Room Sealed Heaters

A room sealed heater is based around a sealed cabinet and as the name suggests this cabinet is air tight (room sealed).

A room sealed cabinet heater has essentially two separate air sections, burner supply air and room air.

BURNER SUPPLY AIR
In some situations it would be unsafe to supply the heaters burner with air from the room which it is heating.

An example of this is in a garage environment where evaporating fuel (petrol) vapour may be drawn into the heater. In a sufficient quantity this could create an explosive mixture which would be fed directly into the heater combustion chamber. It would eventually ignite with disastrous consequences.

The flue is coaxial (a tube inside a tube) similar to a domestic combination boiler. In the above photograph you can see the two flu's leaving the heater and they combine at the terminal before it exits the building.

Fresh air is pulled from outside the building down the flue and into the combustion side of the heater. It is burnt and products of combustion leave the heater through the other flue pipe then leave the building through the same terminal.

This ensures that no air inside the room is ever used to support combustion inside the heater.

If this option is not required, the supply air flue can be left disconected and a normal flue and terminal used instead of the coaxial system.

ROOM AIR
Another example could be the effects of a standard heater in a property with extraction and process plant. Under normal conditions building extraction removes any hazardous products directly from the process plant.

A standard warm air heater may cause pull against the extraction and attract products of combustion to be drawn into and circulated around the room. A room sealed heater allows 100% fresh air to be drawn from the outside of the building or outside of the Class 1 zone. This air is heated and introduced fresh into the room.

The photograph above shows externally ducted air being drawn from outside the building and into the heater through a filter. The ducting is manufactured to suit to assemble directly to the heater.

The external is fitted with an aluminium louvre sized to fit the ducting directly. The ducting is telescopic and therefore provides a liner through the building fabric into the inside section and provides a firm fixing for the louvre.

This installation was installed to a Mezzanine Floor inside the property and was fully room sealed.

Use of a combination flue makes the unit room sealed or a standard flue can be used (combustion air would not be room sealed).

Room air can be re-circulated (not room sealed) or drawn externally to the building (room sealed).

This offers the most flexibility for the installation.

 

Thursday 3rd November 2011
Philip Hamer
Magma Energy Services Ltd