I bought a (nearly) new build house two years ago. Along with solar panels, it came with a design and nature of build that means that it is really inexpensive to heat in winter, but the indoor temperature stays really high at night (the highest need for AC is at bedtime to go to sleep). I therefore installed AC in several rooms of the house, told by the supplier that though there are no grants, they at least don't have to charge VAT on the system or the labour as they install air to air heat pumps, so get that VAT exemption on green heating.
As well as loving being cool, I also love two things. First, that in autumn and spring I can use this system to quickly heat rooms rather than turn on the central heating. Second, I love that the solar panels on the house directly supply a lot of the power the AC system uses (at least until early evening when the sun drops), and yes, I pre-cool the house during those hours.
Modern AC systems are very quiet, very efficient and, with solar and other green power, make a lot of sense. I hope the policy makers listen to you, Sam.
The lens through which it's seen being "Boiler Replacement" is also problematic.
I'd been told (don't know if it's still correct) that TPTB don't want to promote A2A is "what about hot water".
So I wander round flats, some of which are heated by _direct heat electric_ no less, which would be an ideal match for A2A, and the answer to "hot water" is, indeed and already "my shower, it is electric". "Please see: rest of world".
The perfect has become the enemy of the good.
When I eventually switch to a heat pump (only when the ROI is before the heat-death of the universe), I've no intention of introducing the overcomplication that's hot water cylinders (that are supposed to be 'serviced' and heat-cycled), and I'm just going to attach a dumb-as-a-rock 3-phase electric tankless water heater .
'only when the ROI is before the heat-death of the universe'- lol. A friend of mine studied Environmental Science at the UEA. Your comment reminded me of the early green subsidies on palm oil production. Apparently, the carbon debt from cutting down the rainforests to create 'green' palm oil production was only repaid after roughly 700 years.
What's puzzling me is why some of you are experiencing over heating in apparently well insulated buildings.
My experience (I had 30+ years in construction): '60's detached bungalow extended at GF level and into the roof with dormer. Spec: plain tiles on battens on counter battens on breathable membrane on 25mm rigid PIR on 50 x 150mm rafters fully filled with Polystyrene and underdrawn with 25mm rigid PIR, 12.5mm p/d & gypsum plaster skim. New GF walls: sand & cement render on dense concrete block outer skin, 125mm cavity with 100mm rigid PIR cavity fill, 100mm dense concrete block inner leaf (yes), render and set. Existing external walls: sand and cement render on SS exmet on protective membrane on mechanically fixed 50mm rigid PIR on existing external leaf, 50mm cavity filled post-construction with 50mm rockwool/injected foam on clinker block inner leaf, render and set finish. New windows: standard rack timber double glazed 20mm glazing cavity, low E glass. Solid floors throughout. Front facade South facing, no tree shade.
Main point to note: high thermal mass inside the external thermal envelope is crucial.
Typical real life performance: one summer's day circa 2020, heat wave 34C outside mid afternoon but only 24C inside without drawn curtains or blinds on South facing windows; outside doors and windows closed. A visitor that day simply could not believe that we did not have AC! Sure, the 24C internal temp' was higher than the house's normal equilibrium of circa 19/20C indicating that the extreme of 34C outside did have an abnormal effect. But it was clearly limited and would have been even more so had we had drawn curtains or blinds or those South facing windows (they weren't fitted at the time).
In other words, warm in winter (slow to lose heat stored in high thermal mass), cool in summer (slow to gain heat through the external thermal envelope). Similar to the well known 'cathedral effect' where the temperature inside 'feels' much cooler even though inside and outside air temp' is not that different. This should not surprise us: the Ballinger (1992) study found that nearly 2/3 of humans temperature equilibrium (at which we feel comfortable) is due to the exchange of RADIANT heat; only 1/3 is due to conduction/convection. It also, intriguingly, found that human skin has the highest absorptivity and emissivity of any substance know to man, matt black metals included. Astonishing.
So it would appear that overheating in well insulated buildings is a result of a mismatch between the thermal envelope and internal mass. A modern flat (sorry, apartment) with a highly insulated thermal envelope but low internal mass is doomed from the off.
That's my pennies worth, anyway. As Pro. Roy Strong (I think it was him) observed a while ago, the proper and balanced thermal performance of a building is either captured at the design stage or lost forever.
This language is typical and misleading. Batteries are improving but they are still a long way from being economic in this context. Heavy subsidy and substantial optimism keep these projects alive. These problems are surely tractable but the current trajectory does not make our 'climate goals' achievable in the the time frames promised by politicians.
The point being made is that AC demand is (marginally) offset to PV production. And that rather than resorting to importing power, users could augment with a battery - "free" energy in.
So battery can never be "not economic" - it's only a question of over what period it would offer a return on investment.
The continuing _plummeting_ of battery costs have helped. My own sums would be a break-even of around 6 years in these types of scenarios.
They can be effective at the grid level for the purposes of demand/surplus dynamics. The main benefit of the Big Battery in Australia was not for the purposes of energy storage. Instead, having an instant source of power available to the grid meant that fossil fuel power plants could be switched off in periods when no excess demand was anticipated, instead of running idle at significant costs for backup sources.
On the other hand, batteries are completely infeasible for energy storage at scale. The same thing is currently true of green hydrogen. Anaerobic digestion is probably the most promising technology as it makes use of existing waste materials like food and agricultural waste, and human and animal waste. It's still a long way from price competitiveness though, but does have significant prospects for improvements through technological innovation.
Biochar/Pyrolysis is another potential technology, but I don't rate it as much as anaerobic digestion, although it does have side benefits in terms of soil health and soil carbon sequestration.
Of course, batteries have a benefit to investors because government is willing to spend taxpayer's money on subsidy schemes.
I live in London, I moved from SF this year. Got a solar array + heat pump installed in my SF place and shocked to not have AC here. How do I get involved to help change the policy around? Does my MP care to know the nuances, or is there a more narrow path of appeal?
A good article. Fwiw, I retrofitted AC into 5 rooms of my semi-detached house. Wasn't ridiculous expensive or disruptive, and I'm very much enjoying it right now. As you suggest, the Octopus Agile tariff helps. I also use it in the winter when it's often cheaper to heat one room while I'm working at home also.
What about exhaust air heat pumps? This too is a missed game changer because these compact units can heat, cool, ventilate and provide dhw too, all at considerably lower capital and running costs than conventional awhp units. The low running costs are very near to island electric if Pv / battery is installed too simply because they recycle existing energy in a good thermal envelope rather than chasing it in from the external environment, but, if we all did this (as I have done) where would the generators pension funds come from???
Interesting point of view, as long as we can avoid US-style freezing aircon forcing to paradoxically wear a jumper when it's 35 degrees outside. Let's hope UK houses can get appropriately designed/renovated to better keep the heat out in the summer. Seems like step 1 to follow.
On another note, a little typo I noticed: you probably mean Norway's cheap hydropower, not geothermal power (that would be the little cousin Iceland 😉).
I bought a (nearly) new build house two years ago. Along with solar panels, it came with a design and nature of build that means that it is really inexpensive to heat in winter, but the indoor temperature stays really high at night (the highest need for AC is at bedtime to go to sleep). I therefore installed AC in several rooms of the house, told by the supplier that though there are no grants, they at least don't have to charge VAT on the system or the labour as they install air to air heat pumps, so get that VAT exemption on green heating.
As well as loving being cool, I also love two things. First, that in autumn and spring I can use this system to quickly heat rooms rather than turn on the central heating. Second, I love that the solar panels on the house directly supply a lot of the power the AC system uses (at least until early evening when the sun drops), and yes, I pre-cool the house during those hours.
Modern AC systems are very quiet, very efficient and, with solar and other green power, make a lot of sense. I hope the policy makers listen to you, Sam.
The lens through which it's seen being "Boiler Replacement" is also problematic.
I'd been told (don't know if it's still correct) that TPTB don't want to promote A2A is "what about hot water".
So I wander round flats, some of which are heated by _direct heat electric_ no less, which would be an ideal match for A2A, and the answer to "hot water" is, indeed and already "my shower, it is electric". "Please see: rest of world".
The perfect has become the enemy of the good.
When I eventually switch to a heat pump (only when the ROI is before the heat-death of the universe), I've no intention of introducing the overcomplication that's hot water cylinders (that are supposed to be 'serviced' and heat-cycled), and I'm just going to attach a dumb-as-a-rock 3-phase electric tankless water heater .
'only when the ROI is before the heat-death of the universe'- lol. A friend of mine studied Environmental Science at the UEA. Your comment reminded me of the early green subsidies on palm oil production. Apparently, the carbon debt from cutting down the rainforests to create 'green' palm oil production was only repaid after roughly 700 years.
Oops!
Air to air heat pumps that allow cooling are now allowed to be installed within the new building regulations that were introduced in May.
That's permitted development (which technically isn't building regs), but there's still plenty of anti-air-to-air rules.
What's puzzling me is why some of you are experiencing over heating in apparently well insulated buildings.
My experience (I had 30+ years in construction): '60's detached bungalow extended at GF level and into the roof with dormer. Spec: plain tiles on battens on counter battens on breathable membrane on 25mm rigid PIR on 50 x 150mm rafters fully filled with Polystyrene and underdrawn with 25mm rigid PIR, 12.5mm p/d & gypsum plaster skim. New GF walls: sand & cement render on dense concrete block outer skin, 125mm cavity with 100mm rigid PIR cavity fill, 100mm dense concrete block inner leaf (yes), render and set. Existing external walls: sand and cement render on SS exmet on protective membrane on mechanically fixed 50mm rigid PIR on existing external leaf, 50mm cavity filled post-construction with 50mm rockwool/injected foam on clinker block inner leaf, render and set finish. New windows: standard rack timber double glazed 20mm glazing cavity, low E glass. Solid floors throughout. Front facade South facing, no tree shade.
Main point to note: high thermal mass inside the external thermal envelope is crucial.
Typical real life performance: one summer's day circa 2020, heat wave 34C outside mid afternoon but only 24C inside without drawn curtains or blinds on South facing windows; outside doors and windows closed. A visitor that day simply could not believe that we did not have AC! Sure, the 24C internal temp' was higher than the house's normal equilibrium of circa 19/20C indicating that the extreme of 34C outside did have an abnormal effect. But it was clearly limited and would have been even more so had we had drawn curtains or blinds or those South facing windows (they weren't fitted at the time).
In other words, warm in winter (slow to lose heat stored in high thermal mass), cool in summer (slow to gain heat through the external thermal envelope). Similar to the well known 'cathedral effect' where the temperature inside 'feels' much cooler even though inside and outside air temp' is not that different. This should not surprise us: the Ballinger (1992) study found that nearly 2/3 of humans temperature equilibrium (at which we feel comfortable) is due to the exchange of RADIANT heat; only 1/3 is due to conduction/convection. It also, intriguingly, found that human skin has the highest absorptivity and emissivity of any substance know to man, matt black metals included. Astonishing.
So it would appear that overheating in well insulated buildings is a result of a mismatch between the thermal envelope and internal mass. A modern flat (sorry, apartment) with a highly insulated thermal envelope but low internal mass is doomed from the off.
That's my pennies worth, anyway. As Pro. Roy Strong (I think it was him) observed a while ago, the proper and balanced thermal performance of a building is either captured at the design stage or lost forever.
You've answered your own question here: great insulation, high thermal mass and low E glass combined.
None of our homes are designed that way. Older houses with high thermal mass have poor insulation and glass. Modern homes are the opposite.
"Battery storage, increasingly affordable...."
This language is typical and misleading. Batteries are improving but they are still a long way from being economic in this context. Heavy subsidy and substantial optimism keep these projects alive. These problems are surely tractable but the current trajectory does not make our 'climate goals' achievable in the the time frames promised by politicians.
I am pretty sure battery storage has a return on investment.
depends what you count or include, in the end it is subsidy that makes it profitable
What subsidy?
The point being made is that AC demand is (marginally) offset to PV production. And that rather than resorting to importing power, users could augment with a battery - "free" energy in.
So battery can never be "not economic" - it's only a question of over what period it would offer a return on investment.
The continuing _plummeting_ of battery costs have helped. My own sums would be a break-even of around 6 years in these types of scenarios.
They can be effective at the grid level for the purposes of demand/surplus dynamics. The main benefit of the Big Battery in Australia was not for the purposes of energy storage. Instead, having an instant source of power available to the grid meant that fossil fuel power plants could be switched off in periods when no excess demand was anticipated, instead of running idle at significant costs for backup sources.
On the other hand, batteries are completely infeasible for energy storage at scale. The same thing is currently true of green hydrogen. Anaerobic digestion is probably the most promising technology as it makes use of existing waste materials like food and agricultural waste, and human and animal waste. It's still a long way from price competitiveness though, but does have significant prospects for improvements through technological innovation.
Biochar/Pyrolysis is another potential technology, but I don't rate it as much as anaerobic digestion, although it does have side benefits in terms of soil health and soil carbon sequestration.
Of course, batteries have a benefit to investors because government is willing to spend taxpayer's money on subsidy schemes.
I live in London, I moved from SF this year. Got a solar array + heat pump installed in my SF place and shocked to not have AC here. How do I get involved to help change the policy around? Does my MP care to know the nuances, or is there a more narrow path of appeal?
A good article. Fwiw, I retrofitted AC into 5 rooms of my semi-detached house. Wasn't ridiculous expensive or disruptive, and I'm very much enjoying it right now. As you suggest, the Octopus Agile tariff helps. I also use it in the winter when it's often cheaper to heat one room while I'm working at home also.
What about exhaust air heat pumps? This too is a missed game changer because these compact units can heat, cool, ventilate and provide dhw too, all at considerably lower capital and running costs than conventional awhp units. The low running costs are very near to island electric if Pv / battery is installed too simply because they recycle existing energy in a good thermal envelope rather than chasing it in from the external environment, but, if we all did this (as I have done) where would the generators pension funds come from???
Interesting point of view, as long as we can avoid US-style freezing aircon forcing to paradoxically wear a jumper when it's 35 degrees outside. Let's hope UK houses can get appropriately designed/renovated to better keep the heat out in the summer. Seems like step 1 to follow.
On another note, a little typo I noticed: you probably mean Norway's cheap hydropower, not geothermal power (that would be the little cousin Iceland 😉).