Dalesman

[Tom65]

Bracing yorkshire atmosphere, and as ____ pipe historic term fir cial mine ventilation

Dialect = in the or is not 

[bhg481]

Your question makes no sense to me. Apart from all the typos, is it one clue or two?

[newmodarmy]

I assume the clue is " Bracing yorkshire atmosphere, and as ____ pipe historic term for coal mine ventilation"

What's the letter count please?

[JJ109]

Wind Pipe

"The safety ventilation system comprises a main wind pipe, an emptying pipe communicated with the main wind pipe, a fan arranged between the main wind pipe.............

[bhg481]

Is "Dialect = in the or is not " a second clue. If three letters the answer is INT - Yorks for "in the" OR "isn't"

[newmodarmy]

jj109- it's your long lost twin here. The answers to the pipe one was actually AIR 

[JJ109]

Thanks twin, newmodarmy!!