reverse flow build

[crayonbone1]

Howdy all. Be got a few questions on building a cooker. I've been making my plans my first. I've followed all the advice I can find and much thanks @DavOmak for his calculator tutorial. I've got all my figures figured out except a couple. In the cook chamber how do I figure the height to place the reverse flow plate? One of the figures gives an area u der rf plate but to me it seems small. Also how do I figure the opening at the end of the baffle into the cook chamber? My plan is to put a slight vee shape and slope in the baffle to make it more of a drip tray /water reservoir with a drain out. Will that have a detrimental effect? Plan is for a patio type cooker. Tank I'm using is about 42" x 18" . thanks a ton

 

[lendecatural]

The area under the RF plate, area of the FB to CC opening, and the area of the end of the RF plate where the smoke turns up to the grates are all the same. Your tank is short and fat, very good thing, as such, short and fat tanks don't require as tall a FB to CC opening since they are working on a larger radius for the length of cook chamber. Your numbers come up to less than 4.5" of height of cutout so you can just go with 4.5" which would allow for the V for the grease drain since that height is 10% more than is required. Close enough and a conservative number for your configuration. Your FR plate will be ~15 5/8" so that should be the width of your firebox with the RF plate extending into the cook chamber.

 

[crayonbone1]

Ok thank you. That makes sense to have the whole path the same size. So i want my rf plate 4 1/2 inches from the bottom of the cook chamber and that is what would be the 15 5/8 wide? And i want the firebox the same width? Last question...for now lol. I was planning the fire box to be 18 inches long and 16 high. Is that do-able? Ideas at what hieght i should place the fire grate?

 

[lendecatural]

Yes, you can take a tape and eyeball the end starting from the top of the CC at 15 5/8 wide, it should be really close to 4 1/2 inches down towards the center. It's easier from the top to do the sanity check. Yes, when you make the firebox that width, the top extends into the chamber, it's easier that way. The numbers will vary a little due to the wall thickness of the CC. If you measure down 4 3/4 from the outside, it will allow for a 4 1/2 inch interior height assuming a 1/4 inch wall thickness.

You are better off with it 18" high and 16 long since you want to leave a 2-3 inches of height below the fire grate. Taller overall height is better since you need some room for the ash buildup, just not too tall, you want it to work like a fireplace with coals close to the bottom of the wood pile if that makes sense.