Raypak 5042004 Engineered Vent Systems, Model, Vent Size, Volume of, Flue Products

4.Place in operation the appliances being inspected. Follow the manufacturer’s instructions for lighting each appliance. Adjust thermostat so appliance will operate continuously.

5.Check the pressure at a pressure tap located 12 in. above the bottom joint of the first vertical vent pipe. Pressure should be anywhere between -0.01 and -0.08 in. WC.

6.After it has been determined that each appliance remaining connected to the common venting sys- tem properly vents when tested as outlined above, return doors, windows, exhaust fans, fireplace dampers and other gas burning appliances to their previous conditions of use.

7.Any improper operation of the common venting system should be corrected so that the installation conforms with the NFGC (U.S.) or B149 (Canada). When re-sizing any portion of the common venting system, the common venting system should be re- sized to approach the minimum size as determined using the appropriate tables in Ap- pendix G in the NFGC (U.S.) or B149 (Canada).

Engineered Vent Systems

Table M provides boiler discharge vent volumes of flue products at full fire for the calculation of appropriate vent sizing for common venting.

WARNING: Vent connectors serving any other appliances shall not be connected into any portion of mechanical draft systems operating under a positive pressure. If an MVB heater is installed to replace an existing heater, the vent system MUST be verified to be of the correct size and Category. If it is NOT, it MUST be replaced.

NOTE: For extractor sizing, typical CO2 levels are 8.5% for natural gas and 9.5% for LP gas and flue temperature of 350° F.

Model	Vent Size	Volume of
		Flue Products
No.	(in.)	(CFM)
504	8	170
754	10	260
1104	10	380
1504	12	510
2004	14	680

NOTE: Data for 100% firing rate.

Table M: Typical Volume of Flue Products

Horizontal Through-the-Wall Direct Venting (Category III)

Fig. 25: Horizontal Through-the-Wall Venting

OPTIONAL HORIZONTAL THROUGH-THE-WALL VENTING

(CATEGORY IV)

Fig. 26: Alt. Horizontal Through-the-Wall Venting

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