Ron Lowe wrote:
Bill Wright wrote:
Our combi boiler is a long way from all the taps, which are all at
one end of the house. The reasons are historical, and also quite
hysterical, but that's beside the point. I stand there drawing water
off for ages before any hot comes, and it annoys me. I'm seriously
considering fitting a conventional electric immersion tank very near
to the taps. So, I need to work out whether it would ever pay back.
I'm not one for doing these things just for show, like those people
who put a wind turbine on their roof. The tap is turned on about
four times per day when the water in the pipe is cold. The volume of
cold water that comes before the hot (and thus of course the volume
of hot left to cool in the pipe) is seven pints. I can find out the
total cost of getting an immersion tank fitted. What I don't know is
how much it costs to heat a given volume (a gallon, say) of cold
water. The boiler is fairly new and runs on a big gas tank in the
yard. The water supply not unusually warm or cold. The hot water
needs to be good and hot, which is it at the moment once it comes. I
am prepared to exclude any savings made when the water in the pipe
is cool but not cold, and just calculate on the basis of the
freezing water that I get when the system hasn't been used for
hours. Bill



Bill,

Here are the options as I see it:

1) A source of hot water near the tanks;

2) 'Secondary Circulation'; a more complex arrangement where we pump
HW around a loop close to the taps, so the water at the 'ring'
remains hot. This is used in hotels etc to ensure hot water is
reasonable available to individual rooms, even though the hot tank is
distant.
Let's assume we don't want to do this, it's non-trivial, and even less
so to retro-fit.

So let's go with option (1); a source of hot water near the taps.

Option 1a) Instant HW heaters. I dislike these, Dribbly HW flow, and
they remind me of portakabins.

Option 1b) Small immersion-based pressurised cylinders under the sink.
These work well. They store a few litres ( and even more pints! )of
HW under the sink, in a smallish unit. So long as you don't want to
fill a bath from it, it's good ( hand-washing, etc. ) Advantages: Easy
retrofit assuming cold supply is adequate; very close proximity:
instant HW. Disadvantages: Lowish volume of stored HW.

Are those the ones that require a vented hot tap Ron? If so the OP should
consider the hige cost of the taps.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk