Microwave Venting, or lack thereof

One would think that something as simple as a microwave vent wouldn't be that difficult to figure out. After all, they are installed on all sorts of motorhomes from Class A coaches to 5th wheel trailers, not to mention almost every house built in the modern world. It's about as basic an install as you can get. So just how this builder could fail so completely is beyond us.

Why re-Invent the Wheel

First off, instead of just buying a regular RV roof top vent cap, these guys feel they have to re-invent the wheel. They go and get a couple of screw down mushroom style air vents that are made for a boat cabin and install them instead. Sure, they are made of stainless steel, but they are meant to be installed on a boat deck where they can be easily screwed down tight to seal out water infiltration when the boat gets underway. The problem with putting them on the roof of a truck, 12 feet off the ground, is that the only way they can be screwed down for sealing, is by climbing up on the roof. Not exactly easy to do, and frankly, pretty idiotic.

Of course if you decide not to climb on the roof, and just travel with the vent caps open, you'll have problems when you run into a rainstorm. The nature of rain drops relative to vehicle motion when travelling at speed is essentially horizontal, and this easily pushes them into the vent cap opening. Which, of course, explains why we had water on our counter every time we travelled in the rain. Genius.

To fix this, we had to replace these boat deck vent caps with a proper one meant to work at any speed, and be open all the time. But of course, because they had already cut into the roof to put the boating vents in, a regular RV vent cap would not fit in their place. So we had to manufacture a special solution to interface with what they had already installed.

This was done using a piece of 3" x 6" aluminum rectangular tubing. By closing off the forward end, and creating a flapper gate at the back, we made a nice clean roof top enclosure that was always open, but never leaks.

It Doesn't End tHere

As if the roof top insanity wasn't enough, the shop workers managed to find another way to screw up the job. In the most common of installations, even ones in a house kitchen, there's often a storage cupboard above a microwave or hood fan when it's mounted over a cooktop. Ducting from the microwave exhaust fan travels up through the cabinet and out through the roof, and it's what we thought we had as well.

In our case, a nicely made wood enclosure was created to hide the ducting. But when we were trying to get the wiring installed for the ceiling LED strip lighting, we had problems getting the wire past what was inside the wood enclosure. So we had to remove the enclosure to feed the wires though. When the cover came off, we couldn't believe what we saw. Well, it's really what we didn't see that flabbergasted us. There was no ducting at all. Not even an attempt to install any.

Every single time we used the microwave hood fan while cooking, all the fumes, moisture and airborne grease from the stove was being blown straight into the cabinet woodwork, and forced all through the wiring chase that runs around the perimeter of the cabin, in the top of the storage cabinets. Over time this would produce mould, start to rot the woodwork, and provide a real fire hazard. This situation goes way beyond incompetence. It now has it's foot firmly planted in the realm of negligence. When we informed the builder and sent them some photos, we never got a reply back. Just how much incompetence can the owners of this company accept?

Once again, we have to take the time to properly finish the work that they didn't do, and for which we paid a handsome sum. The really sad thing here is that putting in the proper metal ducting is not a difficult job at all. The components needed to do the job are all available at the local building supply store for about $20.00, and it took less than an hour to complete.