[Equest-users] ERV in Ottawa

[Daniel Knapp]

Hello,

I've been trying to understand how ERV works because I am finding the energy savings to be somewhat less than I had expected.  Ottawa has a very cold climate in the winter and a warm, humid climate in the summer and I would expect enthalpy wheels to be a very good energy saving strategy.  Instead, I am finding that in many cases the building uses more energy and in the best case scenario (OA exhaust DH, mixed air reset, modulate HX) on a VAV system saves only 0.15%.  I have built a simple box model with one system in a two-storey office building and tried a number of different control strategies (see attached tables for results).  I have tried a VAV and a SZ system.  The ERV is able to save marginally more energy in the SZ system, but in neither case are the results what I was expecting.

My question is this:  are these results to be taken at face value and believed or is there a better way to model ERVs in a Canadian climate?  It seems very unlikely to me that ERVs cannot be controlled in such a way as to save significant energy in a climate of extremes.  (.inp file attached as well).  

With thanks and best wishes,
Dan

 
—
Daniel Knapp, PhD, LEED® AP O+M
danielk at arborus.ca

Arborus Consulting
Energy Strategies for the Built Environment
www.arborus.ca
76 Chamberlain Avenue 
Ottawa, ON, K1S 1V9 
Phone: (613) 234-7178 ext. 113
Fax: (613) 234-0740


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