We are working on a project which falls under the category of System 6 - Packaged VAV with PFP Boxes for the Baseline Building. The cooling system associated with this is "Direct Expansion" and you are referred to Section 6.4 for Efficiency Ratings/Levels.
In Section 6.4, it is not clear which equipment type corresponds to Packaged VAV with Direct Expansion? It appears that it could be from Table 6.8.1A, Table 6.8.1B or Table 6.8.1D. We believe the most representative system would be Table 6.8.1A Air Conditioners, Air Cooled (Package System).
Clarification on the above would be appreciated - thank you in advance!
Jean Marais
b.i.g. Bechtold DesignBuilder Expert832 thumbs up
January 5, 2016 - 2:29 am
I agree that these definitions are pretty murky. No, I don't think you are correct. See Table G3.1.1B...Package "terminal" units are system 1 and 2. The rest are all "rooftop" units. Whether the reheat occurs decentrally at the terminal (which is common in America) or centrally at the AHU is very unclear. However, in the USA these VAV terminal boxes are typically contain the reheat coil at the terminal (decentral). As they are also used to control the heating setpoint and not just to condition the air to say 22 C but used to heat by supplying air at up to 40 C (bear in mind for the baseline it must be Heating Setpoint + 11C and Cooling Setpoint - 11C), this makes sense.
DX means no chilled water, so you don't have a chiller.
Heating is electric, so no gas or oil
It's not a Vertical, Room or Terminal unit
DX is air cooled
As you have an electric heater, the DX is not a reversable HP, so not Table 6.8.1B either
That leave just Table 6.8.1A which applies to split AND single package systems. You have single package (split refers to the cooling dx coil being decentral as in the indoor units of a VRF system...again murky as this could also fit the system description, but VRF is not old and baseline enough, ha ha...again murky because the heating is split, ha ha).
As this is DX (air cooled), forget about water or evap cooled for equipment type. Then sort by kW and Heating Section Type.
To all those Americans reading this...I hope this offers a view into our world of confusion.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
January 6, 2016 - 9:46 am
As Americans we expect everyone to know the vagaries of English and IP units and are equally confused when you don't! :-)
Despite the murkiness you have reached the right answer I think. Use Table 6.8.1A.