<div>Hi,</div>
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<div>I have two questions:</div>
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<div>1. I am modeling a single family residential building in the pacific Northwest with a Ground Source Heat Pump which apart from providing hot water for the radiant slabs also provides heating for domestic hot water (DHW). How does one model DHW in this situation? I have calculated the flow rate (gpm) required for the house and have an annual schedule. I tried to assign a process load to the Water Loop HP and when i modeled one case with the process load and the the other without the process load the difference in the pump energy does not confirm to the hand calculation.
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<div>2. This question is independent of the first one (ie no process load attached to the Water Loop HP). I modeled one case with double low e glazing on all orientations and the other case had South facing glazing changed to double clear and rest of orientations with the same double low e glazing. Both the glazing types were modeled using the library method. The difference in the results show a penalty of 2% in space heating for the case with South facing glazing changed to double clear. Understandable, the building configuration (amount of glazing + shading) is such that insulating property of glazing provides more benefit than solar penetration. However, I also note there is a penalty of 11% for the pump energy. There is no daylighting and nothing different in the two models accept the South facing with different glazing. There is no cooling modeled for the house as well and hence no difference in that end use as well. I can understand some increase in pump energy, but can anyone provide some insight as to why such an impact on pump energy?
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<div>I would greatly appreciate your response.</div>
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<div>Thanks.</div>
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<div>Gaurav</div>
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<div>Sustainable Building Analyst,</div>
<div>Stantec</div>