Desiccant dehumidifier and CO

[Grampus]

We have always cruised with a desiccant dehumidifier to keep the boat dry and usually have it running over night. Helps dry any towels or steam from the breadmaker etc. We also have CO monitors in the cabins.

Last week we were awoken by the alarming scream of one detector, closely followed by the second.

Taking both detectors outside allowed them to switch off but they immediately began to sound alarms upon re-entering the saloon where the dehumidifier was operating.

It turns out that it was the dehumidifier that was the source of the high levels of CO.

Now binned, we'll replace it with another but if you carry one and use it while onboard, then CO monitors would seem a good idea.

 

[Vanilla]

How weird! I thought something had to "burn" in order to produce CO?

 

[Grampus]

In all the desiccant dehumidifiers there is a substantial heating element that 'dries' out the desiccant wheel which is why the things blow out warm air.

I have had a coulpe of these things expire and they always begin to fail by smelling like they are overheating.

New ones don't trigger the CO alarms but clearly there is significant CO produced by the failing heater element to be of concern.

 

[asteven221]

Wow that's a bit scary! I have never heard of that problem. We have one that failed on us but it just failed! No bad smells or anything sinister - at least we didn't die of CO poisoning AFAIK.

We leave ours on when we're in bed during the winter months. Maybe won't bother now. In fact we'll move it out to the saloon where we have a CO detector.

Thanks for the warning.