General > General Technical Chat
Electric shower, anything I can do?
SteveyG:
--- Quote from: paulca on July 29, 2019, 11:39:46 am ---Well anyway, I'm going to get another company to do a quote also.
As to which system I want I'm still undecided. If I wasn't considering the solar water heating at all, then it would be 100% combi. The house only has me in it with the option later of my daughter spending the odd night here and there is always the potential of a partner later. But the point is the hot water demand is small. On an average day I maybe use 5 litres of hot water in the mornings washing, a handful of litres rinsing some dishes before they go in the dishwasher or washing my hands. Every other day (yes, you can call me a smegger and judge all you want), a shower. Thus storing a full tank of hot water would not be that efficient.
--- End quote ---
Just as a reference point: Standing losses for a cylinder are usually between 35 and 55W depending on the cylinder of choice. So you lose around 1kWh per day if you use no water, or somewhere in the region of £10 per year. Worth also bearing in mind, heating a cylinder is more efficient than instantaneous heating of water as the boiler will not be operating at optimal condensing point.
richard.cs:
Solar aside, that sounds like a good use case for a combi.
But, if you did decide to go for the solar do you even need a gas heated hot water at all? I suppose if you want a new gas boiler for space heating the extra install cost is fairly low. You could alternately keep your existing boiler for space heating, get an unvented electrically heated tank for the hot water and spend the difference on a larger solar array so as to get free hot water for much more (potentially all) of the year. It depends how elderly/inefficient your existing boiler is and if you therefore want to change it anyway for more efficient space heating.
If you have a 60 L 45 C shower on alternate days, and otherwise use 10 L of 65 C water per day, then if your incoming temperature was 15 C your total heat required is well under 2 kWh per day, plus a kWh for standing losses. If you can angle your solar panels for best winter performance (south facing and about 20 degrees from vertical) then in Northern Ireland you should be able to get over 1 kWh per average winter day per kWpeak installed. More panel area needed if they just have to go at whatever angle your roof is. A 2-3 kWpeak install would give you free hot water year round and minimal maintenance cost with the gas boiler only used for winter heating. Your big problem would be if you had a future partner who likes 30 minute showers every day.
soldar:
--- Quote from: paulca on July 29, 2019, 10:32:50 am --- As I understand them...
System boiler = a single out/return boiler that feeds through a heat exchanger coil in the hot tank before circulating the radiators, thus providing both hot water and radiators. With or without the "S plan" diverter valves to switch between hot water only and/or radiators.
Combi = Combination boiler. Provides an out/return for the radiator circuit and separately a direct inline on-demand hot water heater. If you turn a hot tap on it immediately fires up and heats the hot water. Turn the tap off, it shuts off. There is no hot water tank or reservoir.
https://www.worcester-bosch.co.uk/products/boilers/explained
--- End quote ---
OK, looking at that page, "combi" is what most homes here would have with the caveat that they need to be installed outside or take the air from the outside and vent the gasses to the outside.
The thing when deciding which one is the best option is that it depends a lot on what kind of use it will get. A family with a steady usage is not the same as a single person with irregular usage and that is different from a week-end second home.
I believe domestic hot water, heating, PV electric, etc are much better used and controlled in larger groups. They work well in large institutions like hotels, hospitals, etc. and compared to single home installations they would work better for groups of homes where it is much easier to balance production and consumption.
paulca:
--- Quote from: richard.cs on July 29, 2019, 12:02:56 pm ---If you have a 60 L 45 C shower on alternate days, and otherwise use 10 L of 65 C water per day, then if your incoming temperature was 15 C your total heat required is well under 2 kWh per day, plus a kWh for standing losses. If you can angle your solar panels for best winter performance (south facing and about 20 degrees from vertical) then in Northern Ireland you should be able to get over 1 kWh per average winter day per kWpeak installed. More panel area needed if they just have to go at whatever angle your roof is. A 2-3 kWpeak install would give you free hot water year round and minimal maintenance cost with the gas boiler only used for winter heating. Your big problem would be if you had a future partner who likes 30 minute showers every day.
--- End quote ---
I would be nervous about elevating the panels that much as it makes them into wind sails and we get 100mph+ gales every 10 years or so and 70mph gusts every year. The surface area of a panel stood up nearly vertical in 100mph winds will need significantly strong mountings to not rip off and that moves the potential to ripping the roof off. They even have strick regulations around them not over lapping the peak of the roof as it allows the wind to get under them and risk lifting the roof!
Maybe I can turn my DIY(OW) to other uses and use solar + a hot water tank and small pump and radiator, to take the cold and damp edge off the garage. I can do this 100% DIY, especially if I can rescue my copper hot tank. however is putting a few kWh of heating into the garage in winter going to make the slightest different when it's not lined, sealed or insulated?
EDIT: Of course, due to me storing a bunch of stuff in the garage, I will probably need someway to at very least keep it above freezing. Most people recommend sealing the edges of the garage door to stop direct drafts and using 2Kw oil filled radiator on a thermostat set to 2*C.
paulca:
--- Quote from: peacekeeperman on October 09, 2020, 12:10:11 pm ---Try the steam shower generator. You'll enjoy it for sure.
--- End quote ---
Is that on ali express or your website?
Navigation
[0] Message Index
[*] Previous page
Go to full version