Home energy saving tips /ideas...

[Cudzoziemiec]

I grew up with no dishwasher, no tumble drier. In my 70s I’ve still never had either. We don’t find old fashioned washing up a chore, 5 minutes at the most. Washing goes outside on the line or in the airing cupboard.
Watching the smart meter ( when it worked) illustrated that heating water is probably the most electron greedy thing that normally happens in a house ( unless you have electric heating)
Am I missing something?

What you're missing is that you have an airing cupboard! Line drying, in suitable weather, is the best way though.

[Paul H]

If I had a larger kitchen, I'd have a dishwasher, though it wouldn't be top of the list to occupy additional counter space.  I use the kettle for kitchen hot water, around 2.5 min @3kw, so 5p for the full 1.7ltr.  I tend to batch cook, so a cooking day will take 3 kettles, a non cooking day 1, though I might skip a day or two midweek.
I can see how a large family washing up three times a day might save a few quid, for me it'd take decades to pay for itself, if ever.

[mrcharly-YHT]

I know some people who live on a canal boat. They've been on it for 30 years now. They have a filter, four layers of charcoal, which can take a bucketful of canal water and turn it into something drinkable. It takes about one hour to filter one litre and has a capacity of 12 litres, which doesn't sound much, but they say it's enough for drinking water for two.

So on that principle, it should be possible to install a higher capacity but lower quality filter to was clothes in canal water?

I'm amazed that they'd drink canal water, even filtered.

There tends to be a fair bit of fuel and oil pollution in canal water.

[Cudzoziemiec]

I know some people who live on a canal boat. They've been on it for 30 years now. They have a filter, four layers of charcoal, which can take a bucketful of canal water and turn it into something drinkable. It takes about one hour to filter one litre and has a capacity of 12 litres, which doesn't sound much, but they say it's enough for drinking water for two.

So on that principle, it should be possible to install a higher capacity but lower quality filter to was clothes in canal water?

I'm amazed that they'd drink canal water, even filtered.

There tends to be a fair bit of fuel and oil pollution in canal water.

True. They don't use it for all their drinking water, only really when they can't get to a mains tap. The filters, judging by their slowness, must be far finer than those commonly used by hikers (Sawyer, Katadyn) but then the water must be dirtier to begin with. Filters sold for tap water in the home claim to remove heavy metals so maybe it's possible, with suitably fine filters, to filter out other liquids?

[quixoticgeek]

I'm amazed that they'd drink canal water, even filtered.

There tends to be a fair bit of fuel and oil pollution in canal water.

This.

There is very little lowland water I would feel comfortable filtering with anything less than industrial spec filtering equipment the scale of which only a water company could own.

J

[neilrj]

Ah, the old "let's make the dishwasher more space-efficient by externalising the bulk of the solenoid valve" trick.  One of Stan's finest works, that one.   

To be fair that is protecting the flexible pipes,if the safety valve was in the machine a split hose would gush until it was noticed.

[Kim]

Ah, the old "let's make the dishwasher more space-efficient by externalising the bulk of the solenoid valve" trick.  One of Stan's finest works, that one.   

To be fair that is protecting the flexible pipes,if the safety valve was in the machine a split hose would gush until it was noticed.

You could do that in a way that was disconnectable, though, so you wouldn't need to cut a massive hole in your worktop/cupboard.  Are split hoses a common problem?  I can imagine it being damaged during installation, but they seem unlikely to fail spontaneously.  A lot of extra faff for a marginal benefit.  Also, if the manufacturer doesn't supply the hose, it's not their problem anyway.

[rogerzilla]

There's a feature on the BBC News webshite about cheap DIY external temperature sensors to reduce the flow temperature of condensing boilers when you don't need maximum power from your rads (which makes the boiler more efficient).

This is a bugbear of mine.  Condensing boiler efficiency is quoted for a low flow temperature of about 63 deg C but, if you have a hot water cylinder, 63 deg is not enough of a temp difference to heat it up within the average human lifespan.  So most installers set 80 deg C or more and everyone's happy, except for 10% more on bills.  Your 85% A-rated boiler is probably running at 77% efficiency or less.

I tried flipping a Potterton 15HE from the 82 to 63 settings by moving the appropriate jumper on the PCB and, after a day of tepid showers and washing-up, changed it straight back.

[Mrs Pingu]

On my boiler there are 2 knobs so that you can adjust the rad and the HW temperature independently of each other. (They just don't work on mine since I've had an OpenTherm controller installed).

[Ham]

The issue in my mind is the control of hot water temperature, which is frankly crap. The cylinder is heated up by a coil running at flow temp, with a single thermostat controlling the valve at the top of the cylinder. On your controller, all you can do is state what time you want the boiler to heat up the tank. I have in my head the idea to use about 3 sensors along the vertical of the tank as a PID deploying an arudino or some such.

Then, you could have some control over how much water you heat up, and keep it at a better constant temperature. That might make a lower temperature flow more effective (or it might not)

[mrcharly-YHT]

There should be a temp sensor on your tank - that will trigger the 'call for hot water'.

Having a separate temp setting for the hot water coil and the central heating would be quite a good idea. I don't think that is an option for any current boiler systems though.

[rogerzilla]

There should be a temp sensor on your tank - that will trigger the 'call for hot water'.

Having a separate temp setting for the hot water coil and the central heating would be quite a good idea. I don't think that is an option for any current boiler systems though.

Apart from the Pingus', it seems!

[Mrs Pingu]

Ours is a combi, not heating a tank, in case that makes a difference.

[Kim]

Yeah, fairly standard for combis to have separate knobs for hot water and CH flow temperature, isn't it?

[rogerzilla]

Ah right - harder to implement for stored hot water, as you'd need a separate primary circuit from the boiler.  They're normally just tapped off the CH run.

[Diver300]

Ah right - harder to implement for stored hot water, as you'd need a separate primary circuit from the boiler.  They're normally just tapped off the CH run.

All modern systems have a valve to turn on and off the primary feed to the hot water. It would be quite easy to increase the boiler temperature when the hot water is being heated. In most houses the hot water is a small fraction of the annual heating requirement.

[Ham]

There should be a temp sensor on your tank - that will trigger the 'call for hot water'.

Having a separate temp setting for the hot water coil and the central heating would be quite a good idea. I don't think that is an option for any current boiler systems though.

The problem I perceive is that the temperature control based on the existing method is coarse and bears no relationship to demand. There is a possibility that maintaining a tank of water at a constant temperature is more efficient than see-sawing hot and cold, whilst energy into water heating is a linear calculation that will depend on the dynamics of the conversion from boiler flow into the tank, efficiencies at the boiler, loss on the run to the cylinder, loss at the cylinder etc. At the simplistic end, you can calculate than a 180 liter tank would take about 9kwh of energy to heat from 15 to 60c, with boiler efficiency at 90% (suspect) without allowing for losses, that's 10Kwh or almost a fiver. Not insignificant. Knowing how much hot water you need and roughly when could allow you to set up a program that would improve efficiency.

Of course, the simplest, easiest, quickest way is simply to improve insulation around the cylinder, thereby mitigating heat loss.

[rogerzilla]

Maintaining it at a constant temperature is much more expensive because (a) heat losses through the tank lagging are larger and (b) the boiler is more efficient (condenses better) when the water returning from the coil has lost most of its heat due to passing through a cold tank.

Also, £5 for 10kWh?  More like £1.  I pay 9.98p per kWh for gas.

[Ham]

Also, £5 for 10kWh?  More like £1.  I pay 9.98p per kWh for gas.

Doh! I was thinking of leccy

[mrcharly-YHT]

Ah right - harder to implement for stored hot water, as you'd need a separate primary circuit from the boiler.  They're normally just tapped off the CH run.

All modern systems have a valve to turn on and off the primary feed to the hot water. It would be quite easy to increase the boiler temperature when the hot water is being heated. In most houses the hot water is a small fraction of the annual heating requirement.

It would be easy. A smart system would start supplying the hot water cylinder with water about 60C, then ramp up the temperature. Keep the boiler running as long as possible in the efficient range.

[rogerzilla]

The optimum balance between shorter heating time (with a higher temp) and higher boiler efficiency is a tricky one.  It probably needs calculus.  I imagine heating a cylinder with a very low delta t is grossly inefficient.  The boiler may condense nicely, but will cycle horribly.

[quixoticgeek]

One of the problems with a typical hot water tank is that if you have a 100l tank. And turn on the tap in the kitchen to put 10l of it in the sink. You then add 10l of cold into the bottom. if you don't add any more heat, that 10l of cold water will disproportionately cool the tank, compared to if you just left the hot tank alone. It's almost as if rather than a 100l tank, you want two 50l tanks. And you drain one. Then refil it and heat it again when the energy is cheap. Then while that's out. Swap to the other. Except of course a smaller tank has a smaller surface area to volume ratio so you then need much better insulation.

J

[Kim]

Probably an argument for storing the heat in something other than water (preferably something that isn't prone to leaking, boiling or growing legionella), and regulating the flow through it to control output temperature.  Ideally, you'd do a really good job of insulation and heat it to much higher temperatures to store more energy, but that precludes using a gas boiler as the heat source.

[quixoticgeek]

Probably an argument for storing the heat in something other than water (preferably something that isn't prone to leaking, boiling or growing legionella), and regulating the flow through it to control output temperature.  Ideally, you'd do a really good job of insulation and heat it to much higher temperatures to store more energy, but that precludes using a gas boiler as the heat source.

Phase change heat battery? Can they be paused once the phase change begins ?

J

[Tigerbiten]

Probably an argument for storing the heat in something other than water (preferably something that isn't prone to leaking, boiling or growing legionella), and regulating the flow through it to control output temperature.  Ideally, you'd do a really good job of insulation and heat it to much higher temperatures to store more energy, but that precludes using a gas boiler as the heat source.

Sand.
But it only really works efficiently for district heating.
https://www.youtube.com/watch?v=sol9FOaKTr0&t=612s&ab_channel=JustHaveaThink

Luck .......