Enough Heat? - Newly installed Furnace

[whankin2]

I have a Daka add-on. I have finally completed my install, and I'm excited. However, my initial burn has been underwelming. Problem is no heat moving t/o the house.
My Daka's 2 top 8" heat outlets are ducted to the main furnace plenum as described in the manual, yet when I turn on the main furnace blower, there really isn't any heat coming out of vents, just cool air. The wood furnace is burning quite well and I can feel the ducting between the wood furnace and main furnace being quite warm, yet it doesn't seem like the warm air is going t/o the house ductwork. Looking for solutions, and thanks in advance. BTW, I only use the 500cfm blower that came w/ the Daka, then the main furnace blower to supposedly get heat t/o the house. fyi...Going into the main plenum, I bend the duct 90 degrees upwards. Any ideas are greatly appreciated, esp since it's single digits here in Michigan!

 

[Suz]

Just guessing, but shouldn't you have a cold air return going into the wood stove? Don't you need to move the cold air from the living quarters through the wood stove then to the main stove to circulate?
I'm trying to remember how I had my old setup in my first house that had forced air (Over 20 years ago). But, I do know that my wood stove was closer to the main stove than yours is.

 

[ericjeeper]

main furnace

Might need to select a lower blower speed. You will have to move a blue black or red wire on the control board. To LOW speed.
I can not really make heads or tails out of your photo.. But I am thinking your main blower is essentially forcing the HOT air from the daka back down the dakas throat.
Maybe hook the twin 8 inchers into the return side

 

[IndyIan]

How many BTU are you supposed to get out of the woodfurnace? Compared to your regular furnace? What temp is the firebox on the daka? I believe heat transfer increases exponentially with increasing temperature differences, so having your firebox 200F warmer might double your BTU output.
Have you run a woodstove before? It took us a while to figure out what we were doing with ours.
Ian

 

[reaperman]

Might need to select a lower blower speed. You will have to move a blue black or red wire on the control board. To LOW speed.
I can not really make heads or tails out of your photo.. But I am thinking your main blower is essentially forcing the HOT air from the daka back down the dakas throat.
Maybe hook the twin 8 inchers into the return side

:agree2: I think there is way too much air moving to "feel heat", My set-up looks somewhat similar to yours. Except I only use the blower fan from the wood furnace to do the work, I can manually turn on the furnace fan in addition if I want, which I have tried for fun. But the result is cooler air coming out of the registers. Which is verified my the thermometer probe I have in a register vent I use to tell me how hot my furnace is running. Try turning off the main furnace blower and see if the temp rises. A 500 cfm blower is not very large, my unit has 3 speeds and I use the lowest 1250 cfm.

I your only using the Daka plenum fan only, the two 8" ducts coming into your main ducting, may benefit by having some kind of "scoop" or maybe 45 degree elbow, to shoot the heated air upward into the ducting rather than blowing strait into what is mainly a T, now. Causing the heated air to backfeed through your main furnace, and return ducts as well. You want all of your air to head for the main ducts.

 

[aandabooks]

Sorry about not responding to the PM but I'll respond here. Just got on the computer.

When I run my furnace blower with the Daka, the air coming through the registers is luke-warm. Still heats the house to around 70, in these kinds of temps, but you don't get that overwhelmingly hot air like if you let the LP run. I attribute this to the 500 cfm blower from the Daka and the Daka is made to run continuously as long as the air jacket is warm enough to switch on the blower. The LP furnace is made to run at short bursts to bring the house up to temp and then shutoff until called upon again.

Also, I don't have the cold air return running into the blower. I also don't use the air filter because of my setup. I do have a small casement window in my furnace room open 2-3 inches all winter. There is a definate difference in the heating ability when the window is open and providing fresh air into the furnace room. Luckily this window is directly above the Daka.

A couple of questions: What did you do with the pipes inside of the plenum? Is your Daka up off the floor on bricks or sitting right on the concrete? Are you running the blower on the furnace manually and have you tried it with/without the main furnace blower? What condition is your wood supply in? Age, moisture etc.

 

[whankin2]

Thanks so much for the responses. I plan to try again this weekend. It is sounding like I may need to see about pushing the air thru with the Daka-attached blower. I will most likely look to upgrade from that blower to a much larger one. I do not currently have the Daka filter box attached to the return of my gas furnace. I just have it located just next to the supply of fresh air from outside. This was based on recommendation from the tech guy at Daka before I installed. Also, I do indeed have the supply ducts angling up into my plenum at 90 degree angles for both wood-heat supply lines into the plenum.

I do wish I could have located my wood furnace closer to the gas furnace, but the layout would not allow it.

Daka sits directly on concrete ( I never ever have basement water issues)
Answers:
Are you running the blower on the furnace manually and have you tried it with/without the main furnace blower? (I was running main furnace blower manually, will try without this weekend)
What condition is your wood supply in? (Good seasoned supply, over 2 years drying)
I will also try some thermometer placement. Will report back with outcome. I eventually want to wire it up so that the main blower comes on only when enough heat has accumulated inside plenum. May do that later.

 

[jdew1920]

Is the blower on main furnace variable speed? If so, if you could get it to run at a lower CFM that may help. If you are running at a high speed I think the air at the registers would be luke warm.

Are you able to keep the temp up in your house at all?

 

[JONSEREDFAN6069]

i tried what you are trying to do the furnace blower is stronger that the wood burner's and it is blowing the hot air back into the wood burner. i had to plumb it into the cool air intake and that solved it. now i have more heat than i know what to do with.

 

[skid row]

I agree with the above post. If you dont want to plumb the wood furnace into the cold air return of the existing furnace then.
You need to run a cold air return to the wood furnace. You can push much positive air pressure into a room without pulling air out. Kinda like blowing air into a 2 litre plastic soda bottle. Only so much will go in= positive air pressure.

 

[laynes69]

Do you have a damper in the central furnace to stop the air from the Daka from backfeeding? When running your central furnaces blower, you are tempering that air. How big is your ductwork, and your square footage? Make sure you have a damper to stop the daka from backfeeding. You can also point the 2 ducts down away from the plenum, or put a plate in there to direct the air away from the plenum. If you get that working w/o the central blower, you will get much better heat.

 

[jdew1920]

Also may want to contact Daka for advice. I emailed them a couple of times during my install and they responded to me the same day with answers.

 

[iowa]

You first need to block off the plenum on you LP furnace. That way your hot air doesn't dump down into your LP furnace. If your LP furnace plenum gets too hot then it's fan will kick on and that fan will outpush the daka units fan. Which will do way more harm then good. I had to make a guilitine to block off my main run from my LP furnace so the air wouldn't dump into it. I had the same problem..

 

[ghitch75]

pull your filter in your furnace and put a piece of sheet metal the same size as the filter.....

 

[Dan_IN_MN]

Here is a picture of my add on

Here are a few pictures of my add on:

I have the propane furnace pulling the heat from the wood one. It's mixing cool return air w/ the hot air from the wood burner. The air comes out of the ducts warm. However, the air is consistant so the house is around 70° F.

 

[olyman]

as eric and jons said--it needs to be plumbed into the cold air return--NOT the hot air side of your main furnace---

 

[jdew1920]

as eric and jons said--it needs to be plumbed into the cold air return--NOT the hot air side of your main furnace---

I'd be very careful about doing that. It would definately extract the most heat of your wood furnace but could also overheat your gas furnace (blower & control board (if newer) and generally I don't think any furnace manufacturer recommends installing like this for that reason. I'm sure in some cases it works fine.

 

[laynes69]

I'd be very careful about doing that. It would definately extract the most heat of your wood furnace but could also overheat your gas furnace (blower & control board (if newer) and generally I don't think any furnace manufacturer recommends installing like this for that reason. I'm sure in some cases it works fine.

I wouldn't do it also. Its a nice way to destroy some parts on a furnace. You can see some high temps, its not worth the risk.

 

[wdchuck]

Running the hot air from a wood burner into the cold air return line on a forced air furnace will ruin the many plastic parts that are in that path.



There are however, high end, very expensive, forced air furnaces with stainless steel internal parts, and if you have that type of system, then a cold air feed would work.

You could always try it, but you would need to budget for a new furnace just in case.

 

[JONSEREDFAN6069]

mine is a gutted lennox, took out the mother board and run the blower switch from my wood stove to a rheostat so i can controll how hard it blows. pretty crude but it works .