Submittal Sheet
Page 3
INSTALLATION OF CV-*VR POWER VENTER (See Table 1) 
Table 1 
UNIT SIZING CHART 
OIL  GAS 
MAXIMUM EQUIVALENT FEET OF 
VENT PIPE 
MAX* 
OIL 
GPH 
INPUT 
MAX** 
BTU/HR. 
IMPUT 
AT MAX BTU/HR 
INPUT 
AT 60% OF MAX 
BTU/HR INPUT 
VENTING 
WITH 
VENT PIPE 
SIZE 
MODEL 
18 83 4" 
48 100 5" 
100 100 6" 
1.10 170,000 
100 100 7" 
CV-4VR 
- 25 4" 
32 81 5" 
76 100 6" 
1.85 290,000 
100 100 7" 
CV-5VR 
*Rating at 100 psi. Sizing based on appliance maximum input rate not actual firing rate. **Do not exceed maximum BTU/HR input rating or maximum oil 
GPH input. For multiple venting system applications, add the input for each appliance. Category I gas-fired draft induced systems require a CV-4 or 
larger. Category III gas-fired draft induced systems require a CV-5 or larger.
P
ROCEDURE FOR CALCULATING TOTAL EQUIVALENT PIPE LENGTH IN FEET 
1.  Calculate the total equivalent feet for each type of fitting used in the venting system from the chart below. 
2.  Calculate the total amount of feet for the straight lengths of vent pipe. 
3.  Add the equivalent feet for the fitting with the total amount of feet of straight lengths. This will approximate the total 
equivalent feet of the vent system. 
Table 2 
EQUIVALENT LENGTH (FEET) OF VENT PIPE FOR VENT PIPE FITTING 
  VENT PIPE DIAMETER 
VENT PIPE FITTINGS 
3” 4” 5” 6” 7” 8” 9” 10” 
TEE 
19 25 31 38 44 50 56  63 
90° ELBOW 
5 7 9 11 12 14 16 18 
45° ELBOW 
3 4 4 5 6 7 8  9 
d/D 
1/4  8  11 14 17 19 22 25  28 
1/2 5 7 8 10 12 13 15 17 
SUDDEN REDUCER 
OR INCREASER 
FOR 3 *RATIOS (d/D) 
3/4 2 3 3 4 4 5 6  6 
*Reducer or increaser ratio (d/D) small diameter divided reducer 
ratio is d/D = 4/8 = 1/2. To estimate the equivalent foot length for 
the fitting, use the smaller pipe diameter for the equivalent length 
figure. Example 4" to 8" reducer; the reducer ratio is 1/2 and the 
smaller pipe diameter is 4". So, from the chart, the equivalent feet 
would be 7 feet. (See Figure 1) 
Example: System Pipe Size = 4" 
Step 1  Two 4" 90° elbows @ 7 feet each = 14 ft. 
Step 2  Ten 2 foot lengths of 4" pipe = 20 ft. 
Step 3  Total equivalent feet = 14 ft. + 20 ft. = 34 ft. 
Figure 1










