Heat Pump.

davezawadi (David Stone): 

It is being suggested that radiators may be used with water at 50-60C. This is mad as we only need to heat the air to 20C, so why not heat it directly which will give a much better COP as the condenser temperature needs to be little more than 20C to work. 

Because if you have a 100+ year old building as I do, with 20+ radiating radiators (the old rib-type, not the newer thinner ones with cladding) then 50°-60° is the temperature you need to get them to radiate warmth into the room effectively. My pipes also run free inside the room, so I get a bit from that also.

Also, all the thermal energy imparted to the heating water starts inside and stays inside the building throughout its life, so it is not as if any thermal energy is being lost that way. 

 

Such systems are in common use in offices and commercial premises. Thus we exchange a temperature difference of 60C for 30C and the COP will approximately double. Surely these “fine minds” planning the Green revolution know just a little science?

Yes. Let's see, I could insulate my building, exchange all the radiators for air-convection heating and live happily ever after ….. except for the €250,000 it would cost me to do all that and the hefty monthly repayment on the loan.

However, your observations do resonate with something I had been thinking of doing. Keeping the building at, say, 14° with the radiators, and installing air spot-heaters in each room, run from a PV installation + battery, that turn on when the room is occupied. Practically, I know it works because I have tried it (a really annoying trial, though, because I only have one spot heater, a Dyson - they are not inexpensive - and had to cart it around with me/us. I also used 16° as the basis heat). The other practical issue is that there are no DC spot heaters on the market, so “direct drive” is not currently possible. 

I am in a different climate, though. We do go down to -15° or lower for a day, or a week, or a couple of weeks, as we did this February.

Actually, I am sure they know none whatsoever, and if they did this Climate and Green nonsense would have stopped dead in its tracks. Clearly, the IET editorial team does not either, as the latest E&T shows, it is simply regurgitated press releases from the COP26 mob. Why an Engineering Institution has so little science and engineering knowledge is completely beyond me. The most interesting point is that they don't want to listen and learn either!

I have plenty of science and engineering knowledge (although by no means as much as some). If you don't get the worry about global warming, I could introduce you to my Californian pals who are worried about the state burning up regularly and that large swathes of it may be rendered unliveable within a couple of decades. Or to my German colleagues trying to clean up after the more-than-thousand-year floods, not to speak of those mourning for friends and relatives they lost. I can also give you a reading list that would make the issues clear. Please ask.

davezawadi (David Stone): 

It is being suggested that radiators may be used with water at 50-60C. This is mad as we only need to heat the air to 20C, so why not heat it directly which will give a much better COP as the condenser temperature needs to be little more than 20C to work. 

Because if you have a 100+ year old building as I do, with 20+ radiating radiators (the old rib-type, not the newer thinner ones with cladding) then 50°-60° is the temperature you need to get them to radiate warmth into the room effectively. My pipes also run free inside the room, so I get a bit from that also.

Also, all the thermal energy imparted to the heating water starts inside and stays inside the building throughout its life, so it is not as if any thermal energy is being lost that way. 

 

Such systems are in common use in offices and commercial premises. Thus we exchange a temperature difference of 60C for 30C and the COP will approximately double. Surely these “fine minds” planning the Green revolution know just a little science?

Yes. Let's see, I could insulate my building, exchange all the radiators for air-convection heating and live happily ever after ….. except for the €250,000 it would cost me to do all that and the hefty monthly repayment on the loan.

However, your observations do resonate with something I had been thinking of doing. Keeping the building at, say, 14° with the radiators, and installing air spot-heaters in each room, run from a PV installation + battery, that turn on when the room is occupied. Practically, I know it works because I have tried it (a really annoying trial, though, because I only have one spot heater, a Dyson - they are not inexpensive - and had to cart it around with me/us. I also used 16° as the basis heat). The other practical issue is that there are no DC spot heaters on the market, so “direct drive” is not currently possible. 

I am in a different climate, though. We do go down to -15° or lower for a day, or a week, or a couple of weeks, as we did this February.

Actually, I am sure they know none whatsoever, and if they did this Climate and Green nonsense would have stopped dead in its tracks. Clearly, the IET editorial team does not either, as the latest E&T shows, it is simply regurgitated press releases from the COP26 mob. Why an Engineering Institution has so little science and engineering knowledge is completely beyond me. The most interesting point is that they don't want to listen and learn either!

I have plenty of science and engineering knowledge (although by no means as much as some). If you don't get the worry about global warming, I could introduce you to my Californian pals who are worried about the state burning up regularly and that large swathes of it may be rendered unliveable within a couple of decades. Or to my German colleagues trying to clean up after the more-than-thousand-year floods, not to speak of those mourning for friends and relatives they lost. I can also give you a reading list that would make the issues clear. Please ask.