Author Topic: Building thermal insulation.  (Read 9498 times)

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Online Zero999Topic starter

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Re: Building thermal insulation.
« Reply #50 on: July 25, 2022, 07:20:54 am »
You can also get monobloc heat pumps:
https://les.mitsubishielectric.co.uk/products/residential-heating/outdoor/ecodan-puhz-monobloc-air-source-heat-pump

which can be installed by a regular plumber, as all the air con stuff is in one self-contained unit.  These, in theory, just fit in place of the heating loop in your property, though you may require some radiators to be changed to handle the lower delta-T.

These cost ~roughly 2-3x the cost of a gas boiler right now.

Personally I'd keep the gas boiler as a backup and use air source heat pumps for the majority of the time.  For the odd day that goes below 0C where heat pumps roll off in efficiency, I can switch to gas.  It's a shame I'll have to pay a gas connection fee all year round but I guess someone's got to pay for the infrastructure.
It's not the cost of the heat pump itself for many people. Heat pumps don't provide instant hot water. I have a combi boiler, which heats the water as it's being used. A heat pump would require a hot water cylinder to be fitted, costing more in pipework, labour and space. At the moment, it wouldn't pay for me to fit a heat pump. I'm better off paying the mortgage off more quickly, or investing the money in stocks and shares.
 

Offline tom66

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Re: Building thermal insulation.
« Reply #51 on: July 25, 2022, 07:38:34 am »
Maybe I'm thinking about this in the longer term but a hot water tank is a benefit, not a cost.

Combi boilers are inefficient for heating hot water because they produce it on demand: they need to burn a tremendous amount of gas to get the heat exchanger up to temperature, if the system hasn't been used for heating recently.  I recall the calculation being that if your system takes 30 seconds before upstairs taps have hot water, then it burned about 200Wh of gas just getting to that point, let alone any actual usage.  It's fine if all you do is take showers (runtime >> startup time), but if you wash your hands with warm water, then it's not going to take many cycles before that pays off.

Whereas a tank, whilst it does use space, consumes relatively little 'lost' energy (our tank is ca. 1kWh/day and better ones do exist) that's made up by the lack of cycling.  And once we have a home with solar, excess power from that can divert into the tank, or cheap electricity can be bought overnight to charge it up. 

You can also get electric instant hot water, usually around 9-12kW.  More expensive than a combi though, and a bit slower admittedly, but an option if you don't want a tank and still wanted heat pumps.

I'm a big fan of 'inflationary hacks' and energy efficiency is one of those.  Paying the mortgage down quicker is also sensible;  it depends on your longer term opinions on energy prices...will they go down or stay where they are, or even go further up?
« Last Edit: July 25, 2022, 07:41:08 am by tom66 »
 

Online Zero999Topic starter

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Re: Building thermal insulation.
« Reply #52 on: July 25, 2022, 10:04:03 am »
Maybe I'm thinking about this in the longer term but a hot water tank is a benefit, not a cost.

Combi boilers are inefficient for heating hot water because they produce it on demand: they need to burn a tremendous amount of gas to get the heat exchanger up to temperature, if the system hasn't been used for heating recently.  I recall the calculation being that if your system takes 30 seconds before upstairs taps have hot water, then it burned about 200Wh of gas just getting to that point, let alone any actual usage.  It's fine if all you do is take showers (runtime >> startup time), but if you wash your hands with warm water, then it's not going to take many cycles before that pays off.

Whereas a tank, whilst it does use space, consumes relatively little 'lost' energy (our tank is ca. 1kWh/day and better ones do exist) that's made up by the lack of cycling.  And once we have a home with solar, excess power from that can divert into the tank, or cheap electricity can be bought overnight to charge it up. 

You can also get electric instant hot water, usually around 9-12kW.  More expensive than a combi though, and a bit slower admittedly, but an option if you don't want a tank and still wanted heat pumps.

I'm a big fan of 'inflationary hacks' and energy efficiency is one of those.  Paying the mortgage down quicker is also sensible;  it depends on your longer term opinions on energy prices...will they go down or stay where they are, or even go further up?
It depends on your usage.

I hardly ever use hot water, so that would be 1kWh/day up in smoke. I live on my own. I normally shower cold and use cold water to wash my hands, as hot dries my skin. If I need hot water to wash the dishes, I boil a kettle, but I find modern detergents are so good I can use cold if they're not very greasy.  The hot water from the combi boiler is used occasionally, normally when I have guests over who want a hot shower. I have the thermostat set to a cool 15°C and it's only on for 6 hours a day on work days and a bit more when I'm off work, although I'm often out.

I doubt the energy savings of a heat pump would ever pay for its upfront cost, then there's all the inconvenience and hassle of getting it done which is more of a deterrent than the money for me.
 

Offline tom66

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Re: Building thermal insulation.
« Reply #53 on: July 25, 2022, 12:31:18 pm »
Yeah, that's fair enough - you're probably a rounding error in terms of savings.

Still, it disappoints me that new properties are being built with combi boilers still.  It's a really bad decision.  These should be super-insulated and use small heat pumps to provide heating and cooling.
 

Online themadhippy

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Re: Building thermal insulation.
« Reply #54 on: July 25, 2022, 01:42:18 pm »
Quote
as most places have huge subsidies for installation, prices skyrocketed, especially with companies licensed to install the "right models" on the list for those subsidies.
And strangely the price increase is around  the same amount  as the subsidy.
 
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Online Siwastaja

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Re: Building thermal insulation.
« Reply #55 on: July 25, 2022, 02:55:35 pm »
so even with the UK's broken energy market keeping gas synthetically cheap....   heat pumps still end up cheaper to run.

Yes, plus:

It's becoming more and more obvious this synthetically cheap gas is not going to last for long. Also here we have this thing called "moral".

For example, right now Finnish taxpayers are paying for Germany's synthetically cheap gas. The problem just is: Germany has 16x the population. Now that Finland subsidized German cheap gas by some ~10 billion euros - 4% of the country's GDP - divided to each German this is mere ~120EUR. Sure it helps them a bit. But divide the same sum to every Finn, and now it is suddenly ~2000 EUR. You could install five ****king million heatpumps (premium models) with this sum. It would be better investment than just paying for more expensive gas.

The only consequence is slow annihilation of Finland as a country, and transition into total poverty and source of some cheap labor, in eternal debt.

Once you have pumped us dry, then there is no Finland left to pay for your bills. The problem is, due to the small size of Finland, we are already very close to that point.

At some point your fixed price gas contracts just can't be maintained because someone has to pay the actual bill.

Thanks to Brexit we don't likely to have to literally pay your (the UK commenters) gas bills. But the bottom line is the same: your bullshit gas is artificially cheap, and that is not going to last forever.

Meanwhile in Finland, successful people avoid earning too much to avoid 70% income tax, and instead do plumbing work for their own houses. This way we can at least try to avoid sending any more money out of this country. But for long-term productivity, it would be more fruitful if I did EE things as full-time job (because I'm relatively good with this) and let others do the plumbing. But can't do that, because then my wage is sent to Germany, Spain etc., and I still can't afford a plumber.

So I have installed my heatpump myself. I have made plumbing for water energy storage system myself. I have installed heat recovery ventilator myself. I have to, because our heating energy bills have quadrupled during this year. We don't have the luxury of 10-year fixed price cheap gas contracts.

Think about that.
« Last Edit: July 25, 2022, 03:01:17 pm by Siwastaja »
 

Online Zero999Topic starter

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Re: Building thermal insulation.
« Reply #56 on: July 25, 2022, 08:42:29 pm »
Gas is cheaper than electricity. There's nothing artificial about that. It's a primary energy source, where as electricity is mostly secondary i.e. generated from nuclear, gas and coal. I know some of it is renewable and there are government subsidies for green energy.

Here's my bill showing my usage over the last year.  To be fair we did have a mild winter. I've seen higher bills, but even then, I don't see how I could save any money with a heat pump. I don't use enough heating for that.

Annual Energy Usage July 2021 to 2022
« Last Edit: July 25, 2022, 09:54:11 pm by Zero999 »
 

Offline tom66

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Re: Building thermal insulation.
« Reply #57 on: July 25, 2022, 09:11:17 pm »
At present, electricity prices are coupled to the cost of the most expensive generation source, which is currently gas due to the Ukraine invasion.   In principle, this exists to ensure that this source is always available for grid stability.  The problem is, this is leading to situations like this on Agile (for today, at least):

https://www.energy-stats.uk/octopus-agile/

... where prices rarely dip below 40p/kWh despite somewhere around 33% of energy being generated by wind which typically has a strike price of around 4p/kWh.  (You can very roughly calculate the cost paid at auction by taking the per kWh price and dividing by 2.2 for Agile.) The most marginal generator sets the half hourly price,  even if it contributes only 5% of the energy.   We've had days when renewables are providing upwards of 80% of all demand but prices remain stubbornly high because of this rule.

Ofgem are consulting on changing this, as they believe that the price should be determined by a true supply and demand auction.  (Frequency reserve auctions will still exist to provide stability.)  The result *should* be lower energy prices, but only when renewables are in high supply.  So there's no reason to expect the 4x or so cost difference between gas and electricity to remain true forever, they may well begin to vary considerably.
« Last Edit: July 25, 2022, 09:13:09 pm by tom66 »
 

Online Zero999Topic starter

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Re: Building thermal insulation.
« Reply #58 on: July 25, 2022, 09:52:56 pm »
My gas has gone up more than electricity. If it was purely due to gas prices, then both should have gone up the same.

Last year had a colder winter and April was especially cold, so my usage was much higher, but this year's lower usage hasn't been enough to offset the higher price. I'm not too bothered as it's still not much money for me spread over a year, as my usage is so low.

Annual Energy Usage October 2020 to 2021
« Last Edit: July 25, 2022, 09:55:03 pm by Zero999 »
 

Offline Someone

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Re: Building thermal insulation.
« Reply #59 on: July 25, 2022, 10:18:30 pm »
Gas is cheaper than electricity. There's nothing artificial about that.
Cheaper yes, cheaper by a factor of 4x or more? Historically true, but not in the past few years (depending on your wholesale market).
https://www.ofgem.gov.uk/wholesale-market-indicators
Gas is up around 1/3 to 1/2 the price per unit of energy compared to electricity pretty much around the world, and this started happening before the eastern European conflict (as tom66 mentions above electricity price will track marginal generation costs so they will lift together somewhat).

UK consumers having their energy regulator force the retail price ratio to be different to the wholesale price ratio is a massive market intervention, its artificial, and that amounts to a subsidy for gas users. Its not sustainable economically, someone is paying for it. But you'll make lots of noise and confusion if people point this out because you're the one benefiting. We're headed for Streisand Effect here, keep making more noise and will only get more attention.
 

Offline PlainName

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Re: Building thermal insulation.
« Reply #60 on: July 25, 2022, 10:34:31 pm »
Does it really matter if gas is cheaper or more expensive? The fact is it's a single source - run out, or get cut off, and you have nothing. With electricity you can switch to whatever fuel you can use to drive a generator - water, wind, solar, gas, whatever. So the end user (meaning the equipment to be powered) should logically be electric.

Of course, electricity consumers are dependent on the grid and whatever thy choose to use for fuel. When they go down, so do we. We might have a local generator of some form and we might even have decent solar or wind, but typically we either live and die with the grid, or completely off the grid. Even with solar and wind, if we are on the grid that all goes down too if the grid does. We need a simple way for a switch between grid and local generation, transparent (apart from how much power) to the consuming equipment.
 
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Offline Someone

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Re: Building thermal insulation.
« Reply #61 on: July 25, 2022, 11:25:01 pm »
Does it really matter if gas is cheaper or more expensive? The fact is it's a single source - run out, or get cut off, and you have nothing. With electricity you can switch to whatever fuel you can use to drive a generator - water, wind, solar, gas, whatever. So the end user (meaning the equipment to be powered) should logically be electric.
The end user (generally) just picks the lowest cost option. When consumers are sold artificially cheap gas, of course they use it. Its those gas to electricity generators that should be stabilizing the relative wholesale market pricing of the two, whenever electricity is more than 3x the cost of gas all the combined cycle gas generators can start printing money (profiting), bringing the price of gas up and the price of electricity down. Around 1/3 of the electricity generation and capacity in the UK is gas fired, and load factors have been steadily dropping with the decline in electricity demand, so they have capacity spare.

When gas burned in a power plant and then used to run a heat pump makes more heat than just burning the gas directly at point of use, consumers should be incentivized to have heat pumps. A free market would have reached that equilibrium long ago. But the UK keep gas pricing low for consumers, and those consumers do "stupid" things in response (but then come on here and shout about how nothing is wrong and its all completely normal).
« Last Edit: July 25, 2022, 11:28:55 pm by Someone »
 
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Online Zero999Topic starter

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Re: Building thermal insulation.
« Reply #62 on: July 27, 2022, 06:05:06 pm »
State interference with markets is seldom a good thing. The government go on about net zero and banning gas boilers, but won't stop meddling with the market. I don't buy into net zero, because our emissions are a drop in the ocean compared to other countries.

I'm not averse to the idea of a heat pump, but there's no point in me installing one. Perhaps if I have to because my gas boiler breaks down, I might consider one, if it can cool as well as heat. My CO2 emissions are well below the average for Brit. I don't drive and cycle most places. I do enough as it is.
 

Offline EPAIII

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Re: Building thermal insulation.
« Reply #63 on: July 28, 2022, 12:53:54 am »
No screens in Germany. Who would have thought that? I guess the need for them, although present, must be rare.

As for US homes, my experience is windows here do have them. But doors are another thing. Most people do not leave their doors open. Closed and locked is more the norm.

That "... poorest tarpaper shack in backwoods US ..." is probably about ready to fall down or blow away with the next stiff breeze. The screen door may be the only door. Believe me, I have seen more than one.





I have been a tourist when northern Europe was having abnormally-high summer temperatures.
(A headline in das Bild translated to "Is Berlin becoming Rome?".)
I was not surprised when inexpensive hotels did not have air conditioning, but I was surprised that there were no window screens to facilitate air breezes without wasps and mosquitos.
Berlin was also suffering from a wasp invasion that had killed at least one police officer;  the sidewalk restaurants had put out glasses of the syrups used for Berliner Weisse to keep the wasps from the customers.
(The poorest tarpaper shack in backwoods US has a screen door.)
Paul A.  -   SE Texas
And if you look REAL close at an analog signal,
You will find that it has discrete steps.
 

Offline EPAIII

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Re: Building thermal insulation.
« Reply #64 on: July 28, 2022, 01:44:26 am »
I did not read all of the responses above, but I do have one GREAT tip on staying cooler in the summer. It is highly reflective roof paint.

I lived for over a decade in the Miami, Florida area. Now it is not the hottest climate where I have lived, New Orleans, El Paso, and my present home town of Beaumont Texas all have hotter weather in the summer. El Paso was the hottest. The asphalt streets softened to the point where trucks sank in at traffic lights. But the humidity was lower so you did not feel it as much. Miami had the advantage of being between the Atlantic Ocean and the Gulf of Mexico and that moderated it's weather.

But back to my point: highly reflective roof paint. My home there had a concrete tile roof: they were very common in that area. It was painted white, probably because that color reflected the most light and, presumably, heat. Good idea. But after I had been there for some years I saw that my roof looked bad and needed a new coat of paint. So I purchased a brand that was highly recommended and I painted it.

The improvement was instant and easily observed. When I walked on the old paint surface, I could feel the heat through my shoes. That part of the roof was HOT. Almost uncomfortably so, even with my shoes. But the newly painted surface was A LOT cooler. I checked this with my hand. I could not keep my hand on the old paint but could easily feel the relative coolness of the new.

I can't remember the brand of paint, but I believe it contained a lot of titanium dioxide. But there may have been other, proprietary ingredients.

Another thing is most houses in the Miami/Ft Lauderdale area had stucco covered exterior walls and they too were usually painted white. And window awnings were also very popular. They stopped direct sunlight from entering the window.

My point is, the roof faces UP and therefore gathers more heat than the walls and it does so ALL DAY LONG while most walls are in shade half the time or more. A highly reflective roof paint/coating will stop the absorption of a large percentage of that heat. And the same applies to the exterior walls. To me this is the first line of defense against heat. Insulation would be second and an AC system third.

Oh, and shade trees also help a lot. But they can be problematic if your area suffers from hurricanes or other severe storms as one close to a house or other building can easily be blown over. I saw a front yard tree once that went from the front door of a home to the back door. It's roots were still in the front yard, but it's top was in the back. It cleared a path that almost perfectly bisected the house.
« Last Edit: July 28, 2022, 01:46:11 am by EPAIII »
Paul A.  -   SE Texas
And if you look REAL close at an analog signal,
You will find that it has discrete steps.
 


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