Indoor ventilation monitoring

How we measure air quality

We use a range of techniques to meet your particular needs.

Short-term measurements

This provides a ‘spot-check’ of the ventilation rate to check compliance with regulations and requirements. These can also be used to investigate the effect of opening/closing vents, trickle-vents and windows, and altering fan speeds. This process typically takes one hour.

Long-term measurements

This gives time-averaged ventilation rates including all effects arising from occupant activities, e.g. opening windows and doors, and using extract fans. This process typically takes 1-4 weeks.

Inter-zonal air flow measurements

This provides time-averaged measurements of the air flow between different parts of buildings. It is especially important in understanding how to avoid either cross-contamination or the transmission of infections. This process typically takes 1-4 weeks.

Combined with air quality

We use ventilation measurements in conjunction with indoor air quality measurements to check if a building complies with health, safety and environmental legislation, and environmental certification schemes.

New techniques

BRE developed the passive PerFluorocarbon Tracer (PFT) technique for measuring ventilation in large and complex buildings. We also pioneered the use of new, more environmentally-friendly ventilation tracers to replace those traditionally used (such as sulphur hexafluoride) which have been withdrawn on environmental grounds.

We also carry out airtightness testing, post-occupancy evaluation and testing on HVAC systems.

Ventilation project case studies

New Zealand homes

We worked remotely with BRANZ (our sister building research organisation in New Zealand) to measure ventilation rates in a project on airtightness and ventilation in NZ homes. Longer-term (2-week) measurements were carried out using the PFT technique:

A survey of airtightness and ventilation rates in post-1994 NZ homes. S. McNeil, L. Quaglia, M. Bassett, M. Cunningham, G. Overton, M. Plagmann, S. Upton, M. Boulic, P. Leardini, K. Rosemeier, I. Smith, T. Bishop. Paper to AIVC Conference, Copenhagen. 2012.

Heat loss in a hospital

Ventilation rates were measured in four separate locations and averaged over two weeks, and this was coupled with infrared thermography and air tightness tests. Following the resulting recommendations could save the hospital thousands of pounds a year.

The effects of cooking in an airtight home

Measurements of ventilation rate and various air quality parameters were carried out in a modern, airtight home to investigate the effect of different types of fuel 

(electricity and gas)’ cooking (boiling, frying) and ventilation rate (NHBC (2013)).

We found that frying food produced more air pollutants than boiling, the use of gas as a cooking fuel produced more nitrogen oxides (NOx) and fine particles, and the ventilation system in the house did not provide a significant change in ventilation rate when operated in the ‘boost’ mode as compared with the ‘normal’ mode. With the ventilation system off (to simulate a potential failure), many of the air pollutants remained in the house for long periods of time.

Guidance on natural ventilation

We calculated the ventilation rates of a low energy office building as part of a European project to advise the construction industry of the viability of naturally ventilated office buildings. The “constant concentration technique” was used to provide a ventilation measurement every 30 minutes over the monitored period.

A guidance document and accompanying CD was produced for architects and designers on how to overcome the barriers that may be preventing them from designing naturally ventilated buildings.

Air quality and ventilation in healthcare buildings

We have previously carried out measurements of ventilation rates and inter-zonal air flows in a number of different UK hospital wards as part of a BRE Trust funded research project. The aim was to understand how ventilation rates can affect indoor air quality and air movement between zones in hospitals of a variety of different building types and ages.

Effective hygiene and adequate ventilation are essential for all hospitals and other healthcare settings, as they are tasked with protecting the health of occupants on a daily basis. It is therefore imperative to balance the health and wellbeing of patients, staff and visitors with the economic and sustainability-based factors associated with use of heating, ventilation, and air conditioning (HVAC) and air cleaning systems when designing, equipping, and operating these buildings.

Hospital campuses typically feature several types of building, a vast range of different rooms and spaces (both clinical and nonclinical), and methods of ventilation which will range from natural to fully mechanical, with mixed mode in between.

Many sources of air pollution will be present both inside and outside of healthcare buildings. The extent to which each pollutant will affect occupants will depend on the source strength of the pollutant and its pathway to the occupants. The pathway can be complex and will be highly dependent on the building layout, ventilation system design and operation, opening/closing of doors and windows and other factors. Those most vulnerable to air pollution, i.e. those patients with respiratory and cardiovascular conditions, infants and the elderly, are likely to spend significant periods of time in healthcare settings, making this an area of particular concern.

We can offer:

• Reactive investigations where there are reported or perceived problems with indoor air quality (IAQ)/indoor environmental quality (IEQ)

• Proactive assessment/monitoring of IAQ, ventilation and general IEQ within your building

• Targeted post occupancy evaluations (POEs)

• Testing of air cleaners and air quality monitors

• Implementation of BS 40102 Part 1 (Health & Wellbeing in Non- Domestic Buildings – Code of Practice)

• Collaborative research

• Indoor environmental quality training