CENTRAL FURNACE INSTALLATION
Figure 3
DUCTS SHOULD BE LARGE
ENOUGH TO HANDLE GRAVITY
AIR FLOW IN EVENT OF ELECTRIC
POWER OR FURNACE FAN FAILURE
(APPROXIMATELY 180-200 SQ. IN.)
WARM AIR DUCTS MUST BE
CONSTRUCTED ENTIRELY FROM
METAL DUE TO HIGH TEMPERATURES
WHEN OPERATED DURING ELECTRIC
POWER FAILURE.
BOX 422 • TOWER, MN 55790 • USA • Tel (218) 753-2330 • www.lamppakuuma.com
6
HOT
CO
LD
RE
TU
RN
H
O
T
H
O
T
C
O
L
D
CHECK
FLAP
STOP
STOP
TWO SPEED SWITCHES
500-1500 CFM ON DEMAND
CHECK FLAP
APPROX.
2’ X 2’ X 2’
OIL
OR
GAS
OR
ELECTRIC
180-200 SQ. IN. DUCT
180-200 SQ. IN. DUCT
VF
100
This is the just a basic
idea to tie the two systems
together. The cold air return
could be just an open
stairway or large floor grill.
FOR POWER
OUTAGE
CHECK FLAPS
MUST ALLOW
FOR GRAVITY
FLOW.