Energy Matters Global and Domestic

[mickthemaverick]

I have located and ordered a 3 litre stainless steel hob kettle with whistle and another 1 litre flask. The new plan will be boil the 3 litres first thing on the gas, make two mugs of tea and pour the remaining water into the two flasks to see us through the day.

I'm not sure what the difference may be between boiling 1 x 3 litre kettle or 3 x 1 litre kettles but I suspect, if anything, due to efficient conduction the single 3 litre boil will use less gas than 3 x 1 litre kettles. Any thoughts?

[bobins]

If you had the water hovering above the gas hob in mid-air, then it'd take exactly the same amount of energy to boil 3x 1 litres as it would 1x 3 litres, but once you add in the need to heat up the kettle itself and the gas hob grill then it'd be marginally more efficient to heat up the 1x 3 litre kettle. However...... all those savings could be jepordised if you don't take the kettle off the hob as soon as it's boiled. And with heating 3x 1 litres you get 3 chances to get it wrong or right, whilst with 1x 3 litres you only get one chance to get it right. I'm sure someone's got a doctorate somewhere by writing on the subject

[mickthemaverick]

Very much what I was thinking bobins It also occurred to me that with the 1 x 3 litre option you actually have most of the kettle's metal conducting the heat up from the gas and passing it into the water over a larger surface area which may be more efficient than having 2/3rds of the kettle's body transferring heat to the air above the water if only boiling 1 litre!!

[NewcastleFalcon]

Ours looks like its quite sexy too



Regards Neil

[mickthemaverick]

Having exhausted my thinking on electric economies I turned my mind to the issue of hot washing and washing-up water. I have formulated a plan in my mind to use a lot of this:
https://www.ebay.co.uk/itm/384968518035 ... R76buPjbYA

arranged on a mirrored board in an up and back matrix fashion and covered with a clear sheet. One end of the 'element' would be connected to a small hand pump fed from a cold water tank and the other to a tap. When you turn the pump you would force cold water into the 'element' and collect the hot water, having been laying in the sun, from the tap for use. Obviously only any use when the sun is shining, but it is a far cheaper way of collecting solar energy than conventional electric panels. Thus it would reduce the demand for hot water from the boiler by a varying amount but as Tesco are famed for saying 'Every little helps!'

In principle the black tube would hold sufficient water in the matrix for a full bowl and thus heat up between uses!!
Something like this:

Own work

[myglaren]

Mrs Hubnut built and installed a full HW solar system in their house, worked very well.

[mickthemaverick]

Volume calculations throwing up a few issues, 30 metres of 13mm pipe gives me 3.9 liters capacity which is enough to fill a bowl with some left behind. laying 30 meters of pipe on a shed roof which is 2100 x 2600 may prove a little tricky in terms of bend radii!! I have also decided to eliminate the pump by having the holding tank along the ridge of the shed with a plumbed feed from the outside water tap manifold, enabling the mains pressure to fill the tank. The outlet would then run down to a hot tap on the end of the shed above an existing table where you can rest a bowl. Thus opening the hot tap would drain the hot water from the pipe and that would refill by gravity from the holding tank, which would top itself up from the mains via a cistern style ballcock!! All the hardware I have in stock except the pipe so the costs will be acceptable. Any thoughts?

[bobins]

If you're using it for direct heating of your hot water, then be extremely aware of Legionnaire's Disease as it'll be a possible breeding ground for it. Far better to have a heat exchanger set-up.

[NewcastleFalcon]

I would experiment with cold water washing up. I think modern detergents should work well enough to disperse minor food/oil/grease residue from crockery and cutlery, and the porridge pan or fry up pan if allowed to overcook while tapping away at a laptop and forgetting you have put it on can easily be rectified with a brillo pad and some vigorous scraping.

You appear to have moved in the plans from 4mm plastic pipe to 13mm. Not thinking about copper are you Cost a fortune time there. Would a metallic black backing plate, not collect more heat for the "element pipes", than the mirrored surface. May have it the wrong way round but the array needs to absorb heat and the metallic black backing plate would do that and conduct the heat into the attached array pipes to heat the water inside the pipes. A gate array without bends but right-angles and a straight pipe top and bottom would avoid any bending, and fill the array from top left to bottom right.

I make no claim to having commented there with any degree of expertise

Regards Neil.

[mickthemaverick]

Thanks for the comments :

If you're using it for direct heating of your hot water, then be extremely aware of Legionnaire's Disease as it'll be a possible breeding ground for it. Far better to have a heat exchanger set-up.

Thanks for that reminder about Legionaires bobins, I will read up on that and see what options I have to control it other than keeping the water above 50.

I would experiment with cold water washing up. I think modern detergents should work well enough to disperse and minor food/oil/grease residue from crockery and cutlery, and the porridge pan or fry up pan if allowed to overcook while tapping away at a laptop and forgetting you have put it on can easily be rectified with a brillo pad and some vigorous scraping.

You appear to have moved in the plans from 4mm plastic pipe to 13mm. Not thinking about copper are you Cost a fortune time there. Would a metallic black surface not collect more heat for the "element pipes", than the mirrored surface. May have it the wrong way round but the array needs to absorb heat and the metallic black backing plate would do that and conduct the heat into the array to heat the water inside the pipes. A gate array without bends but rightangles and a straight pipe top and bottom would avoid any bending, and fill the array from top left to bottom right.

I make no claim to having commented there with any degree of expertise

Regards Neil.

I have changed to 13mm but still black plastic pipe. The reason for the change is to accomodate the volume of water I need to be subjected to the sun within a workable length. I think reflecting the sun from a mirrored surface back to the black pipes would be better as a black background would absorb the heat and not transfer it to plastic pipe very well. I am considering making the backing plate from ally foil in a corrugated way to try and focus the rays back to the pipes!!

And I am certainly no expert but I love an experiment!!

[Gibbo2286]

One of my pals did his shed roof with black plastic pipe but didn't zig zag it he did it in two large spirals with a black back board.

By the way Mick I can't do your kettle trick on account of not having a gas cooker.

[myglaren]

By the way Mick I can't do your kettle trick on account of not having a gas cooker.

One of my pals did his shed roof with black plastic pipe but didn't zig zag it he did it in two large spirals with a black back board.

Been done successfully with re-used radiators painted black with polystyrene behind them.


Today I have used none electric and none gas either. Will be away all day tomorrow so will be the same if there is a reasonable amount of light. Used 2kWh during the night.

[mickthemaverick]

One of my pals did his shed roof with black plastic pipe but didn't zig zag it he did it in two large spirals with a black back board.

By the way Mick I can't do your kettle trick on account of not having a gas cooker.

Did his system work well?

You could always heat the kettle with the blowlamp!!

[mickthemaverick]

Been done successfully with re-used radiators painted black with polystyrene behind them.

I have a feeling that SWMBO wouldn't go for that option, she would accuse me of trying to set up a scrap yard on the quiet!!

[Peter.N.]

I was thinking of a kettle on the LPG hob, got to be cheaper than electric. If some people have so much money they can use an electric kettle the price rises haven't bitten them hard yet. I am seriously considering using some of the last of our savings on some more solar panels and going on to pension credit.

Peter