question about SIM output data (building load and HVAC load)

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Hi folks,

Here is a question.

simple steps by ourselves, we can know the yearly building heating load is 6
kwh/ft2

Meanwhile, From SS-D (building HVAC system load summary), we can know the
yearly HVAC heating load is 25 kwh/ft2

There is a 19 kwh/ft2 difference between each other.

Could I ask what the reason is? (Note: I know this is the HVAC system
efficiency, but could I know more detailed quantitive reasons? ) For
example. the duct heat loss, the returning air heat loss. (Can we get these
data from eQUEST output?, like the heat loss from the wall, window, roof,
ground...)

Do you guys know any paper or documents about this question?

Thank you very much.

Sincerely yours,
Yang

xiaoyang shi's picture
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Joined: 2011-09-30
Reputation: 0

The LS-A, -B, -C reports show the gains to the space(s) from envelope,
occupants, lights, equipment, infiltration, etc. These are reported at the
time of the greatest cumulative effect during the simulation. (W or BTU/hr)

As you mention, the SS series of reports shows the energy used to operate
the systems, including equipment efficiencies, outside air, etc. Reheat
also could add significantly to SS report energy compared to the space gains
from the LS reports.

David

*
*

David S. Eldridge, Jr., P.E., LEED AP BD+C, BEMP, BEAP, HBDP

*
*

*From:* equest-users-bounces at lists.onebuilding.org [mailto:
equest-users-bounces at lists.onebuilding.org] *On Behalf Of *xiaoyang shi
*Sent:* Tuesday, April 05, 2011 4:11 PM
*To:* equest-users at lists.onebuilding.org
*Subject:* [Equest-users] question about SIM output data (building load and
HVAC load)

Hi folks,

Here is a question.

simple steps by ourselves, we can know the yearly building heating load is 6
kwh/ft2

Meanwhile, From SS-D (building HVAC system load summary), we can know the
yearly HVAC heating load is 25 kwh/ft2

There is a 19 kwh/ft2 difference between each other.

Could I ask what the reason is? (Note: I know this is the HVAC system
efficiency, but could I know more detailed quantitive reasons? ) For
example. the duct heat loss, the returning air heat loss. (Can we get these
data from eQUEST output?, like the heat loss from the wall, window, roof,
ground...)

Do you guys know any paper or documents about this question?

Thank you very much.

Sincerely yours,
Yang

David S Eldridge's picture
Joined: 2011-09-30
Reputation: 2000