Heater vent stack

[MichaelGruber]

I've had my pool setup for 2 and a bit years now and am wondering about a vent stack/chimney for my pool heater.
The heater is a Hayward H250FDN and currently doesn't have a chimney. The equipment now enclosed in a shelter and I'm thinking I need to change the vent from the stock to a chimney style vent. The question that I have though is that Hayward offers 2 different vent stack kits for their heaters - a positive-pressure vent kit and a negative-pressure vent kit.
Can someone explain the difference between the two and what should I use for my setup if I want to vent straight up?
Thanks!

 

[ajw22]

I think you want negative pressure stack for a straight up vent.

From

Ready, set, Gadgets Go at GadgetsGo.com!

Our Gadgets Go all out to make your life better. Easy checkout. Personal service by phone or contact form. Low prices.

gadgetsgo.com

Use positive pressure vent adapters with heaters that are power vented, when going through a side wall of your home or building. Use negative pressure vent adapters with heaters that are naturally drafted, vertically through roof.