Humidity monitoring in family houses

11-01-2019

Background
In Sweden it is common to use elevated foundations (the foundation walls are standing directly on the ground) when building one family homes. In these constructions you often get to high humidity in the space below the house and inside the foundation walls.

The humidity comes both from the ground and during the warm season also the outside air. If the humidity rises above 75%RH there is a risk for condensation and in the end growth of mold and fungus which can destroy the building and make people sick.

Solution
In this house we blocked all ventilation openings in foundation walls and installed a dehumidifier with a piping system that distribute the dry air inside the foundation.
The dehumidifier was supplied with a simple hydrostat with a hysteresis of about 10% RH which made it run for too long and drying the air more than necessary with higher energy costs as a result.
Also it didn’t provide the customer with any information about whether or not it was functioning properly.
To solve this issue we have installed a COMET System H3531 temperature and humidity controller with Ethernet interface, internal webserver and alarm functions to control the dehumidifier and send alarms via e-mail if the humidity gets too high.
Since there was no Ethernet connection beneath the house the controller is connected to the network in the building via Devolo DLAN modules that make it possible to get an Ethernet connection through the power lines.
Apart from the alarm function via e-mail the internal webserver makes it possible to check the status via internet from any computer, tablet or smartphone over the internet.
The customer got a more energy efficient solution but more importantly he got peace of mind. He didn’t have to worry about his family getting sick or their house being damaged by mold or fungus. If the humidity rises above the set limit he will get an alarm and will have time to take action.