Passively Achieving the Power of Dreams

Passively achieving the power of dreams, Honda Showroom, Romford

Passivent natural ventilation is helping
Honda realise the dream of reducing carbon footprint whilst simultaneously achieving an energy demand reduction of over 80%, a ‘very good’ BREEAM rating and a ‘good to best’ sustainability appraisal.
As part of its market strategy, Honda UK has built a new 600m2 car showroom on a
brownfield site in Romford, Essex. Not only
has the showcase building had to comply
with Honda’s own commitment to reducing
its carbon footprint, but with the local
Council’s requirement that a minimum 10%
of energy needs are produced using on-site renewable energy.
The services solution, developed by building services design specialists Cunnington Clark, has been found largely by utilisation of Passivent natural ventilation technology.

As a result, conventional air conditioning
cassettes for the showroom, staff and sales
offices, meeting room and customer service
areas have been replaced with Passivent
Aircool® inlet louvres at low level and Passivent Airstract® roof terminals.

The 36 modulating wall Aircool® units draw
fresh air into the space on demand,
maintaining internal air temperature and
CO2 at preset levels. Natural air movement
principles, in which warm air rises, are
harnessed to exhaust the warm, ‘used’
internal air through the six roof-mounted
Airstract® terminals with ceiling louvres.
The Passivent system functions 24/7, allowing night air to be drawn in when the building is unoccupied to provide ‘free’ cooling.

Underfloor heating powered by a heat pump ensures the showroom remains comfortable in the cold winter months, with the heat pump providing chilled water through the pipework in peak summer temperatures to maintain the space temperature below 28°C.

The combination, coupled with the
building’s increased thermal mass is
predicted via thermal modelling to reduce
energy demand from 61,551kg/CO2 to just
11,058kg/CO2, a saving of 82% compared
with a traditional showroom design. A
BREEAM (Building Research Establishment
Environmental Assessment Method) Retail
Design & Procurement Pre-Assessment
classified the building as thus achieving a
‘very good’ rating. A regional sustainability
appraisal using the SEEDA (South East
England Development Agency) checklist
concluded a sustainability practice level of
‘good to best’ for the project.


Dean Barker of Cunnington Clark observed,
“We aimed to create a benchmark energy
model for Honda. The design brief was to
design the services for an environmentally
friendly building in accordance with the
planning requirement to achieve at least
Building Regulations Part L and the Greater
London Assembly’s energy standards, and to show Honda’s commitment to reducing its
carbon footprint. The showroom is also to be a showcase for Honda’s new corporate image.

We modelled the building using Passivent
motorised louvres at low level and roof
mounted terminals. The concept has been
used to great effect in office and school
environments and we felt the same
technology would work in a showroom

The thermostatically controlled Aircool® units
open automatically to draw replacement,
fresh air into the building. Excellent weather
protection and security are provided by
external weather louvres, and internal louvres provide a U-value of 0.86W/m2K to minimise heat loss when closed. A thermally broken frame, and insulated and orientated louvres minimise the risk of nuisance condensation and draughts.

Environmentally-friendly energy saving
Passivent Airstract® terminals require no
power other than natural forces of buoyancy, wind and convection to move the air. Patented double-bank louvres provide
maximum rain rejection whilst allowing air to
flow freely. Independently tested at BSRIA.
Terminals are resistant to continuous wind
loads at 50m/s, demonstrated by independent BRE tests.

To download the Case Study PDF click here