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Hi Matt and Gamaliel,
Gamaliel, I took your advice and read up in the document you attached. I don’t know what you are talking about though. What Matt was asking, I think, is what measurements we need to take to enter the Conditioned Area for Optimiser as well as the Volume for the infiltration. The Foundations is another question but an important one if we want these things to calibrate right (which is a problem).
The document says that the Gross Conditioned Floor Area of a building is defined as: ” Total interior floor area of a building’s conditioned spaces, measured from the inside surface of the exterior walls or from the interior surface of walls of adjoining buildings. The areas of interior walls, columns, and pillars are included in this measurement.”
This means your advice to use outside dimensions is wrong according to nrel. If Optimiser is using the Gross Conditioned Floor Area as the definition but is calculating to the Gross Building Floor Area (defined as the exterior dimensions) then we have a problem of semantics and your program should NOT say “Enter Conditioned Area here” but say, “Enter Gross Building Floor Area” and give a definition.
Likewise, the NREL document states that the Building Conditioned Volume is defined as the
Volume inside the building envelope of the conditioned spaces. This metric can be calculated as
the volume of the building if every space is conditioned or on a floor-by-floor basis. For spaces
with vertical walls and horizontal ceilings and floors, this is calculated as the Gross Conditioned
Floor Area times the height from the top surface of the finished floor to the top surface of the
finished floor separating levels of the building or to the inside surface of the roof for the top floor.This is the Infiltration Volume that we need to include when we are calculating the ACH50 from the CFM50 number we get from our Blower Door Test.
Could you take a look at my comments and let me know if I am on the right track here.
Does Optimiser use the Gross Conditioned Floor Area calculation for Conditioned Floor Area in its calculations or does it use the Gross Building Floor Area?
Again, for Volume, Does Optimiser use the Wall Heights multiplied with the Gross Conditioned Floor Area for its infiltration volume calculation or does it use the Gross Conditioned Floor Area multiplied by the ceiling heights (plus extra calculations for non-rectangular room spaces like vaulted ceilings, etc.)?
Thank you.
Chris West
Caleb Contracting, LLC
Cambridge, Vt
