While many houses have a over the range hood venting system to remove fumes from the stove when it’s in use, you might not be aware of another option for kitchen venting, namely the downdraft vent. Increasingly popular in North America, it’s already well-established in Europe where many older homes don’t have venting and newer homes aren’t being built with vents.
Rather than the vent being above the stove to remove cooking fumes with gravity and suction from the fan, a downdraft ventilation system is built into the cooktop and sucks air down as it exits your pots.
Is downdraft ventilation any good? Do you even need such a system in place in your kitchen? And where exactly does the cooking fumes go to if not through a vent and out of the house?
So many questions and we have the answers below!
Why do you need ventilation in your kitchen?
Stoves and cooktops can produce significant dirty air. Grease, smoke and steam are commonly produced while cooking, more so when you make greasy or fried food.
At a minimum, local building codes usually require an entry level fan in the kitchen to remove cooking air so chances are your home is going to have some air filtration option above your stove already.
It’s increasingly known that the fumes and particulates found in cooking air can be hazardous to our health so it’s important to properly filter it out while cooking. Small bits of solid waste along with tiny liquid droplets can be breathed in if not filtered out during cooking which can lead to health problems.
In fact, particulate matter is considered to be carcinogenic (cancer-causing) by the World Health Organization.
While the standard option in North America is an over the range (stove) hood fan to remove cooking air and fumes, a newer option called downdraft ventilation exists.
How does downdraft ventilation work?
Downdraft vents can be built in the center of a stove cooktop as an integrated unit. When the fan is turned on, it sucks air in so when you are cooking and producing steam and fumes, the suction pulls the air down into the filtration system.
Another option is to add a pop up downdraft vent that raises up when it’s in use and sucks air at a 90 degree angle to the stove top. The vent then pushes down flush with the stovetop when not in use.
Depending on your model, the air may run through a charcoal filter to remove fumes and then a washable stainless steel filter to clean the air. This two-step system ensures both cooking debris and fumes are filtered out.
Typically, the filtered air is returned at the bottom of the cabinetry or kitchen island through small vents near the ground.
How well do downdraft vents work to remove cooking steam?
Downdraft vents always have a disadvantage when compared to range hood vents: While hood range vents have the suction of the fan plus gravity pulling the fumes upwards, downdraft venting is fighting against gravity and has to forcibly suck air down to remove it.
Range is just another word for a stove. So the range hood is the cover that is installed over the range/stove and houses the air vent and usually a light as well.
In my experience with a downdraft vent, they do work but you may need to operate them at a high speed to compensate for the design. The fan gets quite loud at the higher speeds but it does work to remove cooking fumes from the air.
The fan works better without a breeze behind it as I found out one summer when I had the kitchen window open during a slightly windy day. While cooking with the downdraft fan on, the air coming in from the window blew the steam in the opposite direction making it harder for the fan to operate successfully.
How well do downdraft vents work to remove cooking smells?
So a fan might remove steam from the pots you’re cooking with but what about strong fumes that often emanate? Some foods are stronger than others in terms of the fumes that are emitted such as when you’re frying foods or cooking something greasy.
In this regard, what sort of filtration system does a downdraft venting system have?
Regarding the fan’s ability to remove the smell of cooking, quality downdraft fans generally come with a two-phase filtration system:
1. A washable and reusable stainless steel filter to trap cooking debris such as grease. It’s helpful when this part of the filter can be popped into a dishwasher to clean it as needed.
2. A removable and replaceable charcoal filter system to remove cooking fumes. Active charcoal is often used to absorb fumes and as such is a common aspect of a downdraft ventilation system.
Typically, the filtration system easily pulls up and out of the cooktop so that the mediums can be washed or replaced as needed.
If you tend to cook fume-heavy foods or fry frequently, your downdraft vent’s filtration system should be something you check closely before purchasing.
Also, modern automated cooktops with downdraft venting often come with a feature that alerts you when the replaceable charcoal filters need replacement.
Why would I buy a downdraft ventilation system instead of a regular range hood?
The main reasons for buying a downdraft ventilation system instead of an over the range hood fan include the following:
No venting in your home – If you have no ventilation currently in your home, a non-vented system is the way to go if you want to avoid the time and cost associated with having the work done.
And if you don’t necessarily want a downdraft venting system, you can choose a non-vented range hood that looks similar to a typical over the range model but works without a vent as they are increasingly available too.
Aesthetics – Some range hoods don’t look great and visually can appear cheap looking. When they get greasy and dirty they look worse and can be hard to scrub clean. They may not be the same color as your stove or cabinets and therefore stand out. A built-in downdraft vent system is flush with the cooktop and is very inconspicuous.
Space – A range hood takes up space. Granted, if you have the space already built in your kitchen and venting is in place, you’d have an empty spot in your cabinetry if you decided to take out your existing range hood fan and replace it with a downdraft vent option. But if you don’t have venting in place already, a built-in downdraft vent in a new cooktop takes up little space especially if you build it into a kitchen island.
In that regard, one of the best times to install a downdraft vent in an existing home is when remodeling a kitchen as you can design it as needed and choose whichever option you require.
Downdraft kitchen ventilation vs hood range ventilation
If you have a hood range ventilation system in place you might just choose to replace it with a similar model. But if you have no ventilation system in place – perhaps you have an older house with no venting or simply want a more compact vent with no ducts used – a downdraft ventilation product might be of interest.
Here’s how the two types compare:
| Downdraft kitchen ventilation | Range hood ventilation | |
| Best use | In kitchen islands and peninsulas and when you have an existing kitchen with no kitchen venting. Also in newly built kitchens when you can redesign it as needed. Existing kitchens may require expensive redesign or retrofitting of cabinets to allow the exhaust hoses underneath. | When you already have venting in your kitchen and are replacing an existing hood range. |
| How it works | The vent is built into the top of a cooktop. Air is sucked downwards to filter it before it is returned to the home through vents in the bottom of kitchen cabinetry. So the downdraft vent works against gravity and pulls the cooking air downwards. | As cooking fumes rise through gravity, the fan sucks them in through a filter and removes the air from the home through an external vent leading outside the home. |
| Effectiveness | A good quality system with both a replaceable charcoal filter and reusable steel filter can effectively remove and filter cooking fumes. | The level of quality ranges from cheap entry level range hoods to more expensive ones that perform better. Typically range hoods have removable and washable metal filters that need to be replaced eventually. |
| Cost | Downdraft ventilation systems are sold as integrated cooktops that include multiple cooking surfaces. A decent-quality cooktop with downdraft venting included can cost $2000 and up. Telescopic downdraft venting systems that pop up to use are also available in conjunction with various cooktop brands. Price for the venting system alone can cost $900 and up. | Basic units cost about $130 and higher end models go for up to $500 with many price points in between. |
| Considerations | Charcoal filters do need to be replaced and the reusable metal filters need to be washed. More so when you cook greasy food or foods with strong fumes. | While metal filters can be washed, they tend to be flimsy and will need to be replaced over time. Fans often only come with a low and high setting. |
| Other | The downdraft fan needs to be run at a high speed to work properly especially when significant fumes or steam are being emitted from foods. | Range hoods tend to get very greasy and dirty over time, particularly the filter and the lighting area since all cooking fumes rise and cover the range hood regardless of whether the fan is running or not. |
Where does the air go with a downdraft vent?
A downdraft venting system is typically set up to return filtered air back within the kitchen area usually out of 1-2 vents located near the floor. This is usually at the bottom of cabinetry or a kitchen island if that’s where the system is located.
So when the cooking air is sucked into the vent system when it’s turned on, it is first pulled through the filtration system. Once the air is cleaned it is then returned through a hose(s) that runs underneath the cabinetry, and out through the vent.
Even if you turn the fan on without actually cooking, it’ll still pull clean air from your kitchen out through the vent so when you are cooking and actively producing cooking fumes, the returned air will be a combination of both filtered cooking air and regular air from your kitchen that was pulled into the vent system.
Summary
A downdraft venting system for a cooktop is an alternative to a standard over the range hood fan that most homeowners have. A downdraft vent is a good option when you don’t have existing ventilation in place.
It’s also good when you redesign an existing kitchen and can start from scratch and design the fitting and placement of the downdraft system to ensure if fits.
Downdraft ventilation systems are often found in kitchen islands and peninsulas due to how they can be fitted in properly including the necessary exhaust hoses and vents. Again, this is also a great choice when you build a new kitchen island and don’t have venting already built into your ceiling to access.