I recently purchased a gas heater (ceiling mount) as a gift for my husband's work shop which is 20'x30' with 9' ceilings. The heater is a 60,000 BTU made by Advanced Distributor Products call a Compact Unit Heater. We live in the northern midwest and he has been using a Kerosene heater while he has been preparing to install this heater. He has been experiencing problems, we believe with carbon monoxide building up in the building even though he as had the service door open a small amount. We are concerned that he will experience the same problem with the heater we have purchased? We plan to have the heater set to maintain a constant 50-55 degrees at all times. He'll probably turn it up higher on weekends, while he's out there. So the building will be closed up a lot of the time with the heater running. The manual instructs to vent the exhaust, but does not address fresh air inlet. Would it be possible to connect a small fan mounted in the attic with the blower fan? This would pull air in through the vented soffits. In other words, when the blower fan kicks in the fresh air fan would also kick in and replenish fresh air in the building. My next question is, he is seriously contemplating not using this unit and using a furnace. Is there a difference between a heating unit and a furnace. Would he encounter the same type of problems with fresh air. For your information, this building houses cars he is restoring, so there will be gasoline involved.

the furnace is a 2 year old armstrong sx ultra 80 gas furnace. The problem is the burners kick on then the blower about 60 sec. later. The blower then shuts down for approximately 3 to 5 min. regardless of how many cycles the burners fire. sometimes the burners fire 2 or 3 times before the blower comes on again. I've tried all three speeds on the blower and the higher the speed the quiker it shuts down. Any thoughts???