Empire Comfort Systems DVLXG75BP90N-1 Installer's Manual page 43

INLET DUCT REQUIRMENTS
For the inlet duct, a transistion from round pipe or insulated flex
duct to air register or grille must be used. This transition must fit
a miminum 12" x 6" air register or grille (example below of
transition).
The Inlet grill MUST be no smaller in restriction than a 12" x 6"
grille, with 1/2" spacing fins set at 55 degrees (see image below).
11 - 1/2
13 - 3/4
WARNING
• If duct outlets are installed into a room used by an infant,
ensure the temperature stays in the range of 60°F and
70°F by use of a thermostatically controlled shut off valve
in the duct that feeds that room.
• Neglecting to allow back-flow of return air to the fireplace
can result in a risk to personal safety to infants or infirm
persons.
• Overheated rooms are NOT SAFE for infants.
• A minimum of 60% return air must discharge into the
same room the fireplace is located.
• The secondary air inlet MUST have a maximum restriction
no greater than 20% = 50.3in² - 20% =
MAX 10ft
• A length of
DUCT VENT INSTALLATION
40.24in²
to be used for secondary inlet.
DUCTING
The designs shown below is indicative only and can be adapted on
a case by case basis to suite individual installations.
RESTRICTION ON DUCTING
• 10" Fully open = 78.54in² (1 minimum)
• 1 x 10" Outlet Maximum Restriction 10% = 78.54in² - 10%
= 70.68in²
• 2 x 10" Outlet Maximum Restriction 40% = (78.54in² x
2) - 40% = 94.24in²
• 3 x 10" Outlet Maximum Restriction 60% = (78.54in² x
3) - 60% = 94.24in²
Notice: Adding more than 3 x 10" outlets requires the open
surface area of the outlets to be => 94.24in²
6" Fully open = 28.27in² (3 minimum = 84.81in²)
•
• 3 x 6" Outlet Maximum Restriction 10% = 84.81in² - 10%
= 76.34in²
• 4 x 6" Outlet Maximum Restriction 30% = (28.27in² x
4) - 30% = 79.16in²
• 5 x 6" Outlet Maximum Restriction 50% = (28.27in² x
5) - 40% = 84.81in²
Notice: Adding extra 6" outlets increases the restriction by 10%
FAN
FIREPLACE
Fan
Fireplace
43