6
Ref. Item
Minimum clearances mm
Natural draft Fan assisted
A
Below eaves, balconies and other projections:
• Appliances up to 50 Mj/h input
• Appliances over 50 Mj/h input
300
500
200
300
B
From the ground, above a balcony or other surface*
300
300
C
From a return wall or external corner*
500
300
D
From a gas meter (M) (see 4.7.11 for vent terminal location of regulator)
1000
1000
E
From an electricity meter or fuse box (P)
500
500
F
From a drain pipe or soil pipe
150
75
G
Horizontally from any building structure* or obstruction facing a terminal
500
500
H
From any other flue terminal, cowl, or combustion air intake*
500
300
J
Horizontally from an openable window, door, non-mechanical air inlet, or any other
opening into a building with the exception of sub-floor ventilation:
• Appliances up to 150 Mj/h input
• Appliances over 150 Mj/h input up to 200 Mj/h input
• Appliances over 200 Mj/h input
• All fan-assisted flue appliances, in the direction of discharge
500
1500
1500
1500
300
500
1500
K
From a mechanical air inlet, including a spa blower
1500
1000
N
Vertically below an openable window, non-mechanical air inlet, or any other opening
into a building with the exception of sub-floor ventilation:
• Space heaters up to 50 Mj/h input
• Other appliances up to 50 Mj/h input
• Appliances over 50 Mj/h input and up to 150 Mj/h input
• Appliances over 150Mj/h input
150
500
1000
1500
150
500
1000
1500
*Unless appliance is approved for closer installation
NOTES:
1. All distances are measured to the nearest part of the terminal.
2. Prohibited area below electricity meter or fuse box extends to
ground level.
3. See Clause 5.13.6.6 for restrictions on a flue terminal under a
covered area.
4. See Appendix J, Figures J2(a) and J3(a), for clearances required from a
flue terminal to an LP Gas cylinder. A flue terminal is considered to be a
source of ignition.
5. For appliances not addressed above, approval shall be obtained from
the Authority.
Figure 1
VENTING
The Lennox Merit Series™ unit is shipped standard for top flue discharge. A flue adapter is supplied with the furnace. It must
be installed on the outside of the furnace.
FLUE TERMINATION
CLEARANCES
