Rail Mounting; Ductwork Connections - Greenheck HRE-20 Installation, operationand Maintenance Manual

RAIL MOUNTING

Rail Layout
• Rails designed to handle the weight of the HRE should be
positioned as shown on the diagram (rails by others) .
• Make sure that rail positioning does not interfere with the supply
air discharge opening or the exhaust air intake opening on the
HRE unit . Avoid area dimensioned "B" below
• Rails should run the width of the unit and extend beyond the unit
a minimum of 12 inches on each side .
• Set unit on rails.
OUTDOOR
AIR
INTAKE
POOR
HOOD
Side view of HRE on rails

DUCTWORK CONNECTIONS

Examples of good and poor fan-to-duct connections are shown below . Airflow out of the fan should be directed
straight or curve the same direction as the fan wheel rotates . Poor duct installation will result in low airflow and
other system effects .
POOR
Length of Straight Duct
GOOD
HRE Model
HRE-20
HRE-45
HRE-55
HRE-90
SYSTEM EFFECT FACTOR CURVES
Dimensions shown are in inches .
1.2
1.0
SUPPLY WEATHERHOOD
Supply weatherhood will be factory mounted .
0.8
EXHAUST WEATHERHOOD
0.6
The exhaust weatherhood is shipped separately as a kit with its own
0.4
instructions .
0.2
DAMPERS
Backdraft dampers are always included as an integral part of the
0.0
0 5 10 15
exhaust hood assemblies . Motorized outdoor air and exhaust air
dampers are optional and are factory mounted (and wired) at the
OUTLET VELOCITY
inlet .
T u rning
Vanes
T u rning
Vanes
GOOD
SUPPLY/EXHAUST
OPENING
B
1 Fan
Wheel
Dia.
Recommended Discharge Duct Size and Length
HRE Blower Size
10
12
15
18
20 25 30 35 40
1 Fan
FPM X 100
Wheel
Dia.
GOOD
A
Duct Size
14 x 14
20 x 20
28 x 28
32 x 32
45
POOR
Isometric view of HRE on rails
OUTDOOR
AIR
INTAKE
HOOD
Rail Mounting
Model
A
HRE-20 5 .1
HRE-45
7 .1
HRE-55 5 .7
HRE-90 6 .6
All dimensions shown are in inches .
POOR
POOR
Length of Straight Duct
Straight Duct Length
40
48
GOOD
60
72
SYSTEM EFFECT FACTOR CURVES
1.2
1.0
0.8
0.6
0.4
0.2
0.0
SUPPLY/EXHAUST
B
OPENING
T u rning
Vanes
25 .0 B A
25 .1
35 .0
36 .1
GOO
5