You can now borrow a CO2 Monitor from the library!

Aranet 4 Carbon Dioxide MonitorVentilation and carbon dioxide (CO2) measurements are two of many precautions that can be taken to protect yourself and your community from airborne infections. Comparing indoor CO2 readings to the baseline outdoors can give us an idea of how well a space is ventilated with fresh air from outdoors.  Learn how to use the monitor


Have you borrowed a monitor? We'd love to hear from you! Please take this short survey to provide us with your feedback. 
Please note: These devices are not carbon monoxide detectors and are not life safety devices. For more information on carbon monoxide alarms, please see the Peterborough Fire Services website.   

Each Kit will include:

  • 1 C02 monitorC02 monitor cases
  • 1 quick start guide
  • a fact sheet prepared by Peterborough Public Health that explains how the carbon dioxide (CO2) monitors work, what the readings mean, and how to improve indoor ventilation or air filtration if CO2 levels are high. 

 Place a hold on a monitor

Loan Periods and Limits


Loan Period



Loans /Card

Replacement Cost

C02 Monitor

7 days





What do I do if the CO2 is high?

  1. Know your risks and make a list of other mitigation factors in place.  For example, if everyone is wearing masks/vaccinated/feeling well we might be more tolerant of a slightly higher reading. 

  2. Look for simple solutions to bring more fresh air into the space. Try opening doors/windows and using fans to promote flow.

  3. Check your HVAC settings to make sure the system doesn’t turn off when the temperature set point is reached. This might involve switching the fan from “auto” to “on”.

  4. Check for other sources of CO2 in your building, vehicle or other closed space.  Other than breathing, combustion (e.g. a gas stove) can also introduce CO2 into a space.

  5. Sometimes a professional engineer or HVAC technician may be able to come help troubleshoot problems that are not an easy fix. 

  6. In cases when it is not possible or practical to further reduce the CO2, you may choose to add additional precautions while in the space (e.g. reducing time spent in the space, wearing masks, or adding a properly sized High Efficiency Particulate Air (HEPA) filter or a homemade Corsi-Rosenthal box).

If you are looking for more information on Indoor Air Quality (IAQ), Health Canada has a comprehensive website on Air quality and health.

Toronto Public Health has pulled together some information and tips on ventilation which you may find useful. 

The CO2 monitoring devices were provided to the Peterborough Public Library for this partnership with Peterborough Public Health by Prescientx and CO2 Check

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