Furnace size in 8x16?

[aczr2k]

Only asking this because I like to second guess.  What size furnace should be put in a 8x16?  I had a 6-1/2 x 16 with an 18k empire furnace and honestly I didn't think it was enough on the cold windy days, mostly because it was mounted in the front and blowing heat to the back.  Once the house was warmed up it was fine but took quite awhile initially.  In this build I plan on mounting the furnace under the front couch so the heat is more central.  I had ordered a suburban 30k furnace, is that overkill?  House will have a spray foam floor and pink insulation in the walls.  Thanks!

[Lip_Ripper Guy]

Which Suburban did you get?  NT30?

[YettiStyle]

I notice in another thread you are finishing off an 8x16 Yetti.  I finished off my 8x16 Yetti build last year and installed a Suburban NT-20SQ (q = quiet model).  I believe it is definitely enough to keep an 8x16 warm.  Even though last year was a milder year I never fished in anything but shorts, a t-shirt, and barefoot.  Best part was that it took me 8 nights/11 days to go through my first 30lb propane tank keeping it at 72+ the whole time.  I honestly didn't notice how long it took to heat the shack up because I usually drill at least 6 holes in my shack and am pretty hot after drilling and moving all the shavings.  My routine was to kick the heater on, drop the shack, drill holes with slush bucket, de-slush holes, remove shavings on floor, then bank around shack.  By the time this was all done it was warm enough inside for me to strip down into shorts and a sweatshirt. 

I kept the yellow foam Yetti installed and filled the gaps between my furring strips with 3/4" foil face insulation panels (LINK).  I also used the same 3/4" insulation in a sandwich style floor (factory plywood on bottom, insulation, 3/4" plywood on top.  Spray foam is great but you will notice that Yetti purposefully raises the bottom of their doors 1.5" to account for most of the installers to install a sandwich style floor.  Don't know if you care about the 2" lip possibly tripping you but just something to think about. 

30K's are nice but I think they cycle more than the 20K's and that annoys me more than anything.  With the 20SQ and installing some noise deadening material inside the furnace enclosure its is very quiet. 

 

Just a side note since I finished off a Yetti as well - if you need any tips, suggestions, pictures just let me know.  For example, if you didn't already know, don't use any steel fasteners (this includes stainless) when connecting to anything aluminum aka the entire frame.  When installing the furring strips you will need zinc coated self drilling screws (your local Fastenal can help you with this).  When steel and aluminum are in contact there is a chemical reaction (galvanic corrosion) that will result in corrosion and weakened metal.

 

Edited September 7, 2016 by YettiStyle

[vtx1029]

anyone use the SF series furnace? I got a 30k for my 8x16 toy hauler.

[Lip_Ripper Guy]

10 minutes ago, vtx1029 said:

anyone use the SF series furnace? I got a 30k for my 8x16 toy hauler.

I had the SF25 if my last house.  It worked well, but I didn't care for the high power draw.  The NT series uses a bigger squirrel cage (less noise), and also quite a bit less power.  

[aczr2k]

I'm not sure on the model number yet, I am waiting for them to get back to me.  I'm guessing it is the NT-30SP.  House was purchased as a package deal with all the stuff needed to finish it out minus the wood.  I know the finished Yetti's only use a 18k unit, not sure what brand, and with only one front vent the rear has to be cooler.  Always had trouble with the two rear holes freezing, never had hole sleeves.

Yettistyle- Thanks for the info on the fasteners, I hadn't thought about that, this is the second Yetti I've done but the first ones they used to fir out from the factory.  I have an account at Fastenal so hopefully they won't ding me too bad.

LRG- I seen in your new house you soundproofed the heater cupboard, I will definitely be doing that, great idea.

 

[Lip_Ripper Guy]

If it is the NT30, I'd stick with it because of the lower power draw than the SF and SFQ series.  If it is the SF or SFQ I'd trade it out.  You probably would be fine with something in the 18-25k btu range, and I think you can get into a 2.7 or 3.1 amp draw model of the NT.  

[aczr2k]

It looks like suburban only has the 19k and jumps to the 30k model.  So that being said is the 30 the better option?

[aczr2k]

It looks like the wrote up an Atwood 30k furnace, model #afmd30xxx.  I looked it up and its the large furnace you have to cut out the side and install a access door, I don't think I want that plus it draws about 7.5 amps.  I think I will get my own and go with the suburban.

Edited September 8, 2016 by aczr2k

[aczr2k]

I haven't wrote a check for anything yet so it's not a big deal. They don't sell suburban so I'll just order it somewhere else.