Model
L
W
ERV-251
30.5
42.5
ERV-361
58.5
47.5
ERV-521
63.5
63.5
ERV-581
71.8
66
ERV-522
120.5
80.5
ERV-582
142.25
93
Roof curb details, including duct
location dimensions, are available on
ERV roof curb submittals.
FIGURE 3
FIGURE 4
5
3. Install Curb
Locate curb over roof opening with dimensions
shown on page 4 and fasten in place.
Check that the diagonal dimensions are within
±1/8” of each other and adjust as necessary.
Shim as required to level.
Lower unit onto curb by following the
LIFTING
instructions on page 3 of this manual. Note, roof
curbs fit inside the ERV unit base.
4. Install Duct Work
Installation of all ducts should be done in
accordance with SMACNA and AMCA guidelines.
The chart on page 6 shows the duct sizes and
straight lengths recommended for optimal
performance (AMCA 201-90). Using duct sizes
less than the recommended lengths will affect fan
performance. Good duct installation practices
should be followed for the remaining ductwork.
ERV-251, 361, 521 and 581
The duct adapter should be used only for properly
locating ducts on these units. The factory duct
adapter
must not
be used for structural support of
the ducts.
ERV-522 and 582
This duct adapter can be used to locate and
support the duct work.
Curb Outside Dimensions
L
W
W
L
ERV-522 and 582
ERV-251, 361, 521 and 581
All dimensions shown are in inches.
