Lochinvar 1, 000 through 2 A Category Iv Positive Pressure Venting System, Category IV Venting

Category IV Venting

A CATEGORY IV POSITIVE

PRESSURE VENTING SYSTEM

FIG. 10 Basic Category IV Venting - Vertical

The flue products in the vent system may be cooled below their dew point and form condensate in the flue. The materials used for a Category IV vent must be resistant to any corrosive damage from flue gas condensate. The flue from a Category IV vent system must have a condensate drain with provisions to properly collect and dispose of any condensate that may occur in the venting system.

Category IV Flue Pipe Materials

Select venting material from the following specified vent distributors:

Heat-Fab Inc. Saf-T CI Vent with AL29-4C stainless steel (Call 1-800-772-0739 for nearest distributor)

Protech Systems Inc. Fas N Seal Vent with AL29-4C stainless steel (Call 1-800-766-3473 for nearest distributor)

Z-FlexZ-Vent with AL29-4C stainless steel (Call 1-800-654-5600 for nearest distributor)

Or other listed Category IV vent systems suitable for a condensing, positive pressure gas fired appliance.

FIG. 11 Basic Category IV Venting - Horizontal

A Category IV venting system for the flue products is required on all models of this appliance. A Category IV venting system operates with a positive pressure in the vent. This positive pressure is generated by the internal combustion air blower which operates the combustion process and also exhausts the flue products from the building. The Category IV flue from this appliance can NOT be combined with the vent from any other appliance. The Category IV flues from multiple appliances can NOT be combined into a common vent. The Category IV flue from this appliance must be a dedicated stack. The flue from this Category IV appliance must have all vent joints and seams sealed gas-tight. A Category IV vent system has specific vent material and installation requirements.

Venting Guidelines for a Category IV Vent

The connection from the appliance vent to the stack or vent termination outside the building MUST be made with listed Category IV vent system and must be direct as possible with no reduction in diameter. The Category IV vent and accessories, such as firestop spacers, thimbles, caps, etc., MUST be installed in accordance with the vent manufacturers instructions. The vent connector and firestop must provide correct spacing to combustible surfaces and seal to the vent connector on the upper and lower sides of each floor or ceiling through which the vent connector passes.

In a typical installation, each appliance must have a dedicated Category IV flue with no other appliance interconnected to any part of the dedicated flue. Each appliance MUST connect to the dedicated flue stack using a properly sealed vent adapter provided by the vent manufacturer. The flues from multiple Intelli-Fin appliances may only be combined when using an engineered vent system incorporating an induced draft fan to ensure that flue products will be properly exhausted from the building at all times. Failure to use a properly sized induced draft fan on a combined vent installation may result in a hazardous condition where flue gases spill into an occupied living space. Consult the induced draft fan manufacturer to size the induced draft fan and to determine the diameter of the common vent pipe required for a combined vent installation.

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