Carol:

I am having the same problem with airflow almost double from what I specified.
I tried the altitude correction and that did not help.

Does the zone air flow and exhaust rate take preference over the fan flow
parameters?

Thank you,

Paul Diglio

I referenced this information from the DOE2 dictionary volume 2. Maybe it
will be helpful.

Pasha

*Zone Air flow key words: (from Vol2, pg 454)*
*

ASSIGNED-FLOW
*

Design supply air flow rate for the zone. Use either ASSIGNED-FLOW or
FLOW/AREA or AIRCHANGES/

HR. Note that FLOW/AREA or AIR-CHANGES/HR establish the minimum allowed
design air

flow; the actual design flow may be larger.
*

FLOW/AREA
*

The minimum design supply air flow rate to the zone per unit floor area. Use
either ASSIGNED-FLOW or

FLOW/AREA or AIR-CHANGES/HR Note that FLOW/AREA or AIR-CHANGES/HR establish
the

minimum allowed design air flow; the actual design flow may be larger.
*

AIR-CHANGES/HR
*

The minimum design supply air flow rate to the zone expressed as the number
of times per hour that the flow rate

replaces the total volume of air in the zone. Use either ASSIGNED-FLOW or
FLOW/AREA or AIRCHANGES/

HR Note that FLOW/AREA or AIR-CHANGES/HR establish the minimum allowed
design air

flow; the actual design flow may be larger.

*Zone Air flow precedence: (from Vol2, pg 454)* *

Airflow
*

The following keywords provide information on the flow of air into and out
of each zone (supply air, exhaust air,

and outside air).

Generally, all air quantities should be input at sea level because the
program makes a correction for altitude. If you

want to input air flow rates that have already been corrected for altitude
you should set SITEPARAMETERS:

ALTITUDE = 0 in LOADS.

There are four different methods of specifying a zone's supply air flow
rate:

? Specify ASSIGNED-FLOW,

? Specify AIR-CHANGES/HR; the flow is the larger of the default or this
value,

? Specify FLOW/AREA; the flow is the larger of the default or this value,

? Allow the program to calculate the air flow rate based on peak
heating/cooling load and difference

between design supply air temperature and zone temperature. This calculation
occurs when

ASSIGNED-FLOW is not entered. If either AIR-CHANGES/HR or FLOW/AREA is
specified, the

design flow is the larger of the default or the specified flow.

*Outside Air flow precendence: (from Vol 2, pg 458)* *

Outside-Air Ventilation
*

The following keywords describe the outside air ventilation requirements of
a zone. If specified, these keywords take

precedence over specifying outside air at the SYSTEM level.

*Exhaust flow precendence: (from Vol 2, pg 459) **

Exhaust Airflow and Fans
*

This set of keywords defines exhaust at the zonal level. If zonal exhaust
requires more outside air that specified for

ventilation, exhaust will take precedence.

Here's the help manual write up on this. Lengthy but invauable.

Volume 4: Libraries & Reports >
Reports>
SYSTEM-REPORT
SV-A System Design Parameters for

This report echoes your input to the program for each system as interpreted
by the SYSTEMS design routines. See ?DESIGN-DAY Command? in the Topics
Manual. The report is divided into three sections: System-Level Design
Values, Fan Design Values and Zone-Level Design Values.

For systems having mixing sections (dual-duct and multizone systems) an
additional section appears detailing the cold duct, hot duct, and total
zonal air flows, as well as the minimum air flow ratios for these
quantities.

Note: the quantities in this report have been adjusted for altitude even
though DOE-2 requires that any flows you enter in SYSTEMS be at sea level.

Design-day sizing of VAV system Show All
Reports

REPORT- SV-A System Design Parameters for
SYST-1 WEATHER FILE- TRY
CHICAGO

---------------------------------------------------------------------------------------------------------------------------------

FLOOR OUTSIDE
COOLING HEATING COOLING HEATING HEAT PUMP

SYSTEM ALTITUDE AREA MAX AIR CAPACITY
SENSIBLE CAPACITY EIR EIR SUPP-HEAT

TYPE FACTOR (SQFT ) PEOPLE RATIO (KBTU/HR) (SHR)
(KBTU/HR) (BTU/BTU) (BTU/BTU) (KBTU/HR)

VAVS 1.020 5000.0 52. 0.179 241.081
0.662 -50.000 0.000 0.000 0.000

DIVERSITY POWER FAN STATIC TOTAL
MECH MAX FAN MIN FAN

FAN CAPACITY FACTOR DEMAND DELTA-T PRESSURE EFF
EFF FAN FAN RATIO RATIO

TYPE (CFM ) (FRAC) (KW) (F) (IN-WATER) (FRAC)
(FRAC) PLACEMENT CONTROL (FRAC) (FRAC)

SUPPLY 5924. 1.00 6.817 3.63 5.5 0.55
0.72 DRAW-THRU SPEED 1.10 0.30

SUPPLY EXHAUST MINIMUM OUTSIDE
COOLING EXTRACTION HEATING ADDITION

ZONE FLOW FLOW FAN FLOW AIR FLOW
CAPACITY SENSIBLE RATE CAPACITY RATE ZONE

NAME (CFM ) (CFM ) (KW) (FRAC) (CFM )
(KBTU/HR) (FRAC) (KBTU/HR) (KBTU/HR) (KBTU/HR) MULT

ZONE1-1 1623. 0. 0.000 0.300
224. 0.00 0.00 32.64 -87.91 -54.50 1.

ZONE2-1 784. 0. 0.000 0.300
102. 0.00 0.00 15.78 -42.49 -26.34 1.

ZONE3-1 1207. 0. 0.000 0.300
224. 0.00 0.00 24.28 -65.40 -40.55 1.

ZONE4-1 765. 0. 0.000 0.300
102. 0.00 0.00 15.40 -41.46 -25.71 1.

ZONE5-1 1545. 0. 0.000 0.300
408. 0.00 0.00 31.08 -83.72 -51.91 1.

PLENUM-1-Z 0. 0. 0.000 0.000
0. 0.00 0.00 0.00 0.00 0.00 1.

*System-Level Design Values*

SYSTEM TYPE

is the code-word identifying the type of system.

ALTITUDE FACTOR

is the altitude adjustment factor for air flows; it multiplies air flows at
sea level to get air flows at the actual altitude of the building.

FLOOR AREA

is the total floor area of all zones served by the system that have
ZONE-TYPE = CONDITIONED or UNCONDITIONED, or, for ZONE-TYPE = PLENUM, that
have non-zero occupancy.

MAX PEOPLE

is the maximum number of people in all of the zones served by the system
that have ZONE-TYPE = CONDITIONED or UNCONDITIONED, or, for ZONE-TYPE =
PLENUM, that have non-zero occupancy. The maximum number of people in a zone
is determined by the NUMBER-OF-PEOPLE or AREA/PERSON keywords in the SPACE
command; any variation in occupancy resulting from PEOPLE-SCHEDULE is
ignored in calculating MAX PEOPLE.

OUTSIDE AIR RATIO

is the ratio of outside air flow to supply air flow at design conditions for
central systems. Its value is either the user input value of
MIN-OUTSIDE-AIR or is calculated by SYSTEMS from the ventilation or exhaust
input at the zone level divided by the supply fan flow (as listed in the Fan
Design Values section, below) . This is a design quantity and so does not
reflect values entered through the MIN-AIR-SCH keyword. For zonal systems,
this value will be zero.

When OUTSIDE AIR RATIO is determined from zone ventilation rates, it is the
sum of the values under OUTSIDE AIR FLOW (in the Zone-Level Design Values
section, below) divided by the supply fan flow. This outside air ratio is
what the program will use as the minimum outside air ratio. It is assumed
that the outside air is brought in at the main system fan and is distributed
to the individual zones in proportion to the supply air to each zone.

Note: The SYSTEMS design routine does not examine the values entered in
schedules. Consequently, if you specify the outside air ratio through
MIN-AIR-SCH but want SYSTEMS to size the equipment, you should also specify
MIN-OUTSIDE-AIR.

COOLING CAPACITY

is either the value you enter for the keyword COOLING-CAPACITY at the system
level or is computed by SYSTEMS from the peak (sensible plus latent) cooling
load.

SENSIBLE (SHR)

is the sensible heat ratio, i.e., the fraction of the total cooling capacity
that is sensible cooling capacity at the peak or design condition. If you
have not entered COOL-SH-CAP at the system level for a central system, this
value is calculated from a simulation of the conditions at peak loads.

HEATING CAPACITY

is the maximum value for heating. It reflects either the user input or a
calculation from peak loads. Like COOLING CAPACITY, this value will be zero
for zonal systems, where the capacity is shown at the zone level.

COOLING EIR

is the electric input ratios for cooling. Values are taken from user input
or are default values.

HEATING EIR

is the electric input ratios for heating. Values are taken from user input
or are default values.

HEAT PUMP SUPP-HEAT

is the heat pump supplemental heating capacity.

*Fan Design Values *

This section gives the characteristics of the system supply and return fans.
Given for each fan are: type, capacity, rated capacity, diversity factor
(capacity*[MAX-FAN-RATIO] / [sum of zone air flows]), power demand, fan
temperature rise, static pressure, supply efficiency, supply mechanical
efficiency, fan placement, type of fan control, and the maximum and minimum
fan ratios.

Note that the static pressure may have a value of zero. This simply means
that the static pressure was not specified and was not used to calculate fan
power consumption.

*Zone-Level Design Values*

The following quantities apply to the base zone and have not been multiplied
by the number of identical zones (as given by the product of MULTIPLIER and
FLOOR-MULTIPLIER).

SUPPLY FLOW

is the calculated or user-specified supply flow for each zone. Only if you
have specified a value for the ASSIGNED-FLOW keyword in the ZONE-AIR command
will the value here correspond to your input. The ZONE keywords
AIR-CHANGES/HR and FLOW/AREA will be accepted by SYSTEMS only if they are
consistent with the user-supplied HEATING-CAPACITY and COOLING-CAPACITY and
are equivalent to a flow larger than that of the exhaust from or the
ventilation to the zone. The ALTITUDE FACTOR will be applied.

EXHAUST FLOW

is the airflow exhausted directly from the zone via an exhaust fan.

FAN

is the total of the zone supply and exhaust fan electrical consumption at
design conditions. This is zero in the example because there are no zone
fans.

MINIMUM FLOW

reflects the your input for MIN-FLOW-RATIO, unless that input is in conflict
with exhaust or ventilation requirements. In the absence of user input,
SYSTEMS will calculate the minimum flow ratio for VAV systems from the
minimum flow needed to meet the minimum ventilation requirements and the
required heating capacity.

OUTSIDE AIR FLOW

reflects the user-specified outside air quantity entered at the zone level.
If OUTSIDE-AIR-FLOW is specified, its value is multiplied by the ALTITUDE
FACTOR and reported here. Otherwise the reported value is the maximum of
the flow-equivalent values of OA-CHANGES and OA-FLOW/PER, multiplied by
ALTITUDE FACTOR. For the actual amount of outside air delivered to the zone
for central systems, see OUTSIDE AIR RATIO above.

COOLING CAPACITY

will be zero at the zone level for central systems. For zonal systems it
will either be the value you specify for COOLING-CAPACITY or it will be
calculated by SYSTEMS to meet the peak loads at the rated conditions for HP,
PTAC, and FC systems or at any conditions for IU systems. This is done
similarly for HEATING CAPACITY for the above-mentioned systems and for UVT
and UHT systems.

SENSIBLE

is the cooling sensible heat ratio for zonal systems.

EXTRACTION RATE

is the cooling extraction rate at design conditions. This is not the value
used in the simulation; that value is recalculated hourly and depends on the
loads, the conditions, the thermostat type and the thermostat throttling
range. ADDITION RATE (heating) is treated similarly.

HEATING CAPACITY

is the design capacity of the zonal heating equipment, if any.

ZONE MULT

is the user-specified number of identical zones (product of MULTIPLIER and
FLOOR-MULTIPLIER for the zone).

For systems having mixing sections (dual-duct and multizone systems), an
additional section details the cold duct, hot duct and total zonal air
flows, as well as the minimum air flow ratios for these quantities.