All 3 types of installation can be used in the attic (Stand Alone, Central Draw Point
or Return-Return). The example shown below is a Return-Return installation
(connection to a forced air system).
VH0051
- 11 -
A portion of stale air is exhausted to the outside and the rest is drawn to the unit.
Outside fresh air is blended with interior air and then filtered. This filtered air is
supplied to the return (plenum) of the forced air unit.
To avoid the cross-contamination and achieve highest efficiencies, the forced air
system blower must always be ON (or the unit efficiency will be affected).
See figure below.
NOTE: Home with multiple forced air systems should have 1 unit on each system.
Do not connect the HEPA 4000 on any forced air system supply duct.
Connect it only to the air return duct. Do not install duct or duct connector
directly above the forced air unit or not less than 9’10’’ (3 m) of the plenum
connection to the forced air unit, as measured along the length of the duct.
CAUTION
Due to the potential temperature difference between the attic and the rest of
the house, all unit ducts must be insulated.
CAUTION
The attic temperature must always be above 0°C (32°F).
CAUTION
2. TYPICAL INSTALLATIONS
(CONT’D)
2.2 I
NSTALLATION FOR
HEPA 4000 O
NLY
(
CONT
’
D
)
2.2.2 HEPA 4000 A
TTIC
I
NSTALLATION
