System Design

Outlet Termination

Flue terminations for oil are subject to BS 6461 Part2. Figure A illustrates recommendations for the most commonly encountered terminations.

Flue terminations for gas in domestic situations are governed by BS5440-1 2000 Section 4.2. Figure B illustratesr ecommendations for the most common terminations.

Adjacent taller structures may require increased height. The minimum flue projection through the roof is 600mm to the underside of the terminal.

Flue routing

Systems should be vertical as far as possible for most efficient evacuation and should not exceed 45° from the vertical, otherwise resistance to flue gas flow will result. Bends should be kept to a minimum and a vertical rise of 600mm minimum should be allowed for immediately above the appliance.

As a general rule, the vertical distance (A) between the appliance and the flue terminal should always be at least twice the horizontal distance (B) between the appliance and the terminal (see Fig C).

The K Vent range includes 30° and 45° fixed bends which can be used where the flue system needs to be offset e.g. to avoid trusses and terminate to a ridge terminal.

Use of K Vent on condensing appliances

K Vent is not suitable for this application. Prima Plus and ICS Plus are the products in the Rite-Vent range specifically designed for or for condensing or pressurised applications.