I have found some US products and sites that suggest 30% of household energy is lost down drains from showers/baths/dishwashers etc. There seems to be some low cost (to buy) but maybe complicated to include / install heat recoevry units...
Does anyone have any experience of these - they are claiming 90% of heat is recovered. I am guessing that they would be plumbed into a heatstore, much like solar panels...
If this is true it is an 'instant' 20%ish gain in household energy saving...
a) are such big claims true (i kind of know the answer here folks!)
b) why cant i find a uk version / importer / manufacturer
Cheers
Matt
Matt Robinson
posted on 24-05-06
sorry for the poor spelling folks :/
The other thought looking at the units is why cant I make one myself... :)
Paul in Montreal
posted on 24-05-06
They only work well for continuous flow devices like showers as they pass the incoming cold water through the heat exchanger to preheat it before it enters the domestic hot water heater (beit a tank or whatever). For intermittent flow devices like baths, washing machines etc. they are ineffective. They do work as advertised, though, and I know in Canada they have been used successfully in places like gyms which have lots of showers. You could probably make one yourself out of copper piping. The best known company over here is GFX.
One thought I had was to place a holding tank under the floor with lots of insulation onderneat and to the sides, but not above.
the heat would naturaly 'flow' upwards back into the house.
Paul in Montreal
posted on 24-05-06
Flow rates are automatically balanced on continous devices like showers. A holding tank has many potential problems with bacterial and mould growth since it won't be hot enough to kill the nasties. Legionaires disease is a serious risk.
If the holding tank is just used as buffer to preheat the incoming cold water than it's OK but there's still some risk.
I wouldn't want an open tank of tepid water sitting in my house increasing the humidity and releasing nasty spores etc!
Paul.
Paul Teather
posted on 24-05-06
Did not say open!
Athough it may have to have a hatch - one of the problems with any solution to this type of problem is clogging up - drains have to have rodding access; This may be appropriate in this case.
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