Hotspur 5 & 9 Issue 2 December 2017
13
Age of Property
Refurbished
Type of Ventilation
Recommendation
Post 2008(Class 1)
NO
Significantly reduced energy demand due to air
tightness of the building. Typically double/triple
glazed windows with high levels of roof and
cavity insulation. Passive ventilation through
trickle vents and mechanical extracts in
kitchens/bathrooms.
Firstly follow building regs recommendation
on Air Permeability of the building. Special
attention needs to be made to any extractor
in the same room as the appliance eg: open
plan kitchen diner etc. DEAS Kit can be used
however a risk assessment and commission
testing needs to be carried out in
accordance with HETAS Technical Note
HETAS_TN_0020 v1.0. Extra ventilation
may be required.
Post 2008(Class 1)
House fitted with
Mechanical heat
Ventilation Recovery
System in same room
as appliance
NO
Significantly reduced energy demand due to air
tightness of the building. Typically double/triple
glazed windows with high levels of roof and
cavity insulation. Passive ventilation through
trickle vents and mechanical extracts in
kitchens/bathrooms. Special attention to
mechanical heat ventilation recovery systems is
required in this type of property construction.
Do Not Fit DEAS Kit
Between 1975-2008
(Class 2)
YES
Reduction to the original energy demand due to
improvements in properties air leakage. Typical
additions include double glazing, cavity wall and
loft insulation and draught proofing of
windows/doors. Typically passive ventilation
through trickle vents and mechanical extracts in
kitchens/bathrooms. Special attention to
mechanical heat ventilation recovery systems is
required in this type of property construction
Special attention needs to be made to any
extractor in the same room as the appliance
eg: open plan kitchen diner etc. DEAS Kit
can be used however a risk assessment and
commission testing needs to be carried out
in accordance with HETAS Technical Note
HETAS_TN_0020 v1.0. Extra ventilation
may be required.
If the property has mechanical heat recovery
Do Not Fit the DEAS.
Between 1975-2008
(Class 3)
NO
A large proportion of properties fall into this
category and the energy requirement of these
dwellings become greater due to higher heat
loss rates through the building fabric. They
normally have basic passive ventilation with
supplementary mechanical ventilation
incorporated. As the age of the property
increases, the amounts of insulation
incorporated decreases, leading to higher
leakage rates.
DEAS Kit can be used however a risk
assessment and commission testing needs
to be carried out in accordance with HETAS
Technical Note HETAS_TN_0020 v1.0.
Extra ventilation may be required.
Pre-1975 (Class 4)
YES
Old style housing with moderate/significant
improvements in the form of double glazing,
inclusion of cavity wall and loft insulation.
Addition of mechanical ventilation in the form of
extract fans in kitchens/bathrooms. Additional
improvements reduce the properties overall
energy requirement.
Special attention needs to be made to any
extractor in the same room as the appliance
eg: open plan kitchen diner etc. DEAS Kit
can be used however a risk assessment and
commission testing needs to be carried out
in accordance with HETAS Technical Note
HETAS_TN_0020 v1.0. Extra ventilation
may be required.
Pre-1975 (Class 4)
NO
Old style housing with single glazing with a high
energy requirement due to increased leakage
through the building structure. Typically basic
passive ventilation through vents in the wall/floor
and by opening of windows with no insulation or
additional draught proofing measures
incorporated.
DEAS Kit can be used. Commission testing
needs to be carried out in accordance with
HETAS Technical Note HETAS_TN_0020
v1.0.
