I currently introduce fresh air into the house by leaving a basement window cracked open. This helps me feel confident enough combustion air is being introduced for the boiler and hot water heater. It is a semi finished space but it obviously gets cold during the winter months and makes the floor above cold for bare feet. The boiler and water heater are now enclosed in a large utility closet and although it has the proper grills for ventilation, I want to run a pipe from outside to this new enclosed space. My hope is that this will allow fresh air to enter for combustion and if its too cold, it will help retain the cool air into this space only however I don't want to create a backdraft where heated air tries going out of the pipe instead of up the chimney. Even better would be if I could warm the air prior to entering this space maybe by running it through a copper pipe parallel to the current trunks lines of the boiler.
Does this sound like an okay idea and are there any one-way vents I can put on the end of the pipe outside so air only comes into the home. I would assume something similar to the valve used on a homes plumbing vent would work.