9 Foundations of a Healthy Building: Thermal Comfort Strategy — Biofilico Wellness Interiors
Introduction
The concept of a healthy building has gained significant attention in recent years, as research has shown that the built environment can have a profound impact on human health and well-being. A healthy building is designed to promote the physical and mental health of its occupants, while also minimizing its impact on the environment. In this article, we will explore the foundations of a healthy building and provide guidance on how to create a healthy indoor environment.
What is a Healthy Building?
A healthy building is a structure that is designed and constructed to promote the health and well-being of its occupants. This includes not only the physical health of the occupants but also their mental health and productivity. A healthy building is one that provides a safe, comfortable, and healthy indoor environment, while also minimizing its impact on the environment.
Foundations of a Healthy Building
The foundations of a healthy building are based on scientific research and public health principles. They are designed to be simple and easy to understand, making them accessible to building owners, managers, and occupants. The nine foundations of a healthy building are:
Air Quality and Ventilation
Air quality and ventilation are critical components of a healthy building. Good air quality is essential for a healthy building, as most people spend up to 90% of their time indoors. To achieve good air quality, building owners and managers should opt for building materials, supplies, and furnishings with low chemical emissions. They should also check for legacy pollutants like lead, PCBs, and asbestos during building renovations. Additionally, they should limit vapor intrusion by using a vapor barrier and maintaining humidity levels between 30-60%. Conducting annual air quality tests and responding to occupant concerns can also help ensure good air quality.
Ventilation is also essential for a healthy building. Building owners and managers should meet or exceed local outdoor air ventilation rate guidelines to control indoor sources of odors, chemicals, and carbon dioxide. They should also filter outdoor and recirculated air with a minimum removal efficiency of 75% for all particle size fractions. Avoiding outdoor air intakes at street level or near other outdoor sources of pollutants can also help improve air quality.
Thermal Health and Comfort
Thermal health and comfort are critical components of a healthy building. Building owners and managers should ensure that buildings meet minimum thermal comfort standards for temperature and humidity. They should also provide individual level thermal control, where possible, to allow occupants to adjust temperature and humidity to their liking. Regularly surveying the space and occupants to identify zones that underperform can also help improve thermal comfort. Responding to and evaluating occupant concerns about thermal comfort can also help ensure that the building is comfortable and healthy.
Moisture and Water Quality
Moisture and water quality are critical components of a healthy building. Building owners and managers should conduct regular inspections of roofing, plumbing, ceilings, and HVAC equipment to identify sources of moisture and potential condensation spots. When moisture or mold is found, they should immediately address the moisture source and dry or replace contaminated materials. Identifying and remediating underlying sources of moisture issues can also help prevent mold growth and water damage. Regular moisture inspections can help prevent moisture-related issues.
In addition to moisture control, building owners and managers should also ensure that the building meets the U.S. National Drinking Water Standards at point-of-use. They should test water quality regularly and install water purification systems if necessary. Ensuring residual disinfectant levels are sufficient to control microbes, but not in excess, can also help improve water quality. Preventing water stagnation in pipes can also help prevent bacterial growth.
By following these foundations of a healthy building, building owners and managers can create a healthy indoor environment that promotes the physical and mental health of its occupants, while also minimizing its impact on the environment.
Healthy buildings / thermal comfort / wellness real estate / well building standard
What is thermal comfort in a healthy building?
Heating and cooling tend to account for around half of a building’s energy consumption, making thermal comfort a key consideration for a green building‘s overall energy use. In addition, thermal comfort is considered one of the leading factors in occupant satisfaction within the built environment, making it a vital component of a healthy building strategy too.
Spaces that are perceived as being too humid or warm have been shown to lead to decreased productivity, increased sick building symptoms (such as cognitive impairment and sleepiness) as well as negative mood states (ref: WELL Building Standard). To enhance these environments, it is also crucial to design spaces that minimize background noise, achieving sound levels of 35db and controlling reverberation time. Additionally, controlling outdoor noises such as traffic and construction is important to maintain a conducive indoor environment.
As a result, a comprehensive thermal performance plan which includes strategies such as thermal zoning, individual thermal control, and monitoring thermal characteristics within the building is now firmly part of the green & healthy building consultant’s toolkit.
Thermal Performance in Real Estate
To achieve acceptable thermal comfort within an interior space, healthy building standards such as WELL designate that 80% of occupants must consider a space to be comfortable - a qualitative (subjective) response. As thermal comfort is determined by the level of perceived comfort from building occupants, it is impossible in this case to lay out a plan based specifically on pre-agreed numbers.
Adhering to fire safety and carbon monoxide monitoring standards is also crucial as part of comprehensive safety and security measures in buildings.
The healthy building standards therefore predict what will cause comfort in spaces through a range of environmental factors such as temperature, humidity, outdoor temperature, occupant density and activity, air movement and more. However, even with all these data points in front of us, getting it right for everyone can be challenge, especially in a workplace environment with both men and women sharing the area.
This is due to varying occupant perceptions of comfort, so even more specific zoning strategies by space type / activity for example as well as providing individual thermal comfort control provide opportunities for further refining a thermal comfort plan. When building occupants are comfortable with their thermal environment, productivity increases and levels of fatigue are reduced (WELL).
Thermal Zoning and Minimum Thermal Comfort Standards in a Healthy Building
When considering the thermal characteristics of a space, the type of activity taking place in that interior area matters greatly. For example, a hotel gym where guests are exercising and emitting body heat will need not just higher ventilation rates to remove the CO2 but also a lower temperature.
A study space such as a school library will be very different in that sense, although again there are considerations around optimal temperatures for cognitive performance and concentration. Breaking a building down into a number of such activity zones can help ensure suitable thermal conditions, leading to enhanced occupant satisfaction.
Using high efficiency filter vacuums can also help maintain clean surfaces and reduce dust, which is crucial for enhancing indoor air quality and preventing pest problems.
Temperature can therefore be influenced by a variety of factors such as human activity, building location and orientation, as well as the type of ventilation strategy - be that natural, mechanical or a combination of the two (WELL). When designating different zones, it is important to consider these various factors in order to regulate the thermal properties of each area in advance of building occupants using the space.
Generally, HVAC ventilation systems are responsible for maintaining thermal conditions, and therefore can be used to create different thermal zones within a building, with the level of zoning precision depending on the HVAC set-up. When natural ventilation options are in use, it is operable windows that are used to regulate temperature and thermal comfort.
Towards Individual Level Thermal Control in a Healthy Building
Individual thermal controls can be used to further delineate zones and create smaller, more personalized areas even within rooms. Strategies such as individually accessible thermostats, fans, flexible dress codes, or easily accessible operable windows can all help contribute to giving individuals a sense of control over their thermal experience indoors.
Clean surfaces regularly as part of a broader strategy to limit dust and pest accumulation in buildings. Using high-efficiency filter vacuums and integrating preventative measures can maintain a healthy environment, thereby reducing the potential for exposure to allergens and chemicals.
No one space will please everyone, especially if there is a mix of ages, genders, and so on. It is clear that women tend to be a few degrees colder than men, and tend to be more sensitive to changes in temperatures (Allen), they also are less likely to be in a full trouser suit every day in formal work environments, as men are (in certain industries) no matter what the season.
In addition to individually manageable thermal controls, the provision of outdoor space such as courtyards or rooftops can provide places of respite to allow building occupants to adjust their comfort levels. Access to the outdoors not only provides space to increase thermal comfort, but also can provide other benefits such as biophilia, which improves mental health and can restore focus.
Monitoring & Displaying Thermal Characteristics in a Healthy Building
Sensors that monitor and regulate indoor air temperatures should be placed intentionally to gauge if any unexpected deviations occur. As with other smart building systems, thermal comfort should also be monitored to provide feedback to building managers and inform potential changes.
Generally, the same sensors can be used to regulate various thermal factors such as temperature and humidity, as well as other interior environmental characteristics such as air quality, for example. Regular commissioning and maintenance of building systems is also imperative to promptly respond to any thermal problems that occur (Allen).
When coupled with occupant preferences and surveys, the combination of thermal data and occupant satisfaction can be applied to provide optimal thermal comfort. Building occupants should be surveyed regularly to maintain desired thermal levels and to gauge comfort.
As thermal preferences vary greatly from person to person and are harder to measure numerically, information from post-occupancy surveys is especially important, giving us perceived comfort feedback as well as hard thermal data to work with.
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