4 ms·

The first thing you do when looking a heat pumps is discover how overdimensioned gas heaters are. My house has a 20kW unit, and I'm replacing it with a 6-7kW he

by brnt 4y ago

The first thing you do when looking a heat pumps is discover how overdimensioned gas heaters are. My house has a 20kW unit, and I'm replacing it with a 6-7kW heatpump, based on a calculation of historical use. Note that heat pump are usually placed in houses that are well insulated and thus never cool down; it's designed to run 24/7, not regularly heat up from eg 15C. Installing a pump without installing insulation (if you need it) is silly.

yetihehe 4y ago
I have new home and designer specified 8kW of heating, but I thought it's ridiculously low for such a big home, so I've bought 24kW pellet furnace. Guess what, it averages about 6kW.
kkfx 4y ago
I know, I've build a new home, electrically heated and well insulated. An water-water heat pump + and air-air in the VMC, for a total of ~1kW suffice for mild climate (like -2/-5℃ at night) it climb to 3kW for -10/12 and to 4kW to -15/18 outside. Never seen more than 6kW for -25. BUT it's a new home. Classic homes here are built with rocks and mortar, laid down on grownd, often stitched together in villages to spare a wall or two. As a result they are essentially impossible to insulate: insulating from the outside means agree with others for a job often as expensive al living the home for a new one. From the inside it's even more costly and not always doable since old homes tend to be irregular and with low ceiling resulting a too much internal space loss, not counting the effect of having loss much thermal mass. Toll buildings from just after WWII to the sixties are in even worse shapes, at that time almost no one care about insulation or thermal design because heating was veeeeeery cheap. The old rule in winter was "if it's too hot just open a window, it's cheaper than a thermostat". These buildings are the MAJORITY of the buildings and their own tend to be not so rich so they'll reach both natural and economical EOL soon and non one have a viable idea of what to do. Rebuilding anything is possible in mere theoretical terms, but in 30+ years, not tomorrow, and only with a public hand keeping costs low and plan with a bit of design instead of building a new real estate rush with similar results of those of the recent past in few decades. In practice though it's next to impossible because vast majority do not want to relocate. In south EU most home owners are middle class or even some low incomes, not just few rich and all other rent from big society. That's the real point. For EVs and p.v. it's essentially the same: those who live in modern homes have both in mean or can have at least. Almost all others can't. Those who lives in cities have already big parking issues since cities was build far before cars, so with not much room for them, and as well no room for reasonable domestic p.v. systems. Classic homes tend to be badly oriented and many still have no garages. As a result most can only recharge cars from public stations who are spread enough not too few but most are 22kW 3-phase as homes, so you need to find one, occupy it for maybe 4+ hours, move the car thereafter to live the place for another and find a parking for yours now charged. Something stressful enough that most who do not have a private garage simply do not buy EVs. Evolving civil infrastructures is not such a quick and easy things, especially in dense areas and during economic/social crisis of various kind.
- brnt 4y ago
  It depends a bit on how houses are built and how the culture of keeping them maintained is. Here it's feasible for most home owners to renovate. My house is from the 80ies, so some work is required, but not much, to get things compatible with a heat pump. Adding false walls in older houses is common though. The beauty is that these things pay for themselves. Also, opening a window if it's too hot (in winter) was never a rule here, we must save a penny wherever we can ;)

by brnt 4y ago

yetihehe 4y ago

I have new home and designer specified 8kW of heating, but I thought it's ridiculously low for such a big home, so I've bought 24kW pellet furnace. Guess what, it averages about 6kW.

kkfx 4y ago

I know, I've build a new home, electrically heated and well insulated. An water-water heat pump + and air-air in the VMC, for a total of ~1kW suffice for mild climate (like -2/-5℃ at night) it climb to 3kW for -10/12 and to 4kW to -15/18 outside. Never seen more than 6kW for -25. BUT it's a new home. Classic homes here are built with rocks and mortar, laid down on grownd, often stitched together in villages to spare a wall or two. As a result they are essentially impossible to insulate: insulating from the outside means agree with others for a job often as expensive al living the home for a new one. From the inside it's even more costly and not always doable since old homes tend to be irregular and with low ceiling resulting a too much internal space loss, not counting the effect of having loss much thermal mass. Toll buildings from just after WWII to the sixties are in even worse shapes, at that time almost no one care about insulation or thermal design because heating was veeeeeery cheap. The old rule in winter was "if it's too hot just open a window, it's cheaper than a thermostat". These buildings are the MAJORITY of the buildings and their own tend to be not so rich so they'll reach both natural and economical EOL soon and non one have a viable idea of what to do. Rebuilding anything is possible in mere theoretical terms, but in 30+ years, not tomorrow, and only with a public hand keeping costs low and plan with a bit of design instead of building a new real estate rush with similar results of those of the recent past in few decades. In practice though it's next to impossible because vast majority do not want to relocate. In south EU most home owners are middle class or even some low incomes, not just few rich and all other rent from big society. That's the real point. For EVs and p.v. it's essentially the same: those who live in modern homes have both in mean or can have at least. Almost all others can't. Those who lives in cities have already big parking issues since cities was build far before cars, so with not much room for them, and as well no room for reasonable domestic p.v. systems. Classic homes tend to be badly oriented and many still have no garages. As a result most can only recharge cars from public stations who are spread enough not too few but most are 22kW 3-phase as homes, so you need to find one, occupy it for maybe 4+ hours, move the car thereafter to live the place for another and find a parking for yours now charged. Something stressful enough that most who do not have a private garage simply do not buy EVs. Evolving civil infrastructures is not such a quick and easy things, especially in dense areas and during economic/social crisis of various kind.

brnt 4y ago
It depends a bit on how houses are built and how the culture of keeping them maintained is. Here it's feasible for most home owners to renovate. My house is from the 80ies, so some work is required, but not much, to get things compatible with a heat pump. Adding false walls in older houses is common though. The beauty is that these things pay for themselves. Also, opening a window if it's too hot (in winter) was never a rule here, we must save a penny wherever we can ;)