Energy efficiency impacts on your
home
 Energy
efficiency how does it affect me?
From April 1st under Part L of the building regulations all new
gas boiler installations or replacement boilers need to be high
efficiency Condensing boilers. Where necessary Heating controls
and systems will also have to be updated, such as converting
from a gravity fed system to a fully pumped system, controls
fitted such as TRV's fitted to Radiators and an Auto by pass
valve fitted where specified. Any property with floor area exceeding
150M² will require Zone controls. Boiler selection will
be based on the whole house boiler sizing method as specified
under SAP ratings.
What is a condensing
boiler?
A condensing boiler is a high efficiency
modern boiler that incorporates an extra heat
exchanger. This allows the hot exhaust gases
to lose much of their energy pre-heating the
water in the boiler system. When working in condensing
mode, the water vapour produced in the combustion
process condenses back into liquid form releasing
the 'latent heat' of vaporisation into warming
the incoming water supply. A side effect of this
process is known as condensate, which is usually
mildly acidic, has to be piped away to a drain
or soakaway. Another side effect is known as
pluming.
It is important to note that condensing boilers do not operate
in the condensing mode all the time. However even when not in
the condensing mode they are significantly more efficient than
conventional boilers.
Who makes condensing
boilers?
All the Major manufacturers make Condensing boilers, even a majority
of the oil fired boiler manufacturers produce condensing boilers
even though mandatory condensing boilers are required until 2007.All
boilers are rated using SEDBUK, a useful guide to the efficiency
of boilers called the 'little blue boiler book' is available.
A web based listing is also available for gas
and oil.
What are TRV's?
Thermostatic radiator valves (or TRVs for short) will add to
the effectiveness of any control system. TRVs will allow control
of individual room temperature by gradually closing down a radiator
if a room starts to overheat due to adventitious heat gains (eg
sunshine). A TRV should not be fitted to the radiator located
in the same room as the controlling room thermostat.
Programable room thermostats
Provides greater control and energy savings
ove a normal room thermostat. Being programmamble allows
it to meet the use of the room with heating on off
or low dependant on the room useage.
What is SAP?
SAP is the government's Standard Assessment Procedure
for energy rating a dwelling.
- lt is a basic energy rating which assumes average factors
for shelter, shade and orientation and considers the space
and water heating only.
- The SAP scale currently runs from 1 (extremely poor) to
120 (extremely good), with a score of 80 or more considered
to represent an energy efficient home.
- The average UK home (ie. not brand new) has a SAP rating
of 40-50.
- Most new homes achieve ratings of 80 or above, and there
are many that reach top scores of 100-120.
- In 1995, Building Regulations changed to require a SAP
rating on every new home and from 2001 builders had to to
post a notice in every finished dwelling stating its rating.
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More information and links
SEDBUK
('Seasonal Efficiency of Domestic Boilers in the UK') is the
preferred measure of the seasonal efficiency of a boiler installed
in typical domestic conditions in the UK, and is used in SAP
assessments and the Building Regulations.
| SEDBUK
range |
Band |
| 90% and
above |
A |
| 86% -
90% |
B |
| 82% -
86% |
C |
| 78% -
82% |
D |
| 74% -
78% |
E |
| 70% -
74% |
F |
| Below
70% |
G |
The SEDBUK efficiency of most current and obsolete boilers can
be found on the website www.boilers.org.uk Although SEDBUK is
expressed as a percentage, an A to G scale of percentage bands
has also been defined in the table above. The table bands are
colour coded green A band most efficient band through to yellow
then on to red band G the least efficient.
Why are boilers targetted?
Boilers are amongst the least energy efficient appliances in
your home, they alone account for up to a third of all domestic
CO2 emissions. As the current lifespan of a boiler is 10-15 years,
making the wrong decision about what boiler to have really could
waste considerable amounts of your money and contribute to climate
change.
A heating system that uses a high efficiency condensing boiler
with the correct heating controls can save you as much a 40%
on your heating bills. It really is time to consider whether
you have the right boiler. (cited from
www.est.org.uk)
All homeowners will be responsible for ensuring central heating
work in their home complies with the relevant Building Regulations.
- From 01 April your local authority must be told when you
have a new or replacement boiler fitted. Your
installer should do this for you and will arrange for you
to receive a certificate to confirm that the new boilers
conform to building regulations.
- Calculate your
homes energy consumption and your Carbon/ CO2 contribution
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