Munchkin VWH High Efficiency Hot Water Supply Boiler - Manual (Page 14)

14
VENTING
RECOMMENDED VENTING CLEARANCES PER THE NATIONAL FUEL GAS CODE*
All venting must be properly supported. The Munchkin is not intended to support any venting
whatsoever. All piping, glue, solvents, cleaners, fittings and components, must conform to ASTM
(American Society for Testing and Materials), and ANSI (American National Standards Institute). It is
recommended that you use one of the optional vent kits specifically designed for Munchkin installa-
tions, available from Heat Transfer Products, Inc.
Example: Installation requires the following material for both inlet and exhaust piping for the
Munchkin 199VWH and the 399VWH.
Required: 4 Pcs. 90 degree elbow (4 x 5 = 20 Equivalent Feet) = 20 Equivalent Feet
Required: 20' of Plastic PVC Pipe (20 x 1 = 20 Equivalent Feet) = 20 Equivalent Feet
Total Friction Loss in Equivalent Feet (20 + 20 = 40 Equivalent Feet) = 40 Equivalent Feet
C. LONGER VENT RUNS
CAUTION
Flue Gas will condense as it exits the vent termination. This condensate can freeze on
exterior building surfaces which may cause discoloration of these surfaces.
Consideration should be given to the plume of condensation that exits the exhaust
which may affect the cosmetic appearance of the building.
12 in.minimum
Forced air
inlet
Grad
e
3 ft.minimum
Less
than 10 ft.
terminal
(see 10.8.1)*
draft vent
Mechanical
C
12 in.minimum
Direct vent terminal clearance
Minimum clearance, C
Input (Btu/hr)
4 ft.minimum
12 in.minimum
minimum
vent terminal
Mechanical draft
(see 10.8.2)*
4 ft.
Clearance (in.)
10,000 or less
10,001 to 50,000
Over 50,000
(see 10.8.3)*
6
9
12
For SI units: 1 ft = 0.305 m; 1 in. = 25.4 mm;
1 Btu/hr = 0.293 W
EXIT TERMINALS OF MECHANICAL DRAFT AND DIRECT-VENT VENTING SYSTEM
* REFERENCE: THE NATIONAL FUEL GAS CODE 2002 EDITION
*IMPORTANT NOTE
HEAT TRANSFER
PRODUCTS
RECOMMENDS A
MINIMUM
CLEARANCE OF 4
FEET WHERE THE
PLUME CAUSED BY
THE UNIT MAY
OBSTRUCT VIEWS
OR AFFECT THE
COSMETIC LOOK OF
THE BUILDING.
NOTICE
Do not exceed the 125 foot maximum requirement for (intake plus exhaust piping
added together). Consider fitting allowance shown in friction loss equivalent table on
the following page.