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#heat#more#system#ground#energy#pump#heating#air#drilling#water

Discussion (56 Comments)Read Original on HackerNews

cassepipe2 minutes ago
I think there's one big issue for massive electrification and insulation of buildings: renting.

As a renter, I have no incentives to invest thousands in my home's betterment because I will have lost those when I am gone. As an owner, I have no incentives to make my apartment/house better because I don't live in it and I don't pay the energy bills.

Something has to be done about that if we want to combat climate change. I know in France it is now forbidden to rent again or sale when the renter leaves if the home's energy grade is F or G (A is best) but it is probably loosely enforced/easy to circumvent. And it is too damn slow ! This is for regulation but maybe there are other levers ?

As a renter I would basically have to wait for energy prices to skyrocket for it to make economic sense. I hate this situation.

ProllyInfamous28 minutes ago
For anybody in TVA's electricity networks (mostly: Tennessee): they offer an annual promotion to single-family homeowners only to purchase an $1800 AO heatpump waterheater for only $250.

Maths: 85% discount on fancy new waterheater, which also dehumidifies and cools your house (passive result of heatpump).

TVA usually offers this promotion between Thanksgiving and NYE. You can order online from HomeDepot, or walk into a local store [0]. This ends up costing LESS than a new traditional resistive-type heater.

[0] either method: they DO verify SFH (by more than just ZIP code) -- duplexes and contractors not authorized/allowed

GenerWork27 minutes ago
I have a heat pump hot water heater, and it's been awesome. It's ROI has definitely improved with all the energy price spikes. It's located in my garage (I live in Florida) so there's no shortage of hot air for it to use.
ProllyInfamous25 minutes ago
Same — I maintain four (one RHEEM and three AO's).

The AO is a much cleaner/simpler/nicer install. The Rheem stupidly requires duct adapters (for small-space, <700sqft "closet" installations). AO won't last as long, but at $250 who cares?!

ejoebstlabout 1 hour ago
In DACH, there's not really an alternative for many homes. Heat pumps are by now cheaper, more efficient, more versatile and definitely greener than other means of heating.

If you get one, just make sure to get the dimensioning right. They are WAY more complex to plan, install and maintain than traditional heating.

pimlottcabout 1 hour ago
> DACH, an acronym for Deutschland (Germany), Austria, Confoederatio Helvetica (Swiss Confederation), the three major German-speaking countries

I was not familiar with this term before, had to look it up.

joe_mambaabout 1 hour ago
>In DACH, there's not really an alternative for many homes.

And yet in Austria, most apartment buildings in big cities are still heated by burning heating oil, gas or even firewood. Worst of the worst for air quality.

Walk through Graz in sub-zero winters and it's like you're breathing in a barbeque bonfire. Even your clothes smell like soot when you get home if you've been out too long. Which is bizarre to me, considering how much posturing and chest thumping Austria is doing about how green and anti-Nuclear they are yet they love burring wood and oil. Male this make sense please.

Sure, rich people in the bacon belt living in single family homes in the suburbs or rural areas, have heat pumps, solar panels on the roof and a Tesla in the garage, but that's a different story compared to those living in the city stuck in the fossil fuel stone age, where they have no choice over their rented building's heating method.

How do you convert the city's apartment buildings to heat pumps? Is it a technological limitation? Money limitation? Bureaucratic and political limitation? All of the above?

ejoebstl20 minutes ago
It's incentives. Landlord pays for the installation and decides, tenant for the operation/heating.

Best way to get around this is making heat pumps more accessible (easy to get, financing options), as well as legislation (banning gas/oil heating).

gpm26 minutes ago
Beurocratic and political limitation.

Firewood and heating oil isn't cheaper, it merely has lower upfront cost in exchange for a higher total cost. An efficient governance system (whether that's capitalism and banks with loans or renting out the hearpumps or a centrally planned replacement program or anything else) would figure out the financing and save the system money by updating.

Technology can make the incentives even larger. Excess money can make it easier for the governance system to reach the solution. But it's at the point where without any improvement to either an ideal system would figure out how to make the switch happen.

c0balt13 minutes ago
There is also a minor incentive problem here, mainly that a landlord can/will often offload the running costs, Nebenkosten, to the renters indefinitely.

That means they are sometimes economically incentivized to choose an option with lower initial cost but a higher running cost. Governments can/do bend these incentives via taxes but it can be hard/expensive to renovate old complexes (and that part cannot directly be offloaded by the landlord).

jakozaurabout 2 hours ago
A heat pump could win as the best HVAC technology, though a better drilling for ground-sourced ones. Just a shallow drilling (up to 100m) that works in retrofit mode, such as drilling from the basement, would be a great upgrade:

- No outdoor unit that looks awful in many settings

- works well, even in the coldest winter, without a spike in electricity usage, COP 5

- very reliable with long durability

- super quiet, no ambient noise

- 20% more efficient

Currently, drilling is very disruptive in retrofits, but there is progress in compact techniques that might change the equation.

Disclaimer: angel investor in https://www.flexdrill.at/

mono442about 2 hours ago
It's usually so much more expensive than an air source heat pump that makes it completely not worth it.
jltsirenabout 1 hour ago
That depends on climate. The longer and colder your winters are, the more you benefit from the reliable efficiency of a ground source. Ground source heat pumps have been the most common choice for heating new single-family homes in Finland for the last ~20 years.
giantg2about 1 hour ago
Installation is probably relatively cheaper there due to volume too. In areas where it is less common, there is less competition and fewer options for competent installers.
cenamusabout 2 hours ago
Yeah, recently saw some numbers for air-to-air vs air-to-groundwater, and it break even after more than 25 years, with more than twice the initial cost
JumpCrisscrossabout 2 hours ago
What were the figures and where are you?
frevibabout 1 hour ago
Drilling alone is €10.000. The whole installation of a air/water heat pump is €10.000. Mostly not worth it.
wattsoabout 1 hour ago
To jakozaur’s point, there’s plenty of reasons drilling can get cheaper and there’s at least one other company working on it [1]—would love to hear about others! I’m a minimally informed amateur but my intuition is that the way it’s typically done (multiple inch borehole, U-tube geometry) is fairly suboptimal since the diameter is a lot wider than you need it to be just for hydrodynamic resistance and you get losses from the outgoing liquid cooling the incoming liquid. Dropping the diameter should make drilling a lot easier—-you can sink a 5/8”x12’ ground rod with hand tools in the right soil! (you’d still have to figure out how to make the holes meet up but I imagine there are ways of doing this).

[1] https://www.borobotics.ch/

croteless than a minute ago
The fact that you need to roll out a drilling rig plus crew at all is going to be a large part of that cost. For it to become interesting for the average homeowner the price is probably going to have to drop by something like 75% - but that basically kills any margins for clever new innovations...
stephencanonabout 1 hour ago
We have a ground-source heat pump for our ADU. We did it because we were curious about just how efficient we could make the house, but I don't expect that it will ever break even financially vs a modern air-source system with resistive backup in our climate (northern New England, typically very few –20˚ nights, –10˚-0˚ more common with daytime highs in the single digits).

It works great, but it's hard to see a way to it making sense for most folks here.

puzzlingcaptchaabout 1 hour ago
You might still get the most out of it when the AMOC collapses.
konschubertabout 2 hours ago
Friends in south Sweden and they got a hole drilled in the front yard like it’s the most normal thing. Is it there?
joe_mambaabout 1 hour ago
The challenge is for people who live in apartment buildings in urban environment where you have no front yard you can drill into at your leisure.
gandreaniabout 1 hour ago
Drilling in the basement seems like a pain to remove the dirt you dig up. Saving yourself a couple of feet cannot be worth the access troubles
double0jimb0about 1 hour ago
Ground source heat pump owner here in the US. The original system was installed in 2007, and the loop field was designed to "best knowledge at the time". Well in the 20 years since then, NREL changed guidance on how far apart and how deep loops need to be installed. Rightly so, because our circa-2007 is "short looped", it's not sufficient for the house loads, but there is nothing we do about it other than putting on more expensive pumps, more expensive antifreeze and live with heat pump compressors dying pre-maturely because they are working at their design limits. All this makes it as expensive as traditional system (and if we tried to go net-zero with solar, the amount of solar required (because it runs so inefficiently) is larger than our roof area.

So I'm looking at a backup gas boiler to take load of the heatpump/ground loop (house has radiant heat).

And they are not quiet. 5-Ton water to water compressors are not quiet.

And the control system (HDX) and amount of expertise required to keep the thing running is a major barrier to getting low cost maintenance.

Maybe a 2026-designed system will work better and actually live up to the hype you talk about, but there are decades of poorly designed and discarded ground loop heat pumps that have "poisoned the well" if you will.

adonovan14 minutes ago
Does the ground source heat up (or cool down) over time, making it less effective? The deep ground is very well insulated, which is why after a century of operation the London Underground is 10 degrees warmer. I wonder whether GSHP users need to balance their load by (say) consuming more heating than they actually need in winter so that summer cooling remains effective.
double0jimb03 minutes ago
I think there are two types of this, only have experience with 1 so far. Within a single season, absolutely. In deep winter entering water temp (EWT) is around 30degF (this is a pretty accurate measure of bulk ground temp). Typical for where I live is 50degF.

Other type is permanent change that persists year over year. Haven't lived here long enough to measure this. But if you pull more heat from the ground in the winter than you put back into it into summer (we use a water to air compressor for AC in summer), then yes, it can happen and does happen. Don't know if we are in this bucket yet.

hvb2about 1 hour ago
Out of curiosity, has the demand stayed the same? I'm asking because you see the same with electricity grids, designed in a different time with much lower demand.

Sorry to hear this, it seems like a great system to me but you have to have the capacity right. I'm planning on getting one in the next year but the drilling will be more than we need and we opt for no glycol (yet) as that also gives us headroom

double0jimb025 minutes ago
I don't think system ever met demand when commissioned (we are 3rd owners). 1st owner largely neglected the system (which I interpret as reaction to it not working well), 2nd owner had local company known for "fixing geothermal" do a lot of retrofits (new higher flow pumps, increasing diameter on plumbing within the utility room to decrease "lift/work" required of the compressors, more feedback sensors / logic boards, added backup electric water tank heating for the radiant system, switch to methanol). These fixes have seamed to limit failure modes to a smaller set of things: mainly compressors dying early.

Currently system is running 20% methanol to combat the 29degF EWT (entering water temp) in deep winter. House is in Zone 6a.

One thing I learned in researching all of this is that use of ground source over many years can move the bulk ground temp permanently. (House also has water-to-air water furnace for AC). If heat pulled from ground in winter is not sufficiently replaced by heat added during summer, can move bulk ground temp over time. (If densely packed residential ground loops ever became a thing, I think this is a real risk.). But I am not sure if we have this issue at our place, still in first year, not enough data points.

raverbashingabout 2 hours ago
Drilling only works if you have access to a garden where to drill. Any kind of apartment has to use the outdoor unit
gpmabout 1 hour ago
If you're an individual with an apartment you don't have the choice to drill.

If you're building the apartment building you have the choice to drill for the entire building, and the number of units that benefit mean this is much more cost efficient than with single family homes.

yxhuvudabout 1 hour ago
In sensible countries each housing unit have a central heating solution, regardless of where the heat comes from.
bluGill2 minutes ago
That is you thinking whatever your area does must be best. Different does not mean better. there are pros and cons.
pandora-health41 minutes ago
I run daily comparisons between a gas boiler and a heat pump in the UK. Given that gas is cheaper than electricity, a well-installed and well-controlled gas boiler can still be cheaper to run. Heat pump running costs can drop drastically when combined with solar and battery storage, but that requires a much greater upfront investment.

https://x.com/AO7186252340513

https://bsky.app/profile/showpiece.bsky.social

PanMan29 minutes ago
I'm no expert on UK energy pricing, but the main difference between a boiler and heat pump is that heatpump can be, eg "500% efficient" - a COP of 5. So even if a KWH of energy is 2x the price for electricity a heatpump often comes out ahead.
double0jimb017 minutes ago
COP of 5 when running in perfect conditions (load, EWT temps, variable stage compressor, infinite heat sink/source). You might want to research how realistic constant COP of 5 really is.
ndr42about 1 hour ago
> [it] become[s] cheaper than gas heating within 11 to 14 years

This a no-brainer for buildings with high energy use. But we looked into getting a heat pump last year but it doesn't pan out because our house (15 years old) has a very low energy use and we would not recover the costs (about 20K euros after subsidies) for 20+ years.

bluGill1 minute ago
Your existing system will not last forever. When you have to spend money anyway that changes things.
teachrdan29 minutes ago
With any luck, oil prices will rise enough to make that conversion worthwhile!
seydorabout 1 hour ago
in the south, a lot of people opt for split Airconditioning instead of heatpumps. Cheaper and much easier to install/maintain
thinkcontext3 minutes ago
Do the places you are referring to not require heat? If so I don't see why having a separate heating and cooling system would be cheaper to maintain than a single system. Come to think of it I don't see why a heatpump would be more expensive to maintain than split AC. I guess there is some extra circuitry to make sure it doesn't ice up in the winter and maybe backup resistance heating builtin.
shellfishgene34 minutes ago
That's the same thing, no?
gosub1003 minutes ago
I think they mean "air exchange" (split AC) vs "heat pump" (dig into the earth to draw/eliminate heat). Not saying that's the right definition though. I am guessing at an auto-correction of what they meant.
masklinn14 minutes ago
In the same way that an electric motor and a generator are the same thing.
wxwabout 3 hours ago
That's a neat proxy measurement to track.
infectoabout 2 hours ago
I am probably simply confused but what’s the proxy measurement?
comrade1234about 2 hours ago
I assume a product related directly to another product. So when energy prices start to go up, invest in heat pump companies.
infectoabout 2 hours ago
Thats what I was guessing but was thrown off because it is a pretty natural nth order effect. Gas prices go up, more efficient cars get sold.
hervatureabout 2 hours ago
Heat pump sales for energy costs.
NewJazzabout 2 hours ago
More efficient hvac tech is a partial substitute for fuel.
ck2about 2 hours ago
imagine the President of the US and his "braintrust" accidentally making the world much more green and efficient by forcing a radical reduction in oil dependency

while they purposely end climate-change research including destroying billions in observation satellites by deorbiting them

the history written about this decade is going to be wild, if we survive it

jochem9about 2 hours ago
EU severely reducing its fossil fuel imports from Russia in 2022 cut down natural gas usage by 17% and overall energy consumption by 3%. So yeah, increased price due to scarcity help a lot in shifting around the energy mix.

It's a bit shit that hits poorer people relatively more than richer people. Governments can reduce this impact by subsidizing sustainable alternatives (like heat pumps). It's still leading to inequality (unless you give more subsidy to the poor), but at least overall people will hopefully benefit.

usrnm29 minutes ago
> overall energy consumption by 3%

Is it possible that some non-trivial part of that number comes not from increased efficiency but from losing some energy-dependent industries?