!WARNING:
CARBON MONOXIDE POISONING HAZARD
1.Seal any unused openings in the vent- ing system
2.Inspect the venting system for proper size and horizontal pitch, as required in the National Fuel Gas Code, ANSI Z223.1 or the CAN/CGA B149 Instal- lation Codes and these instructions. Determine that there is no blockage or restriction, leakage, corrosion and other deficiencies which could cause an unsafe condition.
3.So far as is practical, close all build- ing doors and windows and all doors between the space in which the appliance(s) connected to the venting system are located and other spaces of the building.
4.Follow the lighting instructions. Place the appliance being inspected in opera- tion. Adjust thermostat so appliance shall operate continuously.
5.Turn on clothes dryers and any other appliance not connected to the vent- ing system. Turn on any exhaust fans, such as range hoods and bathroom exhausts, so they shall operate at maxi- mum speed. Do not operate a summer exhaust fan.
6.Close fireplace dampers.
7.Test for spillage from draft hood equipped appliance at the draft hood relief opening after 5 minutes of main burner operation. Use the flame of a match or candle.
8.If improper venting is observed during any of the above tests, the venting sys- tem must be corrected in accordance with the National Fuel Gas Code, ANSI Z223.1/NFPA 54 and/or CSA B149.1, Natural Gas and Propane Installation Codes.
9.After it has been determined that each appliance connected to the venting system properly vents when tested as outlined above, return doors, windows, exhaust fans, fireplace dampers and any other gas burning appliance to their previous conditions of use.
Vent Pipe Material
Vent and combustion air pipe and fittings must be one of the following materials and must conform to the indicated ANSI/ASTM standards:
Material | Standard |
Schedule 40 PVC | D1785 |
D2665 | |
D2241 | |
& |
|
| D2661 |
Schedule 40 ABS | F628 |
Foam/Cellular Core PVC F891
*In Canada, check the local codes to ensure that SDR is approved for use. SDR is not approved for all Canadian installations.
Cement and primer must conform to ATSM Standard D2564 for PVC and Standard D2235 for ABS. When joining PVC piping to ABS, use PVC solvent cement. (See procedure specified in ASTM Standard D3138.)
Vent Pipe Length and Diameter
In order for the furnace to operate properly, the combustion air and vent piping must not be excessively restrictive. To ensure this use Table 5, which indicates the maximum allowable pip- ing length for a furnace of specified input rate, when installed with piping of selected diameter and number of elbows. This table applies to the length and number of elbows for each pipe. To use the table, the furnace input rate, the center- line length and the number of elbows on each pipe must be known. Choose the diameter for which the tabulated length is equal to or greater than required.
Proper use of the table is illustrated by the fol- lowing example:
Example:
An 80,000 Btu/h furnace is to be installed in a
Solution:
For this particular installation, the equivalent vent length must be calculated. This equivalent vent length will then be compared to the maximum allowable vent length given in Table 5. Then, the diameter of the piping can be chosen for which the
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