B. for longer vent lengths, C. venting table, Friction loss equivalence table – HTP Munchkin High Efficiency Heater User Manual
Page 7

All venting must be properly supported, as 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 Standard Institute).
12)
It is recommended that you use one of the optional vent kits specifically for Munchkin
installations.(KGAVT0601CVT (3 in.) or V1000). NOTE: WHEN USING THE HGAVTT601CVT KIT,
REMOVE THE 2 SCREENS FROM THE PROVIDED INLET TEE AND INSTALL THEM IN THE
INLET SOCKET AND OUTLET SOCKET OF THE KIT PRIOR TO INSTALLING THE SCHEDULE
40 PIPE AND GLUING
4-B. FOR LONGER VENT LENGTHS
All venting must be 3", both intake and exhaust, NEVER use any piping less than 3", or different size pipe on the intake
and exhaust.
You may use 4" venting on both intake and exhaust, to lower the pressure drop, to provide additional venting
length. It is imperative when using 4", to follow these instructions very carefully. For longer lengths, the first 10’ of
both the intake and exhaust piping are 3". For the intake 10’ of 3" PVC Schedule 40 pipe plus one 90 degree or two 45
degree elbows and for the exhaust 10’ of PVC Schedule 40 pipe, NOT FOAM CORE, or CPVC plus one 90 degree or
two 45 degree elbows.
Use a 4" x 3" PVC reducing coupling. Then proceed with PVC 4" (NOT FOAM CORE) pipe and
fittings for both the intake and exhaust piping. On 4" piping you may go an additional 125 equivalent feet of pipe and fittings
for a combined total length. The 4" fittings have a friction loss allowance as follows: 4" 90 degree = 3’ , and a 4" 45 degree =
1’. The total maximum venting length can be 125’, plus the first 10’ of each 3" and a maximum fitting allowance of the
3", total two 90 degree or four 45 degree before increasing to 4". Total equivalent would be 30’ of 3" plus 125’ of 4".
Never use different pipe sizes for intake and exhaust. The vent system must be balanced by a friction loss equivalent.
NOTE:
THE METHODS DESCRIBED ARE SUGGESTED GENERIC METHODS ONLY. SPECIFIC
JOB SITE OBSERVATIONS AND SIZING MAY REQUIRE ALTERNATE INSTALLATION
METHODS. CONSULT THE FACTORY WITH SPECIFIC JOB REQUIREMENTS FOR
ADDITIONAL RECOMMENDATIONS.
4-C. VENTING TABLE
Note: Do not exceed the total combined length of pipe (intake piping plus exhaust piping added together) including fitting
allowances shown below should not exceed 85’. The table shows the friction loss for plastic pipe and fitting in 3" and 4" sizes.
FRICTION LOSS EQUIVALENCE TABLE
JOB EXAMPLE:
Note: this example totals both intake and exhaust piping.
4 pcs. - 3" 90 = 20’ ; 20’ - 3" PVC SCH. 40 PIPE = 20’
40’ Total combined length is under max allowable vent run of 85’
This job is okay!
3" VENTED MODELS EQUIVALENT
TABLE
EQUIVALENT
FITTING
FEET
DESC.
OF PIPE
3" 90
5’
3" 45
3’
3" COUPLING
0’
3" TEE
0’
3" PIPE
1’=1’
3’ CONCENTRIC
VENT KIT
3’
3’ V1000 VENT KIT
0’
(AFTER THE FIRST 10’ OF 3" ONLY)
4" VENTED MODELS
EQUIVALENT TABLE
EQUIVALENT
FITTING
FEET OF
DESC.
PIPE
4" 90
3’
4" 45
1’
4" COUPLING
0’
4" PIPE
1’=1’
4" TEE
0’
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