Unconditioned spaces

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Here's my latest fiasco:
I have some conditioned and some unconditioned spaces. The
unconditioned spaces contain loads from electric water heaters and lighting
and the water usage, itself. All of these electric and water loads must, of
course, be modeled.
However, these unconditioned spaces do not include HVAC systems. The
unconditioned spaces simply exhaust air from the conditioned spaces to the
outside via exhaust fans. I've been advised by previous listserve e-mails
to model the conditioned spaces as directly exhausting to the outside.
The problems are these:

1. How do I get eQuest to model the temperatures of the unconditioned
spaces without specifying HVAC systems (which don't exist)? This is
important insofar as the unconditioned spaces can conduct heat to the
adjacent conditioned spaces via shared interior walls/floors/ceilings.

2. In order to model the plumbing and lighting systems (for water and
electricity use), I have to assign them to spaces. If I assign them to the
conditioned spaces, this will artificially inflate their affect on the
cooling loads of those conditioned spaces. However, if I assign them to the
unconditioned spaces, then I have to assign those spaces to respective
thermal zones, which, in turn, require assignment to HVAC systems that don't
exist. How can this be simply and correctly modeled?

Thanks again.

Lars Fetzek, EI

Lars Fetzek's picture
Joined: 2011-09-30
Reputation: 0

For (1.), set your DESIGN-HEAT-T and DESIGN-COOL-T per the guidance in
the help menu.
For (2.), put the lighting and miscellaneous loads in the unconditioned
spaces if that's where they actually are. When you create your DHW
heater you can specify a zone where it is located. Your unconditioned
spaces still need to be assigned to thermal zones and HVAC systems. I
usually assign them to the HVAC system of an adjacent space. The system
will not try to heat or cool the space directly, but the
DESIGN-HEAT/COOL-T can create loads on the interior walls.

William Bishop, EIT, LEED(r) AP

Bishop, Bill2's picture
Joined: 2011-09-30
Reputation: 0