This is a great resource of independent information!
I am considering a hi-efficiency boiler with direct venting except I really do not have a great place to vent. The shared laneway (not paved) seems the best but because I have an old brick house will the condensate from the flue gases cause damage to the soft brick in 10-15 years?
How much condensate is produced by direct venting and what are the observed problems? Hoar frost?
If the flue gasses are blown back on the brick it will damage it.
If its a shared lane, you'll have to be 7' above it, to prevent ice from forming, and some one slipping on it.
If you are replacing an existing boiler how is it vented? Could you use the same vent and put PVC in it? Is it shared with the WH? If so maybe put in an ID water heater with the new boiler. Just some thoughts!!
The old boiler was vented through a old chimney. The 35' chimney needs to be repointed and repaired if it is to be used. I was hoping to bring it down a few feet and have it capped. Also venting PVC pipe up a 35' chimney might be an option. The intake will not fit in the chimney so it would have to vented from the side of house to an equivalent length as the flue vent.
Most manufacturers will want the intake piped to the same location as the vent, so the atmospheric pressure is the same on both pipes.
Check with the manufacture of the brand your looking at first.