Common Vent Questions

[gmanmdg]

I just purchashed a Modine Hot-dawg garage heater. I cant vent it thru the garage roof or wall my only option is tieing it into the common vent to the house. I have talked to a couple hvac guys and they say it can be done. The common vent is capable of handling the extra btus. The way most of the hvac guys want to connect to the common vent is by taping off it with a wye in the attic and slopeing the connection down to the garage heater. My question is: Has anyone ever had this done or does this sound right? I want to make sure these guys are correct in what they say needs to be done.

Thanks Mike

[m kilgore]

Hard to tell if it will work or not without all the specs. Would need to know the flue size, BTU of all applianes and all lengths and offsets. If they measured and said it would work then if they are fom reputable firms it should work. Per forum rules no pricing is allowed so I won't go there.

[Austin59]

Local codes vary too much to give a difinitive answer to your question without getting into the specifics of the other appliances connected to the existing vent. Are you using a contractor for the installation? If so, they should be able to answer your questions and if not I would seriously consider using one as it would be cheaper in the long run.

[gmanmdg]

Yes I am using a local hvac contractor. I just wanted to make sure if what he said was correct. I currently have around 20Ft of 5in b-vent for the common vent. The furnace and water heater are in the basement total 100,000btu's the modine garage heater is 45000btus. The contractor wrote that he would install a 12in peice of 3" b-vent hortizontal to a drip tee up approx 24in's to a 45* into the house, use another 45* straight up approx 5ft to a 45* into the wye attached to the 5" common vent. There will be approx 5ft of 5" b-vent above the wye that goes through the roof. Im not worried about the price I just want to make sure before I tell him to go ahead that I had all of your suggestions

Thanks Mike