DOE-2 Reference Manual Version 2.1 - DOE2.com

7. SPACE-CONDITIONSThe primary use of this subcommand is to define the internal loads in thespace. The subcommand, and its associated keywords and code-words,specify the conditions that are appropriate to a SPACE (or to groups ofSPACEs) in the building (any value listed here may be overriden in aSPACE instruction by re-entry of the keyword with a different value).The conditions refer to people, lighting, process equipment, andinfiltration. The conditions are primarily specified as a function oftheir maximum values and their schedules. The conditions can be variedin time and amount via the use of schedules that contain fractional valueinputs (see Chap. II).Before specifying the input data for SPACE-CONDITIONS, the user shouldunderstand some of the logic built into the DOE-2 Program. All of theenergy sources associated with a particular SPACE do not necessarilyaffect the heating and cooling loads of that SPACE. Some energy sourcescontribute all of their energy to the SPACE and other energy sourcescontribute from 0 to 100 per cent of their energy to the SPACE.1. All of the energy associated with people, task lighting, andinfiltration is assumed to enter the SPACE. These energy sourcescontribute their entire energy consumption to the heating/coolingloads of that SPACE.2. Only part of the energy associated with the other heat sourcesin the SP~(overhead lighting, process equipment, and processutilities) escapes into the SPACE and thus contributes to theheating/cooling loads of the SPACE. That energy that does not enterthe SPACE is consumed by a product or process, is added to the returnair duct or plenum, or is exhausted from the SPACE. The portion ofenergy that enters the SPACE, versus the portion that does not enterthe SPACE, can be controlled by the user through the use of theLIGHT-TO-SPACE keyword and the "sensible and latent" keywords.That portion of the energy that does not escape into the SPACE hasno effect upon the subsequent sizing of HVAC equipment in theSYSTEMS simulator. That energy demand is, however, added to thedemands made on the equipment, or purchased utilities, in the PLANTsimulator. It is not chargeable to the secondary HVAC system.When the program attempts to automatically size equipment in thePLANT simulator, it adds all of the SPACE heating/cooling loads, allof the SPACE process loads, and the building-level utility loads(elevators, exterior lighting, and domestic hot water) and thensizes the equipment accordingly to meet the total. This way, thetotal utility demands for the building will be correct and thesecondary HVAC system will not be charged with energy that rightfullybelongs to the process in the building. Only that portion ofthe process load that escapes into the SPACEs as a heating/coolingload will show up in the secondary HVAC system.It is important that all of the lighting, equipment, and utilitiessupplied to a SPACE, for whatever reason, be included in the SPACE-II 1.42 (Revised 5/81)