Category 1 Vent Pipe

Double wall type b gas vent for approved category i natural gas or propane fired appliances gas furnaces heaters fireplaces and boilers in accordance with nfpa 211 standards for chimneys fireplaces vents and solid fuel burning appliances and nfpa 54 the national fuel gas code.

Category 1 vent pipe.

Category i is defined as a gas heating appliance with a flue loss equal or greater than 17 non condensing with a negative vent static pressure. A category i vent system works by allowing heated flue products to rise vertically so the vent pipe must rise vertically from the boiler vent connection as soon as possible. In some cases transrite has been used which may contain asbestos. 1 avoid an excessive number of turns and bends figure 5 and 2 maximize rise.

Type b gas vent 3 12 type b gas vent 14 30. Venting guidelines for category i gas appliances single appliance vent tables 1 and 2 continued 10. Ul 1738 standard special gas vent for category ii iii iv appliances 2. And is approved for such residential and commercial applications as category 1 water heaters boilers furnaces space heaters or wall heaters.

Ul 641 standard type l vent 3. Masonry will use vitreous clay liner. Ul 103 standard building heating appliance chimney swkl vt 5. Ul 103 standard building heating appliance chimney canada.

That code may also be used to size venting systems for drafthood equipped central furnaces or for fan assisted combustion system central furnaces. First consider the ambient temperature of the air around the vent pipe. As well as those suitable for category i gas fired appliances with b vent or appliances with a draft hood. Category i vent materials are found with older appliances.

Ul 1738 standard special gas vent for category ii iii iv appliances 6. Ul 441 standard type b gas vent 4. Vent connectors shall not be upsized more than two sizes greater than the listed appliance categorized vent diameter flue collar diameter or draft hood outlet diameter. As stated earlier heat loss through the vent pipe walls can take away from the draft force.

Single wall galvanized pipe 26 gauge is only used as a connector on 70 percent afue and lower gas appliances and all oil appliances. The venting tables within this booklet have now been included in the national fuel gas code nfpa 54 ansi z223 1 1999. The amerivent all metal double wall gas vent is listed as type b by underwriters laboratories inc. Gama venting tables for category i central furnaces.

All horizontal runs of vent pipe must rise 1 4 inch per foot of run to maintain proper draft in the vent. Ambient temperature two ambients must be considered. Kits in this category include those designed for natural draft appliances using gas oil or wood.