DOE-2 Reference Manual Version 2.1 - DOE2.com

3. ZONE-AIRThe function of the ZONE-AIR instruction is to provide information on theflow of air into and out of each zone (supply air, exhaust air, and outsideair). A number of ZONE-AIR instructions may be required to account forvariations in zone size and/or usage or for parametric runs.ZONE-AIR is a "subcommand" of ZONE and, as such, can be used to input asubset of data to ZONE.An alternative mode for data entry is to complete and enter ZONE-AIRkeywords and their values directly into the ZONE command (if this approach ischosen, omit the ZONE-AIR keyword in ZONE).All air quantities should be input as sea level (standard) values becausethe program makes a correction for altitude. Input of air quantitiescorrected for altitude above sea level will result in a double correction.There are four different methods of determining supply air flow rate toeach zone. Three of the four methods are by specifying input data(ASSIGNED-CFM, AIR-CHANGES/HR, or CFM/SQFT) and the fourth method is bydefault (specifying no data), which allows the program to calculate the zonesupply air flow rate based on peak heating/cooling load and temperaturedifferential.This large amount of program flexibility often leads to rather confusingsituations. As an example, there are certain circumstances under which theuser will specify data for AIR-CHANGES/HR or CFM/SQFT only to find that theprogram reports back a different value. This can be explained as follows.Normally, the program will calculate HEATING-CAPACITY and COOLING-CAPACITY,but it is possible for the user to specify these values. If the user choosesto specify HEATING-CAPACITY and/or COOLING-CAPACITY, the program more thanlikely will be faced with conflicting data.For information on how the program adjusts user-specified values tomaintain balanced equations, see Sec. D of the chapter.ZONE-AIRASSIGNED-CFMinforms the SDL Processor that the data to follow are relatedto zone air flow (supply air, exhaust air, and outside air).A unique user-defined name must be entered in the U-namefield of each ZONE-AIR instruction. Omission of this entryin the "subcommand" will cause an error.specifies (in standard cfm) the design supply air flow ratefor the zone. Two other keywords AIR-CHANGES/HR and CFM/SQFThave been provided as alternative methods of assigning thisdesign parameter; however, any entry for ASSIGNED-CFM willtake precedence and be used by the program. If data entry ismade for both AIR-CHANGES/HR and CFM/SQFT, the program willcalculate a flow rate based on each and use the largervalue. If data entry is omitted for all these keywords, theprogram will calculate design flow rate based on peakheating/cooling loads calculated by the LOADS program and theI V.188 (Revised 5/81)