18
Operations
poor burner conditions.
If this machine is going to be
installed to a 90° or extended exhaust vent run length
which may restrict air flow it is recommended that a
contractor install a power vent. When a contractor has
found it impossible to vent through the ceiling then power
venting can be calculated to help eliminate exhaust
restriction on this natural draft machine. This draft inducer
(power vent) must be installed by a licensed contractor
who can calculate size, operation connections and associ-
ated dampeners. Hotsy is not a licensed contractor and as
such we are unable to make recommendations for suitable
make and model of power vents.
It is important that the licensed contractor consult local
building codes. Hotsy can only make recommendations
and the selection of the venting must take into account the
type of roof or wall material it contacts which could change
the vent requirement for compliance with local building
codes
Room Vents for Combustion and
Ventilation Air
Properly sized vents are vital for the safe and efficient
operation of a pressure washer installed in a confined
space. When combustion and ventilation air are
supplied from inside the building, each opening must
have an area of one square inch for every 1,000 BTUH
input. When combustion air is supplied from the
outside, each opening must have an area of one
square inch for every 2,000 BTUH for horizontal ducts
and one square inch for every 4,000 BTUH for vertical
ducts (refer to NFPA 54).
NOTE: Air vents for combustion and ventilation and
exhaust flue sizing must conform to methods outlined
in current American Standard (ANSI-Z223.1),
National Fuel Gas Code of National Standard of
Canada CSA-149.1 and CSA-149.2 “Installation
Code for Gas Burner Appliances”.
Exhaust Stack
The purpose of venting a gas-fired pressure washer is
to completely remove all products of combustion and to
vent gasses to the outside air without condensation in
the vent or spillage at the draft hood (except in cases of
downdraft or poor stack conditions). Always use strong,
gas-tight, insulated pipe.
The design of this pressure washer depends on natural
draft (heat induced) to pull combustion gas out of the
combustion chamber. The design of the exhaust stack
can have a significant impact on the proper operation of
the burner and coil.
During vent installation, avoid sharp turns, long hori-
zontal runs and improper pitches. Maintain proper
support of vent connectors and joints, observe clear-
ances from all combustibles and top the vent outlet with
an approved cap.
All venting installations must conform to local codes. In
the absence of local codes, refer to "National Fuel Gas
Code" NFPA 54 and be constructed of materials
approved by the Uniform Building Code.
Vents penetrating ceilings or walls should be double-
wall approved appliance vents and should be one to
two inches from combustibles. Vents passing through
enclosed spaces and vents exposed to the weather
should also be the double-wall type. Sometimes vents
have to be built of such great length that they come
apart at their joints under their own weight. These
should be screwed together at the joints with sheet
metal screws, usually three per joint. If the inspector
indicates that the vent is too close to combustibles, it
may be necessary to chisel away some of the combus-
tible or route the vent pipe around the combustible. The
cross-sectional area of any flue shall not be less that
the cross-sectional area of the flue vent connection
outlet of machine.
The pressure washer includes a collar that will mate
with standard HVAC ducting. The user will be respon-
sible for installation of an exhaust stack. The exhaust
stack should include a Draft Diverter/Inducer, Damper,
Sampling Port and Rain Cap. An adapter can be
installed between the collar and stack to adjust the
diameter from 10” to 8” or 12” to 10”.
MANUAL, OPERATOR, HOTSY, STAT ELEC NG-LP 9.808-037.0-A
Illu
s
tration
s
howing air opening
s
nece
ss
ary
to
s
upply air for combu
s
tion when in
s
talled
in an enclo
s
ed room.
Ventilation
