Trane OABD, OABE, OADD, OADE, OAGD Catalogue

...

Product Catalog

Horizon™ Outdoor Air Unit For 100% Outdoor Air Applications

Models: OABD, OABE, OADD, OADE, OAGD, OAKD, OAKE, OAND, OANE

October 2014

OAU-PRC001E-EN

Introduction

Standard Direct

Drive w/VFD Plenum

Fan and Slide Out

Service Access

Optional Head

Pressure Control

w/VFD

Microprocessor

Based Control

w/Easy to Read

Human Interface

Standard 6-in. Max

Internal Capacity

Adjustable Filter Rack

w/Dirty Filter Switch

Standard 2-in.

Double Wall R-13

Foam In sulation

2-in. Aluminum Mesh

Filters w/Optional

Outdoor Airflow

Monitoring System

Optional On/Off

Electric Preheat for

ERV Applications

Optional Digital Scroll or

APR Refrigeration

Capacity Controller on

First Circuit

Optional High Turndown

Indirect Gas-Fired

Stainless Steel Heat Exchanger, Modulating SCR Electric Heater, or

Hot Water Coils

Optional

Modulating

Hot Gas

Reheat C oil

Standard 6-Row

Interlaced

Evaporator Coil

w/Stainless Steel

Drain Pan

Optional 2-Position

or Modulating w/Economizer

Return Air Damper

Optional Direct Drive

w/VFD Plenum Fan

Powered Exhaust

w/Gravity Dampers or

Isolation Dampers

Optional Auxiliary Cabinet

for Total-Energy Wheel w/Standard Modulating

Bypass Dampers

The Horizon Outdoor Air Unit...

The Trane DX Horizon™ Outdoor Air Unit for 100 percent outdoor air or dew point design applications leads the industry in:

• Indoor Air Quality (IAQ) Features

• Moisture Management

• High Quality and Durability

• Advanced Controls

Trademarks

Revision History

This document and the information in it are the property of Trane, and may not be used or reproduced in whole or in part without written permission. Trane reserves the right to revise this publication at any time, and to make changes to its content without obligation to notify an y person of such revision or change.

All trademarks referenced in this document are the trademarks of their respective owners.

OAU-PRC001E-EN (27 Oct 2014)

• Model number update and inclusion of OAG product information

Table of Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Model Number Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Horizon Outdoor Air Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Features and Benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Application Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

System Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Horizon OAU Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

OAU with Reheat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

OAU Outdoor Air Control without Reheat . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Establishing Capacity Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Cooling & Dehumidification Selection Criteria . . . . . . . . . . . . . . . . . . . . . . . 19

Outdoor Airflow Balancing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Air to Air Energy Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

The Horizon Outdoor Air Unit... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Models: OABD, OAGD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Models: OADD, OADE, OAKD, OAKE, OAND, OANE . . . . . . . . . . . . . . . . . 9

Indoor Air Quality (IAQ) Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Energy Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

High Quality and Durability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Advanced Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Flexibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Enhanced Serviceability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Standard Unit Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Standard Control Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Optional Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Outdoor Air Unit Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Dehumidification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Cooling or Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Dehumidification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Cooling or Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Evaporator Design Entering Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Evaporator Design Leaving Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Reheat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Capacity Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Discharge Air Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Cooling Setpoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Unoccupied Space Humidity Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Space Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Controlling the Total-Energy Wheel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Cross Leakage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

OAU-PRC001E-EN 3

Condensate Drain Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Acoustical Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Clearance Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Duct Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Controls Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Selection Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Horizon OAU Selection Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

General Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Unit Clearances, Curb Dimensions, and Dimensional Data . . . . . . . . . . . . . . . 44

OAB Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Unit Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Curb Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Dimensional Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

OAD Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Unit Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Curb Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Dimensional Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Indirect-Fired OAG Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Unit Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Curb Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Dimensional Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Direct-Fired OAG Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Unit Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Curb Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Dimensional Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

OAK Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Unit Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Curb Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Dimensional Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

OAN Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Unit Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Curb Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Dimensional Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Indirect Gas-fired Furnace Heater and Power . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Unit Weight and Rigging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Unit Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Corner Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Rigging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Mechanical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Horizon Outdoor Air Mechanical Specifications . . . . . . . . . . . . . . . . . . . . . . 75

Refrigeration and Dehumidification Systems . . . . . . . . . . . . . . . . . . . . . . 75

4 OAU-PRC001E-EN

Electrical and Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

OAU Filter Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

OAU-PRC001E-EN 5

Model Number Descriptions

Horizon Outdoor Air Unit

Models: OABD, OAGD

Typical model number (example):

OABD036A4-D1A1A0AB-G1CB0AC3AB-A11B102A0

1 2 3 4 5 6 7 8 9 101112131415161718192021222324252627282930313233343536373839

Digit 1, 2 — Unit Type

OA = Outdoor Air

Digit 3 — Cabinet Size

B = 500–3000 CFM G = 1250–7500 CFM

Digit 4 — Major Design Sequence

D = Revision 1 E = Heat Pump

Digit 5, 6, 7 — Normal Gross Cooling Capacity (MBh)

000= No Cooling 036= 3 Tons High Efficiency 048= 4 Tons High Efficiency 060= 5 Tons High Efficiency 072= 6 Tons High Efficiency 084= 7 Tons High Efficiency 096= 8 Tons High Efficiency 108 = 9 Tons High Efficiency 120 = 10 Tons High Efficiency 144 = 12 Tons High Efficiency 180 = 15 Tons High Efficiency 210 = 17 Tons High Efficiency 240= 20 Tons High Efficiency 264= 22 Tons High Efficiency 300 = 25 Tons High Efficiency 360= 30 Tons High Efficiency

Digit 8 — Minor Design Sequence

A = Vertical Discharge/Vertical Return B = Vertical Discharge/Horizontal

Return

C = Horizontal Discharge/Vertical

Return

D = Horizontal Discharge/Horizontal

Return

Digit 9 — Voltage Selection

3 = 208-230/60/3 4 = 460/60/3 5 = 575/60/3

Digit 10 — Reserved for Future Use

Digit 11 — Evaporator Type

0 = No Cooling C = DX 4-Row Interlaced D = DX 6-Row Interlaced F = Glycol/Chilled Water

Digit 12 — Hot Gas Reheat

0=No HGRH 1 = Fin and Tube Modulating 2 = Fin and Tube On/Off 3 = Microchannel Modulating 4 = Microchannel On/Off

Digit 13 — Compressor

0=No Compressors A = Scroll Compressors B = Digital Scroll—1 C = Digital Scroll—1 D = Variable Speed Scroll—1

E = Variable Speed Scroll—1

Circuit Only

Circuit

Circuit Only

and 2nd Circuit

and

Digit 14 — Condenser

0 = No Condenser 1 = Air-Cooled Fin and Tube 2 = Air-Cooled Fin and Tube

3 = Water-Cooled DX Condenser 4 = Air-Cooled Fin and Tube 5 = Air-Cooled Microchannel

6 = Air-Cooled Microchannel 7 = Air-Cooled Microchannel 8 = Water-Cooled DX Condenser

w/Head Pressure On/Off Control Copper/Steel w/Head Pressure Variable Speed

w/Head Pressure On/Off Control Variable Speed Copper/Nickel

Digit 15 — Refrigerant Capacity Control

0 = No RCC Valve A = RCC Valve on 1 B = RCC Valve on 1 C = ERCC Valve on1 D = ERCC Valve on 1 E = HGBP Valve on 1 F = HGBP Valve on 1

Circuit

and 2nd Circuit

Circuit

and 2nd Circuit

Circuit

and

Digit 16 — Indoor Fan Motor (IFM)

0 = ECM w/Backward Curved 2 = Belt Drive

3 = Belt Drive w/VFD 4 = Special Motor Option

Plenum Fan

Digit 17 — Indoor Fan Wheel

A = 355 B = 450 X 2 C = 12/9 (single belt drive) D = 12/9 BT (dual belt drive)

Digit 18 — Indoor Fan Motor (hp)

ECM Belt Drive

A = 1 kW 2 hp B = 2 kW 3 hp C = 3 kW 5 hp D = 4 kW 7.5 hp E= 10 hp F= 15 hp

Digit 19 — Reserved for Future Use

Digit 20 — Heater Type (PRI/SEC)

0 = No Heat A = Indirect-Fired (IF) B = Direct-Fired (DF) C = Electric—4-Stage D = Electric—SCR Modulating E = Dual Fuel (PRI-IF/SEC-DF) F = Dual Fuel (PRI-ELEC/SEC-DF) G = Dual Fuel (PRI-IF/SEC-ELEC) H = Dual Fuel (PRI-ELEC/SEC-ELEC) J=Hot Water K = Steam

Digit 21 — Primary Fuel Type

0 = No Heat 1=Natural Gas 2=Propane 3 = Electric—Open Coil 4 = Electric—Sheathed Coil 5=Hot Water 6 = Steam

6 OAU-PRC001E-EN

Model Number Descriptions

OABD, OAGD Units

Digit 22 — Heater Capacity— Primary Heat Source

IF ELEC

0 = No Heat No Heat A = 50 MBh 5 kW B = 75 MBh 10 kW C = 100 MBh 15 kW D = 125 MBh 20 kW E = 150 MBh 24 kW F = 200 MBh 28 kW G = 250 MBh 32 kW H = 300 MBh 40 kW J = 350 MBh 48 kW K = 400 MBh 60 kW L = 500 MBh 68 kW M = 600 MBh 79 kW N = 99 kW O = 111 kW P= 119 kW X = Special Heater Option

Digit 23 — Heat Capacity— Secondary Heat Source

ELEC DF

0 = No Heat/No Secondary Heat A = 5 kW 300 MBh B = 10 kW 650 MBh C = 15 kW 814 MBh D = 20 kW E = 24 kW F = 28 kW G = 32 kW H = 40 kW J = 48 kW

Digit 24 — Corrosive Environment Package

0 = No Corrosive Package 1 = S/S Cabinet, Basepan,

Eco-Coated Coils 2 = S/S Cabinet, Basepan 3 = S/S Basepan, Eco-Coated Coils 4 = S/S Coil Casing 5 = S/S Interior Casing 6 = Eco-Coated Coils 7 = S/S Coil Casing with

Eco-Coated Coils 8 = Copper/Copper Condenser,

Evap, HGRH Coils

Digit 25, 26 — Unit Controls

00 = Non DDC—Electromechanical AA = Trane—Discharge Air Control

AB = Trane—Space Control w/LON AC = Trane—Discharge Air Control AD = Trane—Space Control AF = Trane—Discharge Air Control AG = Trane—Space Control AI = Trane—Discharge Air Control AJ = Trane—Space Control AK = Trane—Multi-Zone VAV Control AL = Trane—Multi-Zone VAV Control AM= Trane—Multi-Zone VAV Control AN = Trane—Multi-Zone VAV Control AO = Trane—Single-Zone VA V Control AP = Trane—Single-Zone VAV Control AQ = Trane—Single-Zone VA V Control AR = Trane—Single-Zone VAV Control XX = Special

w/LON Read-Write w/Display Read-Write w/Display w/BACnet w/BACnet (No Display) w/BACnet w/Display w/BACnet w/Display w/LON Read-Write (No Display) w/LON Read-Write (No Display) w/LON Read-Write w/Display w/BACnet w/Display w/LON Read-Write (No Display) w/BACnet (No Display) w/LON Read-Write w/Display w/BACnet w/Display w/LON Read-Write (No Display) w/BACnet (No Display)

(No Display)

Digit 27 — Pow ered Exhaust Fan Motor (PFM) and Exhaust Dampers

0 = No Powered Exhaust 3 = Belt Drive 4 = Belt Drive w/VFD 5 = Special Motor Option 6 = ECM w/Backward Curved

7 = ECM w/Backward Curved

8 = ECM w/Backward Curved

9 = Barometric Relief Dampers

Plenum Fan Plenum Fan and Barometric

Relief Damper Plenum Fan and Isolation

Dampers w/End Switch (No PFM)

Digit 28 — Pow ered Exhaust Fan Wheel

0 = No Powered Exhaust A = 355 B = 450 X 2 C = 12/9 (single belt drive) D = 12/9 BT (dual belt drive)

Digit 29 — Pow ered Exhaust Fan Motor (hp)

ECM

0 = No Powered Exhaust A = 1 kW 2 hp B = 2 kW 3 hp C = 3 kW 5 hp D = 4 kW 7.5 hp E= 10 hp F= 15 hp

Belt Drive

DIGIT 30 — Reserved for Future Use

Digit 31 — ERV (Requires Powered Exhaust)

0=No ERV A = ERV—Composite Construction

B = ERV—Composite Construction C = ERV—Aluminum Construction D = ERV—Aluminum Construction

w/Bypass with Frost Protection w/VFD w/Bypass with Frost Protection w/VFD

Digit 32 — ERV Size

0=No ERV 1=3014 2 = 3622 3 = 4136 4 = 4634 5 = 5856

Digit 33 — Damper Options

0 = 100% OA 2-Position Damper 1 = 100% OA 2-Position Damper

2 = Modulating OA and RA Dampers

w/RA 2-Position Damper w/Economizer

Digit 34 — Filtration Options

A = No Filters B=MERV-8, 30% C = MERV-13, 80% D = MERV-14, 95% E = MERV-8 30%, MERV-13 80% F = MERV-8 30%, MERV-14 95% G = MERV-8, 30%, with UVC H = MERV-13, 80%, with UVC J = MERV-14, 95%, with UVC K = MERV-8 30%, MERV-13 80%,

L = MERV-8 30%, MERV-14 95%, M = MERV-8 30%, and TCACS

N = MERV-13 80%, and TCACS P = MERV-14 95%, and TCACS Q = MERV-8 30%, MERV-13 80%,

R = MERV-8 30%, MERV-14 95%, X = Special Filter Options

and UVC and UVC

and TCACS and TCACS

OAU-PRC001E-EN 7

Model Number Descriptions

OABD, OAGD Units

Digit 35 — Smoke Detector— Factory Installed

0=No Smoke Detector 1 = Supply Smoke Detector 2 = Return Smoke Detector 3 = Supply and Return Smoke

Digit 36 — Electrical Options

0 = Terminal Block A = Non-Fused Disconnect B = Fused Disconnect Switch C = Non-Fused Disconnect

D = Fused Disconnect Switch E=Dual Point Power

F=Dual Point Power G = 65 SCCR Electrical Rating H = 65 SCCR Electrical Rating J = 65 KAIC Electrical Rating K = 65 KAIC Electrical Rating

Digit 37 — Air Flow Monitoring

0 = No Airflow Monitoring 1 = Airflow Monitoring—IFM

2 = Airflow Monitoring—PE 3 = Airflow Monitoring—Outdoor Air

4 = Airflow Monitoring—IFM 5 = Airflow Monitoring—Outdoor Air

Digit 38 — Accessories

0=No Options A = Hailguards B = LED Service Light and

Digit 39 — Altitude

0 = Sea Level to 1,000 feet 1 = 1,001 to 2,000 feet 2 = 2,001 to 3,000 feet 3 = 3,001 to 4,000 feet 4 = 4,001 to 5,000 feet 5 = 5,001 to 6,000 feet 6 = 6,001 to 7,000 feet 7 = Above 7,000 feet

Detectors

w/Convenience Outlet

w/Non-Fused Disconnect

w/Fused Disconnect

w/Non-Fused Disconnect

w/Fused Disconnect

Piezo Ring

with Display and IFM

w/Piezo Ring

Piezo Ring and PE Piezo Ring

Monitoring w/Display Supply Air

and Exhaust Air w/Piezo Rings

Hailguards

8 OAU-PRC001E-EN

Model Number Descriptions

Models: OADD, OADE, OAKD, OAKE, OAND, OANE

Typical model number (example):

OAKD300A4-D1A1A0GM-G1KB0AC3CJ -A41B102A0

1 2 3 4 5 6 7 8 9 101112131415161718192021222324252627282930313233343536373839

Digit 1, 2 — Unit Type

OA = Outdoor Air

Digit 3 — Cabinet Size

D = 625–4,000 cfm K = 1,500–9,000 cfm N = 3,750–13,500 cfm

Digit 4 — Major Design Sequence

D = Revision 5 E = Heat Pump

Digit 5, 6, 7 — Normal Gross Cooling Capacity (MBh)

000= No Cooling 060= 5 Tons High Efficiency 072= 6 Tons High Efficiency 084= 7 Tons High Efficiency 096= 8 Tons High Efficiency 120 = 10 Tons High Efficiency 144 = 12 Tons High Efficiency 180 = 15 Tons High Efficiency 210 = 17 Tons High Efficiency 240= 20 Tons High Efficiency 264= 22 Tons High Efficiency 300 = 25 Tons High Efficiency 360= 30 Tons High Efficiency 420= 35 Tons High Efficiency 480= 40 Tons High Efficiency 540= 45 Tons High Efficiency 600 = 50 Tons High Efficiency 648= 54 Tons High Efficiency

Digit 8 — Minor Design Sequence

A B

Digit 9 — Voltage Selection

1 = 115/60/1 2 = 208-230/60/1 3 = 208-230/60/3 4 = 460/60/3 5 = 575/60/3

Digit 10 — Reserved for Future Use

Digit 11 — Evaporator Type

0 = No Cooling A = DX 3-Row B = DX 4-Row C = DX 4-Row Interlaced D = DX 6-Row Interlaced E = DX 8-Row F = Glycol/Chilled Water Coil G = DX 4-Row with

MSP

Technology

Digit 12 — Hot Gas Reheat

0=No HGRH 1 = Fin and Tube Modulating 2 = Fin and Tube On/Off 3 = Microchannel Modulating 4 = Microchannel On/Off

Digit 13 — Compressor

0=No Compressors A = Scroll Compressors B = Digital Scroll—1 C = Digital Scroll—1 D = Variable Speed Scroll—1

E = Variable Speed Scroll—1

Circuit Only

Circuit

Circuit Only

and 2nd Circuit

and

Digit 14 — Condenser

0 = No Condenser 1 = Air-Cooled Fin and Tube 2 = Air-Cooled Fin and Tube

3 = Water-Cooled DX Condenser 4 = Air-Cooled Fin and Tube 5 = Air-Cooled Microchannel

6 = Air-Cooled Microchannel 7 = Air-Cooled Microchannel 8 = Water-Cooled DX Condenser

w/Head Pressure On/Off Control Copper/Steel w/Head Pressure Variable Speed

w/Head Pressure On/Off Control Variable Speed Copper/Nickel

Digit 15 — Refrigerant Capacity Control

0 = No RCC Valve A = RCC Valve on 1 B = RCC Valve on 1 C = ERCC Valve on1 D = ERCC Valve on 1 E = HGBP Valve on 1 F = HGBP Valve on 1

Circuit

and 2nd Circuit

Circuit

and 2nd Circuit

Circuit

and

Digit 16 — Indoor Fan Motor (IFM)

0 = Direct Drive w/VFD 1 = Direct Drive (VFD by Others) 2 = Belt Drive 3 = Belt Drive w/VFD 4 = Direct Drive w/Shaft

5 = Special Motor Option

Grounding Ring w/VFD

Digit 17 — Indoor Fan Wheel

A=122 B = 122.6 C=150 D = 150.6 E=165 F = 165.6 G=182 H = 182.6 J=200 K = 200.6 L = 182 X 2 M = 182.6 X 2

Digit 18 — Indoor Fan Motor HP

A = 1/2 hp—1800 rpm B = 1/2 hp—3600 rpm C = 3/4 hp—1800 rpm D = 3/4 hp—3600 rpm E = 1 hp—1800 rpm F = 1 hp—3600 rpm G = 1.5 hp—1800 rpm H = 1.5 hp—3600 rpm J = 2 hp—1800 rpm K = 2 hp—3600 rpm L = 3 hp—1800 rpm M = 3 hp—3600 rpm N = 5 hp—1800 rpm P = 5 hp—3600 rpm R = 7.5 hp—1800 rpm S = 7.5 hp—3600 rpm T = 10 hp—1800 rpm U = 10 hp—3600 rpm V = 15 hp—1800 rpm W = 15 hp—3600 rpm

Digit 19 — Reserved for Future Use

Digit 20 — Heat Type (PRI/SEC)

Digit 21 — Primary Fuel Type

0 = No Heat 1=Natural Gas 2=Propane 3 = Electric—Open Coil 4 = Electric—Sheathed Coil 5=Hot Water 6 = Steam

OAU-PRC001E-EN 9

Model Number Descriptions

OADD, OADE, OAKD, OAKE, OAND, OANE Units

Digit 22 — Heat Capacity— Primary Heat Source

IF ELEC

0 = No Heat No Heat A = 50 MBh 10 kW B = 75 MBh 20 kW C = 100 MBh 24 kW D = 125 MBh 28 kW E = 150 MBh 32 kW F = 200 MBh 40 kW G = 250 MBh 48 kW H = 300 MBh 60 kW J = 350 MBh 68 kW K = 400 MBh 79 kW L = 500 MBh 99 kW M = 600 MBh 111 kW N = 700 MBh 119 kW P = 800 MBh 139 kW R = 1000 MBh 159 kW S = 179 kW T = 199 kW U = 215 kW X = Special Heater Option

Digit 23 — Heat Capacity— Secondary Heat Source

IF ELEC DF

0 = No Heat/No Secondary Heat A = 50 MBh 10 kW 300 MBh B = 75 MBh 20 kW 600 MBh C = 100 MBh 24 kW 900 MBh D = 125 MBh 28 kW 1200 MBh E = 150 MBh 32 kW F = 200 MBh 40 kW G = 250 MBh 48 kW H = 300 MBh 60 kW J = 350 MBh 68 kW K = 400 MBh 79 kW L = 500 MBh 99 kW M = 600 MBh 111 kW N = 700 MBh 119 kW P = 800 MBh 139 kW R = 1000 MBh 159 kW S = 179 kW T = 199 kW U = 215 kW

Digit 24 — Corrosive Environment Package

0 = No Corrosive Package 1 = S/S Cabinet, Basepan,

2 = S/S Cabinet, Basepan 3 = S/S Basepan, Eco-Coated Coils 4 = S/S Coil Casing 5 = S/S Interior Casing 6 = Eco-Coated Coils 7 = S/S Coil Casing with

8 = Copper/Copper Condens er,

Eco-Coated Coils

Eco-Coated Coils Evap, HGRH Coils

Digit 25, 26 — Unit Controls

00 = Non DDC—Electromechanical AA = Trane—Discharge Air Control

AB = Trane—Space Control AC = Trane—Discharge Air Control AD = Trane—Space Control AF = Trane—Discharge Air Control AG = Trane—Space Control AI = Trane—Discharge Air Control AJ = Trane—Space Control AK = Trane—Multi-Zone VAV Control AL = Trane—Multi-Zone VAV Control AM= Trane—Multi-Zone VAV Control AN = Trane—Multi-Zone VAV Control AO = Trane—Single-Zone VA V Control AP = Trane—Single-Zone VAV Control AQ = Trane—Single-Zone VA V Control AR = Trane—Single-Zone VAV Control

w/LON Read-Write w/Display w/LON Read-Write w/Display w/BACnet w/BACnet (No Display) w/BACnet w/Display w/BACnet w/Display w/LON Read-Write (No Display) w/LON Read-Write (No Display) w/LON Read-Write w/ Display w/BACnet w/Display w/LON Read-Write (No Display) w/BACnet (No Display) w/Lon Read-Write w/Display w/BACnet w/Display w/LON Read-Write (No Display) w/BACnet (No Display)

(No Display)

Digit 27 — Pow ered Exhaust Fan Motor (PFM) and Exhaust Dampers

0 = No Powered Exhaust 1 = Direct Drive w/VFD and

2 = Direct Drive (VFD by Others) 3 = Belt Drive 4 = Belt Drive w/VFD 5 = Special Motor Option 6 = Direct Drive w/VFD and

7 = Direct Drive w/VFD and 8 = Barometric Relief Dampers

Gravity Dampers

Barometric Relief Damper Isolation Dampers w/End Switch (NO PFM)

Digit 28 — Pow ered Exhaust Fan Wheel

0 = No Powered Exhaust A=122 B = 122.6 C=150 D = 150.6 E=165 F = 165.6 G=182 H = 182.6 J=200 K = 200.6 L = 182 X 2 M = 182.6 X 2

Digit 29 — Pow ered Exhaust Fan Motor (hp)

0 = No Powered Exhaust A = 1/2 hp—1800 rpm B = 1/2 hp—3600 rpm C = 3/4 hp—1800 rpm D = 3/4 hp—3600 rpm E = 1 hp—1800 rpm F = 1 hp—3600 rpm G = 1.5 hp—1800 rpm H = 1.5 hp—3600 rpm J = 2 hp—1800 rpm K = 2 hp—3600 rpm L = 3 hp—1800 rpm M = 3 hp—3600 rpm N = 5 hp—1800 rpm P = 5 hp—3600 rpm R = 7.5 hp—1800 rpm S = 7.5 hp—3600 rpm T = 10 hp—1800 rpm U = 10 hp—3600 rpm V = 15 hp—1800 rpm W = 15 hp—3600 rpm

Digit 30 — Reserved for Future Use

Digit 31 — ERV (Requires Powered Exhaust)

0=No ERV A = ERV—Composite Construction B = ERV—Composite Construction

with Frost Protection w/VFD

C = ERV—Composite Construction

with Bypass

D = ERV—Composite Construction

with Frost Protection and Bypass E = ERV—Aluminum Construction F = ERV—Aluminum Construction

with Frost Protection w/VFD G = ERV—Aluminum Construction

with Bypass H = ERV—Aluminum Construction

with Frost Protection and Bypass

10 OAU-PRC001E-EN

Model Number Descriptions

OADD, OADE, OAKD, OAKE, OAND, OANE Units

Digit 32 — ERV Size

0=No ERV 1=3014 2 = 3622 3 = 4136 4 = 4634 5 = 5856 6 = 6488 7 = 6876 8=74122

Digit 33 — Damper Options

0 = 100% OA 2-Position Damper 1 = 100% OA 2-Position Damper

w/RA 2-Position Damper

2 = Modulating OA and RA Dampe rs

w/Economizer

Digit 34 — Filtration Options

A = Aluminum Mesh Intake Filters

(ALM) B = MERV-8,30%, and ALM C = MERV-13, 80%, and ALM D = MERV-14, 95%, and ALM E = MERV-8 30%, MERV-13 80%, and

ALM F = MERV-8 30%, MERV-14 95%, and

ALM G = MERV-8, 30%, and ALM, with

UVC H = MERV-13, 80%, and ALM, with

UVC J = MERV-14, 95%, and ALM, with

UVC K = MERV-8 30%, MERV-13 80%,

ALM, and UVC L = MERV-8 30%, MERV-14 95%,

ALM, and UVC M = MERV-8 30%, ALM, and TCACS N = MERV-13 80%, ALM, and TCACS P = MERV-14 95%, ALM, and TCACS Q = MERV-8 30%, MERV-13 80%,

ALM, and TCACS R = MERV-8 30%, MERV-14 95%,

ALM, and TCACS X = Special Filter Options

Digit 35 — Smoke Detector— Factory Installed

0=No Smoke Detector 1 = Supply Smoke Detector 2 = Return Smoke Detector 3 = Supply and Return Smoke

Detector

Digit 36 — Electrical Options

0 = Non-Fused Disconnect A = Fused Disconnect Switch B = Non-Fused Disconnect

w/Convenience Outlet

C = Fused Disconnect Switch

w/Convenience Outlet

D = Dual Point Power

w/Convenience Outlet

F = 65 SCCR Electrical Rating

w/Non-Fused Disconnect

G = 65 SCCR Electrical Rating

w/Fused Disconnect

H = 65 KAIC Electrical Rating

w/Non-Fused Disconnect

J = 65 KAIC Electrical Rating

w/Fused Disconnect

Digit 37 — Air Flow Monitoring

0 = No Airflow Monitoring 1 = Airflow Monitoring—IFM

Piezo Ring

2 = Airflow Monitoring—PE

Piezo Ring

3 = Airflow Monitoring—Outdoor Air

with Display and IFM w/Piezo Ring

4 = Airflow Monitoring—IFM

Piezo Ring and PE Piezo Ring

5 = Airflow Monitoring—Outdoor Air

Monitoring w/ Display Supply Air and Exhaust Air w/Piezo Rings

Digit 38 — Accessories

0 = No Options A = Hailguards B = LED Service Light C = Hailguards and LED

Service Light

Digit 39 — Altitude

0 = Sea Level to 1,000 feet 1 = 1,001 to 2,000 feet 2 = 2,001 to 3,000 feet 3 = 3,001 to 4,000 feet 4 = 4,001 to 5,000 feet 5 = 5,001 to 6,000 feet 6 = 6,001 to 7,000 feet 7 = Above 7,000 feet

OAU-PRC001E-EN 11

Features and Benefits

We designed the Horizon™ Outdoor Air Unit based on customer requirements from across the country. Thorough analysis of the performance requirements resulted in a robust design with the ability to effectively operate over an expansive performance envelope required for the year -round treatment of outdoor air.

Also, we took into account today’s HVAC market issues, such as indoor air quality (IAQ). We equipped the Horizon Outdoor Air Unit to meet your ventilation needs—in direct response to the ventilation and humidity control requirements of ASHRAE standard 62.1.

Trane’s Horizon Outdoor Air Unit leads the industry in the key areas of:

• indoor air quality (IAQ)

• energy efficiency

• high quality and durability

• advanced, integrated controls

• flexibility (including indoor installation)

• enhanced serviceability

Indoor Air Quality (IAQ) Features

• Stainless steel drain pan sloped in two directions to ensure proper drainage and reduce the potential for microbial growth

• Double-wall foamed panel construction throughout the indoor section of unit to provide, nonporous, cleanable interior surfaces

• Inlet hood with moisture eliminators

• High efficiency throwaway filter option with standard 2-, 4-, or 6-inch adjustable filter rack

• Piezometer airflow measurement option

• Easy filter access encourages frequent changing

• Refrigerant hot gas reheat for low dewpoint supply air for superior humidity control

• Capable of providing low dew point supply air for superior humidity control

Energy Efficiency

• Total energy wheel option for recovered energy from centralized building exhaust

• Optional modulating recovered refrigerant reheat for unit supply air

High Quality and Durability

• Robust unit construction with 2-inc h do uble wall panels with foam insulat ion for an R-value of 13

• Reversible, hinged access doors

• High quality, long-lasting latches and hinges for all access doors

• Protective standard prepainted finish on cabinet exterior with optional corrosion inhibiting coatings available for the unit exterior, interior and coils

Advanced Controls

• All controls are factory-engineered, mounted, configured and tested to minimize field startup time

•UC600 microprocessor control

• Human interface with touch-pad screen for monitoring, setting, editing and controlling

• Capable of supply-air control or zone control of both temperature and relative humidity

• Occupied and unoccupied control sequences

• Optional remote human interface for ease of control access without going outdoors

• Optional LonTalk building management system or other control systems that support LonTalk

communications interface communication link with a Tracer Summit™

12 OAU-PRC001E-EN

Flexibility

Features and Benefits

• Numerous heater options and temperature rise capabilities available

• Multiple roof curb options (1- or 2-inch vibration isolation, horizontal discharge, multiple heights) and seismic certification

• Dual fuel (indirect/electric) option

•Custom colors

Figure 1. Condenser side view of the Trane Horizon™ Outdoor Air Unit

Enhanced Serviceability

• Hinged access doors for ease of maintenance and service

• Easy-open door latches

• Slide out access direct-drive plenum fan

• Optional slide out, self-cleaning total-energy wheel

• Sight glass for each refrigeration circuit

• Optional control display

• High voltage cover

Standard Unit Features

• Multiple cabinet sizes with airflow range from 500 to 13,500 cfm

• Two-inch double-wall, R-13 construction with heavy gauge galvanized metal skin

• Outdoor air inlet hood

• Prepainted exterior finish

• Air-coo led DX refrigeration system

• Completely factory-piped and leak-tested refrigeration system

• Stainless steel drain pans sloped in two planes

• Scroll compressors

• Single-point power connections for units with optional total-energy wheel, powered exhaust, and electric heat

• Filter rack adjustable for 2-, 4-, or 6-inch filters

• Factory-assembled inlet hood with 2-inch mist eliminators (OAD, OAK, OAN)

• Non-fused disconnect switc h

• Type 439 stainless steel heat exchanger

• Low leak parallel blade outdoor air damper with edge seals

• High-efficiency fan motors

• Low ambient operation down to 40°F.

OAU-PRC001E-EN 13

Features and Benefits

Standard Control Features

• Fully integrated, factory-installed and commissioned microelectronic controls

• Supply airflow proving

• Emergency stop

• Mechanical refrigeration capacity control (RCC)

• Occupied/unoccupied control modes

• High turn-down (up to 20:1) modulating indirect gas-fired heat

• Clogged filter switch

Optional Features

• Modulating electric heat

•Hot water coils

• Steam heat (future)

• Indirect-fired (all cabinet sizes) and direct-fired (OAB and OAG cabinets) gas heat.

• Low leak parallel blade return air damper with edge seals

• Modulating damper control systems

• Low ambient/head pressure control down to 0°F

• Pleated media filters (2-inch MERV-8, 2-inch MERV-13, 4-inch MERV-14, or a combination 2-inch/4-inch filter)

• 120 V UVC downstream of evaporator coil

• High static fan

• Adjustable powered exhaust

• Exhaust dampers (gravity, barometric relief, and 2-position isolation)

• Fused disconnect switch

• Factory-installed smoke detectors (supply and/or return)

• Integral total-energy wheel

• Protective coatings for the unit and/or coils

• Remote human interface

• Factory or field-wired convenience outlet

• Air source heat pump and water source heat pump

•Hailguards

• LED service lights

• Direct drive BI airfoil plenum fan

• Factory-installed variable frequency drive (VFD)

• Digital scroll compressors on 1

• Variable speed compressors (future)

• Unit mounted human interface panel

and 2nd circuits

14 OAU-PRC001E-EN

Application Considerations

Overview

Outdoor Air Unit Functions

The Horizon™ Outdoor Air Unit (OAU) provides conditioned outdoor air suitable for mechanical ventilation or make-up air. The OAU conditions outdoor air as necessary to meet system performance requirements by ventilation with filtration, cooling, dehumidification, and/or heating. The OAU may deliver ventilation air in a number of ways. Refer to “System Configurations,” p. 15 and Figure 5, p. 17, Figure 6, p. 17, and Figure 8, p. 18 for more information.

• V entilation with Filtration

• Cooling

• Dehumidification

•Heating

System Configurations

Dedicated outdoor air systems can deliver conditioned outdoor air in one of the following ways:

1. Conditioned outdoor air supplied directly to each occupied space, with the local terminal unit controlling the space dry-bulb temperature. Refer to Figure 2, p. 15.

2. Conditioned outdoor air supplied directly to local terminal units, or return ducts of lo cal RTUs, which deliver a mixture of the conditioned outdoor air and (conditioned) recirculated air to the space. Refer to Figure 3, p. 16.

3. Conditioned outdoor air supplied directly to a single space to control the space temperature and humidity. F o r example, this application will provide temperature and humidity control of ventilated spaces, such as commercial kitchens or laboratories.

Figure 2 . Direct discharge to conditioned space

OAU-PRC001E-EN 15

Application Considerations

Main Condenser

Reheat Coil

Main Evaporator

Expansion Valves

Compressors

Indoor Fan

Figure 3. Indirect discharge to fan-coil units

Horizon OAU Operation

The Horizon™ OAU can use either DX cooling, condenser reheat, electric or gas heat to condition outdoor air. The unit controls modulate cooling and heating capacity, reducing the supply air temperature swings associated with staged heating and cooling.

OAU with Reheat

Dehumidification

16 OAU-PRC001E-EN

Figure 4, p. 16 shows the OAU system with a DX refrigerant circuit design using reheat.

Figure 4. Refrigeration system diagram with reheat

Consider Figure 5, p. 17. If the outdoor air dew point is above the dehumidification setpoint (or in the case of zone control, the zone RH is above the RH setpoint), the OAU will:

• cool the outdoor air to remove required moisture and

• reheat to meet the discharge temperature setpoint.

Application Considerations

Dry Bulb Temperature

Dewpoint Temperature

Wet Bulb Temperature

heating

cooling

At h1, 100 percent outdoor air enters the O A U . The OAU filters, cools, and dehumidifies the air as it moves through the evaporator coil. Air leaves the evaporator coil saturated at the preset dew point condition (h3) and is reheated by the reheat coil to the pre-set reheat temperature setpoint (h4). The reheat coil transfers energy to the airstream. A liquid solenoid valve effectively modulates the reheat capacity. The outdoor condenser rejects surplus heat. The reheat circuit is first on and last off, so reheat energy is available at full and part load conditions. Since both the dew point setpoint and discharge temperature setpoint are fully adjustable, the desired supply air conditions are maintained at all load conditions.

Figure 5. Psychrometric chart with dehumidification and reheat

Cooling or Heating

OAU Outdoor Air Control without Reheat

OAU-PRC001E-EN 17

Consider Figure 6, p. 17. If the outdoor air dew point or zone RH is equal to or below the dehumidification setpoint, the O AU will heat or cool the outdoor air to separate cooling or heating setpoints. At t1 or t3, 100 percent outdoor air enters the OAU . The OAU filters, and cools or heats the air as it is drawn through the evaporator and heating section. The air leaves the OAU at the cooling or heating discharge setpoint (t2 or t4).

Figure 6. Psychrometric chart with cooling or heating only

Figure 7, p. 18 shows the Horizon™ OAU DX system, using a refrigerant circuit design without

reheat.

Note: Space control not available without reheat.

Application Considerations

Main Condenser

Main Evaporator

Expansion Valves

Compressors

Indoor Fan

Dry Bulb Temperature

Dewpoint Temperature

Wet Bulb Temperature

Dehumidification

Figure 7. Refrigeration system diagram without reheat

Dehumidification

Cooling or Heating

Consider Figure 8, p. 18. If the outdoor air dew point is above the dehumidification setpoint, the OA U will dehumidify the outdoor air. 100 percent outdoor air enters the OAU (h1). The unit filters, cools and dehumidifies the air as it is drawn through the evaporator coils. Air leaves the evaporator coils saturated at a preset dew point setpoint (h3) . Since the dew point setpoint is fully adjustable, the desired dew point condition is maintained at all load conditions.

Figure 8. Psychrometric chart with dehumidification, no reheat

Consider Figure 9, p. 19. If the outdoor air dew point is below the dehumidification setpoint, the OAU will heat or cool the outdoor air to separate cooling or heating setpoints. 1 00 percent outdoor air enters the OAU (t1 or t3). The unit filters and cools or heats the air as it is drawn through the evaporators and heating section. The air leaves the OAU at the cooling or heating setpoint.

18 OAU-PRC001E-EN

Figure 9. Psychrometric chart with cooling and heating only

Dry Bulb Temperature

Dewpoint Temperature

Wet Bulb Temperature

heating

cooling

Establishing Capacity Requirements

Determining the OAU capacity requirements requires careful thought. Light Commercial equipment is typically selected based on design sensible conditions. Since latent loads drive the need for the OAU, base the selection on design latent conditions.

Application Considerations

Cooling & Dehumidification Selection Criteria

Evaporator Design Entering Conditions

Evaporator Design Leaving Conditions

OAU-PRC001E-EN 19

For many climates the peak outdoor air enthalpy occurs at a time when the outdoor dry-bulb temperature is not the highest. Refer to the ch apter on climatic design information in the A SHRAE Handbook of Fundamentals. The cooling and dehumidification design condition data is provided three ways:

1. Design dry-bulb temperature with mean coincident wet bulb temperature

2. Design wet-bulb temperature with mean coincident dry-bulb temperature

3. Design dew point temperature with mean coincident dry-bulb temperature

The design wet-bulb condition typically represents a significantly higher ou tdoor air enthalpy than the design dry-bulb condition. Use the condition that represents the highest enthalpy as the entering evaporator selection condition.

Due to the uncertainty of the local terminal unit’s latent capacity at part load, it is usually most straightforward to size the OAU to handle the entire latent load on the system, both indoor and outdoor. With this design approach, the terminal units may do some latent cooling (dehumidification) during periods of higher sensible load. At these times, the space will run slightly drier than the design RH limit. This is why it makes sense to select the OAU to limit the space RH to a maximum allowable level for those conditions when the terminal units are pro viding no space latent cooling, such as 60 percent RH. Using lower humidity limits may result in an unnecessary increase in system operating energy use.

Use Table 1, p. 20, Table 2, p. 20, and Table 3, p. 21 to identify the appropriate supply air dew point for specific design conditions. Fo r a more detailed discussion on determining the selection criteria of a OA U, refer to SYS-APG00 1-EN (Application Guide: Designing Dedicated Outdoor -Air Systems) or SYS-APM004-EN (Applications Engineering Manual: Dehumidific ati on in HVAC Systems).

Application Considerations

Reheat

Table 1. Supply air dew point temperature, 75°F at 60 percent RH space limit

Latent Load Btu/h per Person

100 54.6 56.6 57.5 58.1 58.4 58.7 58.9 59.0 59.2 59.2 59.3 120 53.3 55.8 57.0 57.6 58.1 58.4 58.6 58.8 58.9 59.1 59.2 140 52.0 55.0 56.4 57.2 57.7 58.1 58.3 58.6 58.7 58.9 59.0 160 50.6 54.2 55.8 56.7 57.3 57.8 58.1 58.3 58.5 58.7 58.8 180 49.2 53.3 55.2 56.3 57.0 57.4 57.8 58.1 58.3 58.5 58.6 200 47.7 52.5 54.6 55.8 56.6 57.1 57.5 57.8 58.1 58.3 58.4 220 46.1 51.6 54.0 55.3 56.2 56.8 57.2 57.6 57.9 58.1 58.3 240 — 50.6 53.3 54.8 55.8 56.5 57.0 57.3 57.6 57.9 58.1 260 — 49.7 52.7 54.3 55.4 56.1 56.7 57.1 57.4 57.7 57.9 280 — 48.7 52.0 53.8 55.0 55.8 56.4 56.8 57.2 57.5 57.7 300 — 47.7 51.3 53.3 54.6 55.5 56.1 56.6 57.0 57.3 57.5 320 — 46.6 50.6 52.8 54.2 55.1 55.8 56.3 56.7 57.1 57.3 340 — 45.5 49.9 52.3 53.8 54.8 55.5 56.1 56.5 56.8 57.1 360 — — 49.251.753.354.455.255.856.356.657.0 380 — — 48.551.252.954.154.955.556.056.456.8 400 — — 47.750.652.553.754.655.355.856.256.6 420 — — 46.950.152.053.354.355.055.656.056.4 440 — — 46.149.551.653.054.054.755.355.856.2 460 — — 45.348.951.152.653.654.455.155.656.0 480 — — — 48.350.652.253.354.254.855.455.8 500 — — — 47.750.251.853.053.954.655.155.6

Note: Minimum dew point selectable is 45°F.

10 15 20 25 30 35 40 45 50 55 60

cfm per person

Table 2. Supply air dew point temperature, 75°F at 55 percent RH space limit

Latent Load Btu/h per Person

100 51.6 53.8 54.9 55.5 55.9 56.1 56.3 56.5 56.6 56.7 56.8 120 50.2 53.0 54.2 55.0 55.5 55.8 56.1 56.2 56.4 56.5 56.6 140 48.8 52.1 53.6 54.5 55.1 55.5 55.8 56.0 56.2 56.3 56.4 160 47.2 51.2 53.0 54.0 54.6 55.1 55.5 55.7 55.9 56.1 56.2 180 45.6 50.2 52.3 53.5 54.2 54.8 55.2 55.5 55.7 55.9 56.1 200 — 49.3 51.6 53.0 53.8 54.4 54.9 55.2 55.5 55.7 55.9 220 — 48.3 50.9 52.4 53.4 54.1 54.5 54.9 55.2 55.5 55.7 240 — 47.2 50.2 51.9 53.0 53.7 54.2 54.6 55.0 55.2 55.5 260 — 46.2 49.5 51.4 52.5 53.3 53.9 54.4 54.7 55.0 55.3 280 — 45.1 48.8 50.8 52.1 53.0 53.6 54.1 54.5 54.8 55.1 300 — — 48.0 50.2 51.6 52.6 53.3 53.8 54.2 54.6 54.9 320 — — 47.2 49.7 51.2 52.2 53.0 53.5 54.0 54.3 54.6 340 — — 46.4 49.1 50.7 51.8 52.6 53.3 53.7 54.1 54.4 360 — — 45.6 48.5 50.2 51.4 52.3 53.0 53.5 53.9 54.2 380 — — — 47.9 49.8 51.0 52.0 52.7 53.2 53.7 54.0 400 — — — 47.2 49.3 50.6 51.6 52.4 53.0 53.4 53.8 420 — — — 46.6 48.8 50.2 51.3 52.1 52.7 53.2 53.6 440 — — — 46.0 48.3 49.8 50.9 51.8 52.4 53.0 53.4 460 — — — 45.3 47.8 49.4 50.6 51.5 52.2 52.7 53.2 480 — — — — 47.2 49.0 50.2 51.2 51.9 52.5 53.0 500 — — — — 46.7 48.6 49.9 50.9 51.6 52.2 52.7

Note: Minimum dew point selectable is 45°F.

10 15 20 25 30 35 40 45 50 55 60

cfm per person

20 OAU-PRC001E-EN

Application Considerations

Table 3. Supply air dew point temperature, 75°F at 50 percent RH space limit

Latent Load Btu/h per Person

100 48.4 50.8 51.9 52.6 53 53.3 53.6 53.8 53.9 54 54.1 120 46.8 49.8 51.3 52.1 52.6 53 53.3 53.5 53.6 53.8 53.9 140 45.2 48.9 50.6 51.5 52.2 52.6 52.9 53.2 53.4 53.5 53.7 160 — 47.9 49.8 51 51.7 52.2 52.6 52.9 53.1 53.3 53.5 180 — 46.8 49.1 50.4 51.3 51.8 52.3 52.6 52.9 53.1 53.3 200 — 45.7 48.4 49.8 50.8 51.5 51.9 52.3 52.6 52.8 53.0 220 — — 47.6 49.3 50.3 51.1 51.6 52 52.3 52.6 52.8 240 — — 46.8 48.7 49.8 50.7 51.3 51.7 52.1 52.4 52.6 260 — — 46 48.149.450.350.951.451.852.152.4 280 — — 45.2 47.4 48.9 49.8 50.6 51.1 51.5 51.9 52.2 300 — — — 46.848.449.450.250.851.351.651.9 320 — — — 46.2 47.9 49 49.8 50.5 51 51.4 51.7 340 — — — 45.547.348.649.550.250.751.151.5 360 — — — — 46.8 48.2 49.1 49.8 50.4 50.9 51.3 380 — — — — 46.3 47.7 48.7 49.5 50.1 50.6 51 400 — — — — 45.7 47.3 48.4 49.2 49.8 50.4 50.8 420 — — — — 45.2 46.8 48 48.9 49.6 50.1 50.6 440 — — — — — 46.3 47.6 48.5 49.3 49.8 50.3 460 — — — — — 45.9 47.2 48.2 49 49.6 50.1 480 — — — — — 45.4 46.8 47.9 48.7 49.3 49.8 500 — — — — — — 46.4 47.5 48.4 49.1 49.6

Note: Minimum dew point selectable is 45°F.

10 15 20 25 30 35 40 45 50 55 60

The Trane OAU utilizes recovered energy from the cooling process to reheat the air leaving the evaporator coil as required to meet the discharge air setpoint. The reheat refrigeration circuit is adequate to deliver enough reheat to supply neutral-temperature air (e.g., 75°F dry-bulb) under most operating conditions. On very low load days, the reheat circuit may not contain enough energy to meet the desired reheat setpoint.

cfm per person

Heating

The OAU has electric, heat pump, hot water, or gas heat options. The electric heat option is available in 0°F–80°F temperature rise offerings with SCR modulation. This means that the lowest temperature rise provided depends only on heater siz e and unit airflow. Calculate the temperature rise to confirm that it provides acceptable contro l. Th e el ectric he at wil l mod ul at e to maintain heating setpoint.

When using hot water heat, the unit controller will modulate a field-provided coil control valve. Provide an ethylene glycol and water mixture or other means of freeze protection for the hot water coil if the OAU will be subject to sub-freezing temperatures.

Capacity Control

The capacity control system on the Horizon™ Outdoor Air Unit is flexible enough to accommodate a variety of system applications. These applications include:

• treating outdoor air to supply a single space or multiple spaces or

• simultaneously meet building make-up air needs while controlling the temperature and relative humidity of a single space.

Each of these applications requires careful consideration to achieve the desired results.

Discharge Air Control

For many multiple spac e, dedicated outdoor air systems, the O AU will continuously supply outdoor air at a dry-bulb setpoint and a dew point that does not exceed its dew point setpoint. Th is control approach is simple because it allows the OAU to function independent of local terminal unit operation or actual space conditions. If the unit selection cri teria is determined using the method suggested in“Establishing Capacity Requirements,” p. 1 9, the Outdoor Air Unit will limit the space relative humidity to the target level.

OAU-PRC001E-EN 21

Application Considerations

Many dedicated outdoor air systems supply reheated air directly to terminal units or to spaces that have terminal units performing local sens ible cooling. This results in the local terminal units recooling the previously re-heated outdoor air. Reset ting the supply air dry-bulb temperature of the Outdoor Air Unit offers the opportunity to minimize the amount of time re-cooling occurs. Refer to

“Cooling Setpoint,” p. 22 for more information.

Cooling Setpoint

Because the T rane O AU dehumidifies the outdoor air by cooling it, th is cool outdoor air can reduce the sensible cooling load on the local terminal unit. At low space sensible loads, the cool outdoor air may sub-cool the space, causing the local terminal unit to add heat (new energy heat). Therefore, reset occupied Space Cooling Setpoint (SPCS—Space Control Sequence) or Evaporator Cooling Setpoint (ECS—Outdoor Air Contro l Sequence) of the O A U to minimize space sensible recooling so the terminal unit with the lowest sensible load is almost at zero cooling capacity (within the limit of the dew point setpoint). To take full advantage of space demand based dry-bulb reset, you may need to size some of the local terminal units based on neutral outdoor air temperature. This strategy will more effectively manage occupant comfort during seasonal changeover for twopipe terminal unit systems. Because the OAU is not connected to the chiller or boiler plant, accomplish this by resetting the Outdoor Air Unit SPCS or ECS to keep the critical zone at zero heating capacity when the boiler is off and zero cooling capacity when the chiller is off. A Trane Integrated Comfort™ system can provide this control capability.

Unoccupied Space Humidity Control

The Horizon™ O AU pro vides conditioned outdoor air for the ventilation and/or make-up air needs of a building during occupied hours. It can also limit building relative humidity during unoccup ied hours. To do this, provide a return air path to the OAU and place a relative humidity sensor in the space served by the OAU or in a common relief air path (like a return corridor) if the OAU serves multiple spaces. The unit will cycle as required to limit the space humidity to the unoccupied Dewpoint Setpoint (NSDS) setpoint. Reheat and return air damper options are required for this operation. For dedicated outdoor air systems ducted to terminal units, these units must cycle with the operation of the Horizon OA U. A Trane Integrated Comfort™ system can provide this control capability.

Space Control

For single space applications, the Horizon OAU can control space temperature and limit space relative humidity. To do this, size the airflow to meet whichever is the highest: the space loads and ventilation and/or make-up air needs of the application. Install a temperature sensor in the space to provide temperature control and reset the supply air temperature. If reset of the supply air dew point is desired, install a space relative humidity sensor in the space to provide relative humidity limit control.

Outdoor Airflow Balancing

Establish final unit airflow through a field air balancing procedure. Change the fan speed through replacement or fan sheave adjustment (belt drive indoor fan motor) or VFD Setpoint via the UC600 controller (direct drive fan motor).

Air to Air Energy Recovery

Energy recovery can significantly reduce HVAC system first-cost and operating energy costs. You can use recovered energy for two purposes:

1. to temper or reheat supply air for independent control of sensible and latent capacity, or

2. to precondition outdoor air as it enters the building for ventilation.

The Horizon™ OAU offers refrigerant heat recovery for reheating the supply air. To precondition

22 OAU-PRC001E-EN

the outdoor air, use the optional total-energy wheel to recover energy from building exhaust.

Controlling the Total-Energy Wheel

One way to control an energy recovery device is to turn it on and off with the OAU system exhaust fan. In this case, the total energy wheel enables when the unit is in occupied mode and the exhaust fan is running. While this control method is certainly simple and effective in some applications, it may not provide the expected energy saving benefit, particularly when cold air (vs. neutral air) is supplied to the building.

Another more effective approach is to use the outdoor air dry-bulb to determine when to energize or de-energize the energy recovery device. See Figure 11, p. 23 for an example of this simpli- fied control. In addition to being more effective from a control standpoint, it’s also a very simple control method because the wheel is enabled when all of the following are true:

• unit is in occupied mode,

• exhaust fan is enabled,

• Unit Main Control Module (MCM) calls for unit to operate in dehumidification, cooling, or heating modes, and

• outside air temperature is above the frost protection setpoint (default setpoint 12°F).

If using the O AU to deliver cold, dry conditioned air to th e building (ou tdoor air is cooled to a low dew point but not reheated), use the cooling setpoint control strategy (see “Cooling Setpoint,”

p. 22).

Application Considerations

Figure 10. Dry-bulb control in a cold DB/dry DP application

Figure 11. Dry-bulb control in a neutral DB/dry DP application

OAU-PRC001E-EN 23

Application Considerations

Cross Leakage

All energy wheels have some cross leakage. Therefore, do not use energy wheels in applications involving toxic or hazardous air streams. The percentage of cross leakage depends on the pressure differentials across the wheel section. With Trane Horizon™ OAU energy wheels, the exhaust air transfer ratios are typically low (less than 4 percent).

Condensate Drain Configuration

OAU units are selected based on dehumidification capability. As such, condensate can form at a high rate. Therefore, the OAU drain pan and condensate line are siz ed and designed accordingly. However, an often-o verlooked element of proper condensate drainage is proper P-T rap and drai n line sizing and installation. An incorrectly-designed and -installed P-Trap can restrict condensate flow or cause water in the condensate drain pan to “spit” or “geyser” which may cause condensate overflow. Carefully install and trap the drain pan to ensure adequate condensate removal under all conditions.

An evaporator condensate drain connection is provided on each unit. For more inform ation, to the Installation, Operation, and Maintenance for your specific product:

• OAU-SVX01*-EN (Installation, Operation, and Maintenance: Horizon™ Outdoor Air Unit - Indirect Gas-Fired/Electric Heat - Models: OADD, OAKD, OAND)

• OA U-SVX02*-EN (Installation, Operation, and Maintenance: Horizon™ Outdoor Air Unit - Indirect Gas-Fired/Electric Heat - Model: OABD)

• OA U-SVX003*-EN (Installation, Operation, and Maintenance: Horizon™ Outdoor Air Unit - Air Source Heat Pump - Models: OADE, OAKE, OANE )

• OAU-SVX005*-EN (Installation, Operation, and Maintenance: Horizon™ Outdoor Air Unit - Direct Gas-Fired/Electric Heat - Model: OAG)

A condensate trap must be installed at the unit due to the drain connection being on the “negative pressure” side of the fan. Install the P-Trap using the guidelines in Figure 12.

Pitch drain lines connected to P-Trap at least 1/2 inch for every 1 0feet of horizontal run to assure proper condensate flow. Do not allow the horizontal run to sag causing a possible double-trap condition which could result in condensate backup due to “air lock”.

24 OAU-PRC001E-EN

Figure 12. Condensate trap installation

PANEL ENCLOSURE

D" NPT FEMALE CONNECTOR

CLEANOUT PLUG

D = PIPE DIAMETER H = INTERNAL STATIC PRESSURE (IN W.G.) + 1" J = H * 0.5 L = H + J + D

NOTES: 1. PITCH DRAIN AT LEAST 1/2" PER 10' HORIZ ONTAL RUN

2. CONDENSATE DRAIN PAN WILL NOT DRAIN PROPERLY IF P-TRAP IS NOT PRIMED & OF ADEQUATE HEIGHT TO A

OW FOR CABINETOPERATING NEGATIVE PRESSURE

Application Considerations

Acoustical Considerations

Proper unit placement is critical to reducing transmitted sound levels from the OAU to the building. Therefore, consider acoustic concerns during the design phase and place the unit accordingly. The most economical means of avoiding an acoustical problem is to place the unit(s) away from acoustically critical areas. If possible, do not locate units directly above areas such as: off ices, conference rooms, executive office areas, and classrooms. Instead, ideal locations to consider are: over corridors, utility rooms, toilets, o r oth er areas where hi gh er so un d levels directly below the unit(s) are acceptable.

Follow these basic guidelines for unit placement to minimize sound transmission through the building structure.

1. Never cantilever the compressor side of the unit. A structural cross member or full perimeter roof curb, supported by roof structural members, must support this side of the unit.

2. Locate the unit’s center of gravity close to or over column or main support beam.

3. If the roof structure is very light, replace roof joists by a structural shape in the critical areas described above.

4. If several units are to be placed on one span, stagger them to reduce deflection over that span.

It is impossible to totally quantify the building structure effect on sound transmission because it is dependent on how the roof and building members respond to the O AU’s sound and vibration. However, following the guidelines listed above will help reduce sound transmissions.

Clearance Requirements

Follow the recommended unit clearances to assure adequate serviceability, maximum capacity, and peak operating efficiency . Reducing unit clearances may result in condenser coil starvation or

OAU-PRC001E-EN 25

Application Considerations

warm condenser air recirculation. If the recommended clearances are not possible on a particular job, consider the following:

• Do the clearances available allow for major service work, such as changing compressors or coils?

• Do the clearances available allow for proper outside air intake, exhaust air removal, and condenser airflow?

• If screening around the unit is used, is there a possibility of air recirculation from the exhaust to the outside air intake or from condenser exhaust to condenser intake.

Review any actual clearances that appear inadequate with your local Trane sales engineer. When two or more units are placed side by side, increase the distance between the units to twice

the recommended single unit clearance. Stagger the units for these two reasons: 1 . T o reduce span deflection if more than one unit is placed on a single span. Reducing deflection

discourages sound transmission.

2. To assure proper exhaust ai r diffusion before contact with the adjacent unit’s outside air intake.

Duct Design

It is important to note that the rated capacities of the OAU can be met only if the unit is properly installed. A well-designed duct system is essential to meet these capacities.

Satisfactory air distri bution throughout the system requires an unrestricted and uniform airflow from the OAU discharge duct.

However, when job conditions dictate installation of elbows near the OAU outlet, using guide vanes may reduce capacity loss and static pressure loss.

Controls Sequence

For sequence of operation, please refer to the Installation, Operation, and Maintenance for your specific product:

• OAU-SVX01*-EN (Installation, Operation, and Maintenance: Horizon™ Outdoor Air Unit -

• OA U-SVX02*-EN (Installation, Operation, and Maintenance: Horizon™ Outdoor Air Unit -

• OA U-SVX003*-EN (Installation, Operation, and Maintenance: Horizon™ Outdoor Air Unit - Air

• OAU-SVX005*-EN (Installation, Operation, and Maintenance: Horizon™ Outdoor Air Unit -

Indirect Gas-Fired/Electric Heat - Models: OADD, OAKD, OAND)

Indirect Gas-Fired/Electric Heat - Model: OABD)

Source Heat Pump - Models: OADE, OAKE, OANE )

Direct Gas-Fired/Electric Heat - Model: OAG)

26 OAU-PRC001E-EN

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