wrote in message
oups.com...
Hello,

I am trying to decide whether I should heat a swimming pool using a
heat pump, or using LPG. I've already ruled out oil (no room for the
tank) and direct electric (too damn expensive!).

snip
Simon.

More than happy to be corrected but here goes:-
The pool dimensions etc are not relevant you just need the comparative costs
of useable energy
Density of LPG around .55 Kg/l
Calorific value around 46000 KJ/Kg
(I believe LPG is a blend and therefore no specific value - unless there is
a BS spec.)

So 1 litre LPG = .55 Kg LPG
Burn .55 Kg and you get .55 x 46000 = 25300 KJ of energy
If the "burn" took 1 hour ( 3600 seconds) that would be the equivalent of
25300/36000 = 7 KWh and with 80% efficiency boiler 5.6 KWh of usable heat
for LPG cost of 24p = 4.2p per unit
Your "electric" costs show 12.4 KWh being released for 2.5 KWh at 6p per
unit ie 1.2 p per unit

Pete K