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Good to see heat pump tech being pushed forward in all sorts of applications. I didn't even think about using CO₂ in car applications. I have a CO₂ heat pump h

Good to see heat pump tech being pushed forward in all sorts of applications. I didn't even think about using CO₂ in car applications. I have a CO₂ heat pump hot water system (integrated by this Australian mob - https://reclaimenergy.com.au/ https://reclaimenergy.com.au/ - but I think the heat pump unit is an OEM Japanese one) and it uses a ridiculously small amount of energy compared to my old conventional electric system (somewhere between 1.2 and 2kWh typically vs 4 to over 6kWh per day - and the new system also has a tank 2.5 times bigger than the small one I had before, which is so much better, and I probably use some more hot water than I did previously since it’s available). I have solar and it’s timed so it basically always is entirely, or almost entirely powered from that, so it’s gone from using more power from the grid than the rest of my usage combined, to now using almost no power from the grid. Yes, it was a bit pricy but should only take a few years to pay back.

hbarka 3y ago
This is from Sanden, the manufacturer of CO2 heat pump water heaters. They are known for the SANCO2. https://www.smallplanetsupply.com/sanc02 https://www.smallplanetsupply.com/sanc02
- stephen_g 3y ago
  Ah, interesting, apparently it is manufactured by Sanden, yes. I thought they were different because you can also buy Sanden branded heat pumps here in Australia too, and I assumed that since Reclaim also sell commercial ones made by Mitsubishi Heavy Industries I though the domestic one might be Mitsubishi too.
- zeristor 3y ago
  You’d think that if you highlighted 150°F iPad Safari could translate it to Celsius, or allow lookup to do the conversion.
  - TheSpiceIsLife 3y ago
    65 degrees Celsius. For context, 54 degrees for 30 seconds will cause full-thickness skin burn.
  - Someone 3y ago
    It does translate it for me (65.56°C). If it doesn’t for you, that likely is because of your settings
  - zeristor 3y ago
    Strange. It does now. It’s not as if someone from Apple did a quick fix is it?
TheSpiceIsLife 3y ago
Thanks for this! I'm in Launceston, Tasmania and have access to no-interest credit up to $10k over three years for energy efficiency improvements including heat pump hot water. Our electricity use is dominated by heating and hot water, and the next step I've been wanting to take is heat pump hot water. I'll have a read of the link you provided when I get home. Thanks again.
- stephen_g 3y ago
  Yeah, it’s been good. I think you should be able to get it installed for something like $5K after rebates. My situation was a bit weird since I bought it in late 2021 directly from Reclaim (for about $4600 with the 315L glass lined tank), it sat in storage for a bit while I was doing other work on the house and then I had it installed more recently (cost $950) and then am claiming the STCs myself (which are worth about the same as the installation). It would be much easier to just have it done by an installer who orders it, installs it and claims the credits as part of the deal…
wkat4242 3y ago
The whole tank thing is really holding me back from moving away from natural gas. With gas you have unlimited hot water when you need it, it never runs out. I hate planning things in advance. And you're not wasting energy keeping it hot when you don't need to. And no wasted space for a big tank. If they ever manage to make electric water heating efficient enough to just heat on demand I'd probably use it. Of course it is more efficient with electric but I hardly use any gas anyway, my bill is like 15€ a month including fixed supply charges. There's just no return there for a big investment. And I can never have solar so free electricity is not a thing (I live in a big city and don't own the roof of the apartment building)
- sgerenser 3y ago
  I have always had tank-type water heaters and I don’t recall ever running out of hot water (family of 4). Is this actually a problem people have or is it just a tankless water heater industry talking point?
  - lightedman 3y ago
    Various places will have different-sized water heaters installed. As a child, I lived in one place that had a measly 20 gallon electric heater. It sucked, badly. Dad showered first, then I got woken up to shower - barely any hot water.
  - mikeyouse 3y ago
    Nope it’s a real problem, an undersized tank, high usage devices (eg a big bath tub) or just low temperature set on the unit for safety’s sake can cause the hot to run out. Modern tanks have a label on them that will let you know how many gallons of hot water it can deliver in its first hour of usage, some of those numbers are much lower than others.
    - stephen_g 3y ago
      The good thing about the heat pump I've got is that it's also surprisingly quick to heat up. If you do run out (I never have, but I experienced the speed the first time it was turned on when it was installed) you can go and press the 'Boost' button on the controller and you will have 50L in 20 minutes and a full tank (mine is 315L) in 3 hours. The system also heats the tank to at least 60 degrees C at the sensor point (about 2/3 of the way down) at least once every 24 hours and then has a tempering valve on the output for safety. That way you don't have scalding water at the point of use, but do have lots of hot water available and no issues with Legionella bacteria.
ajb 3y ago
That's really cool. Hope someone does one with integrated aircon soon.
- stephen_g 3y ago
  I have often dreamed about solutions for this, but at the end of the day I'm not sure that your average household would really have enough coincident demand for heating and cooling to make it worth it... Definitely for larger buildings it makes a lot of sense though (and there are chillers that have heat recovery now for this kind of thing)
  - ajb 3y ago
    I was not thinking of running heating and cooling at the same time. Simply that if you run a heat pump in reverse, you can use it for cooling. So you should be able to use the same device for heating in winder and cooling in summer. Even portable aircon's do this. The tricky part here is that you want heating to transfer heat to water, because radiators are much nicer than heated air. These Co2 based heat pumps are good because they can heat to a higher temperature which is necessary if you want to use your existing radiators or your house is difficult to insulate. But I'm not sure it would work well to use 'radiators' for cooling. Apart from any other reason, you won't want to risk freezing them.
    - deleted 3y ago
      [deleted]

hbarka 3y ago

This is from Sanden, the manufacturer of CO2 heat pump water heaters. They are known for the SANCO2. https://www.smallplanetsupply.com/sanc02 https://www.smallplanetsupply.com/sanc02

stephen_g 3y ago
Ah, interesting, apparently it is manufactured by Sanden, yes. I thought they were different because you can also buy Sanden branded heat pumps here in Australia too, and I assumed that since Reclaim also sell commercial ones made by Mitsubishi Heavy Industries I though the domestic one might be Mitsubishi too.
zeristor 3y ago
You’d think that if you highlighted 150°F iPad Safari could translate it to Celsius, or allow lookup to do the conversion.
- TheSpiceIsLife 3y ago
  65 degrees Celsius. For context, 54 degrees for 30 seconds will cause full-thickness skin burn.
- Someone 3y ago
  It does translate it for me (65.56°C). If it doesn’t for you, that likely is because of your settings
- zeristor 3y ago
  Strange. It does now. It’s not as if someone from Apple did a quick fix is it?

TheSpiceIsLife 3y ago

Thanks for this! I'm in Launceston, Tasmania and have access to no-interest credit up to $10k over three years for energy efficiency improvements including heat pump hot water. Our electricity use is dominated by heating and hot water, and the next step I've been wanting to take is heat pump hot water. I'll have a read of the link you provided when I get home. Thanks again.

stephen_g 3y ago
Yeah, it’s been good. I think you should be able to get it installed for something like $5K after rebates. My situation was a bit weird since I bought it in late 2021 directly from Reclaim (for about $4600 with the 315L glass lined tank), it sat in storage for a bit while I was doing other work on the house and then I had it installed more recently (cost $950) and then am claiming the STCs myself (which are worth about the same as the installation). It would be much easier to just have it done by an installer who orders it, installs it and claims the credits as part of the deal…

wkat4242 3y ago

The whole tank thing is really holding me back from moving away from natural gas. With gas you have unlimited hot water when you need it, it never runs out. I hate planning things in advance. And you're not wasting energy keeping it hot when you don't need to. And no wasted space for a big tank. If they ever manage to make electric water heating efficient enough to just heat on demand I'd probably use it. Of course it is more efficient with electric but I hardly use any gas anyway, my bill is like 15€ a month including fixed supply charges. There's just no return there for a big investment. And I can never have solar so free electricity is not a thing (I live in a big city and don't own the roof of the apartment building)

sgerenser 3y ago
I have always had tank-type water heaters and I don’t recall ever running out of hot water (family of 4). Is this actually a problem people have or is it just a tankless water heater industry talking point?
- lightedman 3y ago
  Various places will have different-sized water heaters installed. As a child, I lived in one place that had a measly 20 gallon electric heater. It sucked, badly. Dad showered first, then I got woken up to shower - barely any hot water.
- mikeyouse 3y ago
  Nope it’s a real problem, an undersized tank, high usage devices (eg a big bath tub) or just low temperature set on the unit for safety’s sake can cause the hot to run out. Modern tanks have a label on them that will let you know how many gallons of hot water it can deliver in its first hour of usage, some of those numbers are much lower than others.
  - stephen_g 3y ago
    The good thing about the heat pump I've got is that it's also surprisingly quick to heat up. If you do run out (I never have, but I experienced the speed the first time it was turned on when it was installed) you can go and press the 'Boost' button on the controller and you will have 50L in 20 minutes and a full tank (mine is 315L) in 3 hours. The system also heats the tank to at least 60 degrees C at the sensor point (about 2/3 of the way down) at least once every 24 hours and then has a tempering valve on the output for safety. That way you don't have scalding water at the point of use, but do have lots of hot water available and no issues with Legionella bacteria.

ajb 3y ago

That's really cool. Hope someone does one with integrated aircon soon.

stephen_g 3y ago
I have often dreamed about solutions for this, but at the end of the day I'm not sure that your average household would really have enough coincident demand for heating and cooling to make it worth it... Definitely for larger buildings it makes a lot of sense though (and there are chillers that have heat recovery now for this kind of thing)
- ajb 3y ago
  I was not thinking of running heating and cooling at the same time. Simply that if you run a heat pump in reverse, you can use it for cooling. So you should be able to use the same device for heating in winder and cooling in summer. Even portable aircon's do this. The tricky part here is that you want heating to transfer heat to water, because radiators are much nicer than heated air. These Co2 based heat pumps are good because they can heat to a higher temperature which is necessary if you want to use your existing radiators or your house is difficult to insulate. But I'm not sure it would work well to use 'radiators' for cooling. Apart from any other reason, you won't want to risk freezing them.
  - deleted 3y ago
    [deleted]