General Lighting Confusion

[M_H]

Hi,

I have a warehouse project. At planning stage we did a preliminary model to test Part L compliance. At concept stage we did not have lighting design so we made assumptions and used inference method to input warehouse lighting at 60ll/W (within software equates to 100,301W general lighting load). BER-7.90 / TER-8.80

Following this the contractor was appointed and they have undertaken actual lighting design calculation. This calculation indicates that warehouse lighting load is likely to be 43,628W. We have now used wattage method (not inference method) and inputted 43,628W into our compliance calculation and we were expecting the BER figure to improve however i noticed the BER has gone worse. BER-10.50 / TER-8.80.

Can anyone please advise on this?

[Complex Potential]

Without seeing the models it is quite difficult to say but my guess is that you may have overlooked something on the inputs.

When using the inference method the lux level is used to determine the overall Wattage but when inputting directly in Watts the lux level is essentially overridden.

As an aside, you should avoid using the direct Wattage input and instead use the Lux input method. It is more in line with the NCM modelling Guide.

[M_H]

OK, thanks a bunch