Greenheck ERV-251 Installation, Operation And Maintenance Manual page 4

INSTALLATION (continued)
SURFACE RAIL MOUNTING
Arrangement A or D
For proper support, rails should be located 6 to 12 inches in
from the outer edges of the unit and should extend at least
6" beyond the sides of the unit. Rails are by others.
Back
CURB MOUNTING
Arrangement B, C and D
ERV-251, 361, 521 and 581
1. Factory Supplied Roof Curbs
Roof curbs are either Model GPNS or GPI, which are
factory fabricated and assembled.
Recommended Roof Opening
ERV-251, 361, 521 and 581
Model U
ERV-251 26.5
ERV-361 43
ERV-521 58
ERV-581 60
All dimensions shown are in inches.
4
Front
V
EXHAUST
INLET
U
SUPPLY
OUTLET
V
20
26
35
30
Front
Refer to pages 8 through 11 for unit dimensions
and appropriate service clearances.
ERV-522 and 582
Roof curbs are Model GKD, which are shipped in a
knockdown kit and require field assembly (by others).
Assembly instructions are included with the curb.
2. Cut Roof Opening and Locate Curb
Locate the unit over the roof opening, so the unit
openings and corresponding ducts line up. See the
drawing below.
Be sure to allow for the recommended service clearances.
Keep the inlet of the ERV away from any other exhaust
fans. See page 6 for Recommended Duct Sizes.
Model
ERV-522
ERV-582
Recommended Roof Opening
ERV-522 and 582
Back
U V
65 37
77 38
U
EXHAUST
INLET
V