ASHRAE 90.1 states:
G3.1.3.6 Piping Losses losses shall not be modeled in either the proposed or baseline
building designs for hot water, chilled water, or steam piping.
What about a tank that is inserted in the hot water loop in order to increase the thermal inertia (heat pumps are controlled on the basis of a temperature and if the thermal inertia increases the frequency of the on/off cycles decreases)? Shall I consider the heat losses through the envelope of the tank? Only in the proposed or also in the baseline model?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5868 thumbs up
April 23, 2018 - 11:53 am
The tank insulation should be modeled as designed. I don't think any of the baseline systems would include such a tank so it is not an issue in the baseline.
Jean Marais
b.i.g. Bechtold DesignBuilder Expert832 thumbs up
April 24, 2018 - 1:42 am
It's never the less an interesting question as you could consider the hydronic buffer part of the distrubution. Like why would you consider the one and not the other...For a small residential building the losses of the buffer would be larger in relation to line losses where as on a large project the line losses would be far more than that of the buffer. As the code is written at the moment, I would agree with Marcus. In fact, if that clause about the line loses was not there explicitly excluding them, you would model this 'equipment' as designed as well.