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.
Front
Front
Back
Back
4
Refer to pages 8 through 11 for unit dimensions
and appropriate service clearances.
CURB MOUNTING
Arrangement B, C and D
Recommended Roof Opening
ERV-251, 361, 521 and 581
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.
EXHAUST
INLET
SUPPLY
OUTLET
V
U
Recommended Roof Opening
ERV-522 and 582
Model
U
V
ERV-251
26.5
20
ERV-361
43
26
ERV-521
58
35
ERV-581
60
30
Model
U
V
ERV-522
65
37
ERV-582
77
38
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.
U
V
EXHAUST
INLET
SUPPL
Y
OUTLET
All dimensions shown are in inches.
