Englander 28-3500 Add-On install thread

[whankin2]

Thanks so much for the side view pic. This is exactly the way I'l be needing to arrange my install; very helpful. I like being able to have the 45 degree stovepipe run. Wonderful install!

 

[Badfish740]

Just thought I'd revive my old thread for an update because us furnace guys don't seem to be that well represented lately. It's probably because we're having to be outside processing more wood than you fancy boiler boys! It's been a semi-mild Jersey fall so I'm still mostly burning at night, but once we head into December it should become more of a 24/7 operation. What I have learned is that the unit itself has a fair amount of thermal mass and will continue to give off heat well after the fire has died into coals. I try to maximize the stretch between feedings which works well in the shoulder season but we'll see once winter comes. We paid $364 to fill the tank this year and the gauge is still hovering around full...

 

[freeburn]

Did you add any firebrick inside? I added one in the back in between the two welded shelf/brackets. Two along each side. All of these on their sides. I also added 1 1/2 bricks on each side in front of the baffle toward the door vertically. I've had probably 4-5 fires total in it. And from a cold start I've gotten burns avg 7-9 hrs. I do top down burns, take a little longer to get going, but I don't have to add anymore at all. I stuff the box full up to the baffle. 3 larger splits on the bottom, 2-3 on that, then my kindling and newspapers. It's always started the stuff underneath since my wood is dry enough.

As for thermal mass. This furnace gets added btu's with the enclosed backside and bottom which is added surface area for the blower. The room that it's in doesn't get unbearably hot either which cooks up the rest of the house. So far it's been worth the $1000 I spent on it even though it doesn't have secondary burn. Although I still think it's quite efficient considering that the air comes in above the door vs underneath.

I also discovered that my old garden hoe works perfect to scrape the ashes/coals in the firebox, as well as remove the ash the doesn't make it into the ash pan underneath (common complaint).

Anyone done anything else to increase that thermal mass or done anything different with the furnace? Don't hold forth.

 

[Badfish740]

Did you add any firebrick inside? I added one in the back in between the two welded shelf/brackets. Two along each side. All of these on their sides. I also added 1 1/2 bricks on each side in front of the baffle toward the door vertically.

I never thought to add some brick, but it certainly can't hurt. Tractor Supply has lots of cheap firebrick-maybe it's time to pick some up.

 

[lexybird]

Anyone done anything else to increase that thermal mass or done anything different with the furnace? Don't hold forth.

yes,i added some bricks along the sides as well ,will likely do the back section here soon

 

[stee6043]

Holy smokes.....77 degrees??? I'd be naked in my house all winter long if I kept it at 77 degrees! Nice looking setup.....

 

[freeburn]

Anyone done anything else to increase that thermal mass or done anything different with the furnace? Don't hold forth.

yes,i added some bricks along the sides as well ,will likely do the back section here soon

All you need is one brick, unless you cut two for the outsides. Or carve out two just right so they fit around the welded brackets.

 

[Badfish740]

Holy smokes.....77 degrees??? I'd be naked in my house all winter long if I kept it at 77 degrees! Nice looking setup.....

Hehe...I don't usually aim for 77-in fact I try to keep it around 70 tops. I've actually gone as far as blocking off the vent serving our bedroom and cracking windows at night, otherwise it gets too hot to sleep. That temperature reading was from the first day I fired it up and I was getting a little over-exuberant with the air control...lol It's not hard to do though-with good hardwood and the air at 85% I'm sure you would see 80 plus degree indoor temps.

 

[kieth4548]

Anyone done anything else to increase that thermal mass or done anything different with the furnace? Don't hold forth.

yes,i added some bricks along the sides as well ,will likely do the back section here soon

All you need is one brick, unless you cut two for the outsides. Or carve out two just right so they fit around the welded brackets.

I never thought of adding more brick to my 28-3500. Are you adding brick to the top of the bracket that holds in the lower bricks? If so how do you keep them from falling over. Also how much more burn time do you gain? Sorry about all the questions just never thought of this. If you can post a picture that would be great.

 

[freeburn]

The bricks just stay there because the bracket is wide enough. As far as gains on burn time, I can't speak to that (I've never tried it without them), but perhaps more of a "keeping the firebox temps up" kind of thing to get a more complete-ish combustion of the wood. If anything, it retains the heat longer once the fire is out and perhaps keeps the firebox from warping/welting if the fire gets too hot. I kind of got the idea from the way all the other stoves are designed as well as the Caddy furnace inside, but without the secondary burn of course.

 

[kieth4548]

The bricks just stay there because the bracket is wide enough. As far as gains on burn time, I can't speak to that (I've never tried it without them), but perhaps more of a "keeping the firebox temps up" kind of thing to get a more complete-ish combustion of the wood. If anything, it retains the heat longer once the fire is out and perhaps keeps the firebox from warping/welting if the fire gets too hot. I kind of got the idea from the way all the other stoves are designed as well as the Caddy furnace inside, but without the secondary burn of course.

Ok I will give it a try. I was looking at the bracket inside and it seems like they would be constantly falling over since there is nothing holding them in but I will give it a try.

 

[lexybird]

The bricks just stay there because the bracket is wide enough. As far as gains on burn time, I can't speak to that (I've never tried it without them), but perhaps more of a "keeping the firebox temps up" kind of thing to get a more complete-ish combustion of the wood. If anything, it retains the heat longer once the fire is out and perhaps keeps the firebox from warping/welting if the fire gets too hot. I kind of got the idea from the way all the other stoves are designed as well as the Caddy furnace inside, but without the secondary burn of course.

Ok I will give it a try. I was looking at the bracket inside and it seems like they would be constantly falling over since there is nothing holding them in but I will give it a try.

well they sit on the side rails and mine stay in just fine ,i never have them getting loose and falling out of location ,i also added a stainless 1/4" thick flat plate ontop of my baffle for more mass on top of the fire .in my thinking the more inner mass you have the longer it retains the heat and the longer it keeps the heat around the firebox.. the longer the blower is running and heating the home

 

[freeburn]

Could you get the same effect by adding firebrick on top of the baffle plate that is already in there?

 

[kieth4548]

Could you get the same effect by adding firebrick on top of the baffle plate that is already in there?

This is a good question. My only thought to this would be that it could block the flow of the smoke and such lowering your draft because you are taking up space above the baffle. I'm no expert.

 

[laynes69]

One thing to think about is the more firebrick, the less heat transfer on the walls of the furnace. Yes alot of firebrick is great, but you need heat transfer from the sides of the firebox. Thats why my old furnace heated so well, only the base of the walls were firebrick, which allowed for more heat transfer to the jacket around the firebox. The thicker the firebrick the more insulated the walls will be. Its better for combustion. Now if the unit had a secondary heat exchanger it would capture the heat from the firebox. Just something to chew on. If the unit already has firebrick on the walls of the furnace then I wouldn't add more to the sides. Only so much can be done without the addition of heated secondary air.

 

[kieth4548]

One thing to think about is the more firebrick, the less heat transfer on the walls of the furnace. Yes alot of firebrick is great, but you need heat transfer from the sides of the firebox. Thats why my old furnace heated so well, only the base of the walls were firebrick, which allowed for more heat transfer to the jacket around the firebox. The thicker the firebrick the more insulated the walls will be. Its better for combustion. Now if the unit had a secondary heat exchanger it would capture the heat from the firebox. Just something to chew on. If the unit already has firebrick on the walls of the furnace then I wouldn't add more to the sides. Only so much can be done without the addition of heated secondary air.

good point!

 

[freeburn]

So the heat isn't going to pass through the firebrick into the metal jacket and keep it hot longer? Firebrick then is more of an insulator for the fire than the metal around it? Am I understanding that correctly? If that is the case, why do the wood stoves have the firebrick all the way up? Is that only to keep the inside temps up for secondary burn to work?

 

[Gooserider]

So the heat isn't going to pass through the firebrick into the metal jacket and keep it hot longer? Firebrick then is more of an insulator for the fire than the metal around it? Am I understanding that correctly? If that is the case, why do the wood stoves have the firebrick all the way up? Is that only to keep the inside temps up for secondary burn to work?

Pretty much yes, the idea is to raise the temperature inside of the firebox so as to enable 2ndary combustion when you add the air through the secondary burn tubes... It is a very tricky balancing act, to get the fire box hot enough to do secondary combustion reliably, but not cause the firebox materials to break down - in many cases you are running fairly close to the boundary. In a stove w/o secondary combustion heat that doesn't transfer out the firebox walls as it's produced is mostly going to just go out the chimney... The heat is not like a bank account that you can keep putting more in and take out later, it's more like a sink full of water, adding more it just runs out the overflow and gets wasted...

I realize that it is always really tempting to try and re-engineer our stoves and such in an effort to make them better, but usually with modern stuff it's fairly unlikely to succeed when you figure how much testing and engineering is put into the product at the factory - The factory engineers will have gotten most of the "low hanging fruit" and you run considerable risk of messing up the always present design compromises made to get the best possible overall performance.

Gooserider

 

[freeburn]

OK, well, I took out the extra firebrick and I thought the stove heated well before, now let's see what happens. . . Thanks for the tips on leaving well enough alone.