Why You Can’t Vent a Kitchen Exhaust Hood Into the Garage
In many homes, the kitchen shares a wall with the garage. When installing a range hood over a cooktop, this can mean that venting the range hood into the garage seems like a viable option. After all, it gets the fumes out of your house, and garages are easy to air out. However, this is actually a dangerous practice. You should never vent a hood into your garage. Keep reading to learn why you can’t vent a kitchen exhaust hood into the garage and the alternative options that are safe for you.
The main reason you can’t vent your kitchen exhaust hood into your garage is that you create a fire hazard by doing so. When you vent your cooking grease into your garage, you fill your garage with flammable vapors and particles. If you turn a car on or pull a running car into this space, then you risk combustion. The vapors and particles in the air and the gas fumes leaving your vehicle can ignite.
You may think that if you don’t use your garage to store a vehicle, then it’s fine to vent your kitchen exhaust hood into the garage. However, even an automatic garage door opener can spark a fire under the right conditions. And when it comes time to sell your home, you’ll have to share this unsafe feature with potential buyers, limiting who you’ll be able to sell to.
Even if you’re not concerned about fire hazards and potential future buyers, building codes in some areas don’t allow anything to penetrate garage walls. This includes vent and ductwork. Check your area’s building codes before puncturing your garage walls for any additions.
Safe Alternative 1: Through the Wall
If possible, arrange your kitchen so that the cooktop and accompanying vent are on an outer facing wall. By having it on an outside wall, you can easily arrange the vent to deposit the dirty air outside, guaranteeing that it doesn’t get anywhere else in your house. This will help your entire home stay cooler and feel and smell better. It’ll also make it easier to install a gas line if you’re adding gas appliances to your home for the first time.
Safe Alternative 2: Through the Garage
Even if you can’t rearrange your kitchen and the cooktop and exhaust hood have to share a wall with the garage, you can still safely route your vent. Instead of leaving the vent to deposit air in the garage, keep it going. Extend the vent and accompanying ductwork through the garage. Then have it go up through the roof or a wall so that it can release your kitchen fumes outside. Seal the vent and ductwork with drywall or a similar material for extra safety.
Safe Alternative 3: Go Up
Instead of finding a horizontal path for your kitchen fumes through various walls, you should consider going up. Vertical venting is best for your home because hot air naturally rises, so going up instead of out is a great way to keep dangerous fumes out of your garage and help them naturally escape. However, this doesn’t mean that your vent can just end anywhere on the upper floors of your home.
It’s unhealthy for smoke and air contaminants to build up in an enclosed space, even if it’s not your garage. That means your venting can’t stop in an unfinished upstairs room or attic, even if you rarely use these areas. The fumes can soak into anything you have in those places, such as cardboard storage boxes and old furniture, making them stink. They can even permeate walls and dirty the air in the rest of your home, defeating the purpose of venting them away from your kitchen in the first place.
Through the Roof
Avoid these problems by venting your exhaust hood all the way up and through your roof. The hot air from your kitchen will continually rise until it’s free, so arranging it to escape through your roof and not just sit in an upstairs room is the safest way to allow it to do that.
Make It Last
Now that you know how to safely route your kitchen air out of your home, you need to choose ductwork that will last as long as your kitchen exhaust hood. Most range hoods can last up to 10 years and even longer if you keep up with their maintenance. Therefore, you’ll want the accompanying ductwork to last the same amount of time or even longer.
Galvanized steel is the best option for long-lasting ductwork, although other types of metal HVAC systems also have long lifespans. These long lifespans are due to the metal’s rigidness, making it durable and guaranteeing less air resistance. Flexible plastic ductwork creates more air resistance because it bends. That bending also makes it less durable. Avoid flexible plastic ductwork throughout your home, especially when building a system for your kitchen exhaust.
Another way to make your ductwork last and create less air resistance is to use two or fewer elbows in your ductwork. Elbows are the curved joints between straight sections of ductwork that guide the air around curves and corners. While one or two elbows may be necessary depending on your home’s structure and where you’re trying to emit the exhaust, you should aim to use no more than two to cut down air resistance. You want the air to easily find its way out of your home so that your range hood doesn’t have to use extra energy to push it out.
A good rule of thumb to achieve this is to use one elbow per every 18 inches of straight ductwork. If you’re venting horizontally through a nearby wall, this ratio may not be realistic due to your home’s structure. But if you’re creating the shortest unobstructed path for your air, then it should work. Keeping 24 inches of straight ductwork between elbows is even more ideal. If possible, aim for this to allow better airflow.
Now you know why you can’t vent a kitchen exhaust hood into the garage, and you have three safe alternatives to try instead. Remember to choose metal ductwork and use as few elbows as possible in that ductwork so that it lasts as long as your range hood. If you’re looking for kitchen range hoods for sale, ROBAM offers various options that will complete your space and keep your kitchen air clean and cool. Contact us with any questions about this important piece of equipment.