Manual J for a Pellet Stove
Hi,
I submitted a plan package for a building permit I put together for a log cabin that I plan on building this summer in climate zone 5. The footprint of the cabin is 24’x32′ and it has a loft above half the cabin making the total sq footage 1140. It is one big great room with with a bath and two bedrooms on the first floor and the loft up above.
I put a note on the drawing for HVAC that said something like “The cabin will be for recreational three season use and will be heated by a dealer installed pellet stove after construction is complete”
So the only review comment I got back from the township’s engineer was “Please provide HVAC design calculations demonstrating code compliant sizing of the equipment. (M1401.3)”
I’m aware of what the manual J calcs are but have never done them. I was looking at the coolcalc website and think I can run through it but my main question is, does a single heat source like a pellet stove or wood stove have any chance of meeting code. It looks like the calcs require duct work sizing etc.
I really hope I don’t have to put a furnace in a recreational 3 season cabin to satisfy this comment.
Thanks for any help.
Travis
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Replies
In general, you don't need calculations that aren't relevant to your system. For example, if you were providing hydronic heat, you would not need duct sizing calculations. Some code officials have qualms about the use of a single heat source for multiple rooms, but some don't mind at all. I would do the load calculation and submit it and see if they are happy. The comment doesn't raise that concern so my guess is that it will be fine.
A common way of meeting this requirement is to install electric baseboard heaters that you never use.
Are you going to insure this cabin? A lot of insurance companies will require a heating system that is controlled by a thermostat.
Charlie, thanks that's encouraging.
Yes it will definitely be insured. I was actually considering adding an electric baseboard to each bedroom just in case the pellet stove dies. They could sit there for 20 years without being used and come in handy when needed. You're right I should add them now and that should help.
I had no idea about the insurance company and thermostats, good to know.
I guess I'll go register at Cool Calc and get started.
Thanks!
Well I ran through the Cool Calc program last night. It was easier to use then I imagined and you were right I was able to put it as ductless. It was nice they had a stacked log wall option. I built each room and added a HVR and the heating requirement is only 21,163 BTUH.
The pellet stove I'm looking at is a max input of 48,000 BTUH at 73% efficiency. So I can get 35,000 BTUH out of it so I should be good. I'm going to submit without the electric heaters and see how it goes.
Thanks for the help.
Travis,
What brand/model of pellet stove have you decided on? Harman? Quadrafire?
James,
We are going with a Harman XXV. The looks of that model will really fit in well with the cabin plus I am a Harman fan.
We mostly heat the house with a 2005 model Harman Accentra insert I bought off craigslist in 2010. Other then replacing fans when the bearings go bad it has been great.
There was an Englander 25 in the basement when we moved in. Other than the fact that it is much more affordable I found the design of the burn pot to be terrible and fought that stove for a couple of years.
I eventually upgraded the Englander to a Quadra Fire Santa Fe which was much better than the Englander but still not as good of a stove as the Harman.