Hi all,
I recently completed some energy modelling for the Webinar where we presented on the updated Hot2000 v11.10. The models seemed to suggest that the new procedure for modelling CCASHP's shows a worse energy performance than a 'regular' (not cold climate) heat pump. This result was duplicated by another member of our team on a MURB modeling project too.
So, I reviewed the Hot2000 User Guide v15.10 and double checked to make sure that I'm modeling heat pumps correctly. Following those procedures and using a new file in v11.10 I found out that the same applies. Some of you commented during the presentation on the capacity of the CC model being higher - this is the new procedure. The new procedure averages the COP and calculates a larger capacity so that the CC model will use the heat pump for more of the primary space heating.
Conclusions:
- A good heat pump (high hspf and cutoff -15 or -20C) with the same HSPF will perform better than a cold climate heat pump.
- An ok heat pump (lower hspf around 7 and cutoff about -9C) will perform worse or equivalent to the cchp depending on the performance.
- Cold climate heat pumps do not appear to provide better performance unless comparing to just a typical model.
- I don't think there is anything wrong with the procedure but it just highlights that a good 'mid' climate heat pump performs just as well or better than a cold climate one.
I've attached some of my modeling files and an excel that summarizes the results for St. John's and Edmonton. The only thing I didn't check was the capacity of the heat pump to see how that changes things relative to the heating load in the house, they may show more benefit in those situations?
Any thoughts or comments?