[Equest-users] IU Systems - Chilled Beam DOAS

[Jonathan Smith]

Hello All:

 

It is my understanding from reading the DOE2.2 Vol.3 Topic Manual that the system type "IU" - induction unit - can be used to simulate an active chilled beam system, without creating a separate eQuest DOA system. How have you or others gone about configuring such a system? I'd appreciate knowing your cautions/recommendations.

 

Other eQuest email threads have indicated that the heat from zone EA/RA streams is not recognized by a DOAS's energy recovery device when using a dual system configuration, DOAS & OA-FROM-SYSTEM. And that an exceptional calculation would be needed to justify such heat recovery. In the interest of capturing exhaust air heat, it seems logical to use the system side parameters for the OA unit and the sub-zone heating/cooling capacities for the chilled beams. What then would be the advantage of creating two systems (DOAS & OA-FROM-SYSTEM)? 

 

Instead of creating a separate eQuest system for a 100% OA system, I am attempting to use the IU system configuration to simulate an active chilled beam system with 100%OA and capture the EA stream heat with an enthalpy wheel component assignment.  Please see the below BDL input and hourly report of the enthalpy wheel heat recovery.

 

Thanks in advance for any recommendations,

 

Jonathan R. Smith AIA LEED®AP

CSArch 

www.csarchpc.com

 

 

BDL input: Typical system /sub-zone 

..

"ERV-1 (IU)" = SYSTEM          

   TYPE             = IU

   HEAT-SOURCE      = HOT-WATER

   BASEBOARD-SOURCE = HOT-WATER

   RETURN-AIR-PATH  = DUCT

   MAX-SUPPLY-T     = 72

   HEAT-SET-T       = 72

   MIN-SUPPLY-T     = 55

   MAX-HUMIDITY     = 55

   ECONO-LIMIT-T    = 65

   ECONO-LOW-LIMIT  = 45

   SUPPLY-FLOW      = 6020

   RETURN-FLOW      = 6020

   MIN-OUTSIDE-AIR  = 1

   MIN-AIR-SCH      = "S1 Sys1 (FC) MinOA Sch"

   OA-CONTROL       = FIXED

   RECOVER-EXHAUST  = YES

   FAN-SCHEDULE     = "S1 Sys1 (FC) Fan Sch"

   SUPPLY-DELTA-T   = 5

   SUPPLY-KW/FLOW   = 0.00186

   RETURN-DELTA-T   = 5

   RETURN-KW/FLOW   = 0.00186

   NIGHT-CYCLE-CTRL = CYCLE-ON-ANY

   RETURN-FAN-LOC   = RELIEF

   INDUCTION-RATIO  = 2.7

   HW-VALVE-TYPE    = TWO-WAY

   HW-LOOP          = "Hot Water Loop"

   CHW-VALVE-TYPE   = TWO-WAY

   CHW-LOOP         = "Chilled Water Loop"

   BBRD-LOOP        = "Hot Water Loop"

   HEATING-CAPACITY = -300000

   EVAP-CL-TYPE     = DIRECT

   DESICCANT        = SOL-VENT-AIR-1

   DESC-HEAT-SOURCE = GAS-HYDRONIC

   ERV-RECOVER-TYPE = ENTHALPY-WHEEL

   ERV-OA-FLOW      = 6020

   ERV-RUN-CTRL     = OA-EXHAUST-DH

   OA-EXHAUST-DH    = 12.313

   ERV-RECOVER-MODE = OA-HEAT/COOL

   ERV-TEMP-CTRL    = FIXED-SETPT

   OA-HEAT-SETPT-T  = 70

   OA-COOL-SETPT-T  = 80

   ERV-CAP-CTRL     = MODULATE-HX

   ..

"EL1 South Perim Zn (G.S7)" = ZONE            

   TYPE             = CONDITIONED

   MIN-FLOW-RATIO   = 1

   HEATING-CAPACITY = -366530

   BASEBOARD-RATING = -100000

   FLOW/AREA        = 0.1

   OA-FLOW/PER      = 9

   DESIGN-HEAT-T    = 72

   HEAT-TEMP-SCH    = "S1 Sys1 (FC) Heat Sch"

   DESIGN-COOL-T    = 75

   COOL-TEMP-SCH    = "S1 Sys1 (FC) Cool Sch"

   BASEBOARD-CTRL   = THERMOSTATIC

   SIZING-OPTION    = ADJUST-LOADS

   SPACE            = "127 Cafeteria"

   ..

 

Hourly Report for Typical IU System:

Month

Day

Hour

Temp of air leaving heat coil - hot deck temp (deg F)

ERV Outdoor air temperature entering HX, after preheat (°F)

ERV Outdoor air temperature leaving HX (to mixed air plenum) (°F)

1

4

9

72

25

58.7408

1

4

10

72

25

59.4445

1

4

11

72

27

59.8008

1

4

12

72

29

60.6705

1

4

13

72

31

61.3672

1

4

14

72

31

61.2842

1

4

15

72

31

61.1658

1

4

16

72

31

61.1586

1

4

17

72

30

60.9037

 

 

 

 

Jonathan R. Smith AIA LEED®AP

 

 

40 Beaver Street
Albany, New York 12207
p: 518.463.8068 x268
f: 518.463.8069 
www.csarchpc.com <http://www.csarchpc.com/> 

 

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