|
Resumen del manual
The equivalent length of the vent system is the total length of straight pipe PLUS the equivalent length of all of the elbows. The following rules must also be followed: 1. Long radius (sweep) elbows are recommended. Standard elbows may be used, but since they have a longer equivalent length, they will reduce the total length of pipe that will be allowed. Short radius (plumbing vent) elbows are not allowed. The standard dimensions of the acceptable elbows are shown below. 2. The maximum equivalent length listed in Table 7, "Maximum Equivalent Pipe Length" is for the vent piping and the air intake piping separately. For example, if the table allows 65 equivalent feet for a particular model, then the vent can have 65 equivalent feet of pipe, AND the combustion air intake can have another 65 equivalent feet of pipe. 3. Three vent terminal elbows (two for the vent and one for the combustion air intake) are already accounted for and need not be included in the equivalent length calculation. 4. All combustion air and vent pipe must conform to American National Standards Institute (ANSI) and American Society for Testing and Materials (ASTM) standards D1785 (Schedule 40 PVC), D2665 (PVC-DWV), F891 (PVC-DWV Cellular Core), D2261 (ABS-DWV) or F628 (Schedule 40 ABS). Pipe cement and primer must conform to ASTM Standard D2546 (PVC) or D2235 (ABS). If ABS pipe is to be used, any joint where ABS pipe is joined to PVC pipe must be glued with cement that is approved for use with BOTH materials. Metallic materials must not be used for venting or air intake. 5. If a flexible connector is used in the vent system, it must be made of a material that is resistant to acidic exposure and to at least 225° F temperature. Flexible connectors are also allowed in the combustion air pipe. 6. All models are supplied with 2" vent connections. When the pipe must be increased to 3" diameter, the transition from 2" to 3" must be done as close to the furnace as possible. For upflow models, the transition from 2" to 3" should be done immediately above the furnace. For downflow or horizontal models, the transition from 2" to 3" pipe should be done immediately after exiting the furnace. 7. In Canada, vents shall be certified to ULC S636, Standard for Type BH Gas Venting Systems. IPEX System 636 PVC is certified to this standard. 8. In Canada, the first three feet (900 mm) of the vent must be readily accessible for inspection. 9. For single pipe systems it is recommended to install the combustion air coupling provided and install approximately 18” of PVC pipe on the furnace. 10. Minimum vent length for all models is 5 feet. TABLE 7: Maximum Equivalent Pipe Length Model Input BTUH (kW) Pipe Size Inches (cm) Maximum Equivalent length feet (m) 4G,GGG (11.7) 2 (5.1) 65 (19.8) 4G,GGG (11.7) 3 (7.6) 90 (27.4) 6G,GGG (17.6) 2 (5.1) 65 (19.8) 6G,GGG (17.6) 3 (7.6) 90 (27.4) 8G,GGG (23.4) 2 (5.1) 65 (19.8) 8G,GGG (23.4) 3 (7.6) 90 (27.4) 1GG,GGG (29.3) 2 (5.1) 30 (9.2) 1GG,GGG (29.3) 3 (7.6) 90 (27.4) 12G,GGG (35.1) 2 (5.1) 30 (9.2) 12G,GGG (35.1) 3 (7.6) 90 (27.4) 13G,GGG (38.1) 3 (7.6) 85 (25.9) TABLE 8: Elbow Dimensions Elbow "A" Dimension 2" Standard 2-5/16" 3" Standard 3-1/16" 2" Sweep 3-1/4" 3" Sweep 4-1/16" Dimensions are those required in Standard ASTM D-3311. Johnson Controls Unitary Products 21 364861-UIM-B-0708 TABLE 9: Equivalent Length of Fittings Fitting Equivalent Length 2" 90° sweep elbow 5 feet of 2" pipe 2" 45° sweep elbow 2-1/2 feet of 2" pipe 2" 90° standard elbow 10 feet of 2" pipe 2" 45° standard elbow 5 feet of 2" pipe 3" 90° sweep elbow 5 feet of 3" pipe 3" 45° sweep elbow 2-1/2 feet of 3" pipe 3" 90° standard elbow 10 feet of 3" pipe 3" 45° standard elbow 5 feet of 3" pipe 2" corrugated connector 10 feet of 2" pipe 3" corrugated connector 10 feet of 3" pipe Example: An 80,000 BTUH furnace requires 32 feet of pipe and four 90° elbows. Using 2" pipe and standard elbows, the total equivalent length will be: 32 feet of 2" pipe = 32 equivalent feet 4 - 90° standard 2" elbows = (4x10) = 40 equivalent feet Total = 72 equivalent feet of 2" pipe This exceeds the 65 foot maximum equivalent length of 2" pipe allowed for that model and is thus not acceptable. By using sweep elbows, the total equivalent length will be: 32 feet of 2" pipe = 32 equivalent feet 4 - 90° standard 2" elbows = (4x5) = 20 equivalent feet Total = 52 equivalent feet of 2" pipe This is less than the 65 foot maximum equivalent length of 2" pipe allowed for that model and is thus acceptable. Alternatively, using 3" pipe and standard elbows, the total equivalent length will be: 32 feet of 3" pipe = 32 equivalent feet 4 - 90° standard 2" elbows = (4x5) = 40 equivalent feet Total = 72 equivalent feet of 3" pipe This is less than the 90 foot maximum equivalent length of 3" pipe allowed for that model and is thus acceptable. TABLE 10: Combustion Air Intake and Vent Connection Size at Furnace (All Models) FURNACE VE...
Otros modelos de este manual:Eléctrico - GG9S*MP (1.97 mb)