Spaces with permanently open ventilation louvres
Posted: Wed Jun 09, 2021 1:05 pm
Dear IES forum
Hoping you can help, there has been previous discussion on here about the inclusion of carparks in both Part L2 and EPC calcs, my question is for these room types in general, so Plant rooms, Bike Stores, switch rooms that are unheated, but have permanently open vent louvres/louvred doors. (not an open sided carpark)
My more recent understanding of modelling these areas using DSM (following advice from both IES and CIBSE) is that, because they sit outside of the thermal envelope, they would be physically modelled in the part L2 but I would tick these areas as 'not to be assessed'. Then for the EPC, I would include the areas in the assessment.
My questions are:-
1) Do I still model the louvres themselves as say 'a door element' in the wall? (not using any macroflo properties etc) If so, what U value/construction?
2) What if the room in question (Tank room for example) actually has a frost protection heater? Do I still exclude the space from the Part L2? Does this not become a heated space/remain as 'none' for the Heating and auxiliary system selection.
3) If the unheated space has also a local extract fan for example as may be in a bin store, I would need to account for this in the EPC, but would I still exclude the space from the Part L2 calc as above? If I put the space as 'none' for heating system' and 'auxiliary system' but still define an extract fan with sfp and ach/hr rate, the fan doesn't appear in the brukl document. Is the energy from it still accounted for?
My response from CIBSE certification was as follows:-
"The approach on this matter from the BRUKL and the EPC is different.
For the BRUKL what usually is the defining factor is whether this space is within the thermal envelope (insulation) of the building. If this space is not in the thermal envelope it is usually not included in the calculations, as it messes up the Criterion 2. So, common practice is to included only when it is within the thermal envelope.
This is our view, but Part L compliance and the BRUKL reports are under the authority of Building Control, so you will need to liaise with the on the matter to be sure they will be happy.
On the EPC side, the question is whether this space is part/attached to the building and is not design to be used separately. If this is part/attached to the building and is not design to be used separately, then it must be included in the EPC. This is of course for the cases where there are some louvres, which is not a problem. Obviously, if these spaces have open sides or big gaps and are open to the ambient air then this should be considered exterior space and not included in the EPC model."
Hoping you can help, there has been previous discussion on here about the inclusion of carparks in both Part L2 and EPC calcs, my question is for these room types in general, so Plant rooms, Bike Stores, switch rooms that are unheated, but have permanently open vent louvres/louvred doors. (not an open sided carpark)
My more recent understanding of modelling these areas using DSM (following advice from both IES and CIBSE) is that, because they sit outside of the thermal envelope, they would be physically modelled in the part L2 but I would tick these areas as 'not to be assessed'. Then for the EPC, I would include the areas in the assessment.
My questions are:-
1) Do I still model the louvres themselves as say 'a door element' in the wall? (not using any macroflo properties etc) If so, what U value/construction?
2) What if the room in question (Tank room for example) actually has a frost protection heater? Do I still exclude the space from the Part L2? Does this not become a heated space/remain as 'none' for the Heating and auxiliary system selection.
3) If the unheated space has also a local extract fan for example as may be in a bin store, I would need to account for this in the EPC, but would I still exclude the space from the Part L2 calc as above? If I put the space as 'none' for heating system' and 'auxiliary system' but still define an extract fan with sfp and ach/hr rate, the fan doesn't appear in the brukl document. Is the energy from it still accounted for?
My response from CIBSE certification was as follows:-
"The approach on this matter from the BRUKL and the EPC is different.
For the BRUKL what usually is the defining factor is whether this space is within the thermal envelope (insulation) of the building. If this space is not in the thermal envelope it is usually not included in the calculations, as it messes up the Criterion 2. So, common practice is to included only when it is within the thermal envelope.
This is our view, but Part L compliance and the BRUKL reports are under the authority of Building Control, so you will need to liaise with the on the matter to be sure they will be happy.
On the EPC side, the question is whether this space is part/attached to the building and is not design to be used separately. If this is part/attached to the building and is not design to be used separately, then it must be included in the EPC. This is of course for the cases where there are some louvres, which is not a problem. Obviously, if these spaces have open sides or big gaps and are open to the ambient air then this should be considered exterior space and not included in the EPC model."