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TRANSCRIPT
5 November 2015
Natural Ventilation
Strategies in Healthcare
Gerry Brannigan BEng(Hons) CEng MCIBSE MASHRAE MSoPHE MAE
Executive Director, Cadogans
Scottish Health & Social Care Facilities Conference 2015
Agenda
Introduction Science of Ventilation
Key Guidance
What to Consider
Healthcare Implications
Conclusions
Why should we consider Natural Ventilation in Healthcare?
Recovery
Health & Wellbeing
Comfort
Energy
Whole Lifecycle Costs
So What is Ventilation For?
The principle role of ventilation is to provide an appropriate level of
indoor air quality (IAQ) by removing and diluting airborne contaminants.
CIBSE AM10
Ventilation is also used to passively cool a space and as a mechanism to
distribute thermally conditioned air from heating and cooling plant.
From an energy perspective, losses resulting from ventilation and general air
exchange can account for more than half of the primary energy used in a
building. These losses comprise space heating and refrigerative cooling
losses as well as the electrical load associated with driving mechanical
services. CIBSE Guide A
What can effect Indoor Air Quality?
IAQ
Pollutants from
materials
External Pollutants
Temperature
Humidity
Internal Pollutants
from Equipment
Carbon Dioxide
Odours
Particulates
Pollutants Entering the air
Particle size and types - CIBSE Guide B
Typical Moisture Emission Rate - CIBSE KS17
Thermal Comfort
Thermal Comfort
Humidity Dry
Resultant Temperature
IAQ
Air Speed
Lighting
Safety Noise
Physiology
Psychology
Culture
Control
Health & Wellbeing
“ During the 1920s, Sir Leonard Erskine Hill, the director of the Department Of Applied Physiology at the National Institute For
Medical Research ... identified several factors that promote health in buildings. He
concluded that the human body needs the stimulus of constantly changing conditions, and so a monotonous indoor environment
was to be avoided. ... he favoured sunlight, fresh air and a radiant heat source.”
Hobday, Richard,
July 2011, Historic Scotland Technical Paper 12: Indoor environmental quality in refurbishment, pp.7
Health & Wellbeing
“Increased average indoor temperatures, reduced background ventilation rates and other changes may have led to a significant increase in the concentration of house dust mite. This, in turn, could be the causal factor in the rising incidence of asthma in
children.
The UK has amongst the highest prevalence of respiratory symptoms and asthma worldwide. Studies indicate that between the mid‐1960s and mid‐1990s, asthma prevalence in the UK
increased by about 5 percent per year. In addition to asthma, increased indoor temperatures have been linked to an increased
incidence of obesity.
The human body expends less energy in temperature ranges typical in modern buildings. Ninety years ago, Prof. Hill, concluded that over‐warm conditions were a factor in
obesity, together with lack of exercise and too much food.”
Hobday, Richard, July 2011, Historic Scotland Technical Paper 12: Indoor environmental quality in refurbishment, pp. 8
Responsibility
Comfort
Building Services Engineer
Thermal Modelling
Architect
Client Operations
Patient
Façade Engineer
Facilities Management
Team
Building Regulations
• Ventilator - 1/30th of the floor area of the room it serves
And
• Trickle ventilator with openable area of 4000mm2 (room <10m2)
or
• 400mm2 per m2 floor area where room is more than 10m2.
Where building is tight 5-10m3/h/m2 @ 50Pa
• Trickle ventilator with openable area of 10000mm2 (room <10m2)
or
• 10000m2 plus 600mm2 per m2 floor area where room is more than 10m2.
The areas of trickle ventilation shown may not suffice to maintain air quality
and therefore an alternative ventilation solution should be adopted.
Health & Wellbeing
“The volume-based ‘air change per hour’ method, and 2ACH, date back over 140 years. In an address to the Queen in 1877, Army Surgeon General WM Muir reported on the new hospital designs in Europe. He noted wards had 100 ft2 per bed, and 1200-1500 ft3 per patient, "the volume of which is to be exchanged
twice per hour" (i.e. 2 ACH).” Interpretation IC 170-2013-5 of ANSI/ASHRAE/ASHE Standard 170-
2013 Ventilation of Health Care Facilities Date Approved: January 27, 2015
Science of Natural Ventilation
“There is more to Natural Ventilation than openable windows and sperm-like
arrows!”
Engineering the Environment
Comfort Criteria
Healthcare Standard
Orientation & Location
Solar/Casual Gain Control
Thermal Losses
Odours Noise
Controllability
Prevailing Wind Control
Ventilation Requirements
General ward Communal ward toilet
Single room Single room
WC Clean utility Dirty utility
Ward Isolation room
Infectious disease Iso
room
Neutropenic patient ward
Critical Care Areas
Birthing Room SCBU
Preparation room (Lay-up)
Preparation room / bay sterile pack
store
Operating theatre
UCV Operating theatre
Anaesthetic room
Theatre Sluice/dirty
utility
Recovery room Cardiac
catheterisation lab
Endoscopy room
Endoscopy cleaning
Day case theatre
Treatment room
Pharmacy aseptic suite
Cat 3 or 4 containment
room
Post mortem room
Circulation Space
Offices Open Plan
Waiting Areas
*From SHTM 03-01 Part A – Appendix 1: Table A1
Ventilation Requirements
General ward Communal ward toilet
Single room Single room
WC Clean utility Dirty utility
Ward Isolation room
Infectious disease Iso
room
Neutropenic patient ward
Critical Care Areas
Birthing Room SCBU
Preparation room (Lay-up)
Preparation room / bay sterile pack
store
Operating theatre
UCV Operating theatre
Anaesthetic room
Theatre Sluice/dirty
utility
Recovery room Cardiac
catheterisation lab
Endoscopy room
Endoscopy cleaning
Day case theatre
Treatment room
Pharmacy aseptic suite
Cat 3 or 4 containment
room
Post mortem room
Circulation Space
Offices Open Plan
Waiting Areas
*From SHTM 03-01 Part A – Appendix 1: Table A1
Areas to be Considered
General ward
Single room
Circulation Space
Offices Open Plan Waiting Areas
*From SHTM 03-01 Part A – Appendix 1: Table A1
What to Consider
Individual space requirements
Procedures, Patient Isolation, Healthcare Operations
Building Physics Holistic Assessment
Thermal Conditions
Engineer a solution
Healthcare Implications
Good IAQ and Ventilation can assist recovery
Infection Control
Healthcare Operations
Healthcare Maintenance & Cleaning
Conclusions
Think Holistically
Natural Ventilation isn’t just an openable Window
Early Building Physics advice and modelling from Building Services Engineering Consultant
Work Collaboratively
Create an Appropriate Integrated Solution
Build Tight – Ventilate Right
Thank you. Questions? Gerry Brannigan, Executive Director [email protected] 0141 270 7060 07968 990 984