The maths on gas.

[busta]

Quick one for any heating engineers on here:

If I want to run a 40kw gas boiler for 8 hours a day on LPG how much gas will I use?

It's for a campsite toilet block serving 100 people with 3 showers and 4 hand basins, based on 10kw/shower (is that about right?) and 100 5 min showers a day.

[cuneus]

40kw x 8 = 320Kwh

LPG produces 6.6 kWh/ltr

so 48 litres

at 100% efficiency! (adjust for the boiler)
and is it going to be running all the time ?

[busta]

Thankyou, that's more straight forward than I thought! Im no expert but I guess it'll be on fairly continuously when all 3 showers are in use. It will be connected to an accumulator tank which will be cooling down fairly quickly with 30-50 litres a minute flowing through it.