Shelves; Plastering; Air Supply; Air Supplied From Room - Jetmaster INSET Installation, Operating And Servicing Instructions

Shelves

If in doubt always consult the building regulations regarding the proximity of combustible materials.
The minimum height from the top surface of the frame of the fire to the underside of any shelf shall be as
follows.
For a shelf depth of 100mm (4") from wall – Minimum height = 375mm (15")
For shelves of a greater depth add 50mm (2") to the shelf height for every 25mm (1") increase in shelf depth.
In certain cases further protection may be required to guard against heat on combustible materials, such as
increasing the shelf height or shielding with a non combustible material.
This i s b ecause o f t he v ariability o f t he h eat p roduced f rom a s olid f uel fi re.
It is dependent on the quantity of fuel used and the refuelling frequency.

Plastering

Hot a ir c an c ause s taining a bove t he fi re i n t he s ame m anner a s o n t he w all a bove a r adiator.
This o ften s hows m ore o n l ighter c oloured fi nished s urfaces.
The area directly above the fire will become very hot. T herefore to reduce the risk of cracking we advise the
following:
When p lastering a bove t he fi re, fi t r einforcing m esh ( expanded m etal l athing) f or a t l east 2 25mm a bove t he fi re
and f or t he f ull w idth o f t he fi re. T his m esh c an b e c ontinued d own t he s ides o f t he fi re.
Use a high temperature or other heat resistant plaster.

Air Supply

All fi res r equire a s upply o f a ir t o s upport c ombustion a nd t o a llow t he c himney t o d raw c orrectly.
Air s tarvation w ill r esult i n p oor fl ue d raw a nd s mokiness i n t he r oom.
All installations will require a permanent dedicated a ir s upply f or t he fi re o f a t l east 5 .5cm2 p er k W o f r ated h eat
output o ver 5 kW. T he s ize o f a ir s upply d uct o r d ucts r ecommended f or e ach fi re i s s hown i n t he i nstallation
data table page 5.
The Building Regulations Document J and L must be taken into account when providing ventilation for
the fi re.
Newly constructed houses, especially those using double-glazing and employing modern draught control
techniques, will need careful planning of air entry.
Extractors o r f ans w hen o perated i n t he s ame r oom o r a djoining r oom o f t he fi re m ay c ause p roblems.
If there is a fan or extractor fitted in the property then allowance for additional air may be required. See
commissioning section.
If there is more than one appliance in the property then each appliance must be supplied with adequate
combustion air and ventilation so that all the appliances can operate simultaneously.

Air Supplied from Room

Bring a ir i n t o t he r oom c lose t o t he fi re. T he i deal p osition i s j ust t o t he s ides o f t he fi replace o pening a s s hown.
It c an b e s plit a nd b rought u p i n t wo p ositions i f r equired, o ne e ach s ide o f t he fi replace o pening.
Careful positioning of the vents is essential so that they are not liable to become blocked and cause cold
draughts.
Where p ossible, d raw a ir f rom t wo w alls a t r ight a ngles a nd d uct t o a m ixing c hamber b eneath t he fl oor b efore
it enters the room. T his will reduce the influence of strong winds on the supply of air. Where an existing floor
is solid, vents may have to be provided through the walls in a manner, which achieves conditions as close as
possible to the above, perhaps, by the use of ducting or of false skirting.
Where t here i s a s uspended fl oor o ver a w ell v entilated u nder fl oor s pace, i t m ay b e s ufficient j ust t o s et v entilation
openings t hrough t he fl oorboards a djacent t o t he c himney b reast. O lder h ouses w ith t he p ossibility o f d raughts
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