Which humidity sensor should I use?

Other Hardware Sensors
1

The project I have working on for the about a year is finding an maintainable alternative to double glazed units.

So what have I come up with?

Simply put, take a conventional single glazed window, add another opening window (similar to secondary glazing) which is sealed to the former and maintain the correct humidity between the “windows” by circulating the air within the cavity through a desiccant. And it works, I've made about 32 windows like this and they work really well.

At the moment I've got the pumps running on a timer. The plan is to insert humidity sensors in the cavity and get an arduino controller to switch the pumps. Basically when the humidity in the cavity reaches a threshold the pump runs for a few minutes. Resample after a few more minutes and pump again or ignore etc. 8 windows in the house (each with 4 panes). Cable run from sensor to controller, up to 10m.

My next job is fix up the humidity sensors....but which one do you think I should use?

Any advice much appreciated

Thanks

Ron

Drawing attached

DG control.jpg
DG control.jpg929×911 52.6 KB

2

You can make use of the honeywell's HumidIconTM Digital Humidity/Temperature Sensors (HIH6130/6131 and HIH6120/6121 Series. It is very small and has high sensitivity. And the arduino library is readily available for you to make use of.

3

Thanks,

I quite look the look of the Honeywell sensors but they are a bit on the expensive side, the DHT22 looks to be a more affordable alternative.

Is there an readily available Arduino library for this sensor?

One thing that I'm not sure about is with the DHT22:

Do I need to include a pull up resistor and bypass capacitor (as in some DHT22 modules)?

If I do then should these components be mounted close to the sensor or can they be sited at the other end of the cable which might be 10m from the sensor?

Cheers

Ron

4

Please not that the DHT are not the most accurate for humidity and might need calibration