is there any heat lose when replacing glass on a door with metal?

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lime4x4

Member
Hearth Supporter
Nov 18, 2005
134
Northeast Pa
I always wondered when u see some old stoves that had the glass in the door that got broken and people just replaced with a peice of steele.Does it make a difference in the heat output of the stove?
 
lime4x4 said:
I always wondered when u see some old stoves that had the glass in the door that got broken and people just replaced with a peice of steele.Does it make a difference in the heat output of the stove?

Dylan is quite right...but I suppose since you said "old stoves" it prob doesn't make a difference. New stoves are prob designed with the glass radiation (and also the heat loss through it) in mind, whereas the old stoves may have had glass as an afterthought.
 
I know when i open the front loading door where the glass is suposs to be i can feel alot of heat coming out
 
The ceramic glass that must be used (per the safety standards) does not conduct heat as well as iron or steel, that is, it is more insulating. Don't confuse light with the amount of heat radiating from the surface - most of the heat energy is emitted in the infrared frequencies and is not visible with our eyes.
If the glass is replaced with metal, you'll get better heat transfer, but you will not notice the difference
You should not do it because of safety concerns. Stoves are designed with "air wash" to help keep the glass clean. If this is modified or changed incorrectly, you may create a hazard from carbon monoxide.
 
VeteranBurner said:
The ceramic glass that must be used (per the safety standards) does not conduct heat as well as iron or steel, that is, it is more insulating. Don't confuse light with the amount of heat radiating from the surface - most of the heat energy is emitted in the infrared frequencies and is not visible with our eyes.
If the glass is replaced with metal, you'll get better heat transfer, but you will not notice the difference
You should not do it because of safety concerns. Stoves are designed with "air wash" to help keep the glass clean. If this is modified or changed incorrectly, you may create a hazard from carbon monoxide.

wow.

no, glass isn't insulating at all, heat waves pass right thru glass in a different way that steel-thats true- glass wont store heat the way steel does

carbon monoxide? is that a joke? smoke inhalation might be a concern, but only if the air wash is blocked, and the op is only talking about replacing the glass, not welding shut air passages
 
no, glass isn't insulating at all, heat waves pass right thru glass in a different way that steel-thats true- glass wont store heat the way steel does

carbon monoxide? is that a joke? smoke inhalation might be a concern, but only if the air wash is blocked, and the op is only talking about replacing the glass, not welding shut air passages[/quote]

Dave:

Wow back at you.

Heat waves?? You have exposed your lack of knowledge concerning heat transfer. Heat is transferred by radiation, conduction and/or convection. So your "heat waves" are the radiation component. The mechanism for heat transfer through non-opaque objects is, in order, absorption on the hotter side, plus transmission, then emission on the cooler side. Most of the energy is in the infrared range and is undetectable by human eyes. You can check this out on the internet. Stoves use low emissivity glass, why the emissivity of steel or iron is about 0.9. Glass is also more reflective than ferrous materials, so a greater amount is reflected back into the firebox. Of course the ferrous material are opaque so transmission in that case is zero.

While you are actually reading about heat transfer, check out the heat conductivity of steel and glass. Then look at the values of heat capacity for steel or iron and glass. Also check out emissivity and black body radiation. These are not high school topics.

No, carbon monoxide is not a joke. I did say carbon dioxide could be admitted to the room if the air wash system is modified. What do you think is in the smoke, which is the product of incomplete combustion? Do you know anything about carbon monoxide poisoning? It can kill you with a big dose in a short period of time or with smaller exposure over longer periods. Once the carbon monoxide bonds with the hemoglobin in your blood, the blood can no longer transport oxygen. The body is out of luck until fresh hemoglobin can be produced. That's why smoke is so dangerous - it's not the particulate matter that's so potentially harmful.

Only a moron criticizes what they don't understand.
 
VeteranBurner said:
no, glass isn't insulating at all, heat waves pass right thru glass in a different way that steel-thats true- glass wont store heat the way steel does

carbon monoxide? is that a joke? smoke inhalation might be a concern, but only if the air wash is blocked, and the op is only talking about replacing the glass, not welding shut air passages

Dave:

Wow back at you.

Heat waves?? You have exposed your lack of knowledge concerning heat transfer. Heat is transferred by radiation, conduction and/or convection. So your "heat waves" are the radiation component. The mechanism for heat transfer through non-opaque objects is, in order, absorption on the hotter side, plus transmission, then emission on the cooler side. Most of the energy is in the infrared range and is undetectable by human eyes. You can check this out on the internet. Stoves use low emissivity glass, why the emissivity of steel or iron is about 0.9. Glass is also more reflective than ferrous materials, so a greater amount is reflected back into the firebox. Of course the ferrous material are opaque so transmission in that case is zero.

While you are actually reading about heat transfer, check out the heat conductivity of steel and glass. Then look at the values of heat capacity for steel or iron and glass. Also check out emissivity and black body radiation. These are not high school topics.

No, carbon monoxide is not a joke. I did say carbon dioxide could be admitted to the room if the air wash system is modified. What do you think is in the smoke, which is the product of incomplete combustion? Do you know anything about carbon monoxide poisoning? It can kill you with a big dose in a short period of time or with smaller exposure over longer periods. Once the carbon monoxide bonds with the hemoglobin in your blood, the blood can no longer transport oxygen. The body is out of luck until fresh hemoglobin can be produced. That's why smoke is so dangerous - it's not the particulate matter that's so potentially harmful.

Only a moron criticizes what they don't understand.[/quote]


I am trying to understand how replacing the glass (ceramic) with a steel plate would affect the air wash system. In my stoves the air wash system would direct @ the inner surface of whatever is in the doorface opening. I can see how there would be a CD issue if the air wash is modified but I am not understanding how the hazard exists simply by changing the material in the door opening. Not trying to be a SA, just trying to understand the concept.
 
My understanding is that on some stoves, quality clear ceramic door glass is coated to reflect a lot of the heat radiation back into the fire.

http://www.us.schott.com/hometech/english/products/robax/kaminbauer/coating.html
ROBAX® IR is manufactured from flat ROBAX® panels for stoves and fireplaces. The application of special oxydic, electrically conductive coatings to one side of the glass results in the infrared portion of the radiation and thus the thermal radiation being largely reflected back into the fire.

(broken link removed to http://pyro.eurokera.com/pages/products.aspx?itemId=1&fsId=1)
Pyroceram III CLEARVIEW PLUS™
Glass-ceramic windows finished with this thin, infrared reflective (IR) coating have a two-fold benefit. First, the coating reduces heat loss by reflecting the IR energy back into the stove, enabling it to burn more efficiently. Second, the increased heat also reduces soot build-up on the glass-ceramic window, allowing a clear view of the fire. The coating maintains the transparency of the window – minimum transmittance of 65 percent in the visible range – while also lending a slight metallic sheen to its appearance.
 
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