guest-blogsheader image
Helpful? 0

Self-Cleaning Ovens

How much energy does it take to burn the congealed grease off the inside of your oven?

Posted on Dec 24 2012 by Marc Rosenbaum

For the first time in my sheltered life, I have a range with a self-cleaning oven. After over a year which included roasting a number of chickens (which we've been raising the past few years), we had an oven covered with enough spattered grease to cause the smoke detector to go off any time we turned the oven on.

The manual that came with the range cautioned against using the usual oven cleaners and recommended the use of the self-cleaning feature. This process locks the oven and heats it up to a very high temperature — Wikipedia (among others) says 900°F.

I was curious what this would be like: Would the range feel really hot to the touch? How much would it smoke? Would it actually clean the oven? How much energy would it use?

Smoke spews out of the oven vent

You have to clean any serious accumulations of stuff out first, perhaps so it doesn't combust. Also, you're not supposed to leave the racks in — they warn against the high temps destroying a finish that makes them slide easily.

This was a major bummer, since we'd been dumb enough to leave the plethora of racks this range comes with in the oven while we only needed one to roast the chicken :- Duh.

They were really grimy and we (OK, not we, Jill) cleaned them by hand. Note to self...

Once we started the process, the oven heats up quickly and smoke comes spewing out the vent. We had windows open and the range hood running. In the first hour of the three-hour cycle the visible smoke stopped. I didn't abort the cycle because I thought I should go through it at least one time. The front and sides of the range felt surprisingly un-scary in terms of temperature — there might actually be some reasonable insulation in there.

Once it turns off, the door stays locked and it indicates on the display that it's still hot for close to another hour, until it cools down.

Result: a clean oven

It did get pretty clean, and there was some ash remaining. And the entire process used 8 kWh of electricity.

That night we had friends come to share homemade pizza, so we added another 3 kWh. The day's total of 11 kWh exceeded our usage tally for the range in some months!

Marc Rosenbaum is director of engineering at South Mountain Company on the island of Martha's Vineyard in Massachusetts. He writes a blog called Thriving on Low Carbon.


Tags: , , ,

Image Credits:

  1. Frigidaire
1.
Mon, 12/24/2012 - 14:13

racks
by K Willets

Helpful? 0

I usually get away with leaving the racks in, along with the porcelain-finished broiler pan, pizza stone, and whatever else I can think of. A little vegetable oil fixes the sliding.

It is indeed a smoky process, and it would be a bit less energy-wasteful if the exhaust were not so noxious. Gas ovens seem designed to waste a huge amount of energy, since the burner vents into the oven, and the exit flue has no automatic damper to keep hot air from leaving when the burner is off.


2.
Tue, 12/25/2012 - 00:37

Why not oven cleaners?
by Gordon Taylor

Helpful? 0

What rationale, if any, was given for the prohibition against oven cleaners?


3.
Tue, 12/25/2012 - 11:26

@Kendall - good to know about
by Marc Rosenbaum

Helpful? 0

@Kendall - good to know about the racks! This oven is electric. I agree about gas ovens - can't see a good reason to use one.
@Gordon - don't know, guessing it's about what they turn into at 900F?


4.
Wed, 12/26/2012 - 00:33

Edited Wed, 12/26/2012 - 10:38.

How ironic...
by Curt Kinder

Helpful? 0

As I read this blog we are 3 hours into the supposed 5 hour cleaning cycle of our electric range. It has been in service 4.5 years and baked many fowl.

What occasioned today's decision to clean was the pool of apple pie overflow at the bottom of the range caused by my dear mother's overstuffed pies.

I didn't think to remove the racks, mostly because I didn't think to read the directions...as a male engineer I normally consider myself above such details when dealing with pedestrian household appliances...OOPS!

When I started the cycle I had a twinge of regret, thinking that I should do it tomorrow, when the evening temperature is forecast to drop into the 30s, as opposed to today's 60s...I figured the extra heat would offset some heating costs if I had waited for chilly weather.

I'm sure glad I did NOT wait for a colder day...the voluminous smoke caused us to crank the range hood to speed 11 and open several windows. I'm not sure how we avoided setting off the smoke detectors and waking Christmas-addled children from a welcome sound sleep.

We have our range on a channel of a TED energy meter, and it looks as though the self clean cycle will burn at least 9 kWH, 1/3 to 1/2 of a typical month's range energy usage.

Update - per TED, self clean consumed 8.22 kWh, and there is quite a bit of white ash dust, so I guess it worked.


5.
Wed, 12/26/2012 - 21:15

Self cleaning oven power use.
by Roger Williams

Helpful? 0

Let us not lose sight of life cycle energy use.

A self cleaning electric range is far better insulated than a standard range. It has to be, to prevent setting fire to the house when the oven is at 900F. Therefore it uses less energy each time you are roasting or baking anything. I read, years ago, that they actually save energy over a conventional oven, and you don't have to use harsh chemicals to clean them.We use a small counter top unit for broiling.

We have been using them for decades and the new ones still say not to leave the racks in, but we do. We also put the surface burner drip pans in during the clean cycle. If your drip pans cannot be put in, then buy some that can withstand the heat.

I used a lot of so called "safe" chemicals cleaning military equipment in the mid sixties. Now, I have trouble keeping skin on my fingers.

Let us remember that it is the life cycle cost that counts, not the momentary power usage.

I hope everyone has a great day.

Regards,
Roger


6.
Thu, 12/27/2012 - 10:30

Range insulation
by Curt Kinder

Helpful? 0

I have noticed how little heat escapes our newer range. It takes a long time to cool, and I routinely power to the elements 10-15 minutes before a cooking task is complete.

Our old range posed a serious burn hazard to small children - glass and metal trim temps exceeded boiling point. Similar surfaces on new one are no more than lukewarm.

A minor negative - it is easy to forget to turn it off since there is little perception of radiant heat thrown off. Fortunately, element duty cycle is only around 10-15% if empty oven is left on at 350*F or so.


7.
Fri, 12/28/2012 - 13:31

Consider washing soda
by Derek Roff

Helpful? 0

For cleaning your oven racks and other kitchen items with baked-on stuff, consider soaking them in washing soda (sodium carbonate). Sodium carbonate is used in a variety of semi-edible products, including ramen noodles, sherbet, moon cakes, and toothpaste. A concentrated solution of sodium carbonate will have a pH of 10-11.6, which is moderately caustic, and worthy of careful use. However, it is much milder than many oven cleaners.

Oven cleaners are often very dangerous, based on our society's demand for instant results and our tolerance of dangerous chemicals in the home. They may contain sodium hydroxide and potassium hydroxide, with pH's of 13 and 13.5. They can remove paint, skin, and other coatings, and cause pitting in various metals. I'm not surprised that the coating on oven racks wouldn't survive these chemicals.

Soaking the racks in a sodium carbonate solution for 1-3 hours will make almost all the baked-on stuff easy to remove with a soft nylon brush. This also works well for cleaning the pitch and other deposits from saw blades and router bits, without harming the paint, carbide, and brazing materials. It doesn't seem to have any effects on the low friction coatings of the tools that I own, but I have no idea how it would affect the proprietary coatings on oven racks.

While there isn't a practical way to soak the inside of an oven in washing soda, a saturated towel can take care of a spill on the oven floor, such as the apple pie spillage mentioned in an earlier posting, and therefore decrease the frequency of using the self-cleaning cycle. Washing soda is a low embodied energy, low cost, fairly safe element in a cleaning arsenal.


8.
Wed, 01/02/2013 - 13:44

We set ours on fire
by Spencer Burnfield

Helpful? 0

So I have been around self cleaning ovens my whole life....as a kid anyways...so I had little direct interaction with the self cleaning mode. My wife and I recently tried to use the self clean function on our new oven. Apparently you should clean grease out of the oven first. We actually had a fire in ours and it burned through or nearly through the baked on enamel on the bottom of the oven...so we will no longer be using the self clean function since we don't want to do any more damage to it. Oops =)


Register for a free account and join the conversation


Get a free account and join the conversation!
Become a GBA PRO!