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How to provide healthy environments & meet climate goals

Three key lessons for making buildings energy- and carbon-efficient and healthy
Friday, September 3, 2021
By Dan Diehl

Just when facility owners thought COVID-19 was coming under control and they could allow broad re-entry of tenants and occupants, the Delta variant arrived on the scene. More than twice as contagious as previous variants, Delta has refocused building owners and occupants on the importance of healthy indoor air quality, especially ventilation rates. At the same time, the U.S. and other leading industrial countries are setting aggressive carbon-reduction goals that push building owners to cut back on energy-intensive systems such as ventilation.

These two goals — providing enough fresh air to ensure a healthy indoor environment for occupants and reducing energy use on the path to carbon neutrality — can seem conflicting. After all, improving performance on one side of the equation can very easily hurt results on the other.

But the equation can balance out, as long as you know the right technologies to invest in and how to manage those investments.

Labs have the answer

Labs — along with vivariums and other “critical environments” — have stringent air quality requirements because of the potential health and safety risks posed by airborne contaminants. Historically, those requirements were met by providing very high volumes of 100-per-cent outside air at all times. That made labs among the most energy-intensive spaces to operate. The Smart Labs Program, for example, has shown that innovative technology can make labs more energy- and carbon-efficient while increasing human health and safety.

Three key lessons are all we need to make dramatic improvements on both fronts in all commercial buildings.

Owners should heed the following derived from the Smart Labs Program:

  • We cannot control what we do not accurately measure
  • Healthy buildings require fresh clean air and active ventilation management
  • We must avoid the “healthy vs. sustainable trap”

Lesson 1: It always starts with accurate measurement

Accurate measurement is the foundation of healthy and sustainable labs, starting with air quality.  Previously, labs were designed with extremely high, continuous flow rates — 10-12 “Air Changes per Hour” — to ensure health and safety. Very expensive to operate — often five to seven times as energy-intensive as similar-sized non-lab facilities — labs also emerged as major sources of greenhouse gas emissions.

What’s more, the end result was only perceived safety. In actuality, no one could prove with any certainty that the air was clean because it wasn’t being measured. This told facility owners that they needed to control and ensure air quality in labs. They asked: can we ensure that harmful chemicals and high particulate levels aren’t present in the space and can this be done more efficiently and sustainably?

The solution was to shift from a fixed, pre-determined air change rate to a dynamically controlled air change rate based on conditions in the space. This approach required very accurate, reliable air quality measurement. That was achieved with an innovative system architecture that allows a single set of industrial quality sensors to measure the air quality in multiple lab spaces at a low life cycle cost.

RELATED: Scientists find lack of focus on air quality

Lesson 2: Effective ventilation — controlling the amount of healthy air based on accurate measurement

Demand Control Ventilation (DCV) is often misunderstood, even by people in the HVAC industry who equate DCV with across-the-board reductions in air flow.

In fact, the highly flexible DCV approach can provide the right amount of healthy air where and when needed. It allows for lower ventilation rates when the air is clean, as well as meeting science-based standards. Of course, spaces sometimes need increased ventilation — and in those cases, DCV automatically adjusts to bring in more fresh air when parameters such as CO2 particles or TVOCs are out of range.

The health of indoor environments is generally determined by five parameters — small particles, carbon monoxide and dioxide, relative humidity, and total volatile organic gases — and DCV helps maintain optimal levels for each in the most efficient, sustainable manner.

Lesson 3: Avoid the “healthy vs. sustainable trap”

Ventilation can be costly both in energy expense and in carbon emissions. At the same time, building owners must increase ventilation rates in work and educational spaces because of clean air’s health and cognitive impacts.

This brings us back to the seemingly conflicting nature of the two key imperatives faced by building owners — increasing both health and sustainability. Must they be traded off in a zero-sum game? Under the old design criteria of fixed ventilation rates, the answer was yes, because they conflicted in the “healthy vs. sustainable trap.” In this sub-optimal cycle, building owners would periodically over-ventilate when prioritizing health, and then under-ventilate when sustainability became more pressing. It’s now understood that fixed ventilation rates exaggerate this conflict, and that DCV resolves the healthy vs. sustainable trap with accurate sensing and control of science-based healthy air parameters.

These lessons learned from critical environments can be applied to other types of buildings, including classrooms and commercial offices. It is true that historically, non-lab facilities would not achieve the same level of efficiency gains by adding DCV systems, due to their use of return air systems (versus 100-per-cent outside air) and lower initial fixed ventilation rates. But occupancy rates will not return to pre-COVID-19 levels for many facilities, and/or they will vary more dramatically going forward.

RELATED: COVID-19 and HVAC systems

In addition, the emerging consensus is to use higher ventilation rates in all buildings. This certainly means that, left unchanged or unmanaged, there is a huge potential to significantly over-ventilate — wasting money and needlessly impairing sustainability goals. The future of healthy and sustainable buildings depends on optimizing — even improving — both of these seemingly conflicting requirements.

The path forward to healthy, sustainable buildings

The path forward must apply the lessons learned from 20 years of experience in labs to all commercial and institutional buildings. Indeed, we believe that the COVID-19 pandemic has made everyone aware that all buildings where people work or learn are critical environments.

The next step is to apply the three big lessons learned to all of those spaces.

Dan Diehl is CEO and President of Aircuity.

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