Page No 14 of 52 Reznor, Photon, Installation Manual, EN 2021-04, D301310 Iss 0
I
The products of combustion from
the unit heater must be flued to the
outside of the building.
A properly sized flue system is
required for safe operation of the
unit heater.
An improperly sized flue system
can cause unsafe conditions and/or
create condensation.
Failure to provide proper flueing
arrangements could result in death,
serious injury and/or damage to
property.
It is important to ensure that there
is an adequate air supply at all
times for both combustion and
heating requirements. Modern
buildings involve greater use
of insulation, improved vapour
barriers and weather proofing.
These practices mean that buildings
are sealed much tighter than in the
past.
Proper combustion air supply for a
power vented Type B installation
requires ventilation of the heated
space. Natural infiltration of air
may not be adequate. Use of
exhaust fans aggravates this
situation. It is important to ensure
that there is adequate combustion
air supply at all times. Reliance
on doors and windows is not
permitted.
Always ensure that an adequate
inlet for fresh air for combustion
is provided sized to suit the total
installation of any combustion
apparatus.
The flue MUST be installed in
accordance with national and local
regulations.
Type B appliances
If the unit heater is to be installed as a Type B
appliance, air for combustion will be taken from
within the space where the heater is installed.
Single wall seamless aluminium or stainless
steel flue pipes are required. All joints must be
sealed to prevent the products of combustion
from leaking into the building. If the flue passes
through a combustible element of the building it
must be enclosed in a sleeve of non-combustible
material and separated from the sleeve by a
minimum of 25 mm air break. The temperature
of any combustible material near to the flue
must not exceed 65°C when the heater is in
operation. The flue must be at least 150 mm
away from any combustible material.
Single wall flue pipe exposed to cold air or run
through unheated areas should be insulated.
Where condensation is unavoidable, provision
must be made for the condensation to flow
freely to a point to which it can be released,
i.e. a drain or gully. The condensation drain
from the flue must be constructed from non-
corrodible material not less than 20 mm
diameter. Copper or copper based alloys must
not be used for condensation drains.
Vertical flue runs greater than 3m long will
require a condensate drain fitting between the
flue outlet of the heater and the vertical flue
pipe. Alternatively, insulated flue pipe should be
considered.
Horizontal flue runs should be installed with a
slight gradient of approximately 5° towards the
terminal. Due consideration should be given to
the possibility of condensation from the flue
freezing on any footpaths that pass below the
terminal.
It is important to ensure that there is an
adequate air supply at all times for both
combustion and heating requirements.
Ensure that the air combustion inlet opening at
the rear side of the unit cannot be obstructed.
