnaces are the same as gas. Ours was 80% efficient. Mitsubishi has air source heat pumps that work well below 0*F. We’re going to put one in our detached garage/MIL apartment, which will give us both a GSHP and an ASHP. Lots of people here in Southeast Alaska have switched to air source heat pumps because the one thing we can get cheaply is hydroelectric power.