Range Hood Vent Question

[scfr]

On aptitude tests, I always score lowest on questions that have to do with mechanical things, so I could use some help here.

Over our gas range, we have a microwave with the range hood vent on the bottom of the microwave.

The hood vent has 2 types of filters: standard grease filters, plus charcoal air filters. There are 2 of each filter type.


I understand the importance of keeping the grease filters clean, to prevent fires. I wipe them off each time I clean and run them through the dishwasher a couple times a year, which seems to be plenty.

My question is, do the charcoal air filters serve any useful purpose? The air that is sucked in to the vent goes outside, right? Why would we need to filter air that is going outside?

If replacing them periodically would improve the quality of air in my house, or reduce cooking odors, I'd be happy to do it and would spend the money. But really, how can they do that if the air is just going outside? It's not like the air is recirculated back inside the house.

Wouldn't I just be throwing my money away on those filters? They're not cheap ($13 each).

Am I missing something?

[Seeker]

Charcoal filters absorb impurities.

If your charcoal filter does not do its job, if it is saturated and cannot absorb, then the impurties will not get filtered out and will also probably not all go up into the air. In other words, there will be odor feedback

You should replace the filters at the recommended times or when you begin to notice that the odors linger in spite of using the fan/vent.

[snafu]

Charcoal filters are imperative if your range hood is not directly connected to an out-door vent. Builders will often use one range hood model on all units whether they filter out doors or not. They work well to filter air impurities and odours. Replacement is dependent on how much frying is being done. Are your metal mesh 'grease' filters sticky when you wipe them? The sellers recommend changing the filter every 3 months but you need to use your own judgement.

[Joan.of.the.Arch]

Scfr, it seems like you should be able to remove the charcoal filters and not replace them if you do have a vent to the outside. But perhaps they remove the last little bit of aerosolized grease that might build up in the vent and be a fire hazard or just would be a source of smell.

My kitchen unfortunately is not vented outside and I clean my grease filter with a grease solvent, but it sure could stand to be replaced. Sadly, I had no idea I might even be able to get a replacement until reading this thread! And if I can also fit in a charcoal filter (there is not one now), then hooray!. Thanks, yall. I'll have to look into this.

[scfr]

The vent goes directly outside. I am 100% certain.

While I still feel I'm essentially filtering outdoors air for the benefit of our neighbors, for now I'll go ahead and spring $26 for new charcoal filters every year or two. The manufacturer recommends every 6 months but I feel that is excessive.

Joan.of.the.Arch: Yes, you can buy replacement grease filters! They come in a multitude of sizes, as you will find when you do an internet search. Since your range doesn't vent outside, definitely look in to charcoal filters if they will fit. Regarding cleaning the grease filters, do you have a dishwasher? I find that throwing my grease filters in the dishwasher every few months is a great way to help keep them clean (and may be less toxic than grease solvent).

[disneysteve]

Another thing to think about. When filters get clogged, it reduces the air flow through the filter and can strain the motor. Even though the point of the charcoal filter is odor reduction, it still ends up sucking up grease just because it is there and the grease is in the air that flows through it. So if you don't periodically replace the filters, you could end up burning out the fan motor. That will cost you a lot more than keeping the filters clean.

[scfr]

Another thing to think about. When filters get clogged, it reduces the air flow through the filter and can strain the motor. Even though the point of the charcoal filter is odor reduction, it still ends up sucking up grease just because it is there and the grease is in the air that flows through it. So if you don't periodically replace the filters, you could end up burning out the fan motor. That will cost you a lot more than keeping the filters clean.

But they don't look, feel, or smell in the least bit greasy tho they've been in use for over 1-1/2 years. And this is the first range I've had that even had charcoal filters.

Oh well, new filters have been ordered. Maybe I'm throwing money away but I guess it's better to be safe than sorry.
Thanks for all the feedback everyone.