6 ms·

Something I don't quite understand about the article: Why is insulation tied to the heating source? In any given house, per unit of heat generated is going to

Something I don't quite understand about the article: Why is insulation tied to the heating source? In any given house, per unit of heat generated is going to leak out at the same rate no matter how that heat is produced, no? Whether that heat comes from a gas boiler, a heat pump, or a resistive heater shouldn't matter...?

eisa01 3y ago
UK and Germany has a hang up that they need to reuse the existing radiators, so you sometimes need to do extra work But it’s quite stupid: In both countries you need AC, so why not install a mini split heat pump+AC system like the Nordics and the US? It also doesn’t help that they don’t tax fossil gas like electricity, hence you often need subsidies to make it worthwhile to switch
- laserdancepony 3y ago
  > But it’s quite stupid: In both countries you need AC, [...] Almost no residential building in Germany has AC, and I'm unsure what you mean by "need". Also the buildings are built to last, so no remodeling every few years like in the US. That means one is stuck with most of the utility built into the house from the start. Remodeling a regular central European brick-and-mortar house to accommodate floor heating or duct vents is difficult and expensive.
  - bafe 3y ago
    Speaking from Switzerland: most building until recently were clearly built for cold winters, not hot summer. They are often insulated quite well and well heated, but recent summers showed that they aren't suitable for hot weather: they lack AC, rely simply on open windows for ventilations and frequently have too many large windows that can't be darkened enough, hence letting a lot of heat in
    - RamblingCTO 3y ago
      I agree with that take. Being like "look at Germany, we don't need ACs" is outdated bs. I absolutely suffer for almost 2 months a year because I don't have an AC including lack of sleep etc. We will see a rise, even though some people feel like that's the wrong thing to do with the climate change. There's a fine line: if you have green energy, why would you care? Consuming more green energy actually improves the overall situation, as more money is available to build out green energy in the first place (especially with things like Green Planet Energy). It's just the need for moral superiority for some folks that's stopping AC distribution in central Europe imho.
      - bafe 3y ago
        I agree with you on the energy use. Even more so because the peak of cooling demand corresponds very well with the peak of PV energy production. If the system is well designed, cooling using an efficient split AC unit will be almost free. Besides, if they really don't want people to adopt AC it's high time to start adapting buildings and cities for hot summers , which means reducing the amount of paved surfaces, planting more trees, adding forced ventilation to buildings and blinds that really darken rooms.
        RamblingCTO 3y ago
        Oh yeah good point! I always wonder why no one sees the very simple things you can do in a city. It shouldn't cost much to add trees etc. to a city with such a big impact
        bafe 3y ago
        They are starting. We had a referendum in Zurich last Sunday to to finance a project to adapt the city to hotter summers. It was a complex situation, with the municipal government recommending people reject the initial project in favor of a similar project organised by the city environment department. It all looks good on paper, but I fear another case of money being spent most on planning instead of using it to adopt simple measures. If you are interested, you can read all about it here: https://www.stadt-zuerich.ch/portal/de/index/politik_u_recht/abstimmungen_u_wahlen/aktuell/230903/230903-1.html https://www.stadt-zuerich.ch/portal/de/index/politik_u_recht...
  - eisa01 3y ago
    Already 13% has air condition, and half of those are the crappy portable AC type where you put a hose through the window. Sales are on the increase as summers are hotter. We even see apartment dwellers in Norway getting these https://www.verivox.de/presse/13-prozent-der-deutschen-nutzen-eine-klimaanlage-1120301/ https://www.verivox.de/presse/13-prozent-der-deutschen-nutze...
    - morsch 3y ago
      A lot of people have bought crappy AC to help cope with the five to ten days of heatwave a year. They're not running often.
      - ClumsyPilot 3y ago
        I've been running mine for about a month. Depends on your house, how much it traps heat, etc. Really it's besides the point - you might not need a plunger to unclog the toilet or a fire extinguisher or a first aid kit often, but when you do, you really need it!
  - yurishimo 3y ago
    What about portable units? They're pretty popular here in NL, but I suppose people are also rapidly installing mini-splits, at least here in the south.
    - Ekaros 3y ago
      Portable units in general are just bad. Not very efficient, noisy and not that performant. And sadly it seems most only have single pipe, not two that would fix lot of issues.
    - bafe 3y ago
      They are just terribly inefficient. Now a lot are sold here, but it's just not a feasible solution to make living in summer more tolerable. A mini split or even better centralised AC for the entire building is much more efficient
- Ekaros 3y ago
  From Nordic viewpoint Air-to-Air heatpumps are affordable and easy enough to install. Couple thousand for unit and professional installation. For single-family and even terrace no brainer. Next step up is more complicated and expensive, but still possible. And for rest district heating is common enough. And there a centralised solutions make sense, even real efficiency gains like using waste heat from factories and datacenters.
  - bafe 3y ago
    It seems you are a decade ahead of Switzerland, where the most common heating system is still an oil/gas furnace and installing a split AC unit requires permissions from the municipality. In some places they are even subjected to restrictions on operating times,as a tenant you can forget about AC unless you move to a very new Minergie unit. Now people are warming up to heat pumps but it seems the wider public fails to understand split AC units are nothing but mini heat pumps
- Angostura 3y ago
  > In both countries you need AC Less than 5% of houses in the UK have AC
  - ClumsyPilot 3y ago
    There are many things people need but don't have. In particular, half the houses in Britain have no insulation in the walls at all. In fact older houses tend to handle heat better - they are naturally drafty, there is a loft taking the heat, they have high thermal mass, and maybe they are even damp and have a leak and mould. All that takes away from the heat. But now we get newbuild apartments without AC's, and that should be a crime. These buildings are air tight, have zero ventilation, trap heat, no thermal mass so they don't stay cool from the night, and in some of them you can't open windows. And you are not allowed to install a split system because the landowner will never give permission. https://www.statista.com/statistics/292265/insulation-in-dwellings-in-england-uk-y-on-y/ https://www.statista.com/statistics/292265/insulation-in-dwe...
    - redeeman 3y ago
      so why would anyone ever move into such an apartment??
- Maxion 3y ago
  > UK and Germany has a hang up that they need to reuse the existing radiators, so you sometimes need to do extra work Air-water heat pumps are a thing
- iamthemonster 3y ago
  I'm really baffled as an Australian. I admit, our climate is mild but we do have 4 degree C nights and 44 degree C days sometimes. I spent AUD$10k (US$6k I think?) on split system aircon for my entire house and they work totally fine. In fact I must have slightly oversized because they have easily performed in the most extreme conditions. Installation took all morning. It's not about the technology. It's about how electricity is priced very highly compared to gas in the UK. Our electricity in Western Australia is only double the cost per kWh compared to gas, but one kWh of electricity generated three kWh of heat in a reverse cycle air con so it's a no brainer.
- sebazzz 3y ago
  “Need” = decide right? They want to reuse the existing radiators, but it comes with a bunch of disadvantages. You either need to replace the radiators with modern low-temperature convection radiators or place radiator ventilators. Air/water heat pumps are better suited for floor heating. You often can’t cool either, at least not with hybrid heat pumps, or you can cool a limited amount in this ever hotter getting climate.
  - jibbit 3y ago
    No one wants to reuse the existing radiators. The problem is that low-temperature radiators/underfloor heating isn’t viable in 200 year old houses
goethes_kind 3y ago
Just guessing but maybe heat pumps have a lower max power rating, so that you'd need better insulation to reach a desired temperature during colder days.
- solardev 3y ago
  This seems to be the case, given the other responses in the thread. Good guess!
pharmakom 3y ago
I think that green credits for heat pumps etc are not available unless your home is already well insulated.
orev 3y ago
In the context of the article, they are talking about replacing old boiler systems which were generally designed at the turn of the previous century. During that time, steam systems were designed to provide heat in buildings where the windows would be open to allow fresh air in (due to the idea that sickness was caused by “bad air”, so opening windows was considered a health thing), so they blasted heat at full tilt without any regard to efficiency. Those same buildings also weren’t designed to be airtight or insulated. With a heat pump, you really need to make an effort to keep the heat inside, as the heat output can’t match a boiler. So you need to redesign the whole building.
- solardev 3y ago
  If I'm understanding you right, heat pumps can't match the BTU (peak power) output of a traditional furnace? You can't just get a bigger heat pump (or several) sized for a larger building?
  - s1mplicissimus 3y ago
    as far as I understand, the challenge with heat pumps compared to traditional boilers is that they operate on a much lower heat. now older homes will often have radiators that are too small to dissipate enough heat given lower-temperature water. in newer setups, this is often solved by using bigger radiation surface (i.e. floor heating) You can size up your heat pump, but you still need to bring the temperature into your room, which requires a big enough surface for the heat to move from the water to the air.
  - Maxion 3y ago
    Lol of course you can.
    - jibbit 3y ago
      It obvious you don’t live in a typical uk house
  - callalex 3y ago
    I can’t speak for every situation, but basically: yes. It’s not the heat pump itself that’s the limit, it’s the energy source that feeds it. The skinny gas pipe going into my home can deliver vastly more energy than the crappy old wires and breaker box can. Upgrading the breaker box is certainly not impossible, but it is enormously expensive. The expense is mostly the expert labor required. If we really cared about making this transition, we would set up collective action and utilize economies of scale by having the utility company come through a neighborhood and upgrade service to every house at the same time to massively reduce the labor costs per home, and amortize the cost of the work. I don’t expect to see that happen in my lifetime, however.
nunodonato 3y ago
Maybe I'm wrong, but my experience with different kinds of heating tell me otherwise. Using AC (or any kind of air heater) has terrible efficiency, in the sense that when you turn it off, any small leak will drain all the hot air and you are left with a cold room. On the other hand, using radiating heat means the heat is "stored" in thermal mass in the room, so opening doors or windows have little effect.
iamthemonster 3y ago
No you're absolutely right, a poorly insulated home does not make any qualitative difference to a heat pump's effectiveness, you just need to buy a bigger heat pump. I think the way costs scale is important - a big gas boiler doesn't cost that much more, you're just burning more gas, but a big heat pump costs more. Heat pumps put more of the cost up front and less down the track. So if the uninsulated homeowner is facing a $10k bill for a massive heat pump they can say "ooh what if I spend $1k on insulation" and they could get the sizing down and spend $6k. There's really no fundamental difference. The heat pump itself doesn't know whether you've got a massive house that's well insulated or a tiny house that's poorly insulated, it's just a heat load.

eisa01 3y ago

UK and Germany has a hang up that they need to reuse the existing radiators, so you sometimes need to do extra work But it’s quite stupid: In both countries you need AC, so why not install a mini split heat pump+AC system like the Nordics and the US? It also doesn’t help that they don’t tax fossil gas like electricity, hence you often need subsidies to make it worthwhile to switch

laserdancepony 3y ago
> But it’s quite stupid: In both countries you need AC, [...] Almost no residential building in Germany has AC, and I'm unsure what you mean by "need". Also the buildings are built to last, so no remodeling every few years like in the US. That means one is stuck with most of the utility built into the house from the start. Remodeling a regular central European brick-and-mortar house to accommodate floor heating or duct vents is difficult and expensive.
- bafe 3y ago
  Speaking from Switzerland: most building until recently were clearly built for cold winters, not hot summer. They are often insulated quite well and well heated, but recent summers showed that they aren't suitable for hot weather: they lack AC, rely simply on open windows for ventilations and frequently have too many large windows that can't be darkened enough, hence letting a lot of heat in
  - RamblingCTO 3y ago
    I agree with that take. Being like "look at Germany, we don't need ACs" is outdated bs. I absolutely suffer for almost 2 months a year because I don't have an AC including lack of sleep etc. We will see a rise, even though some people feel like that's the wrong thing to do with the climate change. There's a fine line: if you have green energy, why would you care? Consuming more green energy actually improves the overall situation, as more money is available to build out green energy in the first place (especially with things like Green Planet Energy). It's just the need for moral superiority for some folks that's stopping AC distribution in central Europe imho.
    - bafe 3y ago
      I agree with you on the energy use. Even more so because the peak of cooling demand corresponds very well with the peak of PV energy production. If the system is well designed, cooling using an efficient split AC unit will be almost free. Besides, if they really don't want people to adopt AC it's high time to start adapting buildings and cities for hot summers , which means reducing the amount of paved surfaces, planting more trees, adding forced ventilation to buildings and blinds that really darken rooms.
      - RamblingCTO 3y ago
        Oh yeah good point! I always wonder why no one sees the very simple things you can do in a city. It shouldn't cost much to add trees etc. to a city with such a big impact
        bafe 3y ago
        They are starting. We had a referendum in Zurich last Sunday to to finance a project to adapt the city to hotter summers. It was a complex situation, with the municipal government recommending people reject the initial project in favor of a similar project organised by the city environment department. It all looks good on paper, but I fear another case of money being spent most on planning instead of using it to adopt simple measures. If you are interested, you can read all about it here: https://www.stadt-zuerich.ch/portal/de/index/politik_u_recht/abstimmungen_u_wahlen/aktuell/230903/230903-1.html https://www.stadt-zuerich.ch/portal/de/index/politik_u_recht...
- eisa01 3y ago
  Already 13% has air condition, and half of those are the crappy portable AC type where you put a hose through the window. Sales are on the increase as summers are hotter. We even see apartment dwellers in Norway getting these https://www.verivox.de/presse/13-prozent-der-deutschen-nutzen-eine-klimaanlage-1120301/ https://www.verivox.de/presse/13-prozent-der-deutschen-nutze...
  - morsch 3y ago
    A lot of people have bought crappy AC to help cope with the five to ten days of heatwave a year. They're not running often.
    - ClumsyPilot 3y ago
      I've been running mine for about a month. Depends on your house, how much it traps heat, etc. Really it's besides the point - you might not need a plunger to unclog the toilet or a fire extinguisher or a first aid kit often, but when you do, you really need it!
- yurishimo 3y ago
  What about portable units? They're pretty popular here in NL, but I suppose people are also rapidly installing mini-splits, at least here in the south.
  - Ekaros 3y ago
    Portable units in general are just bad. Not very efficient, noisy and not that performant. And sadly it seems most only have single pipe, not two that would fix lot of issues.
  - bafe 3y ago
    They are just terribly inefficient. Now a lot are sold here, but it's just not a feasible solution to make living in summer more tolerable. A mini split or even better centralised AC for the entire building is much more efficient
Ekaros 3y ago
From Nordic viewpoint Air-to-Air heatpumps are affordable and easy enough to install. Couple thousand for unit and professional installation. For single-family and even terrace no brainer. Next step up is more complicated and expensive, but still possible. And for rest district heating is common enough. And there a centralised solutions make sense, even real efficiency gains like using waste heat from factories and datacenters.
- bafe 3y ago
  It seems you are a decade ahead of Switzerland, where the most common heating system is still an oil/gas furnace and installing a split AC unit requires permissions from the municipality. In some places they are even subjected to restrictions on operating times,as a tenant you can forget about AC unless you move to a very new Minergie unit. Now people are warming up to heat pumps but it seems the wider public fails to understand split AC units are nothing but mini heat pumps
Angostura 3y ago
> In both countries you need AC Less than 5% of houses in the UK have AC
- ClumsyPilot 3y ago
  There are many things people need but don't have. In particular, half the houses in Britain have no insulation in the walls at all. In fact older houses tend to handle heat better - they are naturally drafty, there is a loft taking the heat, they have high thermal mass, and maybe they are even damp and have a leak and mould. All that takes away from the heat. But now we get newbuild apartments without AC's, and that should be a crime. These buildings are air tight, have zero ventilation, trap heat, no thermal mass so they don't stay cool from the night, and in some of them you can't open windows. And you are not allowed to install a split system because the landowner will never give permission. https://www.statista.com/statistics/292265/insulation-in-dwellings-in-england-uk-y-on-y/ https://www.statista.com/statistics/292265/insulation-in-dwe...
  - redeeman 3y ago
    so why would anyone ever move into such an apartment??
Maxion 3y ago
> UK and Germany has a hang up that they need to reuse the existing radiators, so you sometimes need to do extra work Air-water heat pumps are a thing
iamthemonster 3y ago
I'm really baffled as an Australian. I admit, our climate is mild but we do have 4 degree C nights and 44 degree C days sometimes. I spent AUD$10k (US$6k I think?) on split system aircon for my entire house and they work totally fine. In fact I must have slightly oversized because they have easily performed in the most extreme conditions. Installation took all morning. It's not about the technology. It's about how electricity is priced very highly compared to gas in the UK. Our electricity in Western Australia is only double the cost per kWh compared to gas, but one kWh of electricity generated three kWh of heat in a reverse cycle air con so it's a no brainer.
sebazzz 3y ago
“Need” = decide right? They want to reuse the existing radiators, but it comes with a bunch of disadvantages. You either need to replace the radiators with modern low-temperature convection radiators or place radiator ventilators. Air/water heat pumps are better suited for floor heating. You often can’t cool either, at least not with hybrid heat pumps, or you can cool a limited amount in this ever hotter getting climate.
- jibbit 3y ago
  No one wants to reuse the existing radiators. The problem is that low-temperature radiators/underfloor heating isn’t viable in 200 year old houses

goethes_kind 3y ago

Just guessing but maybe heat pumps have a lower max power rating, so that you'd need better insulation to reach a desired temperature during colder days.

solardev 3y ago
This seems to be the case, given the other responses in the thread. Good guess!

pharmakom 3y ago

I think that green credits for heat pumps etc are not available unless your home is already well insulated.

orev 3y ago

In the context of the article, they are talking about replacing old boiler systems which were generally designed at the turn of the previous century. During that time, steam systems were designed to provide heat in buildings where the windows would be open to allow fresh air in (due to the idea that sickness was caused by “bad air”, so opening windows was considered a health thing), so they blasted heat at full tilt without any regard to efficiency. Those same buildings also weren’t designed to be airtight or insulated. With a heat pump, you really need to make an effort to keep the heat inside, as the heat output can’t match a boiler. So you need to redesign the whole building.

solardev 3y ago
If I'm understanding you right, heat pumps can't match the BTU (peak power) output of a traditional furnace? You can't just get a bigger heat pump (or several) sized for a larger building?
- s1mplicissimus 3y ago
  as far as I understand, the challenge with heat pumps compared to traditional boilers is that they operate on a much lower heat. now older homes will often have radiators that are too small to dissipate enough heat given lower-temperature water. in newer setups, this is often solved by using bigger radiation surface (i.e. floor heating) You can size up your heat pump, but you still need to bring the temperature into your room, which requires a big enough surface for the heat to move from the water to the air.
- Maxion 3y ago
  Lol of course you can.
  - jibbit 3y ago
    It obvious you don’t live in a typical uk house
- callalex 3y ago
  I can’t speak for every situation, but basically: yes. It’s not the heat pump itself that’s the limit, it’s the energy source that feeds it. The skinny gas pipe going into my home can deliver vastly more energy than the crappy old wires and breaker box can. Upgrading the breaker box is certainly not impossible, but it is enormously expensive. The expense is mostly the expert labor required. If we really cared about making this transition, we would set up collective action and utilize economies of scale by having the utility company come through a neighborhood and upgrade service to every house at the same time to massively reduce the labor costs per home, and amortize the cost of the work. I don’t expect to see that happen in my lifetime, however.

nunodonato 3y ago

Maybe I'm wrong, but my experience with different kinds of heating tell me otherwise. Using AC (or any kind of air heater) has terrible efficiency, in the sense that when you turn it off, any small leak will drain all the hot air and you are left with a cold room. On the other hand, using radiating heat means the heat is "stored" in thermal mass in the room, so opening doors or windows have little effect.

iamthemonster 3y ago

No you're absolutely right, a poorly insulated home does not make any qualitative difference to a heat pump's effectiveness, you just need to buy a bigger heat pump. I think the way costs scale is important - a big gas boiler doesn't cost that much more, you're just burning more gas, but a big heat pump costs more. Heat pumps put more of the cost up front and less down the track. So if the uninsulated homeowner is facing a $10k bill for a massive heat pump they can say "ooh what if I spend $1k on insulation" and they could get the sizing down and spend $6k. There's really no fundamental difference. The heat pump itself doesn't know whether you've got a massive house that's well insulated or a tiny house that's poorly insulated, it's just a heat load.