Ventilation in a healthy indoor environment plan

indoor air quality / healthy building certification / ventilation rates / healthy indoor environment / consultants

What is ventilation in a healthy building plan?

There has never been a more urgent time to consider an enhanced ventilation strategy as part of a healthy indoor environment. Why does this ventilation matter and what can landlords, developers and workplaces do about it?

‘Ventilation’ describes the cyclical process of supplying outdoor air and removing the existing indoor air through either natural or mechanical methods.

Natural ventilation in a healthy building strategy aims to introduce outdoor air into a space thanks to operable windows, doorways and ceiling vents for example, without relying on electricity. This approach typically benefits from an accompanying CO2 monitor plan to ensure healthy indoor air at all times.

Mechanical ventilation for a healthy indoor environment meanwhile does the same albeit in a far more calculated and energy intensive manner via a powered system of vents, piping, filters and fans.

Mechanical systems should ideally be designed with the anticipated occupant numbers and type of activity in mind; for example a busy gym full of cardio machines will require a different ventilation rate than a boardroom used for occasional meetings.

A mixed or hybrid ventilation model would deploy a combination of both healthy building strategies but in all three cases the ultimate purpose remains the same - to increase occupant comfort and create a healthy indoor environment by removing dust and particulates, unpleasant odors, CO2 and Volatile Organic Compounds (VOCs) that off-gas from toxic materials in furniture, fittings and adhesives.

Ventilation and indoor air quality for workplace wellness

From a workplace wellness perspective, adequate ventilation rates are fundamental to ensuring healthy indoor air that in turn plays a role in promoting cognitive function and reducing the transmission of viruses, amongst other things.

Ventilation in healthy building certifications

It is also worth noting that ventilation rates are often designated by regional codes, as well as healthy building certifications such as the USGBC’s LEED, BREEAM and WELL. This means a healthy building consultant and/or MEP engineer can be a helpful resource when creating and implementing a comprehensive wellbeing interiors or workplace wellness strategy.

Finally, for home upgrade to indoor air, there is also the option of a standalone air purifier such as those made by Dyson for smaller spaces (25m2-50m2 let’s say). These are limited in impact compared to a mechanical system but still represent a viable option in certain circumstances, for example in a bedroom for a sleeper with asthma or allergies.

Healthy indoor environments and air filtration

Filtration is a key aspect of ventilation, this is the process of removing potentially harmful particulates from the outside air intake before that air is sent into the building interiors.

Air filtration is done via increasingly advanced filters in the ventilation system, meaning this is an area where we as healthy building consultants can make a tangible difference simply by encouraging an MEP Manager or consultant engineer to upgrade the filter, for example.

A High Efficiency Particulate Air (HEPA) filter removes dust, mold, pollen and particulates. The Minimum Efficiency Reporting Value (MERV) is a 1-20 scale that measures the effectiveness of these filters and is commonly mentioned in building certification systems as an indication of enhanced indoor air quality.

A MERV 13 or above filter is now seen as the gold standard - with local equivalents applicable - the higher the number the greater the removal of small particles from the air. Note that all filters require regular maintenance and upkeep as part of an ongoing healthy building strategy delivered by facilities management.

In contemporary buildings, standard practice is to use mechanical ventilation with a filtration system but natural ventilation and other more advanced strategies can be used to reduce energy use in certain specific locations and with adequate planning by the engineers and architecture team. Simply opening a lot of windows and hoping for the best is not a healthy indoor air strategy!

UV light for enhanced indoor air quality

Anti-bacterial ultraviolet (UV) light systems can be incorporated into an indoor air management plan to reduce the risk of harmful organisms lingering in the indoor air. This system can be used in tandem with other ventilation systems or on its own, and uses UV light to kill airborne pathogens.

Using UV light systems to enhance the indoor air quality is especially relevant in spaces with high occupant densities such as restaurants, in places where occupants are especially vulnerable such as hospitals, or in health clubs and gyms where optimizing the health of members is a priority.

Healthy Building Certification System Benchmarks and Guidelines

There are several guidelines to help determine the ventilation rates for appropriate indoor air quality levels. ASHRAE Standard 62.1 designates “Ventilation for Acceptable Indoor Air Quality” and is used as an industry benchmark as a minimum value, rather than a target to aim for.

As is often the case when it comes to consulting for healthy buildings and healthy indoor environments, we are in fact looking to go beyond the bare minimums to achieve excellence, wherever possible.

In addition to the ASHRAE standard, certification systems such as LEED and WELL include numerous credits denoting indoor air quality and ventilation guidelines.

In the LEED standard, for example, a MERV value of 13 or higher contributes to the “Enhanced Indoor Air Quality Strategies” credit. In the WELL standard ‘Air Filtration credit’, different MERV values are recommended based on the average outdoor air quality levels.

In addition, both the LEED and WELL standards denote the importance of maintaining proper air quality throughout the construction, pre-occupancy and occupancy phases.

Strategies such as a full flush-out (the elimination of indoor air pollutants that were accumulated during the construction phase through the introduction of outdoor air), replacement of air filters pre-occupancy and ongoing indoor air quality testing are all recommended strategies to ensure enduring air quality levels.

The guidelines and recommendations for the LEED standard are present within the Indoor Environmental Quality credit category, while WELL’s reside within the Air concept.

The LEED and WELL standards focus on different things—LEED places emphasis on the environmental impacts of the built environment, while WELL focuses on the human health and wellbeing side of the built environment.

Both standards overlap closely in the arena of indoor air quality, ventilation, and filtration however, reflecting the importance of this aspect for a healthy indoor environment and minimizing a building’s environmental impact.

Indoor Air Quality Monitors as part of a healthy building plan

In many green building certification systems, constant monitoring of indoor air quality is a key strategy. Indoor air quality can range greatly throughout the day depending on factors such as outdoor air quality and interior pollution sources, which can all affect what the optimal ventilation rates should be to maintain healthy conditions.

RESET Air advocates for commercial grade air quality monitors connected to the cloud as a way to monitor and assess indoor air quality factors such as airborne particles, temperature, humidity and CO2. Constant monitoring provides a level of transparency and insight that can in turn help to reduce wasted energy costs, not just make for a healthy indoor environment.

See Kaiterra here https://www.kaiterra.com/en/index/

Indoor Air Quality and Ventilation

Proper ventilation and HVAC filtration systems are important components of a healthy indoor air quality plan however due consideration should also be given to additional factors, such as healthy materials, outdoor air quality, green cleaning policies, entryway systems (walk-off mats) and pest management protocols.

If consistently delivered, suitable ventilation rates and healthy indoor air quality supports occupant wellbeing, promotes concentration and productivity, helps improve attention and memory, and can in reduce the possible spreading of viruses indoors.

A cohesive, joined-up indoor environmental quality plan is required that may well involve some combination of healthy building consultants, architects, interior designers, mechanical engineers and facilities management.

Sources:

Allen, Joseph. “The 9 Foundations of a Healthy Building.” For Health, Harvard T.H. Chan School of Public Health, https://forhealth.org/9_Foundations_of_a_Healthy_Building.February_2017.pdf.

“Upper-Room Ultraviolet Germicidal Irradiation (UVGI).” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 9 Apr. 2021, https://www.cdc.gov/coronavirus/2019-ncov/community/ventilation/uvgi.html.

Ventilation and healthy building design