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

Cadogans & Healthcare

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

Guidance and Regulation

Building Regulations

SHTM 03-01 Part A

SHFN 30 - HAI-Scribe

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.

CIBSE Guide A – Environmental Design

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!”

Natural Ventilation Strategies

CIBSE AM10

Wind Pressure

Typical Layouts

Engineering the Environment

Comfort Criteria

Healthcare Standard

Orientation & Location

Solar/Casual Gain Control

Thermal Losses

Odours Noise

Controllability

Prevailing Wind Control

Image published in Building - 19/06/2014

£430m Southmead Hospital in Bristol

Queen Elizabeth University Hospital

Natural Ventilation Strategy

Openings for Natural Ventilation

CIBSE AM10

Windows

From BSRIA Illustrated Guide to Ventilation

It Doesn’t NEED to be a Window

From BSRIA Illustrated Guide to Ventilation

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 g.brannigan@Cadogans.com 0141 270 7060 07968 990 984