How Healthy Is the Indoor Air Quality in Your Home Office?

Recently, I acquired an AirAssure™ Indoor Air Quality Monitor and installed it in my home office.  I’ve always been interested in air pollution and weather, but primarily outdoor.  I’m a bit of a data junkie, so I figured I would learn about my indoor space. 

Home Office Set-Up

For most of the past year, I’ve been in what was my college-age kid’s upstairs bedroom.  It has a nice south-facing window and I installed a standing desk and dual monitors for my laptop.  It is a pretty nice setup, but the room has only a single air-conditioning vent under my desk.  I didn’t give any thought to my indoor air quality until a colleague and I were reviewing data from my AirAssure™ monitor TSI Link, and it was pointed out that my CO2 levels were “very high.” 

Tracking More Than PM2.5 Levels

With recent wildfires in northern Minnesota, I had been mostly paying attention to the high PM2.5 levels.  But, when I looked back at the history data, the CO2 levels were well over 1000 ppm, and sometimes− when I had been in the room all day− higher than 1500, and occasionally peaks over 2000 ppm. 

Carbon Dioxide Levels

For reference, here is a guide on how to interpret your CO2 levels:

• 250 – 350 ppm + background (normal) outdoor air level
• 350- 1,000 ppm – typical level found in occupied spaces with good air exchange.
• 1,000 – 2,000 ppm – level associated with complaints of drowsiness and poor air.
• 2,000 – 5,000 ppm – level associated with headaches, sleepiness, and stagnant, stale, stuffy air. Poor concentration, loss of attention, increased heart rate and slight nausea may also be present.
• >5,000 ppm – Exposure may lead to serious oxygen deprivation symptoms

Figure 1.  CO2 levels high with windows closed on left and lower with windows open on right

Making the Connection Between High CO2 Levels and My Symptoms

Other references to air quality and sick building syndrome were also eye-opening.  Of course, I started thinking back to how drowsy I’ve been feeling and perhaps that headache I had a few days ago was related to my indoor air quality. 

Steps to Improving IAQ

The easy and recommended first solution, of course, is to open windows and let in fresh air. However, living in Minnesota, there are only certain seasons where that is practical.  During this particular period in time it was warm out, however, we were in a long string of days with serious outdoor air quality alerts due to forest fires in the north and in Canada. 

Running my air conditioning in “fan mode” didn’t really help much either.  I discovered that the intake for my air system was plugged with a lot of cottonwood tree seed fluff, and I cleaned it out.  After that, the CO2 levels got marginally better, but still not good.  So, now I’m in the market for a home HVAC upgrade including a fresh air heat exchanger to allow for more fresh air with minimal energy loss. 

For now, I’m able to open my windows, but that won’t last long.  My AirAssure™ IAQ monitor was a great source of useful information and I look forward to improved results with my new HVAC system.  I’ll let you know if the drowsiness gets better.

To learn more about the AirAssure™ IAQ monitor, visit tsi.com/AirAssure.

Written by: Rob Caldow, Director of Engineering at TSI Incorporated.