This thread won't be for everyone, but a place to share some ideas if you do like the idea of using less power (gas/electric/oil) and ways to achieve that. If you're a leave all the lights on "because you can afford it" type of person, well, don't read on !
My latest foray into using less electric was re-evaluating my hot water usage. My present house shows evidence of previously running instant gas hot water (from bottles) and Instant electric hot water, from a three phase electric hot water heater. It presently uses a 200 litre insulated electrically heated tank.
The first thing I did was double insulate this with polyurethane. This certainly helped, but as someone presently living alone with no bath in the house, a 200 litre tank is excessive as it will ultimately loose most of it's heat to the atmosphere around it. The tank also had quite a long run to the main water usage areas in the house. In France the present regs say that is a 10 meter limit to avoid wastage, it fell within that, but you still waste a huge amount of water waiting for warm water to arrive and a huge amount of warm water that then goes cold sitting in those pipes.
I was talking with some friends last night. Their house is setup so when you turn a bathroom light on, it starts to circulate hot water around the pipes to that room so you get hot water straight away. She has cold showers for various reasons, so ultimately wastes energy as the pipes will radiate that hot water into the house without it being used
I looked at instant hot water heaters as these would ultimately be the most efficient for low use - with no water heated which wasn't used.
Unfortunately, here, you can't have a 24kva supply (which is what you'd need to run one) on a fixed rate tariff, only on day rate and night rate, so when you showered, you'd be using peak electric rates which then makes the system no longer economical.
Instead I went for a 45 litre twin tank system with "intelligent" ?!?! usage monitoring. Basically, instead of one large tank, there are two smaller ones, so if it works out that most of the time you only need 20 litres for instance, it only heats one of them. Then based on how much you do use, it will vary the temperature it heats the water too. For example, if you used 20 litres in a shower - say 40 degrees. It would just heat 1 tank to 45 degrees. If you used 4 showers at 40 degrees with 80 litres of usage, it would heat both tanks to 80 degrees so once you'd mixed with cold, you'd have enough water.
The other "sales pitch" of the twin tanks is that they're slim. Two smaller tanks don't stick out as much as one large round one ! Sadly, this obviously became a high point in the development process, so SLIM ! became a priority over ecology and economy. The actual insulation thickness over the tanks at the front and back is minimal. Add in that with a plastic case, the support brackets are attached straight to the tank chassis, you have a perfect thermal bridge !
So, for example .. your very expensive super eco hot water tank .... looks like this :
It's effectively become a storage heater !
And the wall brackets are perfect radiators !
Or when it heats just the first "output" tank (you can even see the tank linkage pipes):
As I'll be boxing the unit into a cupboard eventually, the "attractive wall mounted" aspect was irrelevant for me, so I boxed the whole thing with a foil backed polyurethane.
This made a vast difference to heat loss and instantly HALVED it's operating cost !
This is with the little cover removed to access the control panel - you can see the heat without the insulation. The strange heat wobble down and left of the square is the reflective heat of me, showing the effectiveness of the foil for reflecting heat.
This next image also shows pipe insulation. The Right pipe is the cold feed. The left pipe at the top is double lagged/insulated pipe on the hot exit and the brighter/hotter is single lagged pipe.
My latest foray into using less electric was re-evaluating my hot water usage. My present house shows evidence of previously running instant gas hot water (from bottles) and Instant electric hot water, from a three phase electric hot water heater. It presently uses a 200 litre insulated electrically heated tank.
The first thing I did was double insulate this with polyurethane. This certainly helped, but as someone presently living alone with no bath in the house, a 200 litre tank is excessive as it will ultimately loose most of it's heat to the atmosphere around it. The tank also had quite a long run to the main water usage areas in the house. In France the present regs say that is a 10 meter limit to avoid wastage, it fell within that, but you still waste a huge amount of water waiting for warm water to arrive and a huge amount of warm water that then goes cold sitting in those pipes.
I was talking with some friends last night. Their house is setup so when you turn a bathroom light on, it starts to circulate hot water around the pipes to that room so you get hot water straight away. She has cold showers for various reasons, so ultimately wastes energy as the pipes will radiate that hot water into the house without it being used
I looked at instant hot water heaters as these would ultimately be the most efficient for low use - with no water heated which wasn't used.
Unfortunately, here, you can't have a 24kva supply (which is what you'd need to run one) on a fixed rate tariff, only on day rate and night rate, so when you showered, you'd be using peak electric rates which then makes the system no longer economical.
Instead I went for a 45 litre twin tank system with "intelligent" ?!?! usage monitoring. Basically, instead of one large tank, there are two smaller ones, so if it works out that most of the time you only need 20 litres for instance, it only heats one of them. Then based on how much you do use, it will vary the temperature it heats the water too. For example, if you used 20 litres in a shower - say 40 degrees. It would just heat 1 tank to 45 degrees. If you used 4 showers at 40 degrees with 80 litres of usage, it would heat both tanks to 80 degrees so once you'd mixed with cold, you'd have enough water.
The other "sales pitch" of the twin tanks is that they're slim. Two smaller tanks don't stick out as much as one large round one ! Sadly, this obviously became a high point in the development process, so SLIM ! became a priority over ecology and economy. The actual insulation thickness over the tanks at the front and back is minimal. Add in that with a plastic case, the support brackets are attached straight to the tank chassis, you have a perfect thermal bridge !
So, for example .. your very expensive super eco hot water tank .... looks like this :
It's effectively become a storage heater !
And the wall brackets are perfect radiators !
Or when it heats just the first "output" tank (you can even see the tank linkage pipes):
As I'll be boxing the unit into a cupboard eventually, the "attractive wall mounted" aspect was irrelevant for me, so I boxed the whole thing with a foil backed polyurethane.
This made a vast difference to heat loss and instantly HALVED it's operating cost !
This is with the little cover removed to access the control panel - you can see the heat without the insulation. The strange heat wobble down and left of the square is the reflective heat of me, showing the effectiveness of the foil for reflecting heat.
This next image also shows pipe insulation. The Right pipe is the cold feed. The left pipe at the top is double lagged/insulated pipe on the hot exit and the brighter/hotter is single lagged pipe.
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