CSA 2.6A-2009 pdf free download

CSA 2.6A-2009 pdf free download.Gas Unit Heaters And Gas-fired Duct Furnaces.
For duct furnaces, outlet air temperatures shall be measured by means of thermocouples composed of wire having a diameter not greater than No. 24 AWG (0.20 mmz), and located in a cross-sectional plane of the outlet duct 36 in (914 mm) from the duct furnace outlet opening. This distance shall be measured along the medial line of the elbow, if one is used. The outlet duct shall be equipped with not less than 16 thermocouples, no two of which shall be more than 6 in (152 mm) apart. Outlet air temperature shall be determined as the average of the temperatures indicated by the thermocouples when each is weighted by the air velocity at the point of temperature measurement. Air velocities shall be determined by a velometer or pitot tube, or equivalent means.
The appliance shall be connected to an uninsulated sheet-metal vent pipe as specified in 2.1.4. On a separated combustion system appliance, the minimum length of vent pipe as specified by the manufacturer shall be installed. Appliances without draft hoods shall use a 5 ft (1 .52 m) length of vent pipe and a vent terminal specified by the manufacturer.
Two lines intersecting at 90 degrees (1.57 rad) shall be established in the horizontal plane of measurement which shall be located 4 ft 6 in (1 .37 m) above the highest point of the draft hood relief opening or on appliances without draft hoods at the point of vent connection. They shall be oriented so they will divide the cross-sectional area of the vent pipe into quadrants. One temperature measurement shall be taken at the intersection of the 2 lines. Eight temperature measurements shall be taken in 2 sets of 4 along each line, at points / and 2/3 of the distance from the intersection to the periphery. The temperature shall be determined with a bead-type thermocouple not larger than No. 24 AWG (0.20 mm2) successively placed at the specified positions. The flue gas temperature shall be the average of these 9 individual readings. For flue pipes of diameters less than 3 in (76.2 mm), the number of thermocouples may be reduced at the discretion of the testing agency. The intent of reading an average flue gas temperature is to be maintained.
All equipment, such as filters and humidifiers, regularly supplied by the manufacturer shall be in place during the test.
The test shall be conducted at normal inlet test pressure. The appliance shall be operated until equilibrium conditions are attained, as indicated by temperature changes in the flue gas of not more than ± 5°F (± 3°C) between readings 15 minutes apart when the flue gas thermocouple is located in the center position of the flue.
For duct furnaces, the air throughput shall be adjusted so at equilibrium the temperature rise above room temperature Is 15 ± 2°F (8.5 ± 1°C) less than the maximum operating temperature rise obtained by computation in accordance with 2.1 .18 from the manufacturer’s specified minimum throughput. Static pressure may be varied as needed in order to maintain the temperature rise.
The gas meter, gas temperature, gas pressure and barometer shall be read and a heating value determination made.
Flue gas temperatures and a sample of the flue gases shall be secured in the plane of measurement specified above. CSA 2.6A-2009 pdf free download.