(for a office building in Sao Paulo)
COP:
For an office building in Sao Paulo, the proposed case uses air cooled system with a COP value of 2.87. The base case calculation from table G3.1.3.7 and table 6.8.1C of the 90.1 standard gives us a COP of 5.50 (i.e. assumes a water cooled chiller).
Does that sound correct ? Is there a case that the baseline building utilises an air cooled chiller of a COP of 2.8 for the purposes of the baseline assessment?
Or is there any other way of calculating the COP of the base case except complying to the above mentioned ASHRAE tables?
SFP (Specific Fan Power):
We got a supply (and extract) flow rate of 60,142 L/s for our building ( calculated from the equation). With the power consumption of fan blower at 108 kW, we get a SFP for supply of 1.80W/l/s. The same applies for the extract fan – i.e. SFP of 1.8W//s. This totals to a combined supply and extract SFP of 3.6 W/l/s, which is significantly higher than the maximum permissible standards that we generally in the UK – i.e. limiting combined SFP value of 2.4 or less)
Can anyone advise on this ?
Thanks
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5907 thumbs up
April 30, 2013 - 9:35 am
COP - Assuming you have correctly selected the baseline system (7 or 8) then yes it sounds possible. It all depends on the correct identification of the baseline system.
SEP - Is this for the baseline? If so all the fans (supply, return, relief and exhaust) associated with the system are included in the calculations. So maybe you are double counting? There is a spreadsheet in the Documentation Toolkit tab above that does the fan power calculations to double check your work. The supply flow rate is auto-sized by the modeling software right?
Jean Marais
b.i.g. Bechtold DesignBuilder Expert832 thumbs up
November 18, 2020 - 9:41 am
SPF is specific (i.e. normalized to the volume flowrate). It's not additive. You are supposed to make a volumeflowrate weighted average.