7 ms·
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
by jakozaur 5mo 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/ https://www.flexdrill.at/
- konschubert 5mo agoFriends in south Sweden and they got a hole drilled in the front yard like it’s the most normal thing. Is it there?
- joe_mamba 5mo agoThe 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.
- deleted 5mo ago[deleted]
- crote 5mo agoThe solution is of course to get a communal system. As a bonus, drilling one giant loop is significantly cheaper than drilling hundreds of smaller ones.
- joe_mamba 5mo ago>The solution is of course to get a communal system. If it's that simple why is Austria not doing this in the cities? I don't know any voter who opposes cleaner air and cheaper heating.
- cyberax 5mo agoIt doesn't work this way. Dense cities just don't have enough space for geothermal heating. It really works for single-family homes only, or maybe just a slightly more dense areas. Not to mention that city infrastructure is WAY too expensive to build, anywhere. You'll spend more money on planning than on doing the actual construction.
- GJim 4mo ago> geothermal heating Ground source heat pumps != geothermal heating. The technologies are completely different.
- quickthrowman 4mo agohttps://mncifa.mn.gov/heights-geothermal-district https://mncifa.mn.gov/heights-geothermal-district Granted, this system is being installed on the grounds of a former 112 acre country club that is being redeveloped, so it’s more of a greenfield project than slapping a geothermal loop in a central business district, but it’s a geothermal district heating and cooling system in a city.
- cyberax 4mo agoTheir resulting density (~450 square meters per housing unit) is only a bit more than a dense SFH zone. And they also are able to tap into an aquifer, significantly improving their capacity. In general, you absolutely can do district-level heating. The former USSR countries are known for doing this on the scale of entire cities. But I don't think it's feasible with geothermal (unless we're talking about Iceland).
- joe_mamba 4mo ago>The former USSR countries are known for doing this on the scale of entire cities. Not today anymore. In my warsaw-pact country, my parents and most of the city residents cut themselves off from district hating since the 2000 and installed natural gas heaters/boilers in their apartments, which is what most people in my city use to this day. It's because the former commie district heating was incredibly wasteful and inefficient in the post commie era, making it cheaper and more convenient to have you own apartment heating. Probably the same thing would happen with heat pumps in apartments now, if air-to-air heat pumps could produce enough heat in cold winters.
- konschubert 5mo agoWhat isn't cheap, though, is maintaining the plumbing of the communal system, especially outside cities.
- mono442 5mo agoIt's usually so much more expensive than an air source heat pump that makes it completely not worth it.
- cenamus 5mo agoYeah, 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
- JumpCrisscross 5mo agoWhat were the figures and where are you?
- thrownthatway 5mo agoThere’s no way the system is designed to last 25 years though?
- apelapan 4mo agoThe well that you drill will last a 100 years if you don't have bad luck. That is half the cost of installation. The water/water heatpump unit in my house is 20 years old and has not had any major failures yet. I hope it will run for another ten years before the compressor gives up, but it is indeed approaching its calculated technical lifespan. I estimate it will set me back €10k to have it replaced. Air/air is the cheaper option over time, even in most of Scandinavia with coldish winters. The main drawback of air/air systems are that they are loud and ugly and therefore annoy both yourself and your neighbours.
- magicalhippo 5mo ago> more than twice the initial cost Here in Norway you can get a decent air-to-air minisplit installed for $2k. I've not heard of anyone who paid less than 10x that for an air-to-ground or water-to-ground system, drilling 500-1000 feet is expensive.
- 4mo ago
- raverbashing 5mo agoDrilling only works if you have access to a garden where to drill. Any kind of apartment has to use the outdoor unit
- gpm 5mo agoIf 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.
- yxhuvud 5mo agoIn sensible countries each housing unit have a central heating solution, regardless of where the heat comes from.
- bluGill 5mo agoThat is you thinking whatever your area does must be best. Different does not mean better. there are pros and cons.
- double0jimb0 5mo agoGround 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.
- hvb2 5mo agoOut 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
- double0jimb0 5mo agoI 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.
- frevib 5mo agoDrilling alone is €10.000. The whole installation of a air/water heat pump is €10.000. Mostly not worth it.
- theshrike79 4mo agoA winter's worth of heating oil is easily 1000€ With the current prices it's nearing 2k€. Very much worth it.
- wattso 5mo agoTo 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/ https://www.borobotics.ch/
- crote 5mo agoThe 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...
- wattso 5mo agoWhat I was trying to get at with the ground rod example is it’s entirely possible that you wouldn’t have to roll out a drilling rig and crew. To zoom about a bit, the main risk for heat pumps is really ugly winter peaks but besides that, ASHPs are perfect 90+% of the time. So the main role I see for GSHPs is backing up ASHPs to shave that peak, and once you scale back their role like that it seems like there’s a lot of ways to cut installation costs significantly.
- stephencanon 5mo agoWe 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.
- puzzlingcaptcha 5mo agoYou might still get the most out of it when the AMOC collapses.
- tenuousemphasis 5mo agoI'm not aware that AMOC collapse is going to significantly alter New England's climate as it will Europe's.
- gandreani 5mo agoDrilling 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
- stephen_g 5mo agoThe 'outdoor unit that looks awful' is an interesting quirk especially with US equipment - most Japanese and European residential units actually look fine, I'm not sure why American ones have tended to look especially ugly. I notice this with electrical stuff too - things like switchboards etc. in residential and light commercial installations we have quite neat stuff that's usually quite streamlined and in light white/grey/cream colours, whereas the switchboards and conduits and thigns I see in videos of US home installations look like grey chunky metal stuff that you'd only see in heavy industrial sites here!
- coryrc 5mo agoBuying the panel box which is unchanged from the last 70 years and costs $50 less than a nicer new style, but also our houses are big enough the panel is nearly always in a mechanical room so who cares what it looks like.
- lazide 5mo agoYou can’t get the ‘nice’ panels in the US - they aren’t approved by local code.
- coryrc 4mo agoThe "new" white Leviton is kinda nice. Or maybe I don't know what I'm missing!
- lazide 4mo agoThis one? [https://leviton.com/products/residential/load-centers https://leviton.com/products/residential/load-centers] It’s only a minor change from a 75 year old square D design, with some (albeit nice) aesthetic improvements. [https://www.se.com/us/en/product/HOM4080L225PC/load-center-homeline-1-phase-40-spaces-80-circuits-225a-convertible-main-lugs-pon-nema1-combo-cover/?selectedNodeId=41993832826 https://www.se.com/us/en/product/HOM4080L225PC/load-center-h...] The ones I think they are referring to a more like industrial control cabinets with DIN mounted breakers, which are indeed (paradoxically) less ‘old industrial’ looking. That Leviton board has a similar look, but with the standard bus bar type mounting in a heavy metal box. The metal box does serve a useful purpose, which is protecting the flammable wood framing typical in North American construction from fire, where most European and Asian boxes are either much thinner metal, or plastic. Because their construction is often concrete and fire danger is much lower.
- fennecfoxy 4mo agoBorehole or the pipe grid they stick under your backyard/garden (if you have a decent sized one) end up way more expensive. But tbf, AI and robotics are rolling along pretty well. I'm surprised there's not a company that's just build the "this robot installs your borehole/underground pipes in 3 hours by itself" robot.