Home insulation

[Iain]

“So renewable energy sold via the grid has an incurred component “
Not sure on the new term “incurred” but induced emissions are proportional to price paid

“but the same renewable energy given to GH2 has none, because there was no transfer price?”
Not given, sold to but for a lower price . See a short distance upthread
Would you pay the same price for electricity supplied as-and-when-available as electricity guaranteed 24/7/365 – of course not
Intermittent RE at landfall from offshore turbines will be cheaper / kWh than the guaranteed supply, esp when there is no other buyer.

“Direct usage of electricty, with heat pumps and electric cars, much more efficient < realistic 1.7 overall CoP – slow ramp up, hysteresis….>than conversion to GH2 <up to 95%>, is somehow much worse than using said GH2 at home?”
Yes, you’re e getting there . The HP starts with a huge carbon debt from being built and installed, the H2 boiler has only a small carbon debt. Over the lifetime of the kit, the H2 boiler wins because the HP can't pay back it's debt. Ref upthread #529

“needs some upgrades ..”
3 more grids (80 GW to 240 GW extra) plus Local networks is a bit more than “some upgrades” – you’re not an estate agent are you?    : )
“over the next two decades”
Way to slow
“gas network that needs quite a few upgrades”
Nearly there, the project to upgrade started in the UK years ago
“with upgrades needed to home equipment as well, hoping”
Agreed, dual CH4 / H2 ready boilers available now from 2x suppliers, cookers are easier – change the jets.
“no one explodes by some leakage?”
They’re not breathing it in    : ) With the boiler on the outside wall that’s unlikely

“Or follow the city of Zurich which “
Has 60% cheap hydro electricity and a strong grid. Similar in Norway with 99% Hydro, gas boilers are very rare there.

“Again, very biased….. only interested in promoting one solution over all else.”
I did say upthread that electrification and GH2 would meet somewhere, though I say H2 will dominate
It’s a forum, I’m making the case for GH2 with cognizance of the Induced energy effect. It’s OK to disagree. Happy to read your case for electrification.

Not sure you are fully onboard with induced emissions, here’s another way to think about it:

A rich man buys some goods
He accepts he is responsible for the emissions from the materials, processes, transport etc.
But it does not end there
All the goods are products of work, the workers get paid and spend their money on more goods
The rich man argues he is not responsible for their spending <edit: nor emissions arising> , I can see that.
However he is the cause (as in cause and effect). He induced their spending and the associated emissions by creating work for them.

That’s the crux of the high cost / low cost solutions argument. The higher cost one has a higher induced emissions component.

[interstitial]

Problems with the UK grid are far from universal. I know they are not relevant in the US. Many places in the US do not have gas so that would be new infrastructure in many places here but electricity is nearly universal.


I switched to heat pump it reduced my energy use from gas to about 1/5th the amount of energy. The cost of electricity was and still is far cheaper on an energy basis. Most electricity will be produced directly by wind/solar/hydro rather than GH2. Maybe 20% or less of electricity will be from GH2. GH2 loses at least 46-63% (https://www.energy.gov/sites/default/files/2022-03/H2-PACE-bloomenergy-4.pdf) of energy when made depending on type. Then it looses even more when gas is cooled compressed and pumped around. GH2 has to be more expensive than electricity because it is made from about double the amount of electricity.


What is stupid is claiming that the amount of resources expended doesn't matter just because it doesn't have an imbedded carbon cost. For all renewable energy is far better for the environment overall than fossil fuels it still has environmental costs so the less we need the better. Insulation pays off financially and with carbon very quickly. While it does very greatly depending on what is needed it can pay off financially in about 1-4 years. After getting insulation often people make comments like if I would of realized how much difference that makes I would have done it years ago. One of the things that keeps poor people poor is the lack of resources / stability / ownership to invest in the future. I have seen an investment of a few thousand dollars cut energy bills in half.


efficiency


BEV  total 69%
Renewable energy
AC grid transmission 90%
AC to DC and Battery charge 85%
battery to motion with regenerative brake 90%

HEV total 19-23%
renewable energy
AC to DC 95%
Electrolysis 75%
cool compress   85-90%
transport/pump 90%
Fuel cell 50%
GH2 to motion 90%


https://www.greenoptimistic.com/hydrogen-cars-efficiency/

BEV is three times more efficient than GH2 plus the convenience of charging at home (where available). No reason to switch to hydrogen in the future.

[Iain]

@#760

“16amp fuse which means its maximum draw is 3kW”
P=IV.  3.84kW

"6KW heat pump"
That's a COP of 2, not 3. Can you post the datasheet to clarify.

“maintaining a steady lower emitter temp instead of blasting temp at to provide instant heat.”

That’s the hysteresis problem. Maximum efficiency is from  a rapid ramp up to a comfy temperature just before the alarm goes off and you get out of bed. Or just before arriving back from school/work
The slow ramp up means it has to start earlier so the house has to be warmer (and losing heat) while all are still in bed / no one in the house
That brings down the overall COP to 1.7 -2, so a loser financially as well as high carbon
Internal insulation is better than external, enclosing mass, but is disruptive (rewire, redecorate) and not practical with fixed furniture, e.g. kitchens

“is being”
Future tense.
“is typically 1-2kW”
Actually is, or expected to be? It’s not commissioned yet?

Far sighted of you to fix ( I bought more panels and battery storage and another wind turbine)  but in Sept 21 you were still paying over the odds. The fact that those prices are no longer on offer to new customers is telling

“day power use is lighting and cooking”
not heating? You are paying more than 3x the gas price (plus the cost of the HP) an optimistic COP of 3 is not enough, a loser financially as well as high carbon

"£4.35 to travel 250 miles compared to £30+ for an ICE."
At 5p /kWh, £6.52 at 7p/kwh or £4.48 for the same distance in a genuinely green GH2 car

[Iain]

@#761


"The costs, risks and efficiency's  of running  100% H2 in large scale retail energy reticulation rule it out of contention"
Not ruled out, actually happened already. Already done small scale with real members of the public, much more to follow.

“when compared to expanding the electricity grid's capacity.”
A 3x expansion. No small task and high carbon.

“Suggested reading.”
Easy to find an opinion piece (it is clearly labelled as such - the “Recharge View”) against GH2, I won’t waste threadspace deconstructing it

GH2 is a disruptor with many advantages, as such it’s a threat to some business models:
Genuinely green from the start (Coal fired BEV derives take note)

Nearly free interseasonal storage
Ability to buy surplus RE cheaply as the only bidder in the room
Cheap and easy to transmit
Genuinely green from the start (Coal / gas fired BEV drivers take note)
Much lower induced emissions
Efficiencies improving for electrolysers to 95% and fuel cells

[Iain]

@#762


I switched to heat pump it reduced my energy use from gas to about 1/5th the amount of energy.”
A COP of 5? Really? Can you post the datasheet.
Are you quite sure you were comparing like for like, not a mild spell v a cold snap?

“claiming that the amount of resources expended doesn't matter just because it doesn't have an imbedded carbon cost.”

I think you are confusing imbedded/embedded with induced. As different as chalk and cheese..
I am concerned about the Carbon cost of resource used for building the HP, rads, 3x grids….etc.
Which can’t pay back even against BAU FFs, far less when compared to extremely low carbon GH2

“renewable energy is far better for the environment overall than fossil fuels”
Yes, of course, but GH2 is 2-3x lower carbon then Renewable electricity at the meter. See upthread

Your numbers on BEV / GHEV are out of date, besides the BEV fuel at charge point is way higher <carbon> than the GHEV fuel at charge point

[Iain]

I’m sure I’m not twisting any numbers, I was using yours, which didn’t make sense, hence the request for clarification

The snip in #737 was dated September 2021 with rates of 5p/24.1p.
I was paying 15p all day up to 29th Sept 21, then Symbio went bust and I got shifted to E.on at 22p all day. It went up to 28p on the 1st of April <2022>

So to clarify
What were you paying in Sept 21 Cheap rate /Day rate
What are you paying now

Also what would you say is the CoP during ramp up?, you could say 3, but realistically it’s zero – wasted heatloss.

[Iain]

You didn’t answer what your present rate is,  so I’ll infer
Octopus existing customers are promised Annual price cap minus £50
So that’s 27.3p / kWh unit rate. They can charge more than the unit PC for the day rate when there are dual tariffs, e.g. the GO tariff

So <Joe Bloggs Octopus> is paying at least 27.3p now, likely more, likely above the 28p / unit price cap


In the video they have to leave it on all day with no one home because it’s so slow to ramp up – what a waste.

It's actually on 80% of the time with no one benefitting most of that time.

The graph shows a Min temp of 16 degrees (once) then never less than 17 degrees 24/7 for January

That’s why CAT put the overall COP at 1.7 – 2 (it depends on hysteresis – mass and insulation)
So you (or any Joe Bloggs) will pay 4x the price for a 2x overall CoP, overall doubling the cost.

They may suit buildings occupied 24/7 but are not suited to intermittent use which most dwellings are.


If not ordered yet, you may want to reconsider the damage to your bank balance as well as the planet

[kassy]

Moved some posts featuring your favourite discussion from the Green hydro thread.

On a very general note in discussions it is interesting to find at least some common ground so you can then get to the more detailed questions but i don't think that discussion is even getting there.

So lets not have the same circular argument over and over.

[BeeKnees]

Why infer when I shared the details earlier

No I will not be changing my mind, I'm happy with the choice I've made and that Octopus will be offering me an intelligent tariff to make best use of it. Losing the gas connection and saving £100 in standing charges is a plus.

That you think a house needs to draw 10kW from the grid to match the heating provided by a gas boiler is where any chance of discussion and common ground ends. 

Part of the process towards a HP has been to monitor temps, my house didn't go below 15C all winter and that's with CH on only in the morning and evening.  So this is just another example of a fallacious argument. 

[kassy]

That you think a house needs to draw 10kW from the grid to match the heating provided by a gas boiler is where any chance of discussion and common ground ends.

And this is what i meant. You can't debate this on specific houses so find some overall numbers.

That’s the hysteresis problem. Maximum efficiency is from  a rapid ramp up to a comfy temperature just before the alarm goes off and you get out of bed. Or just before arriving back from school/work
The slow ramp up means it has to start earlier so the house has to be warmer (and losing heat) while all are still in bed / no one in the house

If you isolate the house it loses less heat which means that you can keep it at a steady rate at a much lower cost. Bet it feels warmer too when it is less drafty.

Anyway the idea is not to take the discussion here.

On another note what temperature difference in house would be needed anyway? I never heat it i just start moving in the morning.

[etienne]

On another note what temperature difference in house would be needed anyway? I never heat it i just start moving in the morning.

Historic Environment Scotland says

• The background heating, provided by a conventional radiator system or in some other
 way, could be controlled to a room temperature of 16°C (or whatever value is decided upon after more experience). This could be done with thermostats that respond to air temperature alone or that are shielded from direct radiation. It would be wise to have the rate of heat input to the system additionally limited in relation to the outdoor temperature. This is to prevent excessive opening of windows during wintertime as a means of temperature control (a procedure that can consume vast amounts of energy, when thermostatic radiator valves alone are used).
• The radiant appliances could be controlled manually. They would need to have a range of settings of the power‐level. It would also be good practice to have them switch off automatically when a space becomes unoccupied for more than a few minutes, provided that mechanisms are such that the heater did not switch off just because the room occupant was sitting still or having a nap.

https://www.historicenvironment.scot/archives-and-research/publications/publication/?publicationId=f2f2ebfd-ff37-4417-be92-a59400bb2665

[BeeKnees]

Something also not mentioned about huge variations in temp is humidity.

Warm air holding more moisture which condenses on cold uninsulated walls and windows, damaging the structure of the building and affecting the health of the inhabitants.

Insulating just makes sense and much of it is natural fibres or recycled plastics.

[sidd]

Insulation is good. But you got to be careful. A lot of the old houses were designes to breather. If you seal airways off when insulating older architecture, you will have problems.

Air to air humidity and heat exchangers are almost essential when doing insulation on older houses, and i have yet, over the last two decades or so, to find a company that sells insulation jobs that talk about them. HVAC people are more aware.

sidd

[Iain]

1/ Heat loss
Heat loss through insulation is measured in watts per square metre per temperature difference in Kelvin or Celsius W/m2K or W/m2C.

Double the insulation thickness halves the heatloss

Scottish Building standards require 0.19 W/m2K in the walls, that’s’s 400mm of glass fibre or 200mm of Rigid boards (e.g. Kingspan). Different values for roof and floor insulation.

If heat was more expensive and higher carbon it would be better to go thicker, if lower carbon and cheaper, the practical maximum would be thinner. Remember there is a carbon cost to the insulation which has to pay back

So if it’s 3C outside and 18C inside the difference is 15C
So that wall will lose 0.19 x 15 = 2.85 Watts for every square metre.
To maintain the internal temperature the heating system has to deliver 2.85 W/m2

For 125m2 of external wall that’s 356 W of power or 0.356kWH of energy for every hour.

That’s what you are paying for – making up the heat loss.

If the house is warm for 19 hrs when there is only benefit for 8 hrs, then 11x0.356 = 3.91 kWh is wasted per day.

That's for what would be considered a well insulated wall to today's standards


2/ Hysteresis:

The efficiency of the heating system is the same for high output or low output
Still true for Heat pumps which have better COP delivering at lower temperatures, but so long as larger emitters  (larger radiators or underfloor heating) are fitted they can deliver the heat.

Say the house is occupied in the morning for breakfast and evening and the occupants want it to be warm during those times
The heating has to start prior to wakeup / return from work to ramp up to the required temperature

A low output heater takes longer than a high output one to ramp up
During ramp up the walls are losing heat so a short duration ramp up loses less heat than a long duration ramp up
So overall the high output heater takes less energy to provide the occupants with their desired comfort, because of the rapid ramp up and shorter duration of unnecessary heatloss

3/ Mass
If the insulation was external to the masonry wall mass or internal the heat loss would be the same
If internal the heating system at start would have to heat a small mass - the air and house contents, internal plaster walls etc.
If external, it would have to heat the large mass of the masonry too, a much longer ramp up and cool down period where no one benefits from either.

In any case there is hysteresis.

Overall efficiency of the system over the heating season is lower and more damaging to the planet with a low output, slow ramp up heating system.

There are plenty of old houses in the UK where external insulation is preferred, because doing it internally is so disruptive.

4/ Humidity
The moisture comes from inside – breathing, showering, boiling rice
If it condenses on cold roof timbers rot can set in

Old houses have ventilated roof spaces to prevent that, modern ones have breathable membranes and foil backed plasterboard on the walls and ceiling.

Modern houses are less leaky (draughty) than old ones
Wind blows against walls and there is a higher pressure on windward, suction on leeward. Pressure is related to the square of windspeed

A sample of houses built by a builder e.g. on a new estate have to pass a pressure test simulating a strong wind
Pass mark is 0.5 Air Changes per hour, old houses have several ACH under the same conditions.

[etienne]

So overall the high output heater takes less energy to provide the occupants with their desired comfort, because of the rapid ramp up and shorter duration of unnecessary heatloss

This is not true with a well insulated house.
The easy way to check the context is to turn the heater off and check how fast temperature goes down. Is it degrees per hour or per day?
In a "per hour" context, you'll be better off with a strong heater and a big hysteresis, but in a "per day" context, you'll prefer a low power and high efficiency heater.
In the first case, you save energy by letting the temperature go down, and in the second case, since temperature doesn't go down, you save energy with an efficient low temperature heater.

[The Walrus]

Insulation is good. But you got to be careful. A lot of the old houses were designes to breather. If you seal airways off when insulating older architecture, you will have problems.

Air to air humidity and heat exchangers are almost essential when doing insulation on older houses, and i have yet, over the last two decades or so, to find a company that sells insulation jobs that talk about them. HVAC people are more aware.

sidd

So true.  A well insulated house traps not only heat, but all sorts of substances.  These range from household chemicals to radon gas.  Hence, indoor plant use is encouraged to clean the air and opening the windows and airing out the house from time to time.

[Aluminium]

Even with perfect insulation, you still need fresh air to breathe. And you probably need to warm up this air.

[Aluminium]

Yes. As for insulation, the obvious theoretical limit is zero heat loss. Is the limit for MVHR is zero too? In any case, I think, heat losses for ventilation are an important component of equation. With more CO₂ in air, it would require more ventilation to prevent unhealthy concentration.

[kassy]

Say the house is occupied in the morning for breakfast and evening and the occupants want it to be warm during those times
The heating has to start prior to wakeup / return from work to ramp up to the required temperature

But this is one specific scenario. What if people are there during the day?

And how much heat would you need to ramp up to get to your desired temperature? If you don't lose a lot of heat you might not have to change it much if at all. What range are we talking anyway since you have such a specific scenario in mind.

What ranges do people keep their houses at anyway?

[El Cid]

I have a geothermal heat pump and an air ventilation system with a heat exchanger. We use only electricity for heating. We also use the same system (electricity) for cooling, lighting, cooking, everything. We are also well insulated.

Our consumption is cca 50kWh/m2/year but we like it quite warm (24 C), so we could consume less if needed

[oren]

Say the house is occupied in the morning for breakfast and evening and the occupants want it to be warm during those times
The heating has to start prior to wakeup / return from work to ramp up to the required temperature

Right. For the carefully picked scenario of someone who needs heating only for half an hour, two times a day, insulation and an efficient lower power heating system are less of a benefit.
But what about normal people, those who spend the whole evening at home? Those who have a family where some members are at home at various times of the day? Those that work from home for some, or all the time? Those that spend weekends at home?
It's quite obvious efficiency and insulation pay back much faster and save carbon much better than waiting 20 years for something that may or may not materialize.

[KiwiGriff]

Beyond my ken as we don't get low temperatures. light frosts are a one a year occurrence.
 I do know the driven air output from a heat pump quickly warms a room.
I would guess that it would do so just as quickly as using passive radiators. 

[Sebastian Jones]

Really interesting thread here!
Retrofit insulation is always exterior here in the coldest part of Canada, because the additional heat mass is a bonus- if the heat source is shut off, the building takes longer to cool down.
We are working out the best way to use Electro-thermal-storage (ETS) as a heater.
It uses off peak electricity to heat up a mass of bricks. When there is heat demand during peak electricity demand, heat can be supplied with only the electricity to power the fan.
More and more people are installing Air Source Heat Pumps (ASHPs) because they are so fantastically efficient, at least they are down to minus 32. It still gets much colder than that here, so an additional heat source (wood, electric resistance, fossil fuel etc) is needed. Our goal is that we can reduce our electricity demand (through super insulation, ETS and ASHPs) that our hydro electric and solar (and hopefully wind soon) grid can supply all our electricity. We are at over 90% so far.

[Iain]

"The efficiency of the heating system is the same for high output or low output"
“This is absolutely untrue.”
It is absolutely true. I said output (in Watts), not temperature (in degrees C)
“so long as larger emitters  (larger radiators or underfloor heating) are fitted they can deliver the heat.”
The condensing boiler condenses at 55C or below. If the radiators are matched to the boiler, they deliver their heat to the rooms and return the water to the boiler at below 55C. More rads, lower return temp. Max efficiency, all comfy.
If you undersize the radiators, of course you get lower efficiency. Return temp is usually set at commissioning by a qualified heating engineer and rarely changed thereafter.

HPs also work most efficiently at lower temps, again you need to match the emitters, that’s why underfloor heating at low temps are recommended. (Needs floor insulation too). I’m sure I mentioned this before more than once, you need bigger/more rads for a heat pump.

“that they cannot supply the energy or they need to be much bigger than is really the case.”
Don’t forget air changes, in the video they expect all the air in the house to change out for the cold outside air every 40 mins. Your 26 kW boiler was fitted by a qualified heating engineer for a reason.(OK 3kw was for hot water, but you will be using an immersion 00:30 to 04:30)
Also note the windows, standard is U value 1.4, so 7 times the heatloss as the walls

“For the carefully picked scenario… only for half an hour, two times a day”
I’m sure I didn’t mention ½ an hour – I expect c. 4 hrs - 6pm to 10pm in the evenings.
Most people go out to work in the UK (pre / post covid) kids go to school so two ramp ups and cool downs a weekday. Once per day at weekends. I did mention a HP might suit a building occupied 24/7 – e.g. a hospital

Typ temp is 18C in the UK inside. Average winter temp (Dec, Jan) outside is 3C in Scotland.
“And how much heat would you need to ramp up to get to your desired temperature?”
Depends on mass. Low mass has lower hysteresis (lag) losses.
I have a small old detatched cottage with 500,mm thick stonework walls refurbished to 2005 standards with internal insulation. It drops to 10C in the morning.
IF it had external insulation (it does not) I would have to ramp up 72Te of masonry at 840J/kgC, 16.8 kWh. Ouch. Unsuitable for external insulation.

Realistically, the temp would not drop so much overnight with all that mass, but still 2.1kWh per degree for all that mass.

The new house is not finished yet so can’t say how it performs  but has  200mm boards/400mm glassfibre insulation to today’s standards plus predominately south facing windows, south garden room / buffer space. Should perform well.

“It's quite obvious efficiency and insulation pay back much faster and save carbon much better than waiting 20 years for something that may or may not materialize.”
Insulation costs to meet today’s standard are £8.70/m2 for the 400mm glass, £41.00 / m2 for the 200mm boards, used sparingly, only when space is a premium.

15mm aerogel would be £161/m2 (though that does exceed the standard)

In the 125m2 example upthread that would be £20125, or 20+ years average heating bill.

Remember there is a carbon cost for that insulation.

Appreciate you have a smaller heating requirement in Israel, but In the UK it’s a big issue. Hydrogen heating is already here for a pilot projects, will roll out to the rest in the next few years.

Genuinely green GH2 for heating will be widely available long before a HP can undo the damage it did to the planet by being installed.

[morganism]

I remember someone in Cali used silver bars for their thermal mass, because it exchanges heat so well.

Then they wrote it off as a depreciation expense over 10 yrs, which used to be the expected lifetime of purchased thermal mass systems !

[Iain]

“You've basically just confirmed that UK homes have undersized emitters to make their boiler run efficiently”

I’m sure I did not, the reverse is true. Larger emitters at lower temps are more efficient. A home with a standard boiler being replaced with a condensing <added: boiler or heat pump>would benefit from larger radiators being fittes. Rad size needs to be matched to the heat source by someone who knows how to do that.

Best to quote me directly and say where you disagree, rather than your own interpretation.

"On a mid terrace property the"
Windows, with higher heatloss make up a higher proportion of the area. Aerogel shutters?
Also are you aerogelling the floor?

Aren't most holidays in the summer?

[oren]

“For the carefully picked scenario… only for half an hour, two times a day”
I’m sure I didn’t mention ½ an hour – I expect c. 4 hrs - 6pm to 10pm in the evenings.
Most people go out to work in the UK (pre / post covid) kids go to school so two ramp ups and cool downs a weekday. Once per day at weekends. I did mention a HP might suit a building occupied 24/7 – e.g. a hospital

Some UK statistics collected from the web:
Of the 28 million households, about 10 million have dependent children, which probably return home 4pm rather than 6 pm.
6 million households of 70+ age, probably don't go to work that much.
In the main brackets 15% of ages 25-54 are not employed, and 35% of 55-64 are not employed.
Proportion of working age adults who did any work from home was 27% in 2019, and I bet will be higher post-Covid.
BeeKnees also mentioned holidays.
So what percent of households have all persons go out at 8pm and return only at 6pm on all days except weekends?

It's enough that even one person stays at home to raise heating needs more than these 4 hours a day you came up with (depending on outside temps of course). Efficiency of heating system is quite important, with choice of heating technology and insulation both playing a part. And the higher the rise in energy costs, the quicker the payback for efficiency investments.

In a more general view, heating is not the only energy use of a household, and given that electricity is already delivered to the home, over the long term it would be much more economical and better carbon-wise to maintain just one delivery method, especially as that electricity can provide higher efficiency heating as well.

[Iain]

“So what percent of households have all persons go out at 8pm<am> and return only at 6pm on all days except weekends?”
I don’t have an exact number for that specific Q, but my thoughts are:

For hysteresis, the number of ramp ups is the important one
I expect them to sleep with the heating off, so at least one ramp up per day
Of the others I expect few to be active inside the house all day, they go to the shops, visit friends, lunch clubs, job interviews etc. on weekdays and weekends.
Those who are home alone would heat only one room – e.g. lounge, study, not the whole house

“over the long term it would be much more economical”
Those not working or retired unlikely to be able to afford the HP and radiators, they will just have to suffer 7p/kWh at CoP 1 rather than 24 to 35p/kWh at overall CoP 2-3………………: )

“maintain just one delivery method”
True, only one day charge, though the day charge for electricity went up from 25p to 45p, for gas from 26p to 27p Gas infrastructure is so much easier to maintain. GH2 could be the only delivery method required if fuel cells continue to improve.

 “higher efficiency heating as well.”
For the reasons given upthread and in the Green Hydrogen thread, in Carbon terms as well £ cost to the user the H2 boiler is better for the planet. Instantaneous efficiency in operation is part of the story but there is much more to consider.

[kassy]

Really interesting thread here!

Since it is a hot topic i think i will split it out as Home insulation or something like that.

[Freegrass]

Really interesting thread here!

Since it is a hot topic i think i will split it out as Home insulation or something like that.

Home improvement and the cost of living?

[kassy]

Both are included in the discussion (also see BKs point below).

[kassy]

I split out the topic.

We are now moving onto a different issue.  Inequality.

Those with means will switch to EVs, install insulation, solar panels and heat pumps.  Their cost of living is plummeting.  They are switching to intelligent\smart tariffs and V2G that mean that even the energy they do use from the grid is cheaper than those trapped using power when demand is highest. 

Obviously at some point we need to do more then just throwing the usual subsidies at the problem.

For private home owners there are groups that can't pay the extra cost themselves. So actually we will need to subsidize that completely. The details still remain to be worked out but having the correct energy savings label is required for a sale. Then of course they should save money so part of that can be used for paying back on the loan. Technically if the owner sold the house when the improvements have just been made the new buyer should finance the lot although another alternative is to just transfer the subsidy so it would be a separate thing from the mortgage.

This is especially useful when changing the all the houses in a neighborhood. They are usually mostly standardized so it would be more efficient to do all at once.

Then there are some problem areas like commercial lenders. They should just write a proposal that reduce rent by a whole lot depending on how much the energy label lags which would move those just milking it into action.

Also where possible the V2G integration should be promoted. Ideally we should also have a simple city electric car which does not weigh that much and that is cheap but of course we forgot to develop that.

[NeilT]

Also we have to remember that no amount of insulation will transition the grid from Fossil Fuels to CO2 neutral technology.

Therefore we should hit the low hanging fruit of insulation pretty hard but still invest the larger share of money in ensuring that when we are fully insulated our generating infrastructure is not still belching out CO2.

There is always a lot of talk about how insulation is THE biggest thing in reducing home energy use.  Personally I found that ensuring your nice warm air does not go flying right out of the doors and windows, floors and in some cases walls which are not sealed, is a far greater benefit than a dramatic push to "insulate".  I have been in a home which was massively insulated but the owner liked the leaky wooden windows and doors and refused to replace them.

He might as well have not bothered with insulation.

[Tor Bejnar]

A decade or so ago I was active in a local-churches(etc.)-supported civic organization that wanted to put 'political' pressure on government agencies on focused topics.  One year the group 'voted' to have an environmental focus and a friend from a conservative Black congregation was greatly disappointed because he was 'all about' discrimination and poverty issues.  I told him, "Don't worry; the environmentalists care deeply about your issues, too."  When the "general theme" turned into "specifics" several months later, we "pressured" the city to actually spend existing funds for upgrading home insulation (and reducing outside air infiltration) for low-income homeowners and renters.  My friend "got it" at a later gathering when the relationship between large utility bills and cycles of poverty was discussed.

An aside, one of my kids bought a house on the "southside" of town (literally and figuratively); I was delighted to see recently installed solar panels on the roofs of her two neighbors (one installation not yet actually connected to the house/mains).  I spoke with the earlier installed panels' homeowner (a solo-parent mom) who said it didn't cost her a penny and her electric bill is 30% of what it used to be [paraphrased - I don't remember her exact words].  Good-bye "the same degree of poverty."   The city-owned utility is obviously doing what it should be doing. 

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When I talk about insulation I assume that includes air leaks. If you have large air leaks they are often even cheaper to fix than poor insulation and pay off much faster as well.

[Sebastian Jones]

Yup, airtightness is key.
Yukon contractors- builders and renovators- have started using this tech, linked below, which consists of little sticky particles that are blowing the house under pressure, try to escape and seal up leaks in the process.
Well, it's less crude than that:https://www.ecohome.net/guides/3364/aerobarrier-home-air-sealing-spray/

[Iain]

I wasn’t kidding about the aerogel shutters on the windows.
I was thinking of putting internal shutters on my N facing windows, though I was thinking of multi foil backing on a frame with tongue and grooved wood

Even a double glazed window to today’s standards is poor – 1.4 W/m2C
For comparison
Solid brick wall: 2 W/(m²K)
Insulated wall: 0.18 W/(m²K).


100% agree on air tightness.

[Sebastian Jones]

Standard windows here are triple paned, argon filled with a rating of 0.5W/m2.
People striving for net zero are installing quadruple paned windows.
I installed triples when I built my log home.
Twice, because I managed to crack every single one of them, one way or another.

[NeilT]

The glass is rated at that.  The frame is usually a section of air filled box UPVC, with or without metal structure.  That doesn't have a very good insulation figure.

Did they do something with that?

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My PVC windows have foam insulation in the frame cavity.

[Sebastian Jones]

The glass is rated at that.  The frame is usually a section of air filled box UPVC, with or without metal structure.  That doesn't have a very good insulation figure.

Did they do something with that?

They came without frames.
I simply glued them into the opening. There is no space between the wall and the glass.
For opening windows, I glued them into wooden frames I hacked together.
I'm not a very good carpenter, which is why I broke so many, but they look pretty good and there is no frost on them, even at minus 50 and no leaks.

[NeilT]

I'm not that good a carpenter either so I have circular saw table, chop saw, radial arm saw and a range of other power tools to make things easier.  Helps a lot.

I just wondered about the frames because our 18 year old windows with Argon gas fill have very cold frame in winter.  Most frames I've seen in Europe are just air filled.  Glad to know that is advancing.

[Iain]

Good windows
In the UK the volume manufacturers make windows to Buildings Standards levels (1.4) If you want something better, it costs disproportionately more.

Oops, made a mistake upthread, 15mm aerogel is 1.0 W/m2K. 78mm would be needed to meet the 0.19 standard.

I mentioned carbon payback times, for glass wool it’s less than a year, aerogel is 5.79y (for a slightly better than UK standard U value) . From #529 in the Hydrogen Economy thread the time to undo the damage is approx. double that.
So more is not necessarily better…
https://eprints.whiterose.ac.uk/169818/3/revision%20manuscript%20clean.pdf

That’s based on gas at intensity 183g/kWh, at 06:30 during ramp up average electricity intensity is 160 g/kWh in Feb 22 (wind may be available, not solar at that time, nor post sunset), https://carbonintensity.org.uk/

Hysteresis. Old semis, flats and terraced houses have masonry party (shared) walls, typ 225mm.
26% of uk population lives in a terraced house, 14% in flats, 32% in semi detached.
https://www.mortgagefinancegazette.com/market-news/housing/type-housing-people-live-11-08-2017/

23Te masonry for each of 2 party walls, that’s a lot of mass inside the insulated envelope on a slow ramp up where the heat soaks into these walls. A lot of energy is required, even to raise it by 2 degrees C, as per the case in the terrace in the example given.  Faster ramp up with less time for it to absorb would be better.

The “efficiency” (heat delivered to party walls v heat loss during ramp up + occupancy) is as low as 2% for 1 hr, rising to 21.3% for a 14 hour occupancy post ramp up. Pants efficiency.

However, if insulated to 0.19 all round and airtight, you only lose 3.42 kWh while out for 8 hrs, so the “efficiency” improves markedly to 11.1% for a 1 hr and to 67% for 14 hrs occupancy
I expect 1.6 ramp ups per day averaged working/weekend/holiday

This is not an ideal building for a low output heat pump. CAT put the average realistic in-use season long CoP at 1.7 for a HP with operational CoP of 3-4 , I expect the number is skewed by lower mass internally insulated detached and semi-detached houses.

Best ways forward:
Keep the quick ramp up 26kW gas boiler and persuade neighbours to fit a heat pump. It has to start much earlier so will heat the party walls before your boiler comes on.
OR
Keep the gas boiler and spend the 6kW HP money and carbon cost on insulating the perimeter exposed to outside to practical max of 0.19, make airtight, and persuade neighbours to do the same (not practical to insulate party walls, U value 2, though with a lower dT). Consider heat recovery ventilation.
OR
If you really want to prolong dependence on the coal shovelling industry, early morning pre dawn or post sunset when wind may or may not be available, fit high power resistance elements plus forced convection for a quick ramp up, that way only the air and contents plus a layer of exposed skin of the 225mm party wall will absorb the heat, so lower hysteresis loss.

There is another solution, my favourite element. It begins with "H"

See attached .csv for the numbers

[Iain]

.csv attached

[kassy]

Decision to ditch zero-carbon homes rule ‘will cost households an extra £525 a year’

Households could have saved more than £500 a year on energy bills during the cost-of-living crisis if the government had not scrapped a green policy for homes, according to new analysis.

UK parliamentary research - seen by The Independent - increased previous estimates to reflect soaring household bills, which are expected to rise even further later this year.

It estimated the missed potential for savings will rise to as high as £525 a year by autumn - up from around £370 a year currently.

The Liberal Democrats - who commissioned the research - said shelving tough environmental rules for new homes was “short-sighted” and ended up “slapping hundreds of pounds” onto bills.

The Zero Carbon Homes policy would have prevented new houses from releasing a net amount of carbon into the atmosphere during day-to-day running.

Among other factors, this would have been achieved through good energy efficiency – considered key to keeping bills, as well as emissions, down.

It was scrapped in 2015 - the year before it was due to kick in.

more on:
https://www.independent.co.uk/climate-change/news/energy-bills-zero-carbon-homes-b2087873.html

Just raising the overall level does so much good but governments often also profit from taxes. Still all money not going into heating could go into other sectors of your economy.

[NeilT]

So because the government didn't force companies to put in a certain level of insulation into new homes and people buying those homes didn't check the insulation level to ensure they have the right amount of insulation to reduce bills, they are paying more money now?

OK I'm good with updating standards for new homes.  But if you buy a new home and don't look at the insulation levels, then there is a certain amount of responsibility coming your way.

The biggest problem in the UK is not new homes, it is the 29m existing homes which are at levels of insulation from zero to fully Net Zero compliant.

There has to be a level of responsibility here.  The government can't do everything or think of everything.  People do have to use that brain they have, especially in the UK where they don't like a lot of government interference in their lives.

[kassy]

The government should optimize for both the owners and renters. What is new should be better.
Since we have no time to waste all owners should be forced to build better too.

For the 29M homes you have to figure out the most efficient way to go about it. It would make sense to go after similar style buildings in areas where they are concentrated first.

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Lots of people do not realize the difference insulation makes and have no interest in learning about it. Being a smart consumer takes time and effort and many people have many different interests. Not everyone is interested in searching out the best deals. A poorly insulated house is always a bad deal and never justified so why not have standards.

[Iain]

Ref #44
That would be David Cameron – “Cut the green cr*p”

When the standard for windows changed from 1.6 to 1.4 W/m2K, the volume manufacturers just made windows to the new standard ant they cost much the same – so Govt regulation makes a difference

Installing insulation in a newbuild is so much easier then retrofitting, there are standards for newbuilds and extensions, enforced by Building Standards.

Same goes for fitting PV when the tiles are going on the roof, with scaffold in place and one team fitting one after the next on the same building site

There are energy performance Certs. Any house for sale in teh UK must have one, so buyers can see what they are getting:
https://energysavingtrust.org.uk/advice/guide-to-energy-performance-certificates-epcs/

[NeilT]

There are energy performance Certs. Any house for sale in teh UK must have one, so buyers can see what they are getting:
https://energysavingtrust.org.uk/advice/guide-to-energy-performance-certificates-epcs/

Yes but for some reason they are mostly not interested in looking.

If the Government wanted to motivate insulation in the most ineffective homes (old, no insulation etc), they should run an advert campaign for years.  One crafted by the best in the business, not some government think tank.  One which shows your money flowing out of the building.

If they were really serious, right now, they would set up grants for insulation improvement then means test energy support based on your energy efficiency of your home.  Low efficiency then you need to apply for a grant to improve it before getting energy support.

It won't happen but these things are what motivate people.  Save the planet for most city dwellers?  They don't know what the "planet" really looks like and have indifferent attitudes to "saving" it.  Losing money?  Very focused.

Such is life.