Furnace Clearances in Basement Remodel?
So…got another basement remodel lined up for this summer (what’s left of the summer anyway). The furnace and water heater are bundled pretty close together in the basement, but they are in a location that doesn’t leave lots of room for enclosures without taking up a big chunk of the view out the walk-out french doors.
Question is this: How close to the furnace can I build the walls? My experience has said that furnace manufacturer makes that recommendation, and code officials yield to them – is that right? I asume there must be limitations in terms of working room, though. I don’t work on furnaces, how much room do you guys need for maintenance?
I’ve attached a quick drawing to help illustrate the situation…was thinking maybe double doors to access the front of the furnace?
I’m sure this plan is somehow flawed, so I’m wondering what other ideas there are?
Justin Fink – FHB Editorial
Your Friendly Neighborhood Remodelerator
Replies
Justin,
It's a shame a view might be compromised but think through the space allowed carefully. It'd be the tits to access all sides of that furnace in the future. Think removal and potential
Perhaps 1-5/8's metal studs could provide the enclosure and gain a few inches. Clip the corner to widen the line of sight. I dunno, something to think about.
Be careful, we'll be calling you basement boy, if you keep this up.
A great place for Information, Comraderie, and a sucker punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
It seems you need 3' of clearance in front of the unit. No, that's electrical pannels.
Where the furnace filters come out there has to be enough room to get to them comfortably, probably 3', but if the doors are directly in front of the unit that requirement is taken care of.
It's always a good idea to look for easy retrofits in remodels. It might be that the furnace can be easily moved to the attic, which happens a great deal in our remodels.
A tankless water heater really hugs the wall and can save probably half the sqft footprint of a traditional water heater space.
When the furnace closet door is closed I'd be surprised if any more than a few inches of clearance are needed between it and the unit.
Although not typical, many hvac units can be reconfigured to be quite narrow by re-ducting and taking the unit apart and reassembly. Also don't forget a unit can be configured long and thin, as when used in attics, and doesn't necessarily have to be mounted at ground level. Perhaps what looks like a series of deep cabinets up high on the wall would be less obtrusive.
If duct work is making your furnace closet larger than it needs to be, consider having the duct re-worked. It's often much less expensive than a person would think, at least with our hvac guys who are used to such things.
Also, to minimize the visual impact it's not uncommon to go trimless and use semi hidden doors that blend in with the wall texture. Bullnose corner bead or even curved walls help to further reduce the visual signature of your enclosure.
If inches are important, don't rule out taking a few inches from the foundation wall if there is enough beef. Likewise, if the furnace is up against a sheetrock wall, cut the studs out and place the unit as tight to the wall as humanly possible.
An inch can probably be gained by using a semi hidden door made from 3/4" sheet goods mounted flush with the sheetrock rather than a 1-3/8" interior door.
Some hvac units can be effectively retrofitted to use the air handler with remote hot water sources. This removes a great deal of the bulk and might allow a high cabinet to hide things. My current digs use such a setup and it's amazing how compact the air handler is with only hotwater heat coils and the AC coils in the furnace area. In my case the furnace shares a large hot water tank with the other plumbing.
Best of luck
Beer was created so carpenters wouldn't rule the world.
Hi Don,
Some great insights in your reply...thanks for taking the time to reply. I had thought of using solid core double doors and weatherstripping them for sound resistance (there are other sound reduction methods being used in teh walls of the mechanicals enclosure. Not sure how that would work with your idea of seamless doors...but maybe I could apply foam to the backside and up the STC rating... hmm...Justin Fink - FHB Editorial
Your Friendly Neighborhood Remodelerator
I had thought of using solid core double doors and weatherstripping them for sound resistance
That's what we usually do as well.
I won't admit to messing with the HVAC guys, but there are situations where the HVAC is oversized quite a bit and functions quite well at a reduced fan speed if it's a newer programable/adjustable model. The difference in sound coming from the mechanical room can be quite a bit. Many HVAC guys leave those decisions and learning all the bells and whistles up to the client, who often doesn't even break open the user manual.
Best of luck
Beer was created so carpenters wouldn't rule the world.
What size are those doors?
The scale looks off to me.
I have 2 furnace and a WH behind 2 30" doors and no other acess.
There is about 6" and 8" on past the doors.
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Justin,
I don't have much to offer in terms of space saving, but I will say that on my last two basement remodels, the inspectors have required additional venting within the utility room to ensure that the water heater had enough combustion air.
HO's typically want to have the utility room as small as possible and as quiet as possible. Unfortunately, code requires sufficient air to allow these appliances to function properly ;).
Just something to consider when planning the space. I have had people want me to insulate/soundproof the utility room only to have the inspector tell me that we need to either use a louvered door or install vents to the common areas to allow sufficient combustion air, completely negating the sound attenuation.
I had thought the same thing about vents negating the sound reduction plans. I'm not handling the HVAC portion, nor overseeing the subs who are, but I think they are planning to draw combustion air from outside...Justin Fink - FHB Editorial
Your Friendly Neighborhood Remodelerator
My impression is that most modern furnaces don't require any specific clearance to walls (though of course try to find mfgr's info on the specific unit). You want an inch or so so that the furnace doesn't rattle against the wall, and prudence would suggest that walls should be drywalled to provide some minimal fire protection.
You do need to consider maintenance access, of course. Not just the furnace, but any controls and dampers. Though for major maintenance (changing out the AC A coil or the whole furnace, eg) it's reasonable to assume you can knock down a wall (but plan for the wall to be "removeable" -- no plumbing, wiring, or supported loads).
Electric water heaters likewise are likely to be zero-clearance, and have no vibration issues. But their lifetime tends to be less than furnaces, so sufficient access for replacement is probably a good idea. Also keep in mind access to the front for thermostat/element replacement and access to the T&P valve.
Gas water heaters generally have restrictions as to clearance at the top, and may have others -- best to check mfgr's specs closely.
And of course flues generally have clearance restrictions.
A lot of good information already presented. Clearance around the vent in critical and the difference between C vent and B vent is a lot. There is a code measurement for clearance in front of gas furnaces, especially for pulling out burners and complete blower assemblies. Of course combustion air will be needed if you don't want a louvered door.The one biggy I see in your diagram is: how do you get the h/w tank out for replacement and you WILL be replacing the tank before the furnace. Many times before replacing hot water tanks I've had to remove furnaces, washer/dryers and walls. Huge expense.
The other (Canada) code thing is that the on/off switch for the furnace should be between the furnace and the exit door. In theory when the service tech (in my younger days) realized the furnace was going to blow I could turn the unit off as I was running out;).
roger
Good theory. In practice you'd be out the door before you remembered, and likely you'd just keep running.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
Nah! When you pay the big bucks for someone like me you get my ability to turn the switch off when I'm running:).
It's never happened but I have stood well back and I mean well back when an oil furnace is trying to fire up with a lot of loose oil in the heat chamber. It literally jumps, rocks and bangs and backfires through the inspection port.
roger