Emissivity Values

[Guest mhun9180]

Any got the emissivity values for J's Sunset Bronze 20, 30 and 50? I've got a customer that wants the value, but I can't seem to find them anywhere! Please help

[Guest darkdan]

Most likely somewhere between .9 and 1.01 if I had to guess.

That's where almost all normal films range.

[Guest haroldshouseoftint]

not sure if this is what your after, but here ya go

[Guest darkdan]

I wouldn't think that people down there would be concerned with keeping the heat in the building.

[Guest mhun9180]

not sure if this is what your after, but here ya go

Yeah I got those specs, but they don't show emissivity. Wasn't sure if they have published them or not. I guess I'll have to wait until tomorrow and give them a call. Thanks anyways

[Guest mhun9180]

I wouldn't think that people down there would be concerned with keeping the heat in the building.

This guy is right down south in Victoria and the winters get very, very cold. He is actually after the summer and winter values Being winter now, I guess its at the top of his list, until summer comes along again that is.

[Guest vclimber]

Most likely somewhere between .9 and 1.01 if I had to guess.

That's where almost all normal films range.

I thought all emissivity values are measured between 0 and 1.?

[Ryker]

emissivity I thought was the inverse of the U factor..... 1/U ???

I think that was what I was told years ago.....

[Guest vclimber]

emissivity I thought was the inverse of the U factor..... 1/U ???

I think that was what I was told years ago.....

You have the right equation for "R value" there. (R=1/U) This is a measurement for the overall heat transfer coefficient of the glazing system. U value (or U factor) is the reciprocal of the R value. Whereas "emissivity" is a measure of a surface's (ie. film, or low e coating, etc.) ability to emit radiation. The two have relevance but are by definition very different.

There are very few MFG's that will list emissivity #'s on the general spec sheets. You may be able to call the Johnson and get the measurement though.

[Guest mhun9180]

Thanks for the help. I'll give them a call tomorrow.