Kiln Vents: Over vs. Under

[GEP]

I've been firing one 7 cubic ft electric kiln with an overhead vent hood for the last 8 years or so. I'm getting ready to purchase a second kiln of the same size.

 

I think it might make sense to also buy the undermounted vent now, because I could use one vent for both kilns, and fire both kilns at the same time, and this would take up less space in my small studio.

 

My other option is to buy the swing-arm bracket for the vent hood, so both kilns could share the hood. This would not be as space efficient, and would only allow me to fire one kiln at a time. I don't think I have room in my studio for two overhead vent hoods. This option would be cheaper. And because I am already used to this vent, I know my firing results will be the same.

 

I guess my main question is ... has anyone made the switch from vent hood to undermounted vent, and were there any differences in your firing results? I'm leaning towards the undermounted vent, but I don't want my pots to look different!

 

Mea

[perkolator]

you shouldn't have any difference switching to undermount venting in an electric kiln. the only time i would assume there may be a difference is if you leave the fan on during cooling with glazes that need to develop in a slow cool - but that's what digital control boxes are for! i'm not even sure if the vent speeds up cooling if left on since heat rises and the vents pull downward, which may cancel it out.

 

based on how expensive steel is these days, i'd guess undermount vents will be cheaper than adding or modifying the overhead vent. new envirovent II system is around $500 and i'm fairly certain you can use one motor on two kilns whereas you couldn't with the old envirovents (perhaps someone else has input on this?).

[Marcia Selsor]

I used two undermounted systems for four kilns last year when I was teaching. They were very efficient for removing the fumes from the room which was actually in the classroom. I was impressed.

I also think they are better for the life of the elements in that they remove the heavy metals from the kiln envirovent and not the heat.

 

Marcia

[Jlinett]

you shouldn't have any difference switching to undermount venting in an electric kiln. the only time i would assume there may be a difference is if you leave the fan on during cooling with glazes that need to develop in a slow cool - but that's what digital control boxes are for! i'm not even sure if the vent speeds up cooling if left on since heat rises and the vents pull downward, which may cancel it out.

 

based on how expensive steel is these days, i'd guess undermount vents will be cheaper than adding or modifying the overhead vent. new envirovent II system is around $500 and i'm fairly certain you can use one motor on two kilns whereas you couldn't with the old envirovents (perhaps someone else has input on this?).

 

 

I have been having trouble with pots exploding in the kiln lately during bisque firing. This is a new kiln to me, my first ceramic kiln with electric controller. I'm used to a kiln sitter in ,my old shop. also, glazes are acting strange I suspect too fast cooling, but don't know what settings to use. This is mid fire cone 6 clay and potters choice glaze. what's made me bring this up is that I have the Orton kiln vent on the old and new kilns, so I hadn't thought that was a factor. But now I do. Should I shut off the vent during cooling phase?

[Marcia Selsor]

you shouldn't have any difference switching to undermount venting in an electric kiln. the only time i would assume there may be a difference is if you leave the fan on during cooling with glazes that need to develop in a slow cool - but that's what digital control boxes are for! i'm not even sure if the vent speeds up cooling if left on since heat rises and the vents pull downward, which may cancel it out.

 

based on how expensive steel is these days, i'd guess undermount vents will be cheaper than adding or modifying the overhead vent. new envirovent II system is around $500 and i'm fairly certain you can use one motor on two kilns whereas you couldn't with the old envirovents (perhaps someone else has input on this?).

 

 

I have been having trouble with pots exploding in the kiln lately during bisque firing. This is a new kiln to me, my first ceramic kiln with electric controller. I'm used to a kiln sitter in ,my old shop. also, glazes are acting strange I suspect too fast cooling, but don't know what settings to use. This is mid fire cone 6 clay and potters choice glaze. what's made me bring this up is that I have the Orton kiln vent on the old and new kilns, so I hadn't thought that was a factor. But now I do. Should I shut off the vent during cooling phase?

 

You should probably post your inquiry separately so more people could help. from my experience with the vents, I would say yes, turn them off when the kiln is done firing.

arcia

[oldlady]

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i am sure you have considered the amount of electric power used with all of these things going at once. is your overhead vent powered?

 

 

 

 

I think it might make sense to also buy the undermounted vent now, because I could use one vent for both kilns, and fire both kilns at the same time, and this would take up less space in my small studio.