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Nine US states are teaming up to accelerate the adoption of heat pumps

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Re: Nine US states are teaming up to accelerate the adoption of heat pumps

#521

Post by Retric »

Aloha wrote: post #479
aero_code wrote: post #435

Earlier quoted context omitted.

I don't think the numbers are accurate in the quantity of gas. Since kWh and BTU are both units of energy, finding the cf of gas is unnecessary (assuming the efficiency numbers are correct). 1 kWh = 3.6 megajoules and 1 BTU = 1055 joules The 6.6 kWh of the heat pump is 23.76 MJ which is 22,521 BTU of energy. Assuming that the power plant and distribution are 60%, it would take 37,535 BTU of gas to produce (22,521/60%…

You kinda do need to figure that out - EIA says that it takes 7.42cf of gas to make 1kWh of energy. https://www.eia.gov/tools/faqs/faq.php?id=667&t=8 I dont know where EIA gets those numbers, but that was the basis of my calculation. Maybe I shouldn't have multiplied that by the efficiency of the plant, but rather just taken of distribution losses.

They are averaging the efficiency from the current fleet of gas turbines after subtracting the useful heat output and coming up with 44.4%.

However, it’s a misleading number in multiple ways because the fleet is made up of a mix of low and high efficiency turbines. Grid operators use a mix of turbine types as a cost optimization, a far cheaper and far less efficient turbine that’s only used 1% of the time it worth it. The average number of kWh per cf of gas is therefore heavily in favor of high efficiency turbines.

Re: Nine US states are teaming up to accelerate the adoption of heat pumps

#522

Post by tootie »

bagels wrote: post #214
mdasen wrote: post #174

One of the big problems with heat pumps in New England is that our electricity costs 1.7x the US average ( https://www.eia.gov/electricity/monthly/epm_table_grapher.ph... ). If you're in the South, a heat pump makes perfect sense. You're going to want AC anyway and it'll be way more efficient and save a ton of money when you want heat. In most of the country, even if it gets cold your electricity prices are still a t…

Right, the heat pump will reduce energy use to maybe 1/3 of a gas furnace, but natural gas is something like 6x cheaper for the same amount of energy, so it is an expensive folly. If California is serious about this, they need to reign in the utilities to reduce prices and or stop the attacks on solar installation.

> 6x cheaper

It will have a lower price but not a lower cost. At this point we can't wait for price efficiency we have to pay whatever dollar amount to avoid the catastrophic human costs of burning fossil fuels.

Re: Nine US states are teaming up to accelerate the adoption of heat pumps

#523

Post by lsllc »

smeej wrote: post #502
theteapot wrote: post #268

Earlier quoted context omitted.

> Heat pumps do work into freezing New England temperatures, but they're a bit less efficient as it gets to zero fahrenheit. What's the temperature in the ground? Did you look at a ground source heat pump ( https://en.wikipedia.org/wiki/Ground_source_heat_pump )

There's a reason NH is called "The Granite State." Planning to put things underground in at least that part of New England is not likely to go very well. It can be done (plenty of places have septic tanks, for example), but it's not easy.

Unless you live in one of the few big cities in NH, you'll likely already have an Artesian (drilled) well. Swap out the pump for a variable speed pump and you should be good to go for a GSHP -- a much better option for NH vs an Air Source Heat Pump. Otherwise, it'll cost $15-20K for a well to be drilled. You get about 1-ton of heating/cooling per 100' of drilled well.

Re: Nine US states are teaming up to accelerate the adoption of heat pumps

#524

Post by icehawk »

jrockway wrote: post #519
icehawk wrote: post #514

Earlier quoted context omitted.

The builder of the apartment complex likely just undersized the unit, they'll do this with the normal kind of heat pumps-- air conditioners-- too, and hope its not so undersized that it becomes an actual problem.

I rented someone's condo circa 2004 that did this with the air conditioning. Hot summer day? Just warm air coming out of the AC. (It was the kind where the cooling is done centrally and you just have an air handler in your unit.) Now that I think about it, that happened in both apartments I lived in in Chicago. I remember going for a bike ride one summer afternoon with a friend. Got home, AC didn't do anything, so I…

Yeah, I had a similar issue, and had to solve it by purchasing a portable AC to supplement the main HVAC.

Re: Nine US states are teaming up to accelerate the adoption of heat pumps

#525

Post by lsllc »

mdasen wrote: post #174

One of the big problems with heat pumps in New England is that our electricity costs 1.7x the US average ( https://www.eia.gov/electricity/monthly/epm_table_grapher.ph... ). If you're in the South, a heat pump makes perfect sense. You're going to want AC anyway and it'll be way more efficient and save a ton of money when you want heat. In most of the country, even if it gets cold your electricity prices are still a t…

The big issue in New England is that heat pumps (ASHP or GSHP) are only really possible for new builds. Most existing homes will likely be forced hot water and there isn't any heat pump out there that will produce water hot enough (e.g. 185F), so your only option is to retrofit ducting (or go mini-split but then you need one in every room).

Even homes with ducted AC, it's likely they are sized for cooling only, not heat (not enough CFMs).

Re: Nine US states are teaming up to accelerate the adoption of heat pumps

#526

Post by jhallenworld »

dripton wrote: post #518
jhallenworld wrote: post #425

Earlier quoted context omitted.

The fossil fuel capitalists are so very unhappy about this ban, they are still going on about it in the financial news. I have to say, I love it. Low natural gas prices directly benefit me, and isn't it our gas? The price has certainly come down (look at henry hub chart..), but also winter has not been too cold.. They should ban oil exports next.. (for "national security") Actually export tariffs would be better than…

Export tariffs are actually unconstitutional in the US. https://en.wikipedia.org/wiki/Import-Export_Clause

Interesting.. the same section banned any limitation on the importation of slaves... at least that clause had a sunset date. Both clauses were basically: "don't touch our cash cow".

Re: Nine US states are teaming up to accelerate the adoption of heat pumps

#527

Post by lsllc »

UncleOxidant wrote: post #185
readingnews wrote: post #86

I just replaced a furnace... everyone I called for a quote would not touch a heat pump with a 20foot pole, or they wanted prices that were 2X what a separate furnace and AC would cost to install. It was very strange. This is the second home where I had this experience.. basically, they really did not want to install it. I ended up going with gas as no local person would install/warranty a heat pump, or, it was priced…

Had exactly the same experience recently. It seems like there are plenty of good mini-split heatpump systems that will work down to 0F (or even lower) without any kind of backup heat source. But if you're replacing a forced air furnace that feeds an existing ducts the only options are heatpumps that need to have backup heat under 30F. So essentially you're buying 2 furnaces in one which increases the cost. I'm in the…

The ideal design (IMHO) for a cold-climate (such as New England) is forced air ducting with a heat pump (better GSHP than ASHP if possible) with a 2-zone high efficiency natural gas boiler for domestic hot water and AUX heat.

People always forget the hot water. A GSHP usually has a de-superheater that can provide some heat during the shoulder seasons, but you can't rely on it and need the backup heat (as you do for the AUX heat for both when it's super-cold out and for the defrost cycle).

Re: Nine US states are teaming up to accelerate the adoption of heat pumps

#529

Post by bagels »

jcalvinowens wrote: post #442

I have NEM2 solar, so obviously a heat pump is a big win. But I'm convinced the heat pump I installed a couple years ago would save money even without the solar: I pay $0.30-$0.40/KWh for electricity, and $0.08/KWh for natural gas ($2.35/therm) *. My heat pump has a COP of 3.62 when the outdoor temperature is 47F: it uses 1KWh of electricity to move 3.62KWh of heat into my home. The old gas furnace was 80% efficient…

Converting from a gas furnace to a heat pump costs tens of thousands of dollars, needs to be factored in as well.

Re: Nine US states are teaming up to accelerate the adoption of heat pumps

#530

Post by lsllc »

billfor wrote: post #215

Has anyone found a good way to control all the features of a heat pump with home automation? I’ve been lookin at Daikin and Mitsubishi but Daikin no longer has an open api and I don’t see much on Mitubishi. It seems like every heat pump comes with its own proprietary remote, and the thermostats and Wi-Fi modules (if available) don’t integrate well.

I have a Trane/Mitsubishi mini-split for a garage and it works via a Nest thermostat, so that's how I monitor/automate that. Google have APIs for Nest ... YMMV.
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