How to extend vent of oil boiler above the snow line?

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Jan 10, 2022
Northeastern Vermont
I do the vast majority of my heating with wood stoves, which is quite satisfying. However, my furnace was destroyed in the flood and I need some backup heat to prevent freezing when I am out of town, and to fill in the heat gaps in a couple areas.

I have acquired a Toyotomi OM128-HH (direct vent oil fueled on demand hydronic heating unit). It installs very simply through the wall, similar to a Rinnai propane wall heater, or a Monitor (Toyotomi) oil fueled wall heater. It has the concentric pipes with air intake and exhaust in one.

The problem is that it is a brick house, and I am going out the boarded up basement window. We get lots of snow in Vermont and I am concerned about the direct horizontal vent/intake getting blocked by snow.

Toyotomi also makes an adapter to connect to a chimney (either 4" or 5"). I have no available chimney, as they are used for wood burning.

On the interior (basement), the vent pipe will go up off of the unit a couple feet, and then make a 90 degree bend out the window. I suppose two 45 bends would be even better, and may be feasible.

On the exterior, I would like to have the vent come out the window a bit, and then turn vertically. A rise of a few feet (3 to 6 feet?) would be ideal to clear the snow line. Going longer will impede the performance of the unit. It would be ideal to keep it no more than 10 feet total from the appliance to the end of the chimney (having spoken with the engineers at manufacturer). It will tolerate 15 feet or so of chimney, but performance is degraded.

- Do I need to extend the chimney x number of feet above the roof line?? This is not a good option here.
- In either instance (whether a long chimney or short chimney), which material can be used?
- I assumed an L-vent. Is this suitable outdoors?
- Class A pipe would obviously be fine, but may be more than what is necessary, no? I would do it if I had to.

My understanding is that some pellet stove installs use a short chimney like this.

If I can not do a short vent / chimney outside to clear the snow... then the only alternative I can come up with is building a small pitched roof (like a dog house or a dormer) over the vent to keep the snow off.

Going up through the flood to the main level on the interior is challenging because of clearance issues, etc. as well as then having to penetrate a double brick wall.

How on earth is anyone able to side vent anything from the basement without running into the snow clearance problem?
Thank you very much for the advice.