Heat Pumps and Part L compliance

fclauson

see attched

Here is a piece of research I have done for my own build. To reach Part L compliance I probably HAVE TO use solar.

Much talk about heat pumps - but as you see above it fails to deliver the required Part L renewable.

Any one who wants help build out examples on this should down load the Excel version of the DEAP s/w and can then model to their heats content,

I think what this shows is that meeting Part L - when you heating demand is equal to or lower than you h/w demand is very very hard.

It basically means you will need Solar or Biomass as a key element in your heating system.

HP just do not do it as for the DHW production you have to down rate the heat pump output (see DEAP manual)

sydthebeat

fclauson wrote: »

HP just do not do it as for the DHW production you have to down rate the heat pump output (see DEAP manual)

The main problem with heat pumps is their inability to boost hot water demand up to required temperatures without the addtion of significant electric immersion. This is simply a factor of the heat pump itself.

The consolation is that it requires a smaller solar input to meet regs as compared to a oil or soild fuel based system.

fclauson

done - pasting tables from excel was the issue

sydthebeat

thanks, quick Q

whats happening with the third selection as theres 0 solar benefit?

fclauson

sydthebeat wrote: »

thanks, quick Q

whats happening with the third selection as theres 0 solar benefit?

because I am assuming that the thermal store is not feeding the heating system

sydthebeat

fclauson wrote: »

because I am assuming that the thermal store is not feeding the heating system

how did you work out your water heating efficiency for the heat pump.. ??

by my calcs:

100 / [(50 / 420) + 0.5]

equals 161.5

fclauson

sydthebeat wrote: »

how did you work out your water heating efficiency for the heat pump.. ??

by my calcs:

100 / [(50 / 420) + 0.5]

equals 161.5

May be I am wrong - but take a look at the new DEAP manual section g1,1 - two senarios
EN 14511-2 and IS EN 255-3

I used the latter as it seems more efficient and I assumed the HP was a newer more fancy one

In retrospect - looking at HPs which are about 420% is optomistic - so things are worse than I have modelled

Chris Arch

I have specified a german brand 2 years ago air to water, cost about 8,000 euro... it was used with under-floor heating at ground floor and radiators at first floor, this dropped the efficiency. It is heating up the hot water too and an open fire place was included, no HRV. This was in compliance with the DEAP.

A year later (spring 2010), the clients came back to me with electrical bills as I had required for feed back. They are spending an average of 105 euro per month during winter for heating and all electrical needs. this is a 4 bedrooms detached dwelling of 155 square meters including a 20 sqm attic room. 2 adults and 2 children live in the house, she is not working and spend most of her time in the house. Their house is heated at an average 20 deg Celcius.

I am still due to test the new DEAP software...

muffler

Chris Arch, the topic is "Heat Pumps and Part L compliance". Please stick to that. Thanks.