[Equest-users] LS-A/ LS-B report shows no space heating load for some zones

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Hi all,

My model report LS-A and LS-B shows that some zones do not have any
heating peak loads/heat load components... I have changed options for
re-heat delta T, T-stat and other options but the heat does not seem to
be getting to these zones. However, the zones beside them seem to be fine.

Any suggestions??

Thanks,
Sheldon

Sheldon Mendonca's picture
Joined: 2011-09-30
Reputation: 0

Hey Sheldon,

Zeroes are not always a sign something is wrong...

Typical scenario / possible explanation: A core zone is surrounded by
other zones with heating equipment. During design day conditions
(coldest day in the winter), this core zone doesn't actually have any
need for heating because there's zero (or close to zero) heat flux
outward, due to the surrounding conditioned spaces.

"...the heat does not seem to be getting to these zones" is a conclusion
that suggests underheated hours however... is that the case?

Adjusting the thermostat/reheat inputs are examples of *possible*
solutions when there is an underheating symptom, but before proceeding
I'd first confirm there's a problem to be fixed, then try to come up
with clues and causes before resorting random fixes. Note that
undercooled/underheated hours are always the symptom of another problem
(and a vague clue at best). Your challenge is not to treat the symptom,
but to identify and resolve what's causing the under conditioned hours.

Another suggestion: review the advice/notes for LS-A and LS-B found in
Help > Tutorials and References > Detailed Simulation Reports Summary.

Best of luck!

~Nick

NICK CATON, P.E.

Nick-Caton's picture
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Joined: 2011-09-30
Reputation: 805

Sheldon,

Loads in LS-A report (and any other "L*-*" report) account only for envelope
and internal gains, but not HVAC-related parameters. I wouldn't expect these
loads to change as you adjust reheat or thermostat setpoints. You should
check SS-A report instead. The Detailed Simulaiton Reports Summary that Nick
suggested below is a great resource for interpreting reports correctly.

Good luck,

Maria

Maria Karpman's picture
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Joined: 2011-09-30
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Hi Maria and Nick,

Thanks, the reports make more sense now.. There is no under-heating or
under-cooling hours so that answers my question "if the heat is getting
to the zones". My SS-A report shows that my systems are working fine
even in the zones the LS-A reports zero load (internal gains and like).

Thanks a lot for taking the time to clarify this non-issue. I have
breaking my head on this model that seems to work just fine :)...

Best,
Sheldon

Sheldon Mendonca's picture
Joined: 2011-09-30
Reputation: 0