How big is your Calorifier tank?

[johnalison]

You are obviously far too young to have granddaughters for whom hot showers are a birthright. My worst nightmare is when they arrive as a covey of 6 - but is the reason we have a gas boiler and de sal unit

Jonathan

We have granddaughters by the quarter-dozen but fortunately they don’t come in covens. They are at breeding age now, which is a bit ominous.

 

[Minerva]

In the caravan its 10 litres heated to 80deg and we manage as it needs a lot of cold water adding to be safe.
On the boat its 75 litres heated to 80deg by the engine and there is more hot water than we need.
In the house its 300 litres heated by the sun to 60deg and we can have many baths

How big an engine do you have / how long do you need to be motoring for to heat 75l of water? That feels awfy big!

 

[Gumpy]

How big an engine do you have / how long do you need to be motoring for to heat 75l of water? That feels awfy big!

50hp Beta, under 2hrs and the calorifier is hot.
Eberspacher heats it in about the same time.
Its not a real boaty boat its a Narrowboat

 

[lustyd]

I mitigated the thermostatic costs and maintenance by fitting a simpler, shunt(ish) type single faucet

This doesn't achieve the same thing as it's at the wrong end of the pipe. The aim of the valve is to reduce the quantity of hot leaving the calorifier, and to reduce the temperature drop in the pipes by reducing the temperature gradient between water and ambient. If the mixing is done at the tap you might have a litre or more of unused hot water in the pipe when you turn off the tap. With the mixer at the calorifier it might be 50:50 mixed with cold at source, so you only waste 1/2 litre of hot in that same pipe.

 

[mjcoon]

This doesn't achieve the same thing as it's at the wrong end of the pipe. The aim of the valve is to reduce the quantity of hot leaving the calorifier, and to reduce the temperature drop in the pipes by reducing the temperature gradient between water and ambient. If the mixing is done at the tap you might have a litre or more of unused hot water in the pipe when you turn off the tap. With the mixer at the calorifier it might be 50:50 mixed with cold at source, so you only waste 1/2 litre of hot in that same pipe.

All through this thread I had an image that you have brought to a head: a plastic bag of solar-heated water hung up outside the heads hatch and feeding through it. I'm sure that was what we had for decades... And it had the advantage that everyone watched how the hot water ration was going!

 

[ChromeDome]

This doesn't achieve the same thing as it's at the wrong end of the pipe. The aim of the valve is to reduce the quantity of hot leaving the calorifier, and to reduce the temperature drop in the pipes by reducing the temperature gradient between water and ambient. If the mixing is done at the tap you might have a litre or more of unused hot water in the pipe when you turn off the tap. With the mixer at the calorifier it might be 50:50 mixed with cold at source, so you only waste 1/2 litre of hot in that same pipe.

Works for me and is a better business case

 

[lustyd]

I didn’t say it wouldn’t work, just that it’s less efficient with the hot water. Useful for people to understand as it’s not entirely obvious that there’s a difference. We have our valve turned up to very hot as I like to have hot showers so my system essentially works the same as yours

 

[ChromeDome]

I didn’t say it wouldn’t work, just that it’s less efficient with the hot water. Useful for people to understand as it’s not entirely obvious that there’s a difference. We have our valve turned up to very hot as I like to have hot showers so my system essentially works the same as yours

Right,- actually also depends on the source capacity. We generate far more hot water than we can use (mobo), so a little loss here and there isn't very important. And with 250 liters on tap it so far has been plenty.

 

[Daedelus]

Definitely 20 litre as minimum, Mrs D put her foot down and the Eberspacher heated water, the engine heated water and the immersion heater ditto. Even when nice shore facilities were available she preferred to shower on the boat and I have found that other female crew were the same. I was glad I had specified an extra ventilation outlet in the heads compartment.