Reznor, PVE, Installation Manual EN 2019-11, D301113 iss D Page 13
PVE free blowing heaters are at their most
effective when located as close to the working
area as possible. However care should be
exercised to avoid directing the discharged air
directly onto the occupants of the area to be
heated
If the heater is posi tioned to discharge towards
or across the cold air source then a distance of
1.5m - 6m is recommended dependent upon
the size of the entrance and the air throw
characteristics
Warm air circulation
The air heater should be positioned to enable
maximum circulation of discharged warm air
within the area to be heated, whilst taking
account of personnel within the area, sources
of cold air ingress, and obstructions.
The air temperature rise on passing the heat
exchanger is typically around 33°C.
A full and unobstructed return air path to the
air heater must be provided.
Where the heater is positioned to deliver
blown air through an opening in a wall, return
air intakes should be located so that they
cannot become blocked.
Similarly these intakes must be positioned so
as not to draw in odours, fumes, hazardous
vapours or particles.
Air supply for combustion
and ventilation
Consideration must be given to the provision
of air for the purposes of combustion and
ventilation of the heated space, plant room
or enclosure where the heaters are to be
installed
.
Ensure combustion and ventilation
air is provided in accordance with the
regulations and rules in force
In areas where it is proposed that more
than one heater is to be installed, a general
scheme of circulation should be drawn up and
maintained, thereby offering the best heat
distribution.
Air pressure within the area heated and the
outside air pressure must remain the same,
factors influencing this would be the presence
of extraction systems, ventilation systems, and
various types of process plant.
Heaters installed within the heated
space
Where the heaters are installed within the
heated space (e.g. not a plant room , or
enclosure) then:
Combustion air or heater related ventilation air
will not be required if:
The heaters are installed in room sealed mode
(ie with a positive connection to atmosphere
of both flue and combustion air). Or
If the design air change rate of the heated
space is 0.5 air changes per hour or greater.
The design air change rate may be satisfied
by natural infiltration or by mechanical
ventilation.
Combustion air ventilation will be required
if:
The heater(s) are installed with flue only (ie
without the positive connection to atmosphere
of a combustion air duct). And
The design air change rate of the heated space
is less than 0.5 air changes per hour.
Where heater(s) are installed without the
positive connection of combustion ductwork
within a heated space where air change
rate of that heated space is less than 0.5 air
changes per hour then it will be necessary to
provide either natural ventilation openings
to the heated space see section Natural
ventilation openings to the heated space or
the mechanical ventilation of the heated space
see section Mechanical ventilation to the
heated space
