[Equest-users] How to properly model this 2-pipe FCU system in eQuest 3.65?

[John Aulbach]

Sir:

Here is what the eQuest DOE2 Help Menu shows. Try to follow their guidelines.
John R. Aulbach, PE






Two-Pipe Fan Coil System (FC)
The two-pipe FC system provides both heating and cooling to individually controlled zones. However, all zones served by the system must be operating in the same mode (i.e., either heating or cooling) at any given time. A fan coil unit consists of a filter (not shown), combination heating/cooling coil, and fan. The coil is connected to a CIRCULATION-LOOP with TYPE=PIPE2 that provides either hot or cold water according to the prevailing mode of operation as defined by the HEATING-SCHEDULE and COOLING-SCHEDULE. The unit provides a fixed quantity of outside air ventilation or merely recirculates conditioned air. Exhaust fans are optional for any or all zones. Temperature control is achieved by throttling the flow of water through the heating/cooling coil. The control thermostat commonly used for this type of system has separate heating and cooling setpoints. The fan coil units, particularly the smaller direct-drive units, may not be available with a fan capacity that matches the calculated value. Therefore, assignment of the fan capacity for a specific, commercially available unit is recommended for improved simulation accuracy.
Figure 25  Two-pipe fan coil system (FC)Suggested minimal input for two-pipe FC system:Note that the input for a two-pipe FC system requires that you specify a CIRCULATION-LOOP of TYPE=PIPE-2 to which the fan-coil units, chiller, and boiler are attached. In the following, this loop is called FCLOOP-1. The fan-coil unit's cooling coil is attached to this loop by entering CHW-LOOP=FCLOOP-1 under SYSTEM. Similarly, the fan-coil unit's heating coil is attached to source loop by entering HW-LOOP-FCLOOP-1 under SYSTEM. On the PLANT side, the BOILER, called HW-GEN, is attached to this loop by entering HW-LOOP-FCLOOP-1; and the chiller is attached by entering CHW-LOOP-FCLOOP-1.SYSTEMS-REPORT
SUMMARY            = (SS-A,SS-O) ..$ SYSTEMS SCHEDULESFANS-ON = SCHEDULE
TYPE               = ON/OFF
THRU DEC 31        (WD) (1,7) (0) (8,18) (1) (19,24) (0)
                   (WEH) (1,24) (0)  ..COOLSETPT = SCHEDULE
TYPE               = TEMPERATURE
THRU DEC 31        (WD) (1,7) (99) (8,18) (76) (19,24) (99)
                   (WEH) (1,24) (99)  ..HEATSETPT = SCHEDULE
TYPE               = TEMPERATURE
THRU DEC 31        (WD) (1,7) (55) (8,18) (72) (19,24) (55)
                   (WEH) (1,24) (55)  ..DHW-1 = SCHEDULE
TYPE               = MULTIPLIER
THRU DEC 31        (WD) (1,7) (0) (8,18) (1.0) (19,24) (0)
                   (WEH) (1,24) (0)  ..HEAT-ON = SCHEDULE
TYPE               = ON/OFF/TEMP
THRU MAY 15        (ALL) (1,24) (1)       [1]
THRU SEP 15        (ALL) (1,24) (0)
THRU DEC 31        (ALL) (1,24) (1) ..COOL-ON = SCHEDULE
TYPE               = ON/OFF/TEMP
THRU MAY 15        (ALL) (1,24) (1)       [2]
THRU SEP 15        (ALL) (1,24) (0)
THRU DEC 31        (ALL) (1,24) (1) ..DHW-PUMP-1 = PUMP ..  $ basic domestic hot water recirc pumpFCLOOP-PUMP-1 = PUMP  $ basic chilled and hot water pump
                   $ for fan coilsDHW-LOOP-1 = CIRCULATION-LOOP
TYPE               = DHW
PROCESS-FLOW       = 0.25                 $gpm$
PROCESS-SCH        = DHW-1
HEAT-SETPT-T       = 120 ..
LOOP-PUMP          = DHW-PUMP-1  ..FCLOOP-1 = CIRCULATION-LOOP
TYPE               = PIPE-2
LOOP-PUMP          = FCLOOP-PUMP-1
LOOP-OPERATION     = SCHEDULED 
HEATING-SCHEDULE   = HEAT-ON
COOLING-SCHEDULE   = COOL-ON  ..CHILLER-1 = CHILLER-1
TYPE               = ELEC-HERM-REC
CONDENSER-TYPE     = AIR-COOLED
CHW-LOOP           = FCLOOP-1 ..HWGEN-1 = BOILER
TYPE               = HW-BOILER 
HW-LOOP            = FCLOOP-1 ..DHW-HEATER = DW-HEATER
TYPE               = GAS
DHW-LOOP           = DHW-LOOP-1 ..AC-SYST = SYSTEM
TYPE               = FC
MAX-SUPPLY-T       = 110                  [5]
MIN-SUPPLY-T       = 55                   [6]
NIGHT-CYCLE-CTRL   = CYCLE-ON-ANY         [7]
FAN-SCHEDULE       = FANS-ON              [8]
CHW-LOOP           = FCLOOP-1             [10]
HW-LOOP            = FCLOOP-1 ..          [10]OFFICE = ZONE
TYPE               = CONDITIONED
DESIGN-HEAT-T      = 72
DESIGN-COOL-T      = 74
HEAT-TEMP-SCH      = HEATSETPT            [3]
COOL-TEMP-SCH      = COOLSETPT            [3]
OA-FLOW/PER        = 15 ..                [4]$ THIS MAY BE FOLLOWED BY AN ECON INPUT$END ..COMPUTE ..STOP ..Subtopic help for this Topic:Additional capability for two-pipe FC system: 

     On Friday, December 5, 2014 9:32 AM, Amit Paul <apaul at altanova-energy.com> wrote:
   

  <!--#yiv9467809444 _filtered #yiv9467809444 {font-family:"Cambria Math";panose-1:2 4 5 3 5 4 6 3 2 4;} _filtered #yiv9467809444 {font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;}#yiv9467809444 #yiv9467809444 p.yiv9467809444MsoNormal, #yiv9467809444 li.yiv9467809444MsoNormal, #yiv9467809444 div.yiv9467809444MsoNormal {margin:0in;margin-bottom:.0001pt;font-size:11.0pt;font-family:"Calibri", sans-serif;}#yiv9467809444 a:link, #yiv9467809444 span.yiv9467809444MsoHyperlink {color:#0563C1;text-decoration:underline;}#yiv9467809444 a:visited, #yiv9467809444 span.yiv9467809444MsoHyperlinkFollowed {color:#954F72;text-decoration:underline;}#yiv9467809444 p {margin-right:0in;margin-left:0in;font-size:12.0pt;font-family:"Times New Roman", serif;}#yiv9467809444 span.yiv9467809444EmailStyle17 {font-family:"Calibri", sans-serif;color:windowtext;}#yiv9467809444 .yiv9467809444MsoChpDefault {font-family:"Calibri", sans-serif;} _filtered #yiv9467809444 {margin:1.0in 1.0in 1.0in 1.0in;}#yiv9467809444 div.yiv9467809444WordSection1 {}#yiv9467809444 _filtered #yiv9467809444 {} _filtered #yiv9467809444 {font-family:Symbol;} _filtered #yiv9467809444 {font-family:Symbol;} _filtered #yiv9467809444 {font-family:Symbol;} _filtered #yiv9467809444 {font-family:Symbol;} _filtered #yiv9467809444 {font-family:Symbol;} _filtered #yiv9467809444 {font-family:Symbol;} _filtered #yiv9467809444 {font-family:Symbol;} _filtered #yiv9467809444 {font-family:Symbol;} _filtered #yiv9467809444 {font-family:Symbol;}#yiv9467809444 ol {margin-bottom:0in;}#yiv9467809444 ul {margin-bottom:0in;}-->Hi everyone I'm trying to model an existing building in eQuest 3.65. The building has a chilled water loop and a hot water loop (the same pumps changeover to pump HW in winter and CHW in summer). All apartments have a non-ducted 2-pipe Fan Coil Unit. Nothing controls the coil (there's no 2-way valve), there's just a fan selector (LOW-SPEED/HI-SPEED/OFF), and there is no outside air being supplied to the apartments. I'm struggling to understand how to properly model this in eQuest: ·        Should I create one HVAC SYSTEM (type FCU) per zone? Or one FCU system serving all of my zones? (Both seem to work, but I'm guessing there could be a drawback to using one versus the other) ·        What is the easiest way to ensure the outside air is zero? ·        How should I configure the FCU to mimic as closely as possible the (lack of) controls I have? Thanks for any insight you can provide!    
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