Doubt on Appendix G- Section G3.1.1

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Hi All,

Section G3.1.1 (b), says,

If the baseline HVAC system type is 5, 6, 7, or 8, use separate single-zone
systems conforming with the requirements of System 3 or System 4 (depending
on building heating source) for any spaces that have occupancy or process
loads or schedules that differ significantly from the rest of the building.
*Peak thermal loads that differ by 10 Btu/h?ft2 or more* from the average
of other *spaces served by the system or schedules that differ by more than
40 equivalent full load hours per week* from other spaces served by the
system are considered to differ significantly. Examples where this
exception may be applicable include, but are not limited to, computer
server rooms, natatoriums, and continually occupied security areas.
*
*
1. Is the term "Peak thermal loads" referring to loads caused by envelope,
occupancy, infiltration and equipment only? or it also includes loads
caused "fresh air" also?
2. From which report of SIM file, we can get data related to "difference of
40 equivalent full load hours"
3. Considering that internal loads in two different spaces are on 50% for
one space and on 100% for other space, Can we assign one air side system of
type 7 for two spaces? or the space which is running at 50% be assigned
with system type 3?

Thanks in advance for the help.

Thank you,
Vamshi.

vamshi ranga's picture
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Joined: 2012-11-12
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Hi All,

Section G3.1.1 (b), says,

If the baseline HVAC system type is 5, 6, 7, or 8, use separate single-zone
systems conforming with the requirements of System 3 or System 4 (depending
on building heating source) for any spaces that have occupancy or process
loads or schedules that differ significantly from the rest of the building.
*Peak thermal loads that differ by 10 Btu/h?ft2 or more* from the
*average*of other
*spaces served by the system or schedules that differ by more than 40
equivalent full load hours per week* from other spaces served by the system
are considered to differ significantly. Examples where this exception may
be applicable include, but are not limited to, computer server rooms,
natatoriums, and continually occupied security areas.
*
*
1. Is the term "Peak thermal loads" referring to loads caused by envelope,
occupancy, lighting infiltration and equipment only? or it also includes
loads caused by "fresh air" also?
2. Is "Thermal loads" referring to Cooling load or Heating load or Sum of
both coooling and heating?
3. What does "40 equivalent full load hours" means? For example, I have one
room whose schedules are 24hrs and 100% occup, light, equip at the same
time I have other rooms, which are 24hrs and 50% occup, light, equip etc.
So, I think, 24hrs with 100% should be modeled with System 3(my heating
source is boiler). Correct me, if I am wrong

Thanks in advance for the help.

Thank you,
Vamshi.

vamshi ranga's picture
Offline
Joined: 2012-11-12
Reputation: 0