10 Common WELL Performance Testing Oversights

Dina Farone

Sep 9

6 min read

How to avoid retesting and get it right the first time

In this article, I break down some of the most commonly missed details when testing a WELL project, even for the most experienced Performance Testing Agents (PTAs). And while some of these items may seem like no-brainers, with a busy testing schedule and multiple pieces of equipment to juggle, certain details may end up being overlooked. This article will help strengthen your on-site checklist and help avoid another trip back to the site.

1. PM device inlet is blocked

As a common name in air testing, many PTAs use the Aeroqual devices or similar to test for Particulate Matter (PM_2.5 and PM₁₀). These sensor heads typically come with a small white cap which covers the intake opening shown in the image below. During my experience as a WELL certification reviewer, I would often notice this tiny cap in the equipment setup photos, thus determining that the cap was left on during the testing period. As an added measure, ensure that the intake is kept unobstructed during your readings.

Aeroqual PM head inlet — Source: aeroqual.com

2. High-VOC objects placed near equipment

Of course your goal is to take an accurate sampling of the air quality of each space, but certain items or materials near your testing setup can cause artificially inflated results. Sneaky objects like markers or even new backpacks placed near your sorbent tubes can elevate results creating an environment not reflective of the average VOC levels of the space.

That being said, if your devices are placed appropriately but the VOC results are still not meeting the WELL thresholds, items like new carpet or paint may just need time to off-gas and a retest in the future may solve the issue. And while it is acceptable to test before construction is complete, it is important to discuss with your project team that the newly-installed materials and added dust may cause a failed test and subsequent retest.

3. Sorbent tube is facing the wrong direction

While it may seem negligible, it is easy to overlook that the VOC and Formaldehyde testing tubes have an airflow direction. When placing the sorbent tubes relative to your pump, ensure that the air is being drawn into the tubes appropriately. In the images below, you’ll see that typical sorbent tubes have an arrow instructing on their placement. Ensure that this arrow is facing, or pointed towards the pump. If your glass tubes do not have an arrow, typically, the sorbent material should be facing the pump.

Sorbent tube and arrow - Markes — Source: markes.com

Formaldehyde tube, air testing - SKC Inc — Source: skcinc.com

4. Testing more than the required quantity of analytes

Performance testing is mandatory for preconditions in the Water concept. However, W02.2: Meet Thresholds for Organics and Pesticides allows either a performance test or a technical document as verification. Many project teams elect to have this part tested on-site since samples are already being collected for W01.1 and W02.1. But many teams miss one crucial detail that can lead to retesting.

For W02.2 Option 2, the WELL standard requires that “Testing must be conducted at drinking water dispensers for at least two of the pesticides [and at least three of the organic contaminants] from the list below. All contaminants in the list below that are reported by the lab must comply with the following thresholds.”

The last sentence there is crucial as this is conveying that if you choose to test more than two pesticides and/or three organic contaminants, all analytes must meet the WELL thresholds. For example, if your lab reports results for four organic contaminants and one contaminant is not passing, the non-passing result cannot be omitted. This part will therefore be shown as NOT MET in the Project Information and Performance Template (PIP), and retesting will be required.

5. Submitting lab-tested Turbidity and/or Chlorine results

While many labs can analyze the water samples for turbidity and chlorine, the WELL Standard requires that these two parameters be tested on-site with appropriate equipment. As noted in the first table of the Water section of the Performance Verification Guidebook (PVGB), these parameters must be tested with a “direct-read” method. Ensure that your device is calibrated and capable of performing these tests according to the PVGB.

6. Not converting lab results to the appropriate unit

Before uploading your final submittal package to WELL Online, all data must be reviewed for compliance, and only passing data may be submitted. Of course oversights happen, but carefully reviewing your lab reports for non-passing results is essential. And often, this requires converting the results to align with the WELL thresholds.

For example, a lab analyzing water samples may report Benzene as 5 µg/L (micrograms per liter) while the WELL threshold is 0.01 mg/L (milligrams per liter). Be sure not to report “5” as the result and instead report 0.005 mg/L to show that the result is below the WELL threshold and the units align. This can be easily missed when a lab report uses mg/L for some results and µg/L for others.

7. Misinterpreting the L02.1 sampling point locations

Since the 2024 updates to the PVGB, there's been a bit of a learning curve when it comes to interpreting the L02.1: Provide Visual Acuity requirements. Before, a grid may be placed across an entire floor plan. Now, grids are to be placed room by room, and testing points are to be taken at grid intersections. This requirement may seem simple enough, but understanding where to place each sample point on the grid may be more challenging.

The PVGB states “Once a task has been selected for measurement, do not select that same task for additional measurements unless each unique task has been sampled at least once.” This line is often misinterpreted as “Take at least one sample per unique task”. However, this is not how it is intended to be read. Instead, consider the requirement to say “Do not sample a second room of the same task before selecting a secondary task to test”.

The simplest way I like to approach this part is by selecting tasks that cover large spaces, such as open offices. This way, since you only have to test two unique tasks, you may only need to test in two spaces. So in a typical office project, you would lay one grid across the open office and get as many samples as you can in this area, and then choose a second space that encompasses another task to hopefully reach your sampling quantity in only two rooms. Understandably, many projects are made up of several smaller spaces, but I still encourage finding the largest spaces first and working backwards to reduce the number of rooms in which you need to test.

Note that for Option 2: Predetermined Light Levels, even though the tasks (or in this case, Room Types) are grouped in a table, they are meant to be read as individual tasks.

8. Incorrect placement of the lighting device for L03.1

This one is a simple fix and a simple addition to any on-site checklist. When sampling for L03.1: Circadian Lighting Design, ensure that the device aperture is placed to simulate the workstation user’s eye, i.e., facing the computer screen. As shown on the device below, the aperture is the white dome found at the top of most spectrometers.

Spectrometer and aperture - Sekonic — Source: sekonic.com

9. Assuming the metabolic rate and clothing value for T01.1

T01.1 Option 1: Performance Verified Environmental Conditions requires a performance test that uses certain inputs from the project team’s Technical Document. The Technical Document is necessary to the overall PMV calculation as it includes the assumed metabolic rate (MET) and clothing values (clo) for each space. These values are stagnant and must be used in your PMV calculations. Often, PTAs will assign their own assumed values based on the conditions observed on site. This can result in a review comment and request for a retest. Always ensure that the PMV calculations use the values shown in the Technical Document as your reviewer will be referencing this when looking over the data.

10. Assuming the acoustic zones for S03.2

Similarly to T01.1, S03.2: Achieve Sound Isolation at Walls has a companion document that is reviewed under S01.1: Label Acoustic Zones. This document asks the team to differentiate between various acoustic zones and is your guide to ensuring that the correct locations are tested. Usually, this document is nicely annotated with color-coding to help visually separate each space. Even though it may seem logical to assign a gym, for example, as a loud zone, ensure that acoustic zones are not assumed based on observations while on-site.