Carrier MODULINE 37HS User Manual
Page 63
VAV HEATING — It is suggested that the following section
be reviewed before reading this section: VAV Cooling,
page 56.
Combining a diffuser-mounted constant volume control pack-
age with a wall-mounted thermostat package (heating only)
allows the use of Moduline
units in VAV heating
applications.
The operation of the heating only thermostat is opposite
to that of the cooling only thermostat in that the heating only
thermostat is reverse acting (RA) instead of direct acting (DA).
The thermostat’s bleed valve is open when the room tem-
perature is above set point. It bleeds air from the low
pressure chamber of the volume controller, lowering its pres-
sure, and allowing the relatively stronger pressure of the air
in the controller’s high pressure chamber to hold closed the
bleed from the controller’s bellows pressure chamber. The
bellows pressure becomes equal to the high pressure in the
unit plenum, closing the unit damper and shutting off the
unit discharge. See Fig. 66.
As the room temperature falls, the thermostat bleed closes
proportionally. This raises the pressure of the air in the low
pressure chamber of the controller, forcing the bellows pres-
sure chamber bleed open and lowering the bellows pressure
proportionally. The damper opens and the unit delivers air to
meet the existing demand in the conditioned space.
See Fig. 67.
Fig. 66 — Variable Volume Controls — Thermostat Open, Controller Shut Off, Unit Shut Off
63
- 42S
- 30GT
- 48SS060
- 50ME
- 38AH024-034
- ZC
- 30GA
- COMFORTLINK 48A2
- 48HE003---006
- 33ZCSECTRM
- 19XRV
- MODU-PAC 50DF
- 17DA
- SINGLE PACKAGED ELECTRIC COOLING UNITS 50GS
- 48JZ (N) 024-060
- 30GX080-176
- 50DL
- 50GL-A
- NP034-074
- 40GXQ
- 30XA080-500
- 39E
- 40KMQ------301
- 38AE
- 48AW
- 38GXQ
- 48ES---A
- 48GL
- 48GH
- 40QA024-060
- TJF004
- 39LD
- 48DL
- 48/50TC04---28
- 50EJ
- 17EX
- 50BA
- 50BB
- 50BB
- 50BJ
- 30H
- 48HJD005-007
- 50ZP
- 50DP016
- 50LJ008-014
- OMNIZONE 50XJ064-104
- 48SX024-048
- 38APS025-065
- 48TM028
- 38BA
- 50LJ
- 07D
- SYSTEM PILOT 33PILOT-01
- 50HG014-028
- 38AUZ
- 50SS018-060
- 50ZH024-060
- 38CKC036 Air
- 51FP
- ROOMTOP 50AH024-096
- WEATHERMAKER 48/50AJ
- 38AF
- 38AK024-044
- 5F
- 50DF034
- WEATHERMASTER 36TE
- 09DK054-084
- 50ZPA
- 48/50PD05
- 40QNC
- MOTORMASTER 48/50P2
- 51CV/GY
- 52F
- 52F
- 38GNA
- 38AKS013-024
- 48TC*D08
- 38AE016
- SEER 48ES
- 50TJ016-028
- MINIMUM LOAD CONTROL ACCESSORY 30XA080-500
- 48/50A020-060
- 48KLA
- 48KLA
- 50GS
- 40RU
- 40RU
- 50PG03-07
- Compressor and Condensing Unit
- PREMIERLINK 33CSPREMLK
- 48/50PG C03-14
- 38GS
- PC 111
- 48EL
- 48PM16---28
- 48VL-A
- 48XL
- 50CD/CH
- 48FK
- OMNIZONE 50XCA06-24
- 48KH
- 00EFN900003000A
- 48DH
- 48GS(N)-2SB
- T--298
- 38ED
- 38TXA
- 38SE
- Packaged Terminal s & Heat Pumps 52P
- WEATHERMAKER 48AJ
- 50AH
- 06D
- WEATHERMAKER ZONEKIT2ZCAR
- 51QC/QG
- 48TC**16
- 30HR
- 50HJ004
- 38CQ
- 38CQ
- P
- 52C
- 50TC
- 50EE
- 50MH
- 30HH
- 38EB
- 38AKS
- 38TRA
- 38CKW
- 39L
- 38CKC
- 50DP
- 040-420
- 38HDR018-060
- 38AKS028-044
- 48VT(N)
- 38GP
- 48/50P030-100
- 51CM
- 52C
- 38AH044-084
- 06E
- 50SX
- 50VL---A
- LIGHT COMMERCIAL CONDENSING UNITS 38HDL018-060
- 50DP020
- 38EC
- 50XP
- 48HJ004-014
- 38JB
- REFRIGERANT R-410A
- 42 SERIES
- 42GW
- 48N
- 48SS018-060
- 48TJF008-012
- 48HDT
- 38TMA
- 38QH
- 40RMQ008-028
- 09BB
- 38GF
- T-326
- 30GX080-265
- MINIMUM LOAD CONTROL ACCESSORY 30RB060-390
- 38HDL018-060
- 49004DP109
- 324423-751
- WEATHERMASTER 48/50Z030-105
- 48TM016-028
- 38CKB
- 09DK054-094
- 48TF004-007
- 38EN
- 38HD
- 38CKC(Q)
- 09DC
- 38VH
- 39E/ER
- 48ES
- RTU OPEN 11-808-427-01
- 38AU
- 07E
- 38GK
- 5H
- 5H
- 19DG
- 50AH024-060
- 42VMC
- 42XQ_42XQA
- 50HJ015
- 19 Series
- 1995 Room Air
- 73Y