Having recently bought a house (circa 1993) where I could set up a *real* shop, I have a question.
The gas forced air furnace in the basement is in the area where I will be using. I know next to nothing about HVAC, so I will try to describe as best as I can. There are two 2″ PVC pipes entering the box, one presumably for intake and the other for exhaust. I was unable to locate and manufacturer’s info, or any information inside the panel that I could discern would help to shed light.
Is it imperative that I make a closet for this unit to protect from dust and other concerns? Can I leave it completely open for service?
Any help is appreciated.
FYI: Same post also in Knots.
Jon Blakemore
Replies
1. DW is paranoid aabout nat gas since the house next door (when she waq a kid in 1950) exploded and burnt down. So, me, I'd disconnect the gas and put in a heat pump
2. Assuming you or DW have not had that experience, unless you do not have a vacuum on your tools, etc, I'd do the closet thing just for that 'good feeling'
3. 'good feeling' aside, only time I've ever seen sawdust (as in airborne sawdust) flame is when a big handfull of fine stuff is tossed into a very hot fireplace -- which says, you do not need to bother.
4. Do whatever DW suggests.
5. After 'discussions', do whatever DW is comfortable with without question, no matter what the cost. Peace of mind is worth much more than that trip to Maui (my boss is there this week is why that is mentioned)
7. Live long and prosper.
The two 2" pvc pipes indicate a 90+ furnace. This would indicate a sealed combustion chamber, so getting dust into the chamber should not be an issue to become a hazard.
Dust getting into the return and supply air stream would be my concern. Therefore, I would build the closet and air seal it. Check your local code about clearances reruired around the furnace.
If it is not a 90+ furnace, I would still build the closet, but install filtered return/combustion air openinigs in the closet walls and/or door. All other areas would be tightly sealed to keep shop dust away from the unit.
Been there, did not do the above. Duct work and house was full of fine shop dust. Had to move the shop to an unheated garage and pay to have ducts cleaned...ouch!
Dave
As Dave said - probably a 90+ with outdoor combustion air. Sometimes the air intake isn't properly connected, though, as in the attached photo.
It's not real obvious, but in the photo you can see where they didn't get the air intake all the way to the combustion chamber.
I can think of four concerns with furnaces in shops: sawdust getting into the combustion air; sawdust getting the distribution air, organic vapors getting into the combustion air (which can quickly ruin the heat exchanger) and vapors getting into the distribution air.
If you enclose the furnace, be sure to allow easy access for annual service. You don't want the service guys saying "gosh darn it" too loudly at service time{Q}
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Thanks to all for the suggestions. I will close off the furnace with a closet, keeping in mind future service access. I'm also going to pick up some AL tape and make sure the ductboard that runs through the space is tight.
Jon Blakemore