Heat pump disappointment for climate-minded Massachusetts state senator • Hacker News Board

Re: Heat pump disappointment for climate-minded Massachusetts state senator

#51

Post by c4mpute » Mon, Apr 10, 2023, 1:27 PM UTC

ab_goat wrote: post #39

Brownberger seems to miss the key fact that you can't run a gas heating system on renewable energy. Just as in switching to an EV isn't going to make things significantly better, switching your heating to heat pump isn't either: Some basic tips from a fellow Bay Stater: 1. Any new or replacement mechanicals should be use heat pumps (water heater too) 2. Make sure your house is well-insulated to get the best bang for…

> Brownberger seems to miss the key fact that you can't run a gas heating system on renewable energy.

Of course you can. You can use nat-gas-like gas mixtures from decomposition of different kinds of waste, e.g. biomethane and the like. You can also use hydrogen (within limits) and methane produced from green hydrogen (though usually inefficiently).

Re: Heat pump disappointment for climate-minded Massachusetts state senator

#52

Post by detourdog » Mon, Apr 10, 2023, 1:27 PM UTC

ct0 wrote: post #15

post_break wrote: post #8

I wonder if we will ever see them switch to R-1234YF refrigerant. "While R-134a has a Global Warming Potential of 1300, R-1234yf’s GWP is less than 1." The only issue is the higher pressures and the fact that it's somewhat flammable might be why. I will say, my heat pump dryer, while it has removed some buttons from shirts, has exceeded my expectations on energy usage. It's night and day compared to my toaster I had…

In your experience, does your heat pump dryer actually dry in a similar amount of time to a conventional electric dryer?

I have installed condensate dryers which are actually more efficient than heat pump dryers but take a couple of hours to dry. They don't need to be vented to the outside.

Re: Heat pump disappointment for climate-minded Massachusetts state senator

#53

Post by cornholio » Mon, Apr 10, 2023, 1:27 PM UTC

tcfhgj wrote: post #22

phkahler wrote: post #19

Earlier quoted context omitted.

>> Of course it's extremely important to switch people to electrified heating systems, regardless of their efficiency. You could use a gas fired heat pump. It won't work as an air conditioner, but it won't stress the grid and could even work when the power goes out.

you are better of adding with a gas plant to the grid, which can be up to 84% efficient (if you reuse the heat generated by the turbine as well) https://en.wikipedia.org/wiki/Combined_cycle_power_plant

And even if you don't, a 60% efficient gas turbine at the power-plant, paired with a 3+ COP heat pump in the home will be 2x more efficient than burning gas directly in the home.

Using gas in an adsorption heat-pump is quite inefficient and unlikely to break even economically. Perhaps a gas turbine home boiler could be produced, that combines a mechanical heat-pump with a high efficiency combined cycle turbine; alas, they do not exist and would be very expensive. It's a startup idea.

Re: Heat pump disappointment for climate-minded Massachusetts state senator

#54

Post by acidburnNSA » Mon, Apr 10, 2023, 1:30 PM UTC

throwaway4aday wrote: post #41

endisneigh wrote: post #18

I intuited this as well, which is why I stayed with gas heat. These days I'm even wondering if wood heat with a high efficiency furnace makes sense. There are so many dead trees around me. The carbon is going to go back either way. In the case of decomposition, there may be other negative effects of leaving it on the ground compared to burning it. I haven't given much thought to a way to capture the heat in a way tha…

If you have hydronic heating anyways then why not get a wood fired boiler? They're extremely common where I am. Why would you need to store the heat? A wood fire isn't instant on but it doesn't take that long either plus you get the heat from the stove itself well before the baseboards heat up.

Not OP, but biofuel combustion is not necessarily better than gas from particulate air pollution or climate metrics.

Re: Heat pump disappointment for climate-minded Massachusetts state senator

#55

Post by c4mpute » Mon, Apr 10, 2023, 1:30 PM UTC

nl wrote: post #3

It seems ridiculous that refrigerator leaks are not "an uncommon occurrence". Does anyone have any insight into why this would be?

Leaks are common with quick-install couplings and shoddy soldering. They seem to be more prevalent in the US, because qualification requirements for the installation of A/C and heatpumps are low to nonexistent, and anyone can just visit the DIY store and get refrigerant refills. So a leak isn't much of a problem beyond getting a cheap refill for most people, so craftsmen don't prioritize leakproofness.

Re: Heat pump disappointment for climate-minded Massachusetts state senator

#56

Post by tialaramex » Mon, Apr 10, 2023, 1:31 PM UTC

post_break wrote: post #26

ct0 wrote: post #15

Earlier quoted context omitted.

In your experience, does your heat pump dryer actually dry in a similar amount of time to a conventional electric dryer?

Nope, the toaster had a full load done in like an hour. The heat pump is like 3 hours. But the difference is the heat pump doesn't absolutely destroy my clothes. I'm noticing how much longer my clothes are lasting since switching. It's also so much quieter than the electric. If you are the type of person who goes "oh crap I need to wash every piece of clothing RIGHT NOW" then heat pump isn't for you because of the ti…

Specifically, what the heat pump dryer is doing is basically pulling air through the clothing which evaporates some water from the clothes into the air, then cooling the air, which causes water to condense, removing the condensed water and warming the air back up to send through the clothes again. The effect is much closer to the clothes hanging from a line in a garden on a perfect drying day, except it's inside a box.

Whereas the other way to do this is just cook the clothes and the water evaporates, then you dump the warm moist air either outside or into a separate dehumidifier which throws much of the energy away. As you observed this is faster, but most people don't need faster if it's unattended. My dishwasher is slower than washing dishes by hand, but I don't need to sit there watching while it does it so who cares?

Re: Heat pump disappointment for climate-minded Massachusetts state senator

#57

Post by trey-jones » Mon, Apr 10, 2023, 1:34 PM UTC

SketchySeaBeast wrote: post #40

nickpeterson wrote: post #32

Earlier quoted context omitted.

I’d love to hear experiences on ground source installs in suburbs. I’d love to do one but feel like I’d be forced into a vertical well which I’ve always heard is an outrageous cost. I’d love to be wrong.

I'm also wondering about the cost of maintenance and repair (say, in case of an underground refrigerant leak). I too would love to be wrong - it'd be a decent solution for a cold Albertan winter. It doesn't matter that the air is -40 if you're below the frost line.

I have two self-installed ground source heatpump units (6 tons total) in operation since summer of 2016 with no maintenance except for the loop pump. I was using two very old second-hand pumps until last summer (one for each unit), when one impeller completely disintegrated. I took the opportunity to reconfigure the plumbing and wiring a little bit to use only one pump (more modern, theoretically better fit for my system), and it has been smooth sailing since then. We'll see how long the new pump lasts I guess.

As for loop installation, I have a few acres and dug a ditch with my dad's backhoe. Most homes around here don't even have room for a septic system, much less a horizontal ground loop. I can't speak to the cost of a vertical system, but I think it would also affect the specs of the loop pump, and not in a good way. Check for tax-incentives as well: I got a 40% tax credit on the units themselves when I bought them.

I have to edit to address the underground refrigerant leak: I haven't had to deal with this. I can only say that it would not be a fun time. I think in a properly installed and tested system, it shouldn't really happen outside of freak seismic events though, at least within a human lifetime.

Re: Heat pump disappointment for climate-minded Massachusetts state senator

#58

Post by detourdog » Mon, Apr 10, 2023, 1:35 PM UTC

I have a 12,000 sqft building in the northwest corner of Massachusetts. Really well insulated and heated entirely with heat pumps. I have a large solar array to offset the costs. I ending up paying around $1.50 this year for all the electricity. If I factor in my SRECs sales it drops to around $.75. Last august the Governor signed new legislation that increased the the price utilities pay for the KWhs I produce so I expect another reduction in cost. The biggest problem I have is that 5 years ago all the HVAC installers claimed one couldn't use a heat pump in our area. Now we need many more installers than are available. Our local vocational school just added an HVAC heat pump program for the build back better funds.

Re: Heat pump disappointment for climate-minded Massachusetts state senator

#59

Post by endisneigh » Mon, Apr 10, 2023, 1:35 PM UTC

throwaway4aday wrote: post #41

endisneigh wrote: post #18

I intuited this as well, which is why I stayed with gas heat. These days I'm even wondering if wood heat with a high efficiency furnace makes sense. There are so many dead trees around me. The carbon is going to go back either way. In the case of decomposition, there may be other negative effects of leaving it on the ground compared to burning it. I haven't given much thought to a way to capture the heat in a way tha…

If you have hydronic heating anyways then why not get a wood fired boiler? They're extremely common where I am. Why would you need to store the heat? A wood fire isn't instant on but it doesn't take that long either plus you get the heat from the stove itself well before the baseboards heat up.

I have a pretty high efficiency tankless boiler so it would be expensive and wasteful to switch at this point. It is possible to buy a wood fired boiler and hook it up to the house to supplement the tankless but I'm skeptical that makes financial sense.

Re: Heat pump disappointment for climate-minded Massachusetts state senator

#60

Post by bluGill » Mon, Apr 10, 2023, 1:35 PM UTC

abakker wrote: post #23

nl wrote: post #3

It seems ridiculous that refrigerator leaks are not "an uncommon occurrence". Does anyone have any insight into why this would be?

Because flare fittings are a concession to make install cheaper, not better. R410a and other similar refrigerants are very high pressure, and the fittings undergo significant thermal cycles. Flared copper tube is a bad design choice. IMO, going back to brazed tubing connections is the most rational choice.

brazed tubes can leak as well. I had that happen in my last house. Little leaks are hard to find, the first time I had the system refilled the tech couldn't find anything and put some sealer in. The next time the tech did the same and was disconnecting the fill lines when he saw a dark spot, then he emptied the lines and did the proper fix.