Anatomy of Kitchen Range Hoods

Kitchen Range Hoods are a critical component in maintaining the indoor air quality of our homes. The kitchen is one of the leading sources of contaminates in our homes and utilizing a range hood decreases these contaminates and makes our homes healthier to live in. So how do kitchen range hoods work?

Having an understanding of how range hoods work and what they are providing is an important component to making sure they are utilized correctly. Range hoods have a two-function purpose. The first is to provide protection to the cabinets above the cooking area. Almost all cabinets are made out of wood so to protect them if there is a flare up on the cooktop is important. Over the years range hoods have greatly advanced to more than just basic protection. They have become part of an indoor air quality solution. The basic principle of kitchen range hood is to take the “bad” air being generated during the cooking process and move it (exhaust it) out or filter it.

There are two types of methods a range hood uses to better the indoor air quality. The first is to utilize an odor filter and recirculate the air back into the room. This type of range hood does not require ducting. While this will provide some improvement to the indoor air quality of the kitchen, they really are not very effective as the filters used only catch a small percentage of the contaminates you really want to remove from the living space. This type falls into the “better than nothing” category. A much better way is to have the air exhaust to the outside. These hoods still have some type of grease filter that prevents grease from building up on the hood’s motor/blower as well as in the ducting. The big benefit is all of the contaminates the hood captures will be exhausted to the outdoors and away from the living area. 

Most kitchen range hoods also have some type of lighting feature to them. These might be LED, incandescent or even halogen. When looking for a range hood, take note of the light both from an efficiency standpoint as well as the location. Generally a hood with the light at the front will provide better overall coverage of the cooking surface.

The next part of the range hoods is the duct collar for hoods that are being exhausted to the outdoors. Hoods that are recirculating the air back into the kitchen typically have an exhaust vent build into the hood itself. Hoods that are exhausting to the outdoors will have some type of duct collar either built into the hood or one that attaches to the hood. Common sizes for these collars are 3.25” x 10” or round. Round duct collars range from 5” to 10” and larger. Many of the duct collars are going to also incorporate a backdraft damper that prevents or at least lessens the amount of air coming back into the home through the ducting. A quick note – if you feel drafts coming from your range hood, you might want to upgrade your backdraft damper. Air travels through the ducting from the range hood to either a wall cap or a roof cap. While these components are not necessarily part of the fan, they are integral components that are required. Wall and roof caps vary in function, features and costs. Two common features are bird screens that prevent birds from building nests in the ducting (yes, it does happen and it is more common than you think) and backdraft dampers. Backdraft dampers on the wall or roof cap provide an extra layer in addition to the one on the range hood to prevent backdrafts.

These are the main components of kitchen range hoods. In addition some fans will have extra features like continuous operation, thermostats that turn the unit on or off and more. For more information of the range hoods available through Air King visit airkinglimited.com

You’re looking to buy a new home. You take a tour and see the bedrooms, the type of flooring and so on. Now you turn the corner into the kitchen and before you even notice the cabinets, flooring and colors you are looking to see if it is a gas or electric cooktop. For some it is gas or nothing. For others electric is fine and now for a handful of people it has to be induction. While this might not be a deal breaker, buyers definitely have strong opinions on the type of cooktop in the home. The type of cooktop can also have a direct effect on the indoor air quality of the home. Matching the ventilation and cooktop is an important consideration. Let's take a look at each of these.

Gas Cooktops
Gas cooktops utilize natural gas or propane to power the burners. An open flame provides almost instant heat allowing pots and pans to heat up very quickly. For this reason it is the preferred method for cooks and chefs. While the cooking benefits are good, it produces a lot more contaminates than electric or induction cooking. If you stop and think about it – you are starting a fire, all be it a controlled one, in the middle of the kitchen. That is going to produce all kinds of contaminates and in large quantities. To properly ventilate the area, you need a more powerful range hood, probably something in the 300 to 600 CFM (cubic feet per minute) range and one that vents to the outside. With the hood removing that much air, you might need to consider how to make that air up depending on how tight the home is (you can read more about tight homes here). In some cities like San Francisco, Seattle, Denver, New York and more, they have either banned gas appliances or there is legislation to do so in the coming years. If this becomes a nation-wide movement the need for more powerful range hoods might be decreased.

Electric Cooktops
Electric cooktops are more common and utilize an element that heats up when current is passed through it. That in turn heats the pot or pan. Electric cooktops are generally less expensive than gas and are easier to install, especially if there isn’t already a gas line to the house. The negative to electric cooktops is the time it takes to heat a pan or especially boil water. For a large pot you might need to start on Monday so it is boiling by Wednesday – okay that might be an exaggeration but you get the point. While electric cooktops still produce contaminates during the cooking process, it is at a reduced rate when compared to gas cooking. Therefore a less powerful range hood can be used, something in the 150 to 300 CFM range. Even with the lower CFM it is still highly recommended that it be exhausted to the outdoors. Unfortunately a hood that the air passes through a filter and then recirculates back into the kitchen is not effective and the indoor air quality of the home will suffer.

Induction Cooktops
This is a new technology that is quickly gaining steam (yes – pun intended). Electric induction cooking utilizes magnets to heat the pot or pan so the cooking surface stays relatively cool. There are some real technical things going on with terms that you need to look up in a dictionary, so for our purposes we will just go with it heats the pan and not the surface. Because it is heating the pan directly, it is the most efficient way to cook as almost all the energy is going directly to the cooking process. With gas and standard electric cooktops, a lot of the energy is lost in the heat transfer. The challenge with using induction cooking is your pots and pans must be magnetic otherwise they won’t work and since this is a newer technology, the price of induction cooktops is still very high. From a ventilation standpoint, they are very similar to standard electric cooktops. Because there is not a lot of wasted energy causing contaminates so a lower CFM range hood can be used. The other benefit is with electric and especially gas cooktops, the residual heat and contaminates being generated can last a lot long than with an induction cooktop.

Summary
In looking at all these technologies, it is important that your kitchen is properly ventilated. How much ventilation depends on the type of cooktop you have as well as how you utilize it. Matching the ventilation and cooktop is an important step as a gas cooktop is going to require a higher CFM range hood while an electric or induction cooktop will require less. Your style of cooking will also factor in. If you are cooking for 20 people every night using all the burners your ventilation needs will be different than someone who is just cooking for themselves.

For more information about matching your ventilation and cooktop as well as Air King range hoods visit the Range Hood section of the Air King website.

Ventus – A Ventilation Story

When the typical person hears the word ventilation it can call to mind different pictures. For most it probably is thought of as a fairly new technology routed somewhere in the mind 1900’s. The fact that you are reading this blog probably means ventilation means exhaust fans and range hoods. You would not be wrong, but we are going to go a little deeper and look back through the ages at ventilation.

Let's start with the word “ventilation”. It comes from the Latin word ventilatio which has its root in the word ventus, meaning wind. In the ventilation field we use terms such as exhaust and air movement which at its root is wind (moving air).

Next, we’ll trace back to the origins of ventilation devices. It might come as a surprise that it can be traced back to thousands of years BC. As humans began to bring fire into the houses/structures they built to either heat them or cook with, it quickly became evident that they had to get rid of the smoke created. The first form of ventilation was a chimney. Archeologists have found examples throughout the years of chimneys being used. The earliest is probably in China approximately 4000 BC. Other significant finds include Roman homes that had a hole in the roof to direct smoke. Thousands of years later we are still using this same technology. A little updated to the times, but in essences the same basic principle.

Another milestone in the history of ventilation was in the 17th century. King Charles I of England recognized that poor ventilation was causing health problems and he decreed that the ceilings in homes must be at least 10 feet high and that windows must be higher than they are wide to allow for ventilation.

Skipping ahead a few hundred years and we come to the 1920’s/1930’s where modern ventilation was created. While chimneys were okay, they were not as effective as they needed to be. The solution was to add a motor to the chimney and force the smoke up and out of the home. This was the first range hood. With most homes now having indoor bathrooms and especially showers, the need for ventilation increased even more and the same technology was now being used in the bathrooms to exhaust steam and odors.

From that first range hood in the early 1900’s we have seen a lot of advancements in the ventilation field. Technology has allowed exhaust fans and range hoods to become more energy efficient, quieter and more effective. Recently even more emphasis has been placed on indoor air quality. Ventilation is a key component of good indoor quality and the more we continue to learn, the more we are finding that a properly ventilated home is a much healthier home. I guess King Charles I did know what he was talking about hundreds of year ago.

To learn more about indoor air quality or ventilation fans browse through the Air King blog or visit www.airkinglimited.com.

Is the Code Enough? Part 2

In our last post we highlighted codes around exhaust fan performance. In this post, we are going to look at kitchen ventilation, specifically range hoods. The codes pertaining to kitchen ventilation have a bit more “gray” area then with bathroom exhaust and in some areas a range hood might not even be required. We’ll start there. This is where you will definitely want to exceed the code. We have spent a good amount of time in previous posts detailing the benefits of a range hood, so going without one in our opinion is just not an option. One reason that could be given for not requiring a range hood is because of other exhaust in a kitchen. While having an exhaust fan anywhere in the kitchen is better than nothing, unless the fan is located right at the source of contamination, it just won’t be effective. Think about this, if the exhaust fan is in the center of the kitchen and you are cooking, where are the contaminates going? Yep, you are standing in the direct line of airflow that has all the contaminates in it.

Another popular code states that you need at least 100 CFM (Cubic Feet per Minute) of airflow. At least now you are exhausting air, so that is getting us closer to where we want to be. Unfortunately, 100 CFM is not a lot of power for over a cooking surface. A lot will be determined by your cooking habits. If you are just warming up some soup or using one burner to cook some eggs – 100 CFM might be fine. If you have two or three burners going, you will need more power. There is also a considerable jump in needed airflow from using a gas cooktop from electric. Just the nature of gas burning is going to produce more harmful contaminates that need to be exhausted.

Some people at this point might jump to the conclusion that to be safe, I am going to get the most powerful range hood on the market and suck every last bit of air out of the kitchen. While this would solve the issue of any contaminates staying in the air, it also has some negative effects. There is a balance between exhausting enough air and exhausting too much air. In some states if you go beyond a certain CFM level you need to introduce make-up air. Simply put, you need to replace the amount of air you are taking out of the home with fresh outdoor air. You will hear it called air balancing. The CFM level that cannot be exceeded is usually in the 300 CFM to 500 CFM range.

Here is the good part. Most range hoods have two or more speeds so you get at least two chances at getting the CFM right. Think about how you cook, what size cooktop you have, does it have anything like a griddle or grill top? Then you can make a better determination on what kind of power you need. Look to match your “everyday” cooking habits with a lower speed then have those higher speeds for times when you need it. As always, we suggest consulting with a professional who knows the codes in your area before making any decisions.

Building codes are in place to ensure safety and health and we are very thankful that we have men and women working very hard to keep up with them and pushing the industry forward. The next time you hear the phrase “meets code” just stop and think  - is meeting the code all I really want to do? For more information about Air King range hoods visit www.airkinglimited.com.

Room-By-Room Home Audit - Part 2, The Kitchen

We are continuing our series on making your home more efficient and comfortable. Last time we went through items in the bathroom. Now we are moving to the kitchen.

The kitchen is full of opportunities to save energy with the appliances making up the largest source of energy usage. Here are a few ways to improve:

Refrigerator: If it is time to replace your refrigerator, look for an ENERGY STAR certified one. These can save a considerable amount of energy/money, even up to $75 per year. Also make sure to recycle your old fridge. If replacing your fridge is not in the cards right now there are steps you can take to improve your current one.

1. Keep your coils clean. Vacuum them regularly and make sure there is a gap between the back of the fridge and the wall to lessen the build-up of dust and debris on the coils.
2. Minimize the number of times you open the doors. Also minimize the amount of time the kids sit there with the door open staring blankly into the fridge looking for who knows what.
3. Keep the fridge full – sounds odd, but a full fridge retains cold better than an empty one.

Range: With a range, it is more about organizing your usage.

1. Use the appropriate size burner for your need.
2. When baking, minimize the number of times you open the door. Each time you open it, a considerable amount of heat is lost.
3. Organize your task to minimize the energy usage. If you have multiple things to bake in a day, do them all at once while the oven is already pre-heated.
4. Don’t have items on the cook top longer then they need to be. Things like boiling water – once it is to temperature make sure to get the items you are cooking in right away instead of wasting energy.

Dishwasher: As with the fridge, if it is time to replace, look for an ENERGY STAR certified one. ENERGY STAR certified dishwashers can reduce the amount of water you use by almost 4,000 gallons over the lifetime of the dishwasher. Other ways to optimize the dishwasher are:

1. Only run the dishwasher when it is full. Sort of goes without saying but we are going to go ahead and say it.
2. Keep the dishwasher’s jets clean. Clogged jets will reduce the effectiveness and cause the need to re-wash items.
3. Use the cycle that you need. If a shorter cycle is all you need, use it.

Range Hood: Yes, we know many people don’t think about the range hood in the kitchen but we are a ventilation company so we think about it everyday! As with other appliances, if it is time to replace, look for an ENERGY STAR certified hood. Here are a few other ways to improve the efficiency of your hood:

1. Keep it clean. Regularly clean the grease filters of the hood. Dirty and clogged filters will reduce the efficiency of the hood.
2. If it has a light, replace the bulb with a LED.
3. Use It! Many people are tempted to not use the range hood – mostly due to the sound level (by the way there are really quiet ones now). This is a huge mistake. When cooking, the kitchen is full of contaminates that are just not good for you. If you are not ventilating them out of the home, that means you are breathing them in.

In addition to the above items also read our last post regarding the lighting and windows, as these can also be places to improve your efficiency and comfort.

Don’t miss our next post when we will take a look at the mechanical room.

To learn more about ways to make your home more efficient, saving money and energy, visit www.airkinglimited.com

Is the Air Inside Your Home Safe to Breath? Part 1 – The Kitchen

According to the American Lung Association, approximately 85% of Americans don’t realize the air in the home can be hazardous. In some cases it can be up to 5 times more polluted than outdoor air. That’s a bit concerning. The question is, what makes the air so bad? In this two part series we’ll take a look at the biggest culprits inside our homes.

The Kitchen. The kitchen can be the largest area of contaminates inside the home. Anytime you are cooking, there will be a source of particulates going into the air. This can be smoke, grease, carcinogens and so forth. This is just part of cooking. The way to combat these contaminates is with a properly functioning range hood. The key is the proper functioning part.

Vented to the outdoors: First and foremost, the range hood has to vent to the outside. There are many range hoods on the market that pass the contaminated air through a filter then recirculate the air back into the kitchen. While these are somewhat better than nothing, they just are not going to provide the level of air filtration that is needed.

Turn it on: The range hood has to be turned on. Yes we know, they can be loud and cause the pets to run and hide but there are now many solutions on the market that operate at a fraction of the sound of older range hoods. Air King has a complete line of range hoods that provide proper ventilation at quiet sound levels.

Power: The hood needs to be powerful enough for the cooking you are doing. If the hood can’t keep up with contaminates coming off the surface that means they are going into the air you are breathing.

Keep it running: The hood should run for an extended period of time once the cooking is completed. Typically there are still a lot of residual particles and contaminates that are still in the air even when you finish cooking. The goal is to get every last bit out of the home and away from the air you are breathing.

There has been a lot of research as well as building codes being implemented concerning Indoor Air Quality (IAQ). More and more studies are pointing to the kitchen as being the most important location to properly ventilate. One of the building codes now calls for an exhaust fan to be running continuously inside the home to make sure the air is being exchanged. Air King has developed products to place that continuously operating exhaust fan in the kitchen. The ECV, ECQ and LE series all have a barely audible low speed that runs continuously then have additional speeds when more ventilation is needed – like when you are actively cooking. The science behind this product is that if the kitchen is the biggest contaminate of the home, why not place the primary source of ventilation there? This takes care of any particulate matter during cooking as well as any residual particulates after cooking. It just makes sense to fight it at the source and prevent any infiltration into the rest of the home.

To learn more about Indoor Air Quality and how you can properly ventilate your home, visit www.airkinglimited.com.

Over The Range Microwaves, Are They a Good Option?

Oh that rectangular masterpiece of modern convenience that has made its way into almost every kitchen across the United States – the microwave. Microwaves have become a kitchen staple and for many people, they couldn’t live without them. Now available in almost any color under the sun, with more features than a new car, how could you possibly not have one?

A popular location for the microwave is over the cooktop or range. They even have a nifty acronym for them – OTR (over the range). While on the surface it might sound like a good idea, lets take a little closer look. The number one reason people place the microwave over the range is to save space. There is no denying it, by placing the microwave there, you do not take up counter space, but at what cost?

By placing the microwave over the range, you need to have a unit capable of ventilating the area. The issue with microwaves is they are designed to be a microwave first with the ventilation system added onto them. The kitchen is one, if not the largest source of air contamination in the home. If not properly ventilated, the indoor air quality of your home will be compromised. A range hood is deigned to do one thing and do that one thing extremely well – ventilate. Often times the microwave is installed to re-circulate the air through a charcoal filter. If you ask anyone who deals with indoor air quality, they will tell you that this is not an acceptable way to “ventilate” the kitchen. In some locations across the United States it is against the building code to install a recirculating unit – it must vent to the outside (this includes recirculating microwaves as well as recirculating range hoods).

The perception of OTR microwaves is that they are more convenient from a space savings perspective, but are they? Consider the installed high of the unit. The top of the range is typically 36” (3 feet), the unit is installed 24” to 30” above the range. That brings the bottom of the microwave to a height of a minimum of 5”. That means that for most people, they will be reaching up to get items out of the oven. For anyone under 5.5 feet, they will probably need a step stool to get items in and out. This can provide a convenience and safety issue. Think about children trying to reach up to get something hot out of the oven or do you really want a cup of hot tea being pulled out of the oven and held over your head?

Back to the effectiveness of the ventilation, another issue with OTR microwaves is the depth of the ovens. Typically they are about 15” deep. This allows them to basically match up to the front of the cabinets or just stick out a little bit. While this might be nice from a visually pleasing standpoint, it decreases the capture area of the hood. Most cooktops are 24” deep, so with an OTR microwave there is typically about a 9” difference is depth. Range hoods are typically 18” to 24” deep allowing them to capture considerably more contaminants coming off the cooking surface.

As with any larger purchase in the home, especially one that will be installed, there is always a need to weigh the pros and cons and make the best decision for your particular need. To learn more about Air King’s range hoods and indoor air quality solutions, visit www.airkinglimited.com.

Make the kitchen the ventilation center of the home - Continuous operation Range Hoods

The kitchen is many times considered the heart of the home. It also provides an excellent ventilation opportunity. New codes have gone into effect across the country (known as ASHRAE 62.2) that require a centralized exhaust fan providing continuous ventilation. 

Builders have a few options for how to solve for this. Many are installing a separate exhaust fan in the main living areas. They are typically very quiet and can barely be heard when running. This is a good solution as it meets the requirements and is usually not even noticed by the occupants of the home. The negative is that it is an additional item that needs to be installed and maintained within the home.

A second option is a dual speed fan installed in the bathroom. This is the “two birds with one stone” theory. These fans have a very quiet low speed that runs continuously to meet the requirements of ASHRAE 62.2 but also have a high speed – sometimes called boost speed that kicks in when the room is in use. They can be controlled by humidity sensors, motion sensors or just by a standard switch. While these work, the challenge is that typically bathrooms are not located in a “central location”. Basically the minute you shut the bathroom door, you have cut off the airflow from the rest of the home. The purpose of ASHRAE 62.2 is to provide air exchanges within your home, brining fresh air in and exhausting stale air out.

There is another solution however – a multiple speed range hood. Much like the two speed exhaust fan, these range hoods have an almost silent continuous speed that meets the ASHRAE 62.2 requirements. When the range is in use, the hood can be turned to an appropriate speed to provide the additional ventilation needed during cooking. As with two speed exhaust fans, using a range hood has the two for one benefit, there is no need to install a separate fan. The added benefit of using a range hood is that in many homes the kitchen is located in a centralized location or at least in a location that is not cut off from the rest of the home.

Air King was one of the first companies to offer a true ASHRAE 62.2 range hood solution and has multiple sizes, colors and shapes to choose from. To learn more about range hood solutions from Air King visit www.airkinglimited.com