A "tank cosy" and estimates of the kWh of heat that is lost from a hot water tank are discussed in the thread at
http://www.ata.org.au/forums/topic/2687#post-25784
from
http://www.rehau.com.sg/files/Technical_Information_RAUTITAN_Water_Services.pdf
For a copper pipe with OD=12.7mm and wall thickness 0.91mm that carries water at 60degC through air at 20degC the heat loss is 27.2Watts per metre.
In 24hrs the heat loss is (24 x 27.2) = 650Watthours per day per metre
= 0.65kWh/day per metre.
For electricity costing 20cent/kWh, 0.65kWh/day per metre costs 13cents/day per metre.
Pipe insulation 9mm thick reduces this heat loss to 10.0W/m, 13mm to 8.5W/m and 25mm to 6.5W/m
For copper pipe with OD=19.05mm and wall=1.02mm the heat loss is 38.3W/m.
With 9mm insulation this reduces to 13.0W/m, 13mm to 10.7W/m and 25mm to 8.0W/m
Posted Monday 2 Apr 2012 @ 10:23:03 pm from IP
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