User Manual - ALLSEASONS Heating And Cooling

11DEFINITIONSfor the following symbols used in the venting calculationsand examples are:> - greater than> - equal to or greater than< - less than< - equal to or less thanH T- total of both horizontal vent lengths (H R) and offsets(H O) in feetH R- combined horizontal vent lengths in feetH O- offset factor: .03(total degrees of offset - 135°*) infeetV T- combined vertical vent lengths in feetELBOW VENT LENGTH VALUESfeetinches1° 0.03 0.515° 0.45 6.030° 0.9 11.045°* 1.35 16.090°* 2.7 32.0* the first 45º and 90° offset has a zero value and isshown in the formula as -45° and -90º respectivelyor -135º when combined.when (H T) < (V T)FIGURE 590°HORIZONTAL TERMINATION45ºFor vent configurations requiring more than one 45º and90° elbow, the following formulas apply:Formula 1: H T< V TFormula 2: H T+ V T< 40 feetExample 1:FIGURE 645º90°H 2V 1H 190°Simple venting configuration (only one 45º and 90° elbow)REQUIREDVERTICALRISE IN FEET(V T)CALCULATED HORIZONTAL VENT RUNPLUS OFFSETS IN FEET (H T)The shaded area within the lines represents acceptablevalues for H Tand V T.V 1= 8 ftV T= V 1= 8 ftH 1= 2.5 ftH 2= 2 ftH R= H 1+ H 2= 2.5 + 2 = 4.5 ftH O= .03(one 45º elbow + two 90º elbows - 135º)=0.3(225-135º) = 2.7ftH T= H R+ H O= 4.5 + 2.7 = 7.2 ftH T+ V T= 7.2 +8 =15.2ftFormula 1:Formula 2:H T< V T7.2 < 8H T+ V T< 40 feet15.2 < 40Since both formulas are met, this vent configuration is acceptable.W415-0496 / B / 08.10.05