How should I
calculate my hot water demand?
|
Calculating the hot water demand for any
given application is usually done by adding
the quantities of water consumed
simultaneously (at a given hot water - cold
water temperature differential, typically 30
or 35 °, e.g. cold water temperature = 10°C
and hot water consumption temperature = 40
or 45°C). The critical demand is generally
known as the peak flow, which means the
demand that occurs during the first 10
minutes. It is also common to check the peak
demand over the first hour (flow 60’) and
the continuous demand (per hour). Based on
its extensive experience in hot water
generation, ACV conducts laboratory analyses
to determine the hot water capacities of all
of its products and lists their performance
ratings at 10’, 60’ and continuous flow.
For example, a standard shower is generally
considered to have a flow rate of 8 to 10 L
per minute and takes an average of 10
minutes, which represents a hot water demand
of 80 to 100 L during the first 10 minutes.
It is also generally assumed that the system
must be able to fill a bathtub (with a
volume of around 150 L) within 10 minutes,
which represents a demand of 150 L in 10
minutes. The sum of these demands gives the
total peak demand.
By comparing this value to the performance
data of ACV systems, you can get an idea of
the type of product you need to meet your
requirements. Your installer will be able to
advise you about the most suitable solution
taking into consideration the specific
conditions relative to your installation.
For tertiary applications, ACV had developed
Archimedes, a sophisticated program designed
to calculate hot water demand that takes the
specific aspects of each application into
account along with a demand simultaneity
factor (see “Archimedes‿).
What option should I
choose if there is no chimney?
|
Also known as a « sealed boiler », the
balanced flue boiler enables you to operate
without a chimney, either in a residence
with no chimney (new construction) or in one
with a decommissioned chimney (renovation).
Piping for flue gas discharge and fresh air
intake comprises either a double concentric
pipe of about 12 cm in diameter (for the
most common residential boilers) or two
separate pipes (one for fresh air, the other
for combustion gases). The external
connection to the balanced flue is either on
an exterior wall or through the roof. ACV
offers a number of balanced flue boiler
models, both gas-fired (fitted with pre-mix
burners) and fuel oil-fired (fitted with
transparent flame fuel oil burners). ACV
balanced flue boilers are approved from 6 to
240 kW (depending on the country).
Here are some tips for saving energy and
heating more ecologically:
- Have maintenance performed on your
boiler regularly (once per year) to
ensure that it always operates at its
maximum efficiency.
- Be sure that your home is well
insulated (double glazing, air-tight
joints along door and window jambs,
etc). If this is not the case, investing
in better insulation can yield
significant savings.
- Close curtains and shutters at
night. Windows are often the main cause
of heat loss in a home.
- When airing out your home, do not
leave the windows open too long (5 to 10
minutes at most). Close the thermostatic
valves in the rooms that you are airing
out.
- Maintain an appropriate ambient
temperature in your home. In general,
the temperature should average about
20°C in living room areas, 16 or 17°C
in the bedrooms (adequate for all but
young children to sleep comfortably) and
about 18°C in the kitchen (given the
fact that there are other sources of
heat). Bathrooms can be maintained at
about 22°C. A high quality control
system (individually
programmable according to time of day
and by area within the home) can help
you save significant amounts of energy.
- Replace your old heating
installation with an up-to-date model.
The latest generation of condensing
boilers now achieves overall annual
efficiencies on the order of 95% versus
levels often below 70% for older boilers
(15 years old or more).
Can I use a water
heater with an electrical heating
element without connecting it to a
heating installation?
|
Yes. ACV offers various water heater
models from 100 to 600 L with an electric
heating element (standard or optional) as an
alternative heat source. On ACV water
heaters, the electric heating element is
always located in the primary circuit (on
the heating side). The essential advantage
of this approach is that it avoids the
problems associated with the formation of
scale deposits on the heating element (loss
of efficiency, bacterial growth in the lime
scale). As these heating elements must
always remain immersed in water, it is
essential that the primary circuit remains
filled with water.
In cases where a water heater is not to
be connected to a boiler, you must
nonetheless include appropriate operating
and safety components for the boiler
installation itself (safety valve, expansion
vessel, fill set). Your installer will be
able to advise you accordingly.
How often must I
perform maintenance on my boiler?
|
It is best to refer to local regulations
currently in force, which can vary from
country to country. With regard to fuel
oil-fired boilers in Belgium, the Royal
Ordinance dated January 6, 1978 requires
chimney cleaning, maintenance and adjustment
of the installation each calendar year (a
maximum of 18 months between two service
interventions). These services must be
performed by a certified company. The
certified company prepares a document
relative to each service intervention, which
you must retain for at least 2 years.
There are no legal requirements in
Belgium relative to the maintenance of
gas-fired boilers. Nonetheless, it is
recommended to have your installation
checked annually, if only to assure yourself
that all components are functioning
properly and to avoid unnecessarily high gas
consumption.
Is it necessary to
have my boiler descaled?
|
Thanks to the Tank-in-Tank technology,
ACV boilers and water heaters normally do
not need to be descaled. Each DHW draw-off
creates a brief underpressure in the
stainless steel inner tank (at the moment
that the draw-off tap is opened), followed
by a slight overpressure (upon closure of
the draw-off tap). As the inner tank is
free to move, its walls expand and contract
very slightly under the influence of these
pressure changes and prevent the formation
of lime scale on the exchanger surface:
thorough testing and the testimony of
numerous users in regions with calcium-laden
water confirm that ACV Tank-in-Tank water
heaters are truly effective in preventing
the formation of lime scale deposits as
opposed to traditional coil systems that
necessitate frequent descaling. Thanks to
this self-descaling feature, the heat
transfer efficiency of our water heaters and
their hot water output remain high
throughout the service life of the
installation.
In some regions with extremely hard water
and under certain operating conditions,
however, a limited quantity of lime scale
deposits may occur. In such cases, we
recommend that you contact a company that
specialises in descaling boilers. |