Cooking For Engineers Forum Index Cooking For Engineers
Analytical cooking discussed.
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Ovens that vent hot air
Goto page Previous  1, 2, 3  Next
 
Post new topic   Reply to topic    Cooking For Engineers Forum Index -> Tools, Equipment, and Gadgets
View previous topic :: View next topic  
Author Message
Guest






PostPosted: Sat Sep 27, 2014 12:13 am    Post subject: Won't heat to 300 Reply with quote

My problem on our oven is way too much heat is coming out to the point that it won't even preheat to 300. I have to run a burner, which somehow makes it so the oven heats up to 425, but it takes very long and the burner has to stay on the hole time. Should I plug the hole?
Back to top
Berniebee



Joined: 17 Dec 2014
Posts: 1

PostPosted: Wed Dec 17, 2014 1:47 am    Post subject: Re: Ovens that vent hot air Reply with quote

If you have been patient enough to read this far, congrats!

To answer the original question: No, you cannot buy a conventional oven without a vent.
And no, you should never block the oven vent.

Despite the OP's comments, I have never seen an oven without venting.
The vent is necessary to maintain an equal temperature through out the oven. Air is typically drawn in through the bottom of the oven door, and then moves by convection out the top of the oven, typically at one of the back elements if you have a coil type. Open your oven door and have a look at the door gasket. Notice the gap at the bottom? That's where room air comes into the oven. And yes, that back coil element gets pretty hot while the oven is on. It's not spewing out air like a hair dryer, but the small amount is very hot.

If you block the vent, the oven temperature will be lower than you expect.
That's because with out any venting, the air in the oven stratifies, that is, the hot air rises to the top and the relatively cooler air stays at the bottom. Because the oven temperature sensor is near the top, it will sense the hotter air, and so the middle and lower parts of the oven will be cooler than your setting. So if you are baking, don't leave a baking pan on that back burner! If you have a stove with a solid top, no worries, the oven vent is out the back. Go ahead and leave those pots and pans on top while baking.

In theory a convection type oven doesn't require a vent, because the fan inside the convection oven ensures that the air is circulated and the temperature is even, top to bottom. But most convection ovens also have conventional bake settings, so a vent will be present.

BTW, an oven vent has nothing to do with venting humidity.
Back to top
View user's profile Send private message
vonronge



Joined: 31 Dec 2014
Posts: 1

PostPosted: Wed Dec 31, 2014 2:12 am    Post subject: Dont believe the guy above Reply with quote

In many counties, ELECTRIC ovens do not have these vents. They are an artifact of government legislation.

Convection, if you remember your first year thermo class, works fine in an enclosed space.

If the oven burns fuel, it needs oxygen, and CO/CO2 needs to vent. If it does not burn fuel, venting is a giant waste of money.

Plug the hole with a steel cap (an empty tin of mustard in my case)
Back to top
View user's profile Send private message
Katie
Guest





PostPosted: Fri Jun 05, 2015 11:40 pm    Post subject: Back burner venting Reply with quote

So this is my first time cooking with a coil top stove and I'm really glad I found this thread. I'm also really glad I discovered that the oven vents through by back right burner before I left something melt able on it. I'm just happy that this is normal, since mine doesn't overheat or anything.
Back to top
jillelaine



Joined: 01 Aug 2015
Posts: 7

PostPosted: Thu Nov 12, 2015 3:50 pm    Post subject: Reply with quote

I found this thread while looking to purchase a new wall oven. We were concerned about heat being dumped into the house while using the oven. We don't have air conditioning and summers can be quite warm.

After research, we purchased a Miele wall oven. It was expensive but works wonderfully. It is very well-insulated and does not heat up the kitchen much when in use. It does vent some heated air out the front: this venting is necessary to prevent over-heating of the electronics in the oven. If this vent was plugged, I think the oven would die an untimely death.

The most heat is dumped into the kitchen when one opens the oven door. (A "Duh" moment, I know) A window in the door and a good oven light minimizes opening the oven to check on the food.

We will install a good on-demand ceiling vent near the oven to suck out excess heat when the indoor temps are already high. When temps are cold, well then, baking cookies helps everything.
Back to top
View user's profile Send private message
Dilbert



Joined: 19 Oct 2007
Posts: 1177
Location: central PA

PostPosted: Fri Nov 13, 2015 7:45 pm    Post subject: Reply with quote

an exhausting vent is a really good idea for any kitchen -

I've never dealt with a non-vented oven in USA, Germany, Sweden or Switzerland. ergo I'm really not so convinced the post that it's a USA issue has much truth in it.

regardless, oven use in the hot season does add to the heat load of the house - with or without a/c. I tend to bake a lot less in the summer.
Back to top
View user's profile Send private message
ronenfe



Joined: 17 Dec 2015
Posts: 2

PostPosted: Thu Dec 17, 2015 5:38 am    Post subject: Reply with quote

It just happened to me yesterday. I put the oven on for 5 minutes on lowest temperature to heat a pita. My range was full with stuff I put on it because my space is limited. after a while I found out that a plastic bag of clementines seating on the small range melted and some clementines got burned. This is a new Frigidaire oven. I didn't understand why it happened. Contacted the company today. The support didn't even know about this vent, he just told me after checking, that the top gets hot and not to place things on it.

Using the oven again tonight I checked it and saw the there is a vent hole in this range causing it to heat. But all other places are cool and safe. As usual they don't have a clue and the manual says nothing about this dangerous safety issue. I'm new to us but I've never had this kind of behavior, but where I came from they use gas range in the stove. I used toaster ovens also in the past and never saw this vents so I guess it's some sort of a stupid regulation?
Back to top
View user's profile Send private message
Dilbert



Joined: 19 Oct 2007
Posts: 1177
Location: central PA

PostPosted: Thu Dec 17, 2015 2:18 pm    Post subject: Reply with quote

every oven I have ever use dating to the 1960's has a vent.

went to the Frigidaire site, picked the first electric range I saw, here's what the manual contains:

/quote
Keep oven vent ducts unobstructed. The oven vent
is located under the left rear surface element if your
model is equipped with coil elements. The oven vent is
located below the backguard for models equipped with
ceramic-glass cook tops. Touching the surfaces in this
area when the oven is operating may cause severe burns.
Also, do not place plastic or heat-sensitive items on or
near the oven vent. These items could melt or ignite.
/unquote

this is what they say for smooth top models:
/quote
Oven vent location
The oven vent is located
under the left side of the
control panel
(See Fig. 1). When the oven is on, warm
air passes through this vent. This venting is necessary for
proper air circulation in the oven and good baking results.
Do not block the oven vent.
/unquote
Back to top
View user's profile Send private message
ronenfe



Joined: 17 Dec 2015
Posts: 2

PostPosted: Thu Dec 17, 2015 10:05 pm    Post subject: Reply with quote

You are right, my fault. I missed it for some reason.
Back to top
View user's profile Send private message
Dilbert



Joined: 19 Oct 2007
Posts: 1177
Location: central PA

PostPosted: Fri Dec 18, 2015 12:07 am    Post subject: Reply with quote

hopefully no serious damage done.

I used the tube vent under the burner to stick copper tubing into the oven, rigged to a tea kettle - my version of "steam injection" for baking bread....
Back to top
View user's profile Send private message
venting
Guest





PostPosted: Sun Mar 19, 2017 3:14 am    Post subject: venting Reply with quote

2 different topics. VENTING of the kitchen range and the bleeder vent from the oven.

Mine has a 1 1/2D x 4" pipe from oven to under the element. Some say it allows the hot air to escape and prevent stratification of hot air and helps in even cooking. All I know is it lets so much hot air out, I can't put anything on the front burner unless I want it boiling. Waste of energy.

Capping it with a lid with a smaller diameter hole, air will still circulate and less escape.
Back to top
Guest






PostPosted: Thu Aug 10, 2017 10:45 am    Post subject: Reply with quote

I know this is an old thread but did you ever get an answer to this?

I've had gas ranges before and my new one blasts out air as you describe. On the older gas ranges, they WERE vented but did not send out air as this new one does. The fan on the old ones must've been running at a low CFM compared to the new.

Quite frankly, given the way this new one runs, I can't imagine anyone ever building such a machine. It'd work fine outside if you had a covered patio.

I do have a range hood that vents to the outside and had even acquired a new one with a much higher CFM for this new stove because I thought the old range hood would be too week.

But since the new range pushes air out so far, there is no way a range hood could capture the vented air unless you had a hood that stuck out about 4 feet from the wall and had a hood that came down to waist height.

I even checked the polarity of the socket to make sure hot was on the right just in case the fan was blowing the wrong way.

It looks like I'm going to return it and try for one that vents out the top. Hope it works.
Back to top
Dilbert



Joined: 19 Oct 2007
Posts: 1177
Location: central PA

PostPosted: Thu Aug 10, 2017 11:39 am    Post subject: Reply with quote

the discussion has several parts -
#1 - there's a difference between gas (nat or LP) and electric ovens
#2 - there's a bigger difference between venting the heat from the appliance vs. venting from the oven chamber

electric oven require less 'total' volume of air venting - since they do not utilize open flame combustion . see the statements regarding air stratification, temperature control, etc.

gas ovens not only need venting for oven chamber stratification/humidity escape/etc, but burning gas requires oxygen in and combustion products out. 100% of the heat produced by the burning gas is not "contained/captured" by the oven - there is excess heat generated. and that has not changed since the beginning of time - every gas burning oven produces more heat than is used "by the oven" and the excess escapes into the kitchen. (the heat from electrics eventually 'escapes' into the kitchen as well; just more slowly.....)

the question is are modern gas ovens 'more powerful' i.e. do they burn more gas and/or require more combustion air flow? I don't know . . .

secondly, what is the effect on this topic of the newfangled "convection" ovens?
and does that effect differ between gas and electric ovens?
Back to top
View user's profile Send private message
Guest






PostPosted: Thu Aug 10, 2017 2:29 pm    Post subject: Reply with quote

I don't know the oven burner BTU/hrs for my older gas ovens so can't compare that. The one I'll be returning uses 14k and 11k for bake and broil respectively.

I understand the combustion process requires oxygen hence more venting than electric. Also, the code requirement of having the vent hood 30" from the top of the range doesn't help the matter, but I think that spec was in place for the last "old one".

But I think you're onto something with the convection aspect.

The convection fan is in the back of the oven and it could be that that extra air flow is what's pushing the exhaust out the front so far.

I'm pretty sure my older gas ovens were of the non-convection (thermal) variety. Convection does seem to be a more modern interest.

Since the venting for my replacement will be on the top, I think it'll be important to ensure the controls are on the front, not on a rear back splash area. I presume the heat from the venting would accelerate any failure of electronics being so close. In range lingo, controls on the back = free standing, on front = slide in. Top venting seems to be on the rear of the range.

So to avoid both the wind tunnel venting requirement for the room and my desire not to replace electronics every couple of years, my replacement is going to be a top vented, thermal (non-convection), slide in.

Keeping my fingers crossed.
Back to top
Guest






PostPosted: Thu Aug 10, 2017 2:36 pm    Post subject: Reply with quote

p.s. per the diff between electric/gas convection, it may simply be that the electric has smaller vent holes. Looking at the arrangement for my gas, I'd say it's effectively "wide open" on the top interior.

So it seems that it'd be harder to trap smoke within a gas oven. If you think of HVAC, smaller ducts = lower air flow for a given pressure.
Back to top
Display posts from previous:   
Post new topic   Reply to topic    Cooking For Engineers Forum Index -> Tools, Equipment, and Gadgets All times are GMT
Goto page Previous  1, 2, 3  Next
Page 2 of 3

 
Jump to:  
You can post new topics in this forum
You can reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group