1. This project demonstrated that there was considerable scope to adjust the HVAC
service time and temperature set-points and schedules. As well as to make full
use of existing variable speed control equipment, and to install a ‘demand
controlled’ ventilation system regime, which was based on carbon dioxide
measurement in treated spaces. There is simply no substitute for a POE audit of
the building services commissioning regime at building completion.
HVAC
Systems
Auditing
POE reveals annual energy savings of £1.6 million at Heathrow...
Barrie Waring audited the
heating, ventilation and air
conditioning systems at
Heathrow Terminal 5...
The audit of HVAC systems was
undertaken two years after the new
terminal opened. Energy savings of £1.6
million per year were achieved for an
implementation cost of just £38,000.
Most of the savings were identified in the
areas of controls and commissioning.
Post occupation evaluation (POE) is
crucial in the early life of buildings to
ensure optimal building performance
and management.
The new terminal is large and
complex, with passenger numbers
reaching a quarter-of-million each week
and over 4,000 an hour at peak periods.
The environmental control systems in
this huge facility match the scale of the
building, which is 405 metres long by
160 metres wide. The total footprint is
about 65,000 square metres and
includes six basement levels, as well as
five storeys above ground.
The mechanical services are a very
sophisticated design with an extensive
controls ability that provides opportunity
for energy efficient operation - with the
right fine tuning and commissioning. The
total annual energy costs for the building
were £17.25 million when Barrie Waring
was engaged. The primary ventilation
fans alone can consume £500,000 of
electricity in a year.
The initial site visit revealed instant
annual savings of half-a-million pounds,
after which an audit of all HVAC systems
was implemented to ensure that they
were operating in an energy efficient
manner. Just over a million pounds of
further energy savings each year were
identified and implemented for the cost
of £38,000.
This project emphasized the
importance of a rigorous building
services commissioning process
to ensure energy efficiency.
!
Heathrow Airport Terminal 5