It’s fun to write about cutting-edge technology, but sometimes it’s worthwhile to take a closer look at the basics. Like mildew-prevention.
The easiest way to prevent mildew is to keep things dry, and the easiest way to keep things dry is to keep the interior of the boat a few degrees warmer than the outside air. Warmer air holds more moisture, so a little interior heat can prevent atmospheric moisture from condensing on surfaces in the cabin.
Any source of (dry) heat will work, but some heat sources are better suited for use aboard an unattended boat.
You’ve probably seen these devices at your local chandlery. You might have considered them, seen the price tag, and said “No way! I can buy a nice little ceramic heater for less than that! It’ll keep my boat dry while I’m away, and keep it warm when I’m there.”
OK, maybe you didn’t say that. But I did, and it seemed pretty sensible at the time.
They’ve had lots of fires on Lake Union over the years. And my new landlord tells me that virtually all of the fires in recent decades were caused by electric heaters aboard boats.
The biggest problem is that these heaters, when operating properly, cycle on and off. Each time the unit cycles there is the possibility of a spark. A tiny spark, to be sure, but if combustible gasoline or propane vapor has collected inside the boat, that tiny spark can ignite it.
A fire aboard a boat is always a bad thing. But when you’re tied up alongside $1m+ houseboats where people live, the stakes are higher. It’s a boat owner’s responsibility to ensure that fuel is stored properly and to eliminate potential ignition sources.
The Davis dehumidifier consists of simple heating coils mounted in an enclosure designed to allow air to flow through it. The coils heat up air within the unit, which rises through convection, without the need for a fan, pulling in colder air through the bottom of the unit.
The exterior never gets too hot to touch, and the unit never cycles on and off. It runs constantly, so there are no sparks. It doesn’t make the cabin comfortable, but it does keep it a few degrees warmer than the outside air, which is enough to keep the boat dry.