Should I Buy an Unvented Gas Heater or Fireplace?
You would never consider removing the flue pipe from your hot water heater. It would be unthinkable to disconnect the vent on your furnace and allow it to dump flue gases into your home. Yet, when choosing a "space heater" for a basement, garage or workshop, consumers convince themselves that an unvented heater will suffice for their particular needs.
But is it safe? Modern unvented gas products have "oxygen depletion sensors" that act as a safety shutoff if the unit produces "too much" carbon monoxide. However, carbon monoxide is not the only potentially harmful byproduct when gas is burned. Gas appliances also produce carbon dioxide, sulfuric acid, hydrochloric acid and large amounts of water vapor. These chemicals can cause respiratory problems in sensitive persons; ruin wood and metal trim on windows, discolor paint, carpet and furniture, rusts tools, freeze garage doors closed and create other moisture/acid related problems.
What can you do if you already have a vented heater? First, consider a vented alternative. There are many decorative direct vent fireplaces for basements and family rooms. There are some very nice vented garage and space heaters available for almost any application.
If you must keep your unvented heater, be sure to follow the manufactures recommendations including opening a window in the room at least two inches while the unit is in operation.
So, should you buy an unvented gas heater or fireplace? Probably not.