Eternal GU125T, Installation And Operation Manual

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19
Venting Speci  cation
GU125T / GU160T is factory configured as a sealed combustion unit with dedicated intake and exhaust
connections.
When installed as a Direct Vent appliance, all combustion air is drawn directly from outside of the home.
Direct Vent configuration is for indoor only.
Recommended for facilities with difficulty accessing combustion air.
Is for indoor only.
Is not sealed combustion if intake is not used to bring air directly from outside.
Direct Vent
Power Vent
Insuf  cient air supply used with Power Vent appliance may cause the building to experience negative pressure
inside. Negative pressure is not allowable by most building codes and can cause back drafting of cold air from
outside through the unit, potentially freezing the heat exchanger / tank.
WARNING
! !
To configure the unit for power vent, leave intake open.
How To Con  gure Unit For Power-Vent
Maximum Allowable Vent and Combustion Air Piping Length
3 inch Piping
Feet Max # of 90 ° elbows
100 6
● Reduce the maximum allowable length for each elbow used as follows:
- 45 degree elbow : Deduct 3 feet
- 90 degree elbow : Deduct 5 feet
● The intake and exhaust vent lengths can be of equal length or less; there is no balancing requirement between intake
and exhaust.
●
Some terminations are considered types of elbows, and correct deduction should be applied. Such as, a turn down
90
˚ or an open T termination is considered 1x90 ˚ elbow, and a candycane termination is considered as 2x90 º elbows.
● To avoid accumulation of condensate water in the exhaust vent run, it is recommended to position the start of
the horizontal section lower, then slope upwards with no less than 1/4" rise per foot of pipe towards the venting
termination to allow condensation flow back into the unit.
●
Horizontal runs require adequate support at 3 1/2 foot intervals and vertical runs suppart at 5 foot intervals.