ModCon venting

Hvacman

One of my lowest days was when I froze an IBN 1700 (Lochinvar Intellifin 1.7mbtu) by running the intake out the side and exhaust through the roof... Lucky thing was that Lochinvar said it was acceptable to do so and the engineer gave his blessing also... Draft up the 8"x70' vent pulled in 15 deg. air all night long. Like many boilers, this one has freeze protection through the integeral pump but when the helpful maintenance staff shut off power to "the spare boiler" the freeze protection don't work! We have since installed powered dampers in the intakes.

Long story short, don't deviate from the manufactures required vent practices and even if this type of venting is allowed, CYA!

Don \"Grumpy\" Walsh

Question about venting

I see that most manufacturers recommend that the intake and exhaust be installed at the same plane. Why is that, and what would happen if the exhaust were vented vertically through the roof, but the intake were to be located two floors lower through a side wall? Static pressure issue? Lack of resistance on the inlet side of the vent motor? What?

Unknown

In many cases the pressure switch needs to see a

certain differentail pressure and when the intake and exhaust are out of balance it causes nuisance shut downs.

Some systems offer alternative venting but each venting system on all these systems is unique to the system. If the manual does not show an alternative then call the manufacturer and they may be able to give you some way to get it done.