How to calculate expected gas usage from heat loss?

[HRP123]

Hi there, thanks for your time to look at this.

I've done an estimated heat loss calculation on Heat Engineer - which comes out to 20kw approx for a 5 bed house.

They also calculate total energy demand of 55,000 kw?

Assuming you have a gas boiler, is this what the gas consumption should be (although given gas boilers are not 100% efficient, it should actually be a little higher?).

Thanks

 

[Rodders53]

No

Assuming you have a gas boiler, is this what the gas consumption should be (although given gas boilers are not 100% efficient, it should actually be a little higher?).

No it's what a 100% efficient heat source would use. Gas would use more energy a heat pump less due to their efficiencies. Recent condensing gas boiler is 90-95% efficient on a good day? So around 60 MWh ?

Note the numbers are just a 'guesstimate' based on whatever assumptions that web calculator uses for annual use and outside temperatures... tweak those assumptions to suit your expected use to be more accurate.

 

[HRP123]

No

No it's what a 100% efficient heat source would use. Gas would use more energy a heat pump less due to their efficiencies. Recent condensing gas boiler is 90-95% efficient on a good day? So around 60 MWh ?

Note the numbers are just a 'guesstimate' based on whatever assumptions that web calculator uses for annual use and outside temperatures... tweak those assumptions to suit your expected use to be more accurate.

Thanks, yes, I understand what you are saying about the 90-95% efficiency, so the actual usage should be higher than projected on Heat Engineer.

So because of this inefficiency your gas usage becomes 60,000kwh per annum+.

Appreciate it.