Options for hot water in outbuilding shower

tired_dad

Hiya. Already have a gardeners toilet and sink outdoors. Having a shed built nearby and planning to have an occasional shower unit in it. Got access to mains water, electricity and drainage. 

I was looking for advice on how to get hot water for this shower. Originally was thinking of an electric shower but this would need a dedicated leccy supply from meter which is impractical due to distances.

ive read about electric water heater that store say 50l. Looks like they don’t need a dedicated elec supply. Am I right in thinking these heat and store a volume of hot water so constantly use electricity? As in they are not heating only water that gets used? 

Any thoughts on options? 

GDB2222

Once the 50 litres of water has been heated up, it will gradually lose heat, depending on how well insulated the tank is. So, there will be some electricity used to keep it hot. 

FreeBear

tired_dad said: I've read about electric water heater that store say 50l. Looks like they don’t need a dedicated elec supply. Am I right in thinking these heat and store a volume of hot water so constantly use electricity? As in they are not heating only water that gets used?

They will heat water to a set temperature and then try to maintain it. So loads of electricity used initially to heat the tank, then a smaller amount to maintain the temperature. And as soon as you start running off the hot water, the heater will kick in again. Could get expensive to run.

An alternative would be a solar (wet) panel with a heating element to boost the temperature.

born_again

https://www.showerking.uk/copy-of-external-l5-horse-2

Brie

I used to spend summers in a very remote camp that had no electricity and no running water.  But we could have hot showers.  There was a large tank that was filled with water from a pump.  This was above a stone fireplace where trashed was burned.  This heated the water which was then put into buckets in a shower stall and these could be poured through a sprinkler head.  It was lush when the alternative was washing in a cold lake.  But I suspect you want something a bit more up to date.

coffeehound

Is it totally impractical to run e.g. a 6 sq mm cable out there?  Presumably the shower would only be required in warmer weather, so a fairly low-powered unit e.g. 7 kW would be fine.  Seems wasteful to have water held at temperature for only occasional use.

mexican_dave

Why do you want a shower in this shed/outhouse? Don't you have perfectly good facilities inside the house.

tired_dad

mexican_dave said:

Why do you want a shower in this shed/outhouse? Don't you have perfectly good facilities inside the house.

large garden, play games, aiming to consider hot tub etc. Would like a shower in a summerhouse for occasional use. The building will be like a wooden summerhouse but insulated to some degree.

I might be able to run a cable for an electric shower but it will need a 40m run. I'll think about it.

The electric water heater is 3w, say it runs for 30min before a shower, that's still < £1 to heat. So not unreasonable if only run over summer months.  Having said that I would be concerned about pipes and stored water freezing in the winter. Suppose that should not happen in a semi insulated summerhouse

coffeehound

Ah, it's a more upscale project than I pictured.  It sounds like a standard hot water cylinder, sized to the expected number of consecutive showers to be taken, would suit.  A 70 litre tank would take about 1½ hours to heat from 15 to 60 deg C.  You might need to be careful with total current draw if adding in hottub, etc.

Doozergirl

coffeehound said:

Ah, it's a more upscale project than I pictured.  It sounds like a standard hot water cylinder, sized to the expected number of consecutive showers to be taken, would suit.  A 70 litre tank would take about 1½ hours to heat from 15 to 60 deg C.  You might need to be careful with total current draw if adding in hottub, etc.

It all sounds rather convoluted, doesn't it.  Heating 70 litres of water, remembering to turn it on/off, having to create room for it etc.  

For me, having a safe electrical installation to the room with its own consumer unit would be most important. Then having an electric shower becomes the most obvious and convenient way of doing things. 

coffeehound

Doozergirl said:

coffeehound said:

Ah, it's a more upscale project than I pictured.  It sounds like a standard hot water cylinder, sized to the expected number of consecutive showers to be taken, would suit.  A 70 litre tank would take about 1½ hours to heat from 15 to 60 deg C.  You might need to be careful with total current draw if adding in hottub, etc.

It all sounds rather convoluted, doesn't it.  Heating 70 litres of water, remembering to turn it on/off, having to create room for it etc.  

For me, having a safe electrical installation to the room with its own consumer unit would be most important. Then having an electric shower becomes the most obvious and convenient way of doing things. 

It sounds like OP already has mains on site, though we don't know the current limit.  If it was say 32A like a standard ring, then that would barely be enough to supply a 7 kW instant shower, and the regs would require a dedicated supply in any case which aint cheap.  

Whereas a standard direct tank would be able to use the existing? basic provision.  So swings and roundabouts really,  

Switching on and off could easily be automated.  Leaving it on full time would help avoid frozen pipes.  Running cost will pale into insignificance compared to running a hottub . .