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

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