Technical
information
Calculate
how much money you will save by using ClearComfort on
your windows
Building physicists describe the thermal transmittance
of a material using the term 'Uvalue'.
Uvalue is measured in watts per square
meter per degree Celsius. Ordinary clear window glass
4mm thick has a Uvalue of 5.5. When treated with the
ClearComfort membrane it is 3.6. This is a 35% reduction
in the amount of heat that will be transmitted through
the window.
This represents a saving of almost 2 watts
per degree of difference between the internal and external
temperatures. For example, with the external temperature
of 0°C and your family room heated to 20°C, the
difference is 20 degrees; thus your heat saving is 40
watts for each square meter of glazing in the room.
If your room has a glass area of 10 square
metres, the difference between heating the room with ClearComfort
treated windows and with untreated windows is the equivalent
of running an extra 400 Watt heater. Multiply this by
the number of rooms that you heat in winter, and you can
quickly see for yourself the difference that ClearComfort
membrane will make to your energy bills.
How much
greenhouse gas will you save?
How much CO2 will you prevent
entering the atmosphere when you use ClearComfort on your
windows?
Each kilowatt hour (kWh) saved prevents
1 kg of CO2 from entering the atmosphere.
So by using the ClearComfort insulation system you will
reduce your space heating or cooling requirements by the
equivalent of one 200 Watt heater in each room, thus sparing
the atmosphere, on average, an extra 1,000 kg of CO2
each year.
A precise calculation of heat
transfer
If you are serious about building
physics you can apply this formula to calculate precisely
how much heat is transferred through your own windows:
Q = A x U x T
Q represents heat lost or flux in units of Watts, or Joules
per second;
A represents the area of glass in your room in units of
square metres;
U represents transmittance of the glass in units of Watts
per square metre per degree centigrade;
T represents the difference in air temperature on each
side of the window in units of centigrade degrees.
When you have calculated the Q value, or
heat transfer, you can then calculate the dollar value
of the energy you are using to heat or cool your room
by applying the Q value to this second formula:
S = [Q/E] x [K/100,000]
S represents dollars per hour
E represents the efficiency of your heating appliance
as a percentage (typically 40% or less)
K represents the fuel cost charged to the consumer by
the supplier, in units of cents per kWh for electricity
or cents per megajoule (MJ) for gas
Working these calculations with accurate
measurements for each hour of the day that you are heating
or cooling your house, and adding the figures over the
year, will give you the annual energy consumption and
energy cost for your household. Repeat the calculations
using the U value of windows with ClearComfort installed,
and the difference in the two annual figures will demonstrate
precisely the difference in energy lost and dollars saved.
