Air side HVAC

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Hi All,
In the Air Side HVAC when we go to heating tab there are two
enteries as

1 Heat Source

2 Zone heat Source

Can anyone ellobrate what is the difference between these two sources

Any response will by appericable.

Sambhav Tiwari

sambhav tiwari's picture
Joined: 2011-09-30
Reputation: 0

Hi All,

I am modeling a building that will be supplied with High Temperature Hot
Water from another building. My building will not have any boilers or
heat producing equipment of its own. Because of this, I would prefer
not to show the Gas Consumption data on the report charts.

Does anyone know if there is a way not to show the Gas Consumption



Antonio Mendoza's picture
Joined: 2011-09-30
Reputation: 0

Yes -- it is as simple as replacing the boilers in your model with a
"steam meter" (in the detailed interface) and then adding a utility rate
of type steam meter to assign a cost to the energy flowing through the
steam meter.

You can do the same for chilled water, replacing the chillers with a
chilled water meter and have BTU or ton-hours reported instead of
electrical input.

The only caveat to this is you may have to go to the detailed .sim file
for your energy info. Some of the summary eQUEST reports did not report
steam meter and/or chilled water meter energy and/or costs (I know this
was true in an earlier version of eQUEST -- not certain about current
release -- please check!). All building energy use is calculated/reportd
in the .sim (of course).

bfountain's picture
Joined: 2011-09-30
Reputation: 201


HEAT-SOURCE is the source of heating for an air handler level of heat. ZONE-HEAT-SOURCE refers to zone level heating, such as reheat coils. Applicability depends on what type of system you specifiy.

John R. Aulbach, PE, CEM

John Aulbach's picture
Joined: 2011-09-30
Reputation: 1

Hi ,
Where can i define my hourly cooling schedule in terms of

In cooling tab there are different options for schedules such as

1 Minimum supply schedule

2 Cold deck schedule

3 Availability schedule

Which one should be take for cooling temp schedule among these three.

Also what should i take heating set point for occupied hrs.

I look forward for some response.


sambhav tiwari's picture
Joined: 2011-09-30
Reputation: 0

I have some quearies pertaning to Air side HVAC system and zone

1: In Air side HVAC system under Fan tab and in flow parameters what should
be taken as min flow ratio if system is VAV and just adjusent to min flow
ratio input there is input as min fan ratio are the two things same ,and
this input min flow ratio is in air side HVAC zone level also in air flow
tab so it has to entered in zone level also? or only at system level and
there are three input for min flow ration in zone level 1 overall 2 cooling
3 heating which one to be filled???.

2 In Air side HVAC at zone level there is thermostat schedule and adjusent
to that is indoor design temp for heating and cooling which is by default
taken as 76 and 70F for cooling and heating respectively my queary is
whether the temperatures mentioned as default heating and cooling design
temperatures are same what we have to take in thermostat schedule for
cooling and heating during occupied hours????

3 In system air side HVAC in cooling tab there is one schedule as cooling
avaibality schedule where it says that whether mechanical cooling is
available or not and we should choose on/off 0/1 schedule type, whether we
should define this schedule as 1 for occupied hrs and 0 for unoccupied hrs??
does this schedule indicates the time of on of the system and off of the

4 For a VAV system whether we can take one system for entire building or
divide the total zone in 2 or more system??as far as i think meaning of one
system is one AHU unit and generally in big building there many AHU rooms.

I shall be highly obliged if any one kindly responed to these quearies of
mine .I look forward for you valuable response.


sambhav tiwari's picture
Joined: 2011-09-30
Reputation: 0