Exhaust fan for convection microwave.

[guy99]

Hello,
When we had our kitchen wall replaced we discarded the original underpowered convection microwave and replaced it with a microwave only unit. We'd like to have oven capability (think fresh bread) so I purchased a small convection microwave.

I know they can radiate a good bit of heat and I have been thinking about how to deal with that. I'd like to vent it somehow. It will be installed adjacent to the refrigerator so I could access the refrigerator vent. Is there a safe way to do this? Maybe with a flapper in the vent and a fan that runs when the oven is on?

I'd love some ideas/suggestions.

TIA

Guy

[olddog299]

If it were me, I'd simply set my mini-convection oven on top of the stove and use the exhaust hood vent fan to remove most of the heat and steam generated. If you were going to use the convection oven daily then doing up a separate vent system is worthwhile, but for occasional use? Not worth it, IMNSHO.

Most convection microwaves I am familiar with already have an internal fan and an external vent on the rear to relieve pressure and vent steam. Perhaps you could cobble together a snorkel for the unit using sheet metal for the collector box and stainless steel marine exhaust tubing into the refrigerator vent. If the outlet of the collector were fitted with a 110 volt duct fan and wired to a switch controlled duplex outlet serving as the supply for the convection oven then you'd have a set-up pretty much as you wished. The duct fan should be available from Grainger's or similar industrial supply. The biggest problem I have is the expense. Better to have purchased a unit designed for exterior venting right from the get go than to go to the trouble and expense of reinventing the wheel , so to speak.

[guy99]

Wil,
Thanks for the suggestion. My main concern with the approach you outline is if I need a valve to preclude the possibility of refrigerator combustion gas getting into the cabinet and then the living space?

Regarding the purchase of a unit designed for external venting, the space available is very restricted, it is 22" wide, 12" tall, and 15" to 20" deep because of the curve of the MH.

I was not able to find a unit that would fit in this space which was intended to be built in and connected to a vent.

Regarding you suggestion to place the unit on the stove when in use, I don't think that would work for us. It's not unusual for us to use the stove and microwave while preparing a meal. My wife wouldn't be able to lift the unit in and out of the compartment it would be stored in (they're heavier than a microwave), and she wouldn't like having to ask me to move it for her whenever she wanted to use it (or the stove).

Your idea of plugging a fan into a switched outlet will be easy since the microwave outlet is already switched (The rig has an Air Conditioner/Microwave switch).

[olddog299]

Makes sense - look for a used, working bathroom vent fan for a source of parts. They are usually the smallest sized vent hose. Good luck!

[guy99]

I bought a small bathroom exhaust fan with an integral flapper valve and ducted it to the refrigerator duct:





Then installed the convection microwave



and adjacent cabinet doors



The exhaust fan and convection microwave are plugged into an outlet which is controlled by an AC/Microwave switch. When this switch is in the 'AC' position the outlet is dead, when it is in the 'Microwave' position the exhaust fan runs and there is power to the microwave.

[olddog299]

Looking good!