Regulations and guidelines
The following regulations and guidelines must
be observed:
– Hoval technical information and installation
instructions
– Relevant British Standards and Guidelines
– Hydraulic and technical control regulations
– Local Building regulations
Water quality
Heating water:
European standard BSEN 14868: 2005
and VDI guideline 2035 must be observed.
Particular note must be taken of the
following regulations:
- Hoval boilers and water heaters are suitable
for heating systems without significant
oxygenation (system type 1 in accordance
below with BSEN 14868: 2005)
- Systems with
-
Continuous
oxygenation (e.g. floor
heating without diffusion-proof plastic
pipes) or
-
Intermittent
oxygenation (e.g. frequent
topping up required) must be fitted with a
system separator
- Treated heating water must be checked at
least once per year or more frequently as
specified by the inhibitor manufacturer.
- If, in the case of existing systems (e.g.
boiler replacement), the water quality of the
existing heating water complies with VDI
2035, it is not recommended that the system
be refilled. VDI 2035 also applies to top-up
water.
- Before filling new systems, or, if applicable,
existing systems, the heating system must
be professionally cleaned and flushed. The
heating system must be flushed before the
boiler is filled.
- Components of the boiler / heat exchanger
that come into contact with water are made
of ferrous materials and stainless steel.
- The combined chloride, nitrate and sulphate
content of the heating water must not
exceed a total of 50mg/l.
- Once the heating has been in operation for
6 – 12 weeks, the pH value of the heating
water should be between 8.3 and 9.5.
Water for filling and topping up the system:
- Untreated drinking water is generally most
suitable for filling and topping up a system
with a Hoval boiler. However, the water
quality of the untreated drinking water must
always comply with VDI 2035 or must be
demineralised and/or treated with inhibitors.
The specifications of BSEN 14868: 2005
must be observed.
- In order to maintain the boiler’s high
efficiency level and to avoid overheating of
the heating surfaces, the values in the table
below must not be exceeded. These values
are calculated in relation to the boiler output
(the smallest individual boiler in the case
of multiple boiler systems) and the water
content of the system.
- The total quantity of water used to fill and
top up the system during the boiler’s life
must not exceed a value equivalent to three
times the water content of the system.
Heating System
- The boilers must not be installed in areas
where halogen compounds occur and could
enter the combustible air (e.g. washing,
drying, workshop areas, hairdressing salons
etc).
- Halogen compounds can be caused by
clean ing, degreasing and solvent agents,
ad hesives and bleaching liquids.
- A suitable supply of combustion air must be
guaranteed. It must not be possible to close
the air supply apertures. Minimum free area
for the air supply aperture is 13cm
2
per 1kW
boiler output at a flow of 4.2m
3
/hr per 1 kW
boiler output.
- High and low level ventilation should be
provided (
1
/
3
high level and
2
/
3
low level
split).
Space requirements
see separate dimensional information on
pages 9 & 10.
Use of Buffer Vessel
The BioLyt Wood Pellet boiler is designed
Engineering
to be fully automatic and is supplied with an
automatic firing or ignition sequence that will
bring the boiler on from cold without manual
intervention and has a timed automatic burnout
once the boiler has satisfied its set point
temperature returning the boiler to an ‘out’
condition. From cold the boiler would typically
reach its modulating mode after approx 20
minutes and similarly it takes approx 20
minutes for the burnout to bring the boiler from
the modulating mode to out. Once the burnout
process is initiated it has to take the boiler
out. It is therefore strongly recommended
that a load balancing buffer or accumulator
vessel is included in the primary boiler circuit
to ensure that any sudden or variable system
requirements can be met promptly. Please
contact Hoval Technical Department for advice
on sizing.
Heating Installation
Low return temperature protection
A boiler low return temperature protection kit is
supplied with all BioLyt boilers to ensure that
the minimum return temperature requirement
of 45ºC is met. Details of this kit are shown on
page 12 of this leaflet and also shown on the
typical hydraulic schematics.
Hydraulic system Design
The boiler hydraulic system design must
comply with an official Hoval schematic.
Various examples are included in this leaflet
and a range of schematics can be downloaded
from www.hoval.co.uk, or can be supplied on
request. Please contact Hoval Technical for
further advice.
Noise Attenuation
The following steps can be taken to reduce
noise:
- Make the walls, ceiling and floor of the boiler
plant room as solid as possible, fit sound
absorbers in the air supply ducting, provide
conduit supports and brackets with sound
dampening fittings.
- If there are living quarters either above
or below the boiler plant room, fit rubber
vibration dampers underneath the base
channels of the boiler and connect pipework
with flexible connections.
- Connect circulating pumps to the system
with flexible connections.
Expansion vessel / expansion
- It is recommended that the system
expansion vessel is connected to the
heating system with a cold fill loop. This
means that the entire system will not need to
be emptied in order to carry out work on the
vessel.
- In the case of open vented, the system
height must be such that the required
minimum operating pressure is maintained.
Safety valve & automatic air vent
- A safety valve and automatic air vent must
be fitted to all boilers.
- A Hoval safety valve and automatic air vent
set (c/w pressure gauge) is included with the
boiler as an accessory. Please see page 11.
Maximum filling quantity based on VDI 2035
Total hardness of filling water up to…
[mol/m3] 1
<0.1
0.5
1
1.5
2
2.5
3
>3.0
f°H
<1
5
10
15
20
25
30
>30
d°H
<0.56
2.8
5.6
8.4
11.2
14.0
16.8
>16.8
e°H
<0.71
3.6
7.1
10.7
14.2
17.8
21.3
>21.3
~mg/l
<10
50.0
100.0
150.0
200.0
250.0
300.0
>300
Conductivity
<20
100.0
200.0
300.0
400.0
500.0
600.0
>600
Boiler size of
individual boiler
maximum filling quantity without demineralisation
up to 50 kW
NO REQUIREMENT
20 l/kW
50 to 200 kW
50 l/kW 20 l/kW 20 l/kW
always demineralise
1 Total of alkaline earths
2 If the conductivity in µS/cm exceeds the value specified in the table a water analysis must be carried
out
6
Hoval BioLyt (50-160)