I installed a laundry/utility type sink in my basement - you know the white plastic ~2'*2'*2' type sink. The drain is about 6 feet away from the main 4" house drain which I tied into - and there was no vent line nearby. I used a 1/1/2" ABS drain line and trap below the sink outlet. Since there wasn't a vent line nearby I installed the drain without a vent but did consider using one of those vacuum breaker type things. The guy at Home Depot (who said he was a plumber) said it may or may not work properly and to try it without the vent or vacuum breaker first - which i did and it works just fine. I fill the sink up completely and it drains quickly with no problem at all and leaves water in the trap when it finishes draining as it should.
My question is - when I go to sell the house - is a home inspector going to fail this installation because it doesn't have a vent. (Installation in Canada).
Thanks for your comments.