IM 930-6 •EnnityVerticalWaterSourceHeatPumps 32 www.DaikinApplied.com
Hot Gas/Water Reheat
Dehumidication (Option) (Unit
Sizes 019 – 070)
HotGasReheat(HGRH)allowssuperiorhumiditycontrol
byutilizingasecondaircoiltoprovidedehumidication
andtemperedairtotheconditionedspace.
Aeldsuppliedhumidistatisrequired.Wirethe
humidistattothedualterminalblock(TB1)ontheI/O
expansionmodule.
Note: Hot Gas Reheat (HGRH) utilizes high fan speed.
Desuperheater (Option) For VFC/
VFW (019-070)
Adesuperheaterheatswaterfordomesticuseby
pumpingwaterthoughacoaxialheatexchangersothat
itpassesbysuperheatedrefrigerantgas.
1. Turnoffgassupplyorelectricsupplytowaterheater
tank.
2. Closewatersupplyvalveonwaterheatertank.
3. Connecthosetodrainonwaterheatertank.Run
hosetosuitabledrain.
4. Opendrainvalveontankandpullpressurerelief
valvetoassistdraining.Lettankdraincompletely.
5. Flushtankofsedimentbyopeningwatersupply
valveuntilclearwaterowsfromhose.
6. Closesupplyvalve.Oncetankisempty,close
pressurereliefandwatertankdrainvalves.
7. Draintankbyopeningdrainvalveonthebottom
ofthetank,thenopenpressurereliefvalveorhot
water faucet.
8. Oncedrained,thetankshouldbeushedwithcold
wateruntilthewaterleavingthedrainhoseisclear
andfreeofsediment.
9. Closeallvalvesandremovethedrainhose.
10. Installpipingfordesuperheaterfollowingthe
guidelinesbelow:
For piping length up to 15 feet:
• •Use3/8"O.D.(orlarger)coppertube.
For piping lengths of 15 feet to 60 feet:
• •Use1/2"O.D.coppertube.
Notes: All exposed water lines must be insulated with
3/8" wall closed-cell insulation.
Install shut-off valves on desuperheater supply
and return lines.
11. Relltankbyopeningthewatertanksupplyvalve.
12. Ventairfromthesystembyopeningahotwater
faucet.Closefaucetwhenairispurgedfromsystem.
13. Checkforwaterleaksandrepairasnecessary
14. Restoregassupplyorelectricsupplytowaterheatertank.
Units with the desuperheater option must be drained prior to
exposure to temperatures that will cause the water to freeze,
resultingindamagetothedesuperheater.Damagefromfreezing
isnotcoveredundertheDaikinproductwarranty.
CAUTION
All Federal, State and local codes should be followed when
installingthedesuperheater.Installationmustbeperformedbya
qualiedplumberandelectrician.
WARNING
Sufcient water ow must be provided. Damage to the
desuperheaterpumpfromlackofwaterowisnotcoveredby
theDaikinproductwarranty.
CAUTION
Figure 32: Typical Connection diagram for VFC/VFW
1. Desuperheaterwatersupplywithstainlesssteelexible
hosewithY-strainer/ballvalve
2. Desuperheaterwaterreturnwithstainlesssteelexible
hosewithowcontroller/ballvalve
3. Flexibleductcollar
4. Isolationpad
5. Lowvoltagecontrolwiring(electricentrance)
6. Linevoltage-unitpower(electricentrance)
7. Waterheatertankdrainvalve
8. P/Treliefvalve
9. Hotwaterout
10. Cold water in
11. Dischargeairtospace
12. Return air
additional aCCessories – general