TRENCH
HEATING
Trench heating cannot be
discussed without first explaining what a radiator is. Radiators as heat
exchangers designed to transfer thermal energy from one medium to another for
the purpose of space heating. Merriam Webster
dictionary defines a radiator as any set of various devices (as a series of
pipes or tubes) for transferring heat from a fluid within to an area or object
outside. The English dictionary also describes a radiator as a finned metal
fixture that carries hot water or steam in order to heat a room. Simply put, a
radiator is any device capable of exchanging heat or simply put, a radiator is
a space heater.
Brief
History of Radiators
The first person to ever
use the term radiator to mean a heating device was Denison Olmsted of New
Haven, Connecticut in 1834. He used it as a patent for a stove that could
radiate heat through a heat exchanger. The heating radiator was invented by a
Prussian-born Russian, Franz San Galli between 1855 and 1857. It is quite
understandable that the inventor of this wonderful device is Russian since the
coldest place on the planet is Russia. The bitter cold would have been a great
incentive to warm up bones while busying himself with the radiator for two
years. Radiators have since the invention, been one of the oldest and most
effective ways of heating buildings apart from the traditional fireplaces.
Radiators transfer heat mainly by the heat transfer method of convection and
can, therefore, be called convectors. The term ‘convector’ is used to describe
a set of devices in which their source of heat is not directly exposed. Wall
mounted radiators and trench heaters are common devices used in heating
buildings nowadays and they operate following the convection method.
The
Trench Heating System
Trench heating is a system of heating that
provides an even distribution of heat along the perimeter of any room and
prevents draughts, condensation, and cold spots. As implied by the name, a
trench is dug in the floor and a simple convector unit is connected up to the
heating system and completed with the Grille (it is in simple terms a grating
or screen of metal bars or wires, placed in front of something as protection or
to allow ventilation or discreet observation.), the single most important
feature that a trench heater has. The
amount of heat likely to be generated from this heating method depends largely
on the size of the trench. Trench heaters are long and rectangular in shape,
designed for the convector unit to fit in snugly. The width and the length of
the trench determine the heating element or convector unit that it contains and
invariably determines the amount of cooler air that can be drawn in through the
grilles to allow for exchange after convection. Subtle fan systems are
installed in trench heaters to allow for a greater influx of air and
consequently heat to prevent the size of the trench from being a problem.
A trench heater has to
have multiple grilles in contact with the tube or casing carrying the liquid or
steam pumped through the radiator to increase the surface area available for
heat transfer or exchange within its environment. Trench heating is most
commonly installed around the edges or perimeter of a room and the location of
the heating grille can be chosen by the home or room owner depending on the layout
of the room or building as a whole. Features like floor to ceiling glass
windows or bay windows do not pose a problem during installation for this
reason.
How
Does a Trench Heating System Work?
Trench heating can be
either water-based or electric. In each case, water pipes or electrical
elements encased in conduits, run in trenches dug beneath the floor of the
room. The trench heating system is made up of a pre-insulated steel boxed
casing containing an aluminium finned copper tube-heating element. This casing
is kept inside a trench or hole in the ground. While cold air easily flows into
the trench through the grilles, provision has been made for hot water to pass
through the element in the casing. The air going into the trench is warmed up
through natural convection as it rises past the element out through the grille.
The fan assisted trench
heating system is only different in that an integral fan draws air into the
trench and pushes the hot air out. The water-based system is designed to run
off a conventional boiler, but it is very important to check that this boiler
has enough capacity. The function of the trench heating system will be impaired
if airflow is obstructed by dirt or damage to the grilles. Dirt or damage
renders that portion of the radiator ineffective as a heat exchanger.
Therefore, it is strongly advised that during summertime, trench heaters should
be protected with a special cover to prevent dust. During cold seasons, the
cover can be removed so that the grilles can function properly.
Possible
Locations of Trench Heating System
They can be run up a
flight of stairs or around the edges or perimeter of a room. They can also be
fitted upstairs because the design system is such that it can be customised as
per the preference of each customer. For rooms with floor to ceiling windows or
bays, trench heating systems can be laid at the foot of windows so it does not
cause blockage of any part of the window. They can also be fitted across the
threshold of patio doors. Trench heating systems can be used in domestic or
commercial buildings, in offices, hotels, restaurants, banks and residential
properties.
Advantages
of Trench Heating Systems over Wall-mounted Radiators.
Trench heating systems
have quite a number of advantages over the wall-mounted radiator. They are the
most practical form of heating glazed façades and offer the most options. They
are efficient in that they use a ‘low water’ high heat output element. This
need to heat very low amount of water proves very effective when used together
with ground source and air source heat pump systems. Trench heating is a system
that takes away the need to have standard radiators fitted on the wall.
Wall-mounted radiator, as the name implies, is a radiator that is fitted to
walls. As an older type of radiator system, the traditional wall-mounted
radiator can be a popular choice for heating around glazed-in façades, due to
its “proven track record” in heating, the fact that most people understand what
it does and how it does it. However, conventional radiators pose several
problems when used to heat glazed façades; they are not often aesthetically
pleasing, they can be obtrusive and can obscure façades. They also tend to use
up floor space and can be very susceptible to damage.
While Trench heating
systems are space saving, taking up minimal floor space, wall mounted radiators
take up a big chunk of space that could have been used for something else. They
are not invisible, but mostly out of sight unlike the wall mounted radiators.
Trench heating is also energy efficient and this makes it very economical to
run.
They are efficient and
quick to heat, they add aesthetic value and some sort of sophisticated look to
the layout of any room they are installed in. This is because the grilles come
in different materials such as wood or aluminium and in various designs. Also,
trench heating systems are not as disruptive and therefore they are less
expensive to install especially when building a new home from scratch. With
trench heating, any finish material such as wood, rug or carpet can be used for
your floors without any specific limits. They are also not as expensive when
renovating a house or fitting into an already built house. Trench heating
systems also dispense heat evenly in rooms such that there are no cold spots or
occurrences of draught. Trench heaters are also perfect when powerful minimal
heat is required. Trench heating systems are also silent in operation and
require very little maintenance.
In addition to all
these, trench heating systems also have health benefits. They are usually
recommended in homes where one or more of the residents suffer from asthma or
other types of allergies. Wall mounted radiators would cause more air
turbulence that would be created by trench heaters. The lesser the air
turbulence trench heaters create, the lesser the circulation of allergens and
dust particles, hence creating a clean environment not just for the residents
with asthma or other allergies but for residents who do not suffer from any
allergies. Also, the risk of condensation building on widows with trench
heating systems is reduced, making makes them ideal for use in conservatories
or buildings that have floor to ceiling windows.
Disadvantages
of Trench Heating
Trench heating systems
have few disadvantages as opposed to their advantages, one of which is that
they tend to accumulate dust. However with roll up grilles access is simple and
a vacuum is perfect for a quick spruce up. They also present trip hazards to
those who wear stiletto shoes!
As versatile as a trench radiator can be, with
its ability to be installed throughout different floor voids and around curved
glazed façades, there are some circumstances where the trench heating system
will not be appropriate for certain applications. Some of these circumstances
are when floor voids are either too shallow or are completely solid. That is
when digging or create a trench would be almost impossible. Also, when
construction costs for creating trench channels are prohibitive, the trench
heating system will not be applicable.
Output
Comparison Control
Most times your heat
requirements may not be exactly the same as the heat output of your chosen
radiator. It is always better to have too much heat than not enough, therefore,
it is recommended that you choose a radiator size with a higher rather than
lower heat output and fit thermostatic valves so that you can regulate the
temperature of the room.
Output range is shown in
Watts and BTUs (British Thermal Units). Wattage is based on the system’s likely
operating temperature and is shown as Delta 50 (∆t 50◦C) which is the current
European rating. The conversion units for calculating what heat output you need
from your radiator for a specific room are below
To convert Delta 50 to
Delta 60, multiply Delta 50 heat output by 1.264
To convert Delta 60 to
Delta 50, divide Delta 60 heat output by 1.264
To convert BTUs to
watts, divide by 3.142
To convert from Watts to
BTUs, multiply by 3.142
Note that the choice of
grille finish may determine final heat output.
Performance
Determination
Until 2015, there had
been no uniform standard for determining the performance of Trench Heating. The
EN 16430 standard was validated in March 2015 and provides common standards of
manufacture and performance which were applied immediately. This new standard
has put an end to uncertainties in the design and output of Trench Heating when
comparing the performance data of different manufacturers.
The EN 16430 test
procedure comprises of three parts which are the Technical specification and
requirements, Test method and rating for thermal output and Test method and
rating for cooling capacity. Part of this test procedure monitors the ambient
room air temperature which is measured in the centre of a test booth at a
distance 2m from the façade at a height of 0.75m above finished floor level
(FFL). To ensure an accurate reading, the test room is designed so the ambient
air temperature is measured and not mixed up with the temperature of the air
entering into the coil which may be variable due to the inevitable dilution
between leaving the air and entering the air.
This test does not only
cover heating and cooling performance but also pressure, noise, electrical and
maintenance safety.
Control
Options
Heat output may be
controlled by screening the radiator or its parts, introducing changes in the
air circulation intensity using forced or induced draught fans or by changing
the temperature of the surrounding. A full set of controls should ideally consist
of a boiler thermostat, a timer or programmer, a room thermostat and
thermostatic radiator valves. Room thermostats are simple dials on the wall
that allow you to control the temperature of the home. They are limited in
options and are inflexible because achieving the desired temperature for
everyone in the building proves difficult when there is more than one radiator.
A new technology for
controlling heat output is the smart heating control. It is generally used for
domestic heating. It allows control remotely from a computer, tablet or
smartphone. A clear advantage of a smart heating control system is that if your
plans change, you can make changes remotely. Using heat controls help to
minimize the emission of carbon dioxide. It also saves money on heating
bills. Heat controls allow you to
schedule your heater to go off and on when needed and the areas of the home
where you want to be heated can be selected also with the desired temperature.
Recommended suppliers of
Premium Brand Trench Heating including Jaga Trench Heaters
The above Trench Heating
Suppliers sell commercial and domestic trench heating.
