Wireless Temperature & Humidity Data Logger For Mold Prevention

by | Oct 17, 2023 | Blog, Wireless Data Logger

Mold is naturally everywhere, all the time. Spores are floating around and sitting on surfaces constantly waiting for the right temperature and humidity conditions to sprout and grow. If you find mold and clean it off and disinfect the area, this does not mean that it won’t come back if your environmental conditions are conducive to mold growth. More spores will settle and grow again.

Here’s a scary example.

Say you have a closed store room about 33 x 33 feet with a 10ft ceiling (10x10x3m) at 70 °F (21°C) and currently at 60% RH, which is a perfectly acceptable RH for most collections. Imagine your HVAC goes down for some reason and there is a small leak in there, just a small one that spills half a gallon of water (2 liters).

Without overcomplicating the calculation with air pressure and air exchange, you could be looking at a spike up to 86% RH. Add to this little incident the fact that at 80-90% RH, mold growth is noticeable between one and five days (Technical Bulletin 26, Canadian Conservation Institute).

Say you only have manual data loggers in there and don’t walk every day. Worst case scenario for this minor incident? You will have some serious mold and associated health risks in one to five days. By the next time you walk in there, you might regret walking in there.

This is why maintaining appropriate climate conditions is so fundamental in collection care, and this is where real-time monitoring can be a game-changer in your preservation efforts.

Understanding the risks: mold and your collection

Mold, a type of fungus, grows best in warm, damp, and humid conditions – although as you well know from cleaning out the fridge, it will also grow in cold conditions. When it takes hold, it can cause irrevocable damage to a wide range of materials including paper, textiles, and organic artifacts. Mold can eat away at organic materials and stain or darken both organic and inorganic objects. See some photos of mold damage on the AIC’s conservation wiki here.

Not only will mold affect your objects, it can also completely disrupt your operations. In the case of libraries, for example, moldy books may have to be thrown out and replaced at great expense and disruption to both staff and patrons. An in-depth disinfection of the building and furniture will not only be costly but protracted. The Canada Science and Technology Museum had to close for at least 6 months between 2014-2015 and have its staff redeployed to other facilities due to the discovery of mold in its walls. Mold infestations will also affect the respiratory health of anyone in the vicinity and vulnerable individuals may develop serious infections from exposure.

In the case of extensive mold problems, chances are you will not be able to solve the problem yourself and contractors will have to be brought in to deal with mold abatement. You may have to move all your collections for this, so on top of the mold problem, you now have a collections move on your hand.

And let’s not forget your reputation and peace of mind. Everyone in your immediate professional circle will find out about your mold issues. This does not mean you should be ashamed. Many of your colleagues have had to deal with mold problems that arose after mechanical system failures, structural building issues with humidity or natural disasters. It is a relatively commonplace event. However, as a well-trained collections care professional with years of experience under your belt, an uncontrolled mold outbreak that could have been prevented can still make you feel a bit worse for wear. If it does happen, remember that you’re not alone. Reach out to your colleagues on the various support groups and communities to ask for advice, supplier information or even volunteers.

Advantages of a wireless temperature and humidity data loggers

A temperature and humidity data logger is an essential tool in any collection care professional’s arsenal. This device measures and records environmental parameters over time, providing valuable data that can guide your preservation strategies.

However, not all temperature and humidity data loggers are wireless, and out of those that can be called wireless, not all are necessarily uploading data in real time. By monitoring conditions in real-time, you can quickly identify any problematic changes and take immediate action. This proactive approach minimizes the risk of mold growth, ensuring your collection’s longevity.

Wireless data loggers with real-time upload capabilities offer the additional benefit of remote monitoring. You can access the data from any location, allowing for constant vigilance over your collection’s environment. You can also set up real-time alerts according to the needs of your collections and their sensibility to incorrect relative humidity or temperature. These will let you know immediately when any of your set parameters are exceeded.

It is also possible to share this environmental data information with several users in your institution, including operations and facilities personnel, who might be able to detect malfunctions in the mechanical ventilation systems even before they cause a problem.

Having wireless data loggers reporting in real-time will be more efficient for your staff and can be an effective tool to help you manage your environmental conditions and prevent costly disasters.



Integrating Data Loggers in Your Mold Prevention Strategy

Integrating a temperature and humidity data logger in your mold prevention strategy is a straightforward process. Here are some important things to keep in mind:

  • Position the devices in key locations throughout your storage and display areas.
  • Regularly review the data, paying close attention to any sudden changes or consistent trends outside your target range.
  • Set up alerts to make sure your software will let you know if anything is going amiss. Make sure everyone who should know about alerts gets them set up on their mobile devices or emails.
  • Make sure all the relevant people in your staff have an account that can access the data.
  • Whenever you have an event, make sure you note an observation associated with the temperature or humidity spikes in the graphed data. (Conserv Cloud allows you to do this easily.)
  • Think about previous locations in your spaces that have caused you to worry before. Consider windows and doors or areas close to pipes, vents or any other potential sources for leaks and pockets of humidity. Is the outside affecting your inside spaces? Look at plant growth or areas of pooling water in your gardens if these spots touch external walls that double up as internal walls for areas with collections.

By taking into account the above suggestions, you’re not just reacting to mold growth, but proactively preventing it. This forward-thinking approach will be crucial in maintaining the integrity of your collection.

Choosing the Right Temperature and Humidity Data Logger

With a range of data loggers available, choosing the right one is crucial. Consider factors such as the size of your space, the nature of your collection, and your available resources.

The Northeast Document Conservation Center (NEDCC) suggests looking for data loggers that offer high accuracy, large data storage capacity, long battery life, and user-friendly software. These features ensure you get reliable data, which is crucial in making informed decisions about your collections care. The NEDCC article has been updated in 2022.

Don’t miss this excellent Conserve O Gram from September 2011 which compares specific models and brands of temperature and humidity data loggers for museum monitoring. Note that the information is from 2011, so prices and specifications will have changed.


A wireless temperature and humidity data logger is an indispensable tool for collections care professionals in the 21st century. Long gone are the days of the paper drum thermohygrograph, and USB data loggers are also slowly on their way out. The ability of wireless data loggers to provide real-time, accurate environmental data allows for proactive management of risky conditions that can lead to mold growth. By integrating this wireless technology into your mold prevention strategy, you’re taking a significant step towards preserving your collection for future generations.

If you have any questions about environmental monitoring, integrated pest management, or just want to talk about preventative conservation, please reach out to us! Don’t forget to check out our blog or join our community of collections care professionals where you can discuss hot topics, connect with other conservators or even take a course to get familiar with the Conserv platform.

Recent posts