Positive Pressure / Negative Pressure Boiler

[skaly]

What is the best way to define a Positive and Negative Pressure Boiler.

 

[Simon F]

position of the fan, before or after the burner.

 

[Simon F]

www.gas-news.co.uk/cleanup/HSE_PPB.pdf

list of positive pressure boilers

 

[kirkgas]

What is the best way to define a Positive and Negative Pressure Boiler.

do you mean "define" or "identify"

 

[diamondgas]

Blow air in or blow fumes out --- ? Older boilers would draw air in from outside and 'blow' in into the burner chamber hence forming a positive pressure on the cas seals! Modern boilers blow fumes out causing a suction within the burner chamber

 

[fuzzy]

positive pressure more dangerous as probs with seals can be pushed back into the room

 

[skaly]

So negative is when the fan is sucking poc from the chamber and creating a negative pressure inside, How is it classed with the pre mix burner as in the HE boilers are they positive ?

 

[GrahamM]

So negative is when the fan is sucking poc from the chamber and creating a negative pressure inside, How is it classed with the pre mix burner as in the HE boilers are they positive ?

Technically new premix burners are positive pressure, but not in the conventional sense. The fan is not putting the case under positive pressure.

 

[diamondgas]

I'd class pre mix burners as mini forced draught burners, negative pressure is still on the inner case and seals though so it's negative yeh?