How many CFMs do you need for your cubic feet?

Many thanks to the gang at Faber Hoods for this very helpful guide on the technical side of kitchen ventilation.  True kitchen ventilation (rather than the cheap and usually ineffective method of hanging a vented microwave over your cooking surface) is an idea that's catching on again. All ventilation uses a measure called Cubic Feet per Minute to indicate how effective the blower motor in a ventilation system is at circulating air. Few topics can confuse people as quickly as CFM ratings. There is a mistaken belief, that like most everything else in appliances, bigger is better. Not necessarily.

Using a hood with higher CFM (above what you need for your cooking surface) means more air is being pulled out of your kitchen and your home than needed. Therefore a lot of cooled or heated air is being pulled out your home, which would lead to higher heating and cooling bills.

Also, a situation of negative pressure can also occur when too much air is being pulled out of the home and isn't being replaced by air from the outside. Homes built today are increasingly air tight and when too much air is pulled out of a home, you need to sometimes make up for that lost air by pumping outside air into the home. There are all kinds of rules of thumb regarding make up air and it's best to consult with an HVAC specialist before you install a high-powered ventilation system in a newer home.

When you're choosing a hood for your cooking surface, one that has too many CFMs won't be energy efficient and too few CFMs won't provide adequate ventilation. The more CFMs, the more energy they use and the more noise they make. The key is to buy the right hood for the job at hand. Somewhere there's an ideal CFM count to match your needs.

So buy a hood that can remove the heat, steam, odor, smoke and grease produced by your cooking properly while at the same time not overdoing it. This diagram below shows a good way to estimate how many CFMs you need for your kitchen. In this kitchen, the ceilings are ten feet tall (Z). The walls are 10 feet (X) by ten feet (Y). So Z x X x Y = 1,000 cubic feet. If you have a 500 CFM rangehood in this kitchen, in 2 minutes you will have completely exchanged all the air out of the kitchen (or 30 exchanges in an hour). The National Kitchen and Bath Association recommends 8 to 15 air exchanges in an hour for proper ventilation, so in this example, we're at double the recommended level. Rules of thumb like this can get you started but the amount of heat generated by some cooking appliances throws a wrench into the works. Heat is measured in British Thermal Units, or BTUs. There are additional calculations that need to be worked out when it comes to using professional-style ranges so be sure to consult with a professional kitchen designer before you commit to buying anything.

So even though the example above has us at twice the recommended CFM, using a four-burner gas cooktop will put you 100 CFMs under the required 600 CFMs for use over gas. If you're upgrading to something more substantial, a 48" range top for example, you're going to need at least 1,000 CFM. In the opposite direction, because induction cooktops generate so little radiant heat, a 300 CFM ventilation hood over it would work out perfectly. Confused? Don't be.

Calculating the volume of your room is helpful and knowing the heat output of your cooking surface is helpful too. Combining the two and coming up with a satisfactory CFM takes a bit of judgement and experience, but that's why I'm here. Me and a whole bunch of compatriots who like nothing better than to figure stuff like this out.

Sears' Blue Crew, the latest update

Who knew, when I wrote this post on 10 October, that it would take on a life of its own? Last Tuesday I reported that I'd heard from Sears and that we were going to arrange a conference call between a bunch of Sears folks and a panel of designers I'd assemble.

Well by last Thursday, I had a panel of 12 people lined up and ready to help build something positive in partnership with the online team from Sears. The 12 people on the panel for what's come to be known as the Spec Summit are a cross section of the industry. We represent the face of kitchen design today and we range from an architect who designs some of the most exquisite rooms I've ever seen to a designer who designs stunning in their own way, lower-budget jobs. Most of us make up the space between those extremes. Some of us are new to the industry, but most of us have been around for a while. Another wild thing is that all of us know one another either personally or by reputation and we know one another through social media. Whether it's Twitter or our blogs or Facebook or some combination of all of those things and none of this would have been possible until very recently. It's pretty neat to be involved in this project. But more than anything, my real excitement about this is that everybody's volunteering to help make something positive.

So as a result of a blog post I wrote about my frustration over some missing dimensions, a group of 12 professionals are helping to solve the problem of missing dimensions. This is now bigger than me and my frustrations, that's for sure. It's satisfying to know that in helping out like this, we'll be playing a role in preventing other designers' frustrations in the future while at the same time helping an esteemed American company find its way in a brave new world.

As of last Friday, our conference is scheduled for Thursday the 22nd. Believe me, I'll keep you posted.

Where the Wild Things Are

I saw this last night.




Maurice Sendak wrote and illustrated Where the Wild Things Are in 1963. I was born two years later and I think my mother read it to me for the first time in 1969, the year I started kindergarten. Where the Wild Things Are was the first book I ever owned and between it and The Story About Ping by Marjorie Flack, my lifelong fascination with the world outside the one I call home was set.

I poured over Wild Thing's ten sentences and 48 pages every day for years as I remember it, but it was probably more like a couple of weeks before I moved on to something else. However, that book looms large in my imagination still. Six months ago, I learned that Spike Jonze was making a film adaptation of it, and I was worried that my childhood memories would be short-changed by a movie version.

I had nothing to worry about. Jonze's adaptation is brilliant, and that he manages to flesh out Sendak's original 10 sentences into a two hour movie is a testament to his skill as a filmmaker and story teller. Honestly, It didn't feel like he added a thing, so seamlessly does the script play into the original story line.

Despite the source material, this is not a children's movie. It's an adult dissection of the memories and moods of a child, Max, the main character. In Max's fantasy world, time speeds up and slows down as needed. His imagination is glorious in its breadth but held in check by the limited experiences of a seven-year-old. He can't see those limitations of course, that's the allure of childhood. But the audience can and the result is a slow motion thrill.

The theater was full of other 40-somethings last night and sometimes, it's nice to share a cultural touchstone with a room full of strangers.

Bring me a Power Mat

An increasingly important consideration I have to take when I'm putting together a design for somebody's kitchen is where to put the chargers? I dislike cluttering up my designs with an assortment of wall warts, so usually I bury a cluster of outlets inside of a wall cabinets. That way, people can plug in their chargers and then just shut the door. This works when I have enough room to make one of these impromptu charging stations. A lot of times though, storage space is a premium and I can't spare the room for a buried charging station.

Enter the Powermat. Check it out.

The iPhone will lie down with the Blackberry... Cool! That Powermat can charge three devices at one time and it has a single, streamlined plug. Brilliant. It looks good too. I wouldn't mind something like this sitting on a counter in the least. Here's a video tour of the new must-have in every kitchen I design from now on. At $99, who can argue?.




It really does make that sound when it engages. I know what I'm buying myself this Christmas.

Quick! Buy a brand new indoor air polluter for just $68!

Someone sent me this yesterday along with a gushing note, "OMG! Did you see Jonathan Adler has reed diffusers now?" No, I didn't know and I suspect that I was happier not knowing than I am now.

Good Lord, in what kind of a world to people gush over a $68 bottle of stink? And no, $68 is not a typo. Further, why would anyone pay someone $68 for a bottle of stink who's previously recommended this for a girl's bedroom?

How is that even remotely attractive? I get it, he's being campy. But please, does an eight-year-old girl need to live with a middle-aged man's idea of what's clever? Does anyone really want their kids to sleep in a room that purposely ugly? If I haven't mentioned this in a while, the emperor has no clothes.

If I want a reed diffuser, why should I not buy this one from Target for $9? At $9, it's still a waste of money but it's a little more palatable than it is when it costs seven-and-a-half times as much.

This same, thoughtful soul who sent me the alert about the Adler reed diffusers takes absurd delight and sending me all sorts of helpful reminders. Most of them have to do with the hidden dangers posed to me by the mysterious "toxins" that surround me and why I need to "live green" and "detoxify" myself regularly. So lady who will remain anonymous, this one's for you.

The conventional wisdom holds that one of the "toxins" that threaten me with every breath are VOCs. Well, conventional wisdom likes to latch onto a scientific concept and then run with it to as many silly ends as are available. VOC is an acronym and it stands for volatile organic compound. Volatile means that something evaporates at room temperature. Organic means that something's carbon-based (not the meaningless label people use to charge more for groceries), and a compound is a blend of two or more chemical elements.

VOC is a generic term and it can describe anything from the scent of a rose to paint fumes. However, the US EPA has identified a subset of VOCs as health threats. A small subset of VOCs are reason for concern,  and one of those VOCs is called dipropylene glycol methyl ether or DPGME. If you ran a business and you allowed you employees to be exposed to high levels of DPGME, you would be shut down and fined so fast you wouldn't know what hit you.

Now, reed diffusers are an odd bird. How they work is that a scented oil concoction is allowed to evaporate slowly through a wicking action. A scented oil (which is a VOC) by itself is too thick to wick efficiently so it's mixed with a chemical like ethyl alcohol (another VOC) to thin it out. Once it's thinned though, it wicks too efficiently and it needs a third chemical, another VOC, to slow it down. That VOC is more often than not our old pal dipropylene glycol methyl ether, or DPGME.

So when you buy a reed diffuser, whether it's an absurdly priced one from Jonathan Adler or a cheaper one from Target, you are filling your bathroom with DPGME and it very rapidly exceeds levels deemed to be safe for occupational exposure by the EPA and OSHA. Here's OSHA's fact sheet on DPGME. Isn't it hilarious that a lot of the same people who claim to get sick from paint fumes can fill their homes with reed diffusers and scented candles and thrive?

Chemistry's your friend folks. Really.