page no. 12 of 36
NVS Range Users, Installation & Servicing Instructions Doc Ref M102 issue 2.4 May 2018.
1.3.6 Ventilation Requirements
Type B flued installations
.
Where NVS heaters are
installed within the heated space
(ie not in a plant room or an enclosure)
and having
a building design air change rate of greater than 0.5/h,
additional provision for ventilation is
not required
.
If the building design air change rate is
less than
0.5/h,
additional provision for natural or mechanical ventilation
is required.
These being:
Natural Ventilation:
Grilles having a free area of at least 2cm² per kW of rated
heat input shall be provided at low level i.e. below the level
of the heater flue connection.
Mechanical Ventilation:
Must ensure that the space air change rate is at least 0.5/h,
must be of the ‘input’ type and interlocked to ensure the
heaters cannot work if the input system is not working.
Type B flued installations
.
Where NVS heaters are
installed in a plant room
or an enclosure (ie not within the heated space)
having combustion air drawn directly from the room
and connected to a flue that evacuates the products of
combustion directly from the room additional provision for
natural or mechanical ventilation
is required.
These being:
Natural Ventilation:
There must be permanent air vents communicating
directly with the outside air, at high level and at low level.
Plant Rooms
Low level (inlet) 4cm²/kw of total rated net heat input
High level (outlet) 2cm²/kw of total rated net heat input
Enclosures
Low level (inlet) 10cm²/kw of total rated net heat input
High level (outlet) 5cm²/kw of total rated net heat input
Mechanical Ventilation:
The minimum flow rate of ventilation shall be 4.14m³/h per
kilowatt of total rated heat input.
Type C flued installations
.
Where NVS heaters are
Installed within the heated
space (ie not in a plant room or an enclosure)
having
combustion air ducted to the appliance and combustion
products ducted to the outside air,
NO additional
provision for the supply of either combustion air or for
combustion products dilution or additional provision
for the supply of air is necessary.
Type C flued installations
.
Where NVS heaters are
Installed in a plant room or
an enclosure (ie not within the heated space)
having
combustion air ducted to the appliance and combustion
products ducted to the outside, air vents
shall be
provided
and be permanently
open
.
To room or internal space
Low level (inlet) 10cm²/kw of total rated net heat input
High level (outlet) 10cm²/kw of total rated net heat input
Direct to outside air
Low level (inlet) 5cm²/kw of total rated net heat input
High level (outlet) 5cm²/kw of total rated net heat input.
Type B
22
Installation
(these refer to section 2.2 of these
instructions)
Air vents shall be permanently open.
In all cases figures are per heater installed.
For multi heater installations the appropriate values for each heater
must be added together
Type C
12
or C
32
Installation
(these refer to section 2.2
of these instructions)
Air vents shall be permanently open.
Figures are for heaters in plant rooms or enclosures ONLY
In all cases figures are per heater installed.
For multi heater installations the appropriate values for each heater
must be added together.
NVS
Input
kW
In the
heated
space
In a plant room,
ventilation to
outside
In an enclosure,
ventilation to
outside
In the
heated
space
Ventilation is to a
room or internal
space
Ventilation is to a
outside air
Low level
grille. Free
area cm²
Low level
grille. Free
area cm²
High level
grille. Free
area cm²
Low level
grille. Free
area cm²
High level
grille. Free
area cm²
Free area
grille cm²
Low level
grille. Free
area cm²
High level
grille. Free
area cm²
Low level
grille. Free
area cm²
High level
grille. Free
area cm²
30
29.02
58.0
116.0
58.0
290.0
145.0
n/a
290.0
290.0
145.0
145.0
60
59.22
118.4
236.8
118.4
592.2
296.1
n/a
592.2
592.2
296.1
296.1
90
86.74
173.5
295.0
173.5
867.4
438.2
n/a
867.4
867.4
438.2
438.2
140
137.95
275.9
551.8
275.9
1379.5
689.8
n/a
1379.5
1379.5
489.8
489.8
Combustion
ai r
socke t
Type C12 Installation.
