by Jacob Deva Racusin
Editors note – The first installment of this series was in TLS Issue #66, which covers the reasons why we should monitor our buildings and the types of monitoring systems available. In this installment Jacob guides us in our choice of a monitoring system.
What System Do I Need?
There is a large range in cost, convenience, and logistics with each of these systems. The best way to select the right system for you is to first understand what you need to monitor, and then understand what parameters govern your system. Some questions and considerations for any monitoring system are(though some of these are more relevant to DIY than off-the-shelf):
– What are you monitoring and where, and how many sensors do you need? Do you want to deploy a combined temp/RH sensor, or individual temp and RH sensors, or just one or the other?
– What is the operating environment in which your sensors are located, and what is the data range your sensors need to provide? This is a big one – if you need to get readings from really cold ambient temperatures all the way up to really warm temperatures, sensors go up in cost (same with RH – it gets more expensive to find sensors that give accurate readings at higher RH). If you go with off-the-shelf systems you need to look at the spec’s and ensure the sensors will read within the environmental parameters you are seeking to evaluate. Otherwise, your data will not be fully representative of the conditions you are analyzing (your RH sensor may cap out at 30% even though the conditions are actually 70%). Accuracy is another important feature (that also affects cost). Many sensors drop off in accuracy as you get to the far ends of their range. If you are doing research-quality testing, or even looking for data of sufficient quality to present to a code official, or at a conference, accuracy becomes all the more important than just for curiosity’s sake or QC. This is a crucial consideration.