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?