trying to reconcile BRUKL with Vistapro

[jerry]

Hi
I am trying to reconcile the various data that appears on BRUKL with the results in vistapro. It seems like an impossible task.
Taking just one example:
From BRUKL table, actual building heating consumption= 3.9 kWh/m2. The BRUKL reported floor area is 5349.7sqm so this is 20.86 MWh/yr.
Yet the figure in vistapro for "Boiler space heating energy" is 17.57MWh/yr (sum of 2 systems providing space heating).

It would be helpful if vistapro included variables which directly relate to the data on the BRUKL sheet, but it is clear that Vistapro isn't really designed to tie in with Compliance in any helpful way. Far from helping me to understand what is going on behind the scenes in creating the data for the BRUKL, all Vistapro does is confuse me.

Jerry

[Complex Potential]

In my experience, using the Vistapro building level annually summed carbon figures that are labelled as NCM do allow me to total up to the BER and TER for the actual and notional buildings respectively. Just make sure you divide by the floor area as shown on the BRUKL.

If needed you can then look at the equivalent energy numbers which can be arrived at by applying the appropriate carbon factor.

It's a bit confusing but tracing from room load to system load to energy to carbon is possible.

When I checked a recent model the vistapro "NCM heating" energy matched exactly to the "AP Sys boiler space cond'g" energy figure which tied up to the energy table in the BRUKL.

I know "it works for me" isn't massively helpful but hopefully something I've written will give you some inspiration.

[NickD]

Hi, I've been looking into this recently and agreem it's not clear how the BRUKL values correspond to the VistaPro variables.

Some of them are straightforward MWh to kWh/m2 conversions as previously noted. The BRUKL "Heating" and "Cooling" values correspond to "NCM heating energy" and "NCM cooling energy" (also "Ap Sys boilers space cond'g energy"). Similarly, the BRUKL "Heating + cooling demand" (MJ/m2) value corresponds to the sum of "Room cooling plant sens. load" (MWh) and "Room heating plant sens. load" (MWh).

Some of the others varaiables are related by system efficiency. For example, "NCM heating energy" can be obtained from "Room heating plant sens. load" if you account for the generator SCoP (generator seasonal efficiency x heating delivery efficiency).
"NCM cooling energy" can be obtained from "Room cooling plant sens. load" if you account for generator SSEER, which is defined in the Part L2 ApacheSim manual as EER * CDE / (1 + (EER + 1) * HRP), where EER is the cooling system generator energy efficiency ratio, CDE is the cooling delivery efficiency, and HRP is the heat rejection pump and fan power fraction.

I've not had time to look at the other BRUKL values, but I assume a similar logic applies.

Hope this helps,

Nick

[jerry]

Thanks Nick, that is helpful
Jerry