Everything Drolet Tundra - Heatmax...

[brenndatomu]

However somethings got to give, I am getting hit with 350 dollar gas bills. If this don’t pan out I’m looking at doing an insert with the fireplaces but not sure if the efficiency and output of heat would be worth the cost

Even if you can't heat the house 100% with a stove, it can/will still take a huge bite outta your heating bill. A modern stove, even though much simpler than a wood furnace, (cheaper too!) is still pretty efficient. With a forced air furnace there are always losses in the duct work, it would be even worse in your situation...using air to transport heat is actually not very efficient. With a stove you also get the benefit of the radiant heat directly to the living area...which you would lose all that with an open basement.

 

[JRHAWK9]

Personally, I would not do a wood furnace in that situation for reasons listed above. Way too many unknowns related to performance, let along not having metal ducts. I would do a stand alone stove. It can't get all too cold in S. Carolina.

 

[KC Matt]

The motors on both of my Honeywell dampers died after two years due to heat. Their damper motor design is horrible. Essentially the motor has to be powered on all of the time ( the motor will get very hot after a while of being on ) to overcome the resistance of the return spring.

Instead of buying their crap again I found a guy on eBay who sold Belimo damper motors. It is a much better design. The gentleman that I worked with over the phone was very helpful too.

Well that's a drag. My 8" dampers shipped today. How much did this guy charge and what did you buy? Do you have him retrofit the motors or does he provide the ductwork?

My supply temp is 105 or less what was yours? My 14x24 damper hasn't shipped yet and it's a return side unit. Should I be looking for other options?

EDIT: I see the dampers you're talking about on ebay and I messaged the seller to see if he can make the 14x24 a hair small so it would fit inside the duct. It appears that they make the dampers to order so hopefully it would be possible to do. If so, that would greatly simplify this process.

So you would wire these to normally be open but close on demand and then open again. Just this week the power was disabled for nearby construction while the Tundra was going. Not sure what happened as I was at work but everything seems to be in order.

 

[wwells48]

What do you have for a fireplace and chimney? What is the house layout? Our Drolet 1400i insert stove will out heat the Tundra hands down...BUT, since the firebox it is half the size, it is also half the burn time, AND it only heats the ground floor...floors get cold because the basement is cold, and it doesn't distribute the heat through the house as evenly as the furnace can/does...but a stove might possibly be a better option for you, dunno, need more info and/or some pics of your setup and floorplan/sq. footage to advise further...

I made a layout of my home to the best of my knowledge and paint skills lol don’t judge haha! I have 2 fire places you’ll see them in my picture they are the red markers. I know the fire place has clay tile in the living room up he chimney and seems to be older than the one in the great room. The great room fireplace has chain mail curtain and glass doors to shut it. I believe that part of the home was an addition.

For some reason the site would not let me upload the photo so here is a link.

 

[brenndatomu]

I made a layout of my home to the best of my knowledge and paint skills lol don’t judge haha! I have 2 fire places you’ll see them in my picture they are the red markers. I know the fire place has clay tile in the living room up he chimney and seems to be older than the one in the great room. The great room fireplace has chain mail curtain and glass doors to shut it. I believe that part of the home was an addition.

For some reason the site would not let me upload the photo so here is a link.

Looks to me like that interior FP would do nicely...might hafta throw a stainless liner in the chimney, but all in all still probably cheaper than a furnace install.

 

[wwells48]

Looks to me like that interior FP would do nicely...might hafta throw a stainless liner in the chimney, but all in all still probably cheaper than a furnace install.

The only thing is I defiantly would want to have the fire inside an insert or behind closed doors. One of the reasons I haven’t used it is because when I moved In not to long ago, They had literally laid carpet everywhere cheap Berber rug. Plans were to pull it up because the floors under are beautiful hard wood. But life happened, wife had a baby so we left the crap carpet in. Its always been a scare with carpet so close and a baby on the run to have an open fireplace like that. Some of the heat exchangers that sit inside the fireplace are nice but again open fires. So I was wanting an insert with a door. But just looking at my house layout what do you think the coverage of heat would be like from the living room fire place?

 

[JRHAWK9]

The only thing is I defiantly would want to have the fire inside an insert or behind closed doors. One of the reasons I haven’t used it is because when I moved In not to long ago, They had literally laid carpet everywhere cheap Berber rug. Plans were to pull it up because the floors under are beautiful hard wood. But life happened, wife had a baby so we left the crap carpet in. Its always been a scare with carpet so close and a baby on the run to have an open fireplace like that. Some of the heat exchangers that sit inside the fireplace are nice but again open fires. So I was wanting an insert with a door. But just looking at my house layout what do you think the coverage of heat would be like from the living room fire place?

A HE (high efficiency) insert is pretty much nothing but a stand alone stove made to fit inside the opening of a fireplace. By code, you will probably have to extend the area in front of the opening with some brick or something.
Here's a video showing an example.

 

[brenndatomu]

Oh yeah, you would want an insert stove in there no doubt! An open fireplace is single digit efficiency, if you are lucky!
Whats the dimensions of the fireplace? W/H/D, and the W/H at the back too. Looks kinda small from the pic.
You would have to come up with some sort of hearth right in front of the FP...and some stoves have more rigid requirements then others.
And as far as keeping the kiddos away from the stove, what I did was to fab up a steel plate that the stove sits on, the plate has tubes that act as receivers for brackets on my screen to slide into. I just took an el cheapo fireplace screen that I found on clearance at lowes, welded brackets to it to make it mate up to the plate...that way if the kids bumped it or grabbed it, it was not gonna go anywhere. It has to be picked up and slide straight back to get to the stove (air adjustments can be made from above without removing the screen)
Your LR FP looks to be kinda central in the house, so it should do a decent job, every house is different though, some work out with stove heating better than others, the closer to the stove the warmer it will be...generally you can move heat around by running a small fan on low at the far corners of the house, the fan on the floor pointing toward the stove. Works pretty good for us using just one fan...the bedrooms stay cooler, by that's fine too. Like I mentioned before, even if you can't go 100% wood heat, would still knock the heat bill down by a very large number!
You probably should open up a thread of your own over in the stove forum...you'll get tons more help on this topic than here in the boiler room...kinda getting off topic for the Tundra thread anyways. You can post a link of the thread here, anybody interested can follow you there. Feel free to continue to post any Tundra questions here though!

 

[wwells48]

Oh yeah, you would want an insert stove in there no doubt! An open fireplace is single digit efficiency, if you are lucky!
Whats the dimensions of the fireplace? W/H/D, and the W/H at the back too. Looks kinda small from the pic.
You would have to come up with some sort of hearth right in front of the FP...and some stoves have more rigid requirements then others.
And as far as keeping the kiddos away from the stove, what I did was to fab up a steel plate that the stove sits on, the plate has tubes that act as receivers for brackets on my screen to slide into. I just took an el cheapo fireplace screen that I found on clearance at lowes, welded brackets to it to make it mate up to the plate...that way if the kids bumped it or grabbed it, it was not gonna go anywhere. It has to be picked up and slide straight back to get to the stove (air adjustments can be made from above without removing the screen)
Your LR FP looks to be kinda central in the house, so it should do a decent job, every house is different though, some work out with stove heating better than others, the closer to the stove the warmer it will be...generally you can move heat around by running a small fan on low at the far corners of the house, the fan on the floor pointing toward the stove. Works pretty good for us using just one fan...the bedrooms stay cooler, by that's fine too. Like I mentioned before, even if you can't go 100% wood heat, would still knock the heat bill down by a very large number!
You probably should open up a thread of your own over in the stove forum...you'll get tons more help on this topic than here in the boiler room...kinda getting off topic for the Tundra thread anyways. You can post a link of the thread here, anybody interested can follow you there. Feel free to continue to post any Tundra questions here though!

I agree, we are definitely getting off topic sorry. I will take your advice and probably go with the fireplace insert, looking like a better option. I just had big dreams with the tundra unit lol. I appreciate all the help from you and everyone eles. Being new here you guys helped me out a bunch. Everyone made me feel welcomed and like I been part of community for awhile. Big thanks again!

 

[sloeffle]

Well that's a drag. My 8" dampers shipped today. How much did this guy charge and what did you buy? Do you have him retrofit the motors or does he provide the ductwork?

Personally, I'd just use the Honeywell motors until they die.

I bought two of the 24V TFB24 motors to replace the Honeywell motors when they died. I couldn't find a link to the Belimo motor on his web site but I am sure he will have them. I think I paid around $100 a piece along with the retrofit kit. The retrofit kit is just a 1/2" steel shaft that he mills one end out to go over the exiting damper shaft and then there is a threaded set screw that keeps it in place.

I bought my dampers from Supply House or somewhere else. It wasn't until the motors went out did I find retrozone.com. I have a 20x20 that sits on top of my furnace and then a 14" round damper coming out of the wood furnace. My regular furnace is a geothermal furnace so there is no A coil to deal with.

My supply temp is 105 or less what was yours? My 14x24 damper hasn't shipped yet and it's a return side unit. Should I be looking for other options?

No idea. My furnace is tied into the duct work on my house. When we had our addition built I had the HVAC contractor setup the wood furnace. He had manual dampers ( because they are cheap ) in the setup and I switched them over to powered dampers because I am lazy.

So you would wire these to normally be open but close on demand and then open again. Just this week the power was disabled for nearby construction while the Tundra was going. Not sure what happened as I was at work but everything seems to be in order.

My dampers are wired to an external 24V power supply. The external 24V power supply is powered by the wire going to the motor. So when the motor on the wood furnace starts the damper on the geo furnace closes. The damper from the wood stove is always open. The 14" round damper is wired into the geo furnace. When the geo furnace kicks on, it closes.

The bad part about my setup is that I cannot run both furnaces without some manual intervention. I am sure one of the electrical wizards ( @JRHAWK9 or @brenndatomu ) could probably figure out a relay setup that could make that happen though.

 

[KC Matt]

I was able to cancel the Honeywell dampers so I ordered three from dampers direct. It doesn't make much sense to spend $300 to upgrade these motors when the whole batch of dampers was $420 and the new ones were $450. Plus they are made 1/8" smaller than the duct size so they will drop into the existing duct, saving a TON of work. I also don't have to buy a new transformer and wire it since I already upgraded the Tundra transformer and it will run these.

Mine will be wired as I described a few posts back, maybe with a few tweaks so that the two furnaces run together. The dampers should be here this weekend. The last part to install my Quadra Fire will be here on Wednesday so we should be nice and warm next year.

 

[JRHAWK9]

The bad part about my setup is that I cannot run both furnaces without some manual intervention. I am sure one of the electrical wizards ( @JRHAWK9 or @brenndatomu ) could probably figure out a relay setup that could make that happen though.

How did I not see this. I don't know how the heck I got that connotation...lol I've seen pictures of @DoubleB 's stuff and it was WAY impressive!

@KC Matt , I have a very crude wiring diagram which may or may not help you. It's how I have things wired so both furnaces can play together as well as using a different speed tap on the wood furnace when the LP furnace kicks in because the speed controller has the wood blower moving so slow at that point the LP blower will backfeed it otherwise. I believe I posted it somewhere on here.

 

[KC Matt]

How did I not see this. I don't know how the heck I got that connotation...lol I've seen pictures of @DoubleB 's stuff and it was WAY impressive!

@KC Matt , I have a very crude wiring diagram which may or may not help you. It's how I have things wired so both furnaces can play together as well as using a different speed tap on the wood furnace when the LP furnace kicks in because the speed controller has the wood blower moving so slow at that point the LP blower will backfeed it otherwise. I believe I posted it somewhere on here.

I'd like to see that. It would be nice to find software that allows you to build these very basic circuits . Even the simplest programs are well beyond this application.

 

[brenndatomu]

Just noticed tonight that this thread is over 3 years old now...my son was only a few weeks old when I started this...now he's a sassy 3 YO!

 

[JRHAWK9]

I'd like to see that. It would be nice to find software that allows you to build these very basic circuits . Even the simplest programs are well beyond this application.

Here's my damper relay and how it's wired. I only have one powered damper, and it's in the supply duct connecting the wood furnace to the main house supply duct. I DON'T have my wood furnace cold air connected to the main house cold air. I believe you do because your furnace is in the garage....IIRC?? In this case my diagram will only work for your supply damper, if it works at all. It uses the 120V EAC (electric air cleaner) circuit on the LP furnace and the 120V circuit from the wood furnace's snap switch. I have a spring open, power closed damper with a 120V motor, which ends up being powered by the EAC circuit of my furnace. The ONLY time my damper closes is when the LP blower in the only one running. ALL other times it remains open. This means in summer the damper is powering close when the AC kicks in and springs open when it shuts off.

I believe for your return damper placed on your LP furnace's return duct you would want it OPEN at all times except when the wood furnace is the only one running, correct? You would then use another relay and swap the positions of the EAC and snap switch leads and then the ONLY time the damper closes would be when the wood blower is the only one running. ALL other times it would remain open.



This is the wiring for my three relay wood furnace blower motor control. It's VERY messy, sorry. The wood furnace blower is under control of the speed control (which is powering the high speed winding on the blower) at all times -except- when the LP furnace is also running at the same time. When the LP kicks in AND the wood blower is still active, then the wood furnace's blower's low speed winding is given 120V instead of the speed control. This was done because whenever the LP kicks in the wood furnace's blower is running very slow at the end of a burn. The LP's blower then backfeeds the wood furnaces blower. Not good! Adding that relay rectifies that situation, as then both blowers are running on low speed. I also have wired up a fail-safe in case the speed control stops working. In this case I have a second 200° snap switch installed in my plenum. If plenum temps ever get that high and that snap switch ever closes, it will take power away from the speed control and send it to the low speed winding of the wood furnace blower.

 

[sloeffle]

Just noticed tonight that this thread is over 3 years old now...my son was only a few weeks old when I started this...now he's a sassy 3 YO!

And the best part is, everyone is civil and people treat each other like they are human beings.

 

[KC Matt]

Here's my damper relay and how it's wired. I only have one powered damper, and it's in the supply duct connecting the wood furnace to the main house supply duct. I DON'T have my wood furnace cold air connected to the main house cold air. I believe you do because your furnace is in the garage....IIRC?? In this case my diagram will only work for your supply damper, if it works at all. It uses the 120V EAC (electric air cleaner) circuit on the LP furnace and the 120V circuit from the wood furnace's snap switch. I have a spring open, power closed damper with a 120V motor, which ends up being powered by the EAC circuit of my furnace. The ONLY time my damper closes is when the LP blower in the only one running. ALL other times it remains open. This means in summer the damper is powering close when the AC kicks in and springs open when it shuts off.

I believe for your return damper placed on your LP furnace's return duct you would want it OPEN at all times except when the wood furnace is the only one running, correct? You would then use another relay and swap the positions of the EAC and snap switch leads and then the ONLY time the damper closes would be when the wood blower is the only one running. ALL other times it would remain open.

View attachment 222944

This is the wiring for my three relay wood furnace blower motor control. It's VERY messy, sorry. The wood furnace blower is under control of the speed control (which is powering the high speed winding on the blower) at all times -except- when the LP furnace is also running at the same time. When the LP kicks in AND the wood blower is still active, then the wood furnace's blower's low speed winding is given 120V instead of the speed control. This was done because whenever the LP kicks in the wood furnace's blower is running very slow at the end of a burn. The LP's blower then backfeeds the wood furnaces blower. Not good! Adding that relay rectifies that situation, as then both blowers are running on low speed. I also have wired up a fail-safe in case the speed control stops working. In this case I have a second 200° snap switch installed in my plenum. If plenum temps ever get that high and that snap switch ever closes, it will take power away from the speed control and send it to the low speed winding of the wood furnace blower.

View attachment 222945

Thanks for the information. You've addressed one of the issues I'm looking at which is what do I want the Tundra fan to do when the gas furnace is running? Like you, it would only be at the end of a burn where there is very little heat in the Tundra. I could allow both to run since it's always at full power or just shut off the Tundra blower while the gas furnace is running.

Either way would work, but since 1) while the gas blower is running, there is plenty of airflow over the heat exchanger 2) the puny blower in the Tundra would likely be overpowered by the gas blower and 3) having air blow counter to the Tundra blower should increase current draw, I see no reason to allow both to run simultaneously.

This thing is going to have a pile of relays.

 

[DoubleB]

I've seen pictures of @DoubleB 's stuff

Yikes, there are certainly some things I'd do different next time on my wiring and control system. But I don't have a setup like you guys with competing furnaces, so my only advice on control design is that there are usually only a couple things that I need the design to do right, and several things I don't want the design to do wrong. So I take some time to dream up and list out all the problems, failures, or dangerous situations that I want to avoid, then design to be fail-safe during them, and half the time that solution also accomplishes the things to do right, too.

And the other half the time I still didn't accomplish my objectives of improved performance, but at least it was safe when I tested the failure modes that I could imagine. I still have a lot to learn...

 

[KC Matt]

Quick update: The dampers are here and I've made a schematic first on paper and then with Edraw Max. I need to review it before wiring anything along with ordering bus bars and relays, but it's close. Edraw is a pretty useable program though it still doesn't show a SPDT relay, only a SPDT switch. I added a relay solenoid and it pretty well gets the point across. Naturally, the software is $250 to purchase so this upload will have a watermark. As anticipated, it's a mess but it should do what I want it to.

I'd greatly appreciate if somebody who is familiar with these circuits could double check my work.

 

[JRHAWK9]

This is the wiring for my three relay wood furnace blower motor control. It's VERY messy, sorry. The wood furnace blower is under control of the speed control (which is powering the high speed winding on the blower) at all times -except- when the LP furnace is also running at the same time. When the LP kicks in AND the wood blower is still active, then the wood furnace's blower's low speed winding is given 120V instead of the speed control. This was done because whenever the LP kicks in the wood furnace's blower is running very slow at the end of a burn. The LP's blower then backfeeds the wood furnaces blower. Not good! Adding that relay rectifies that situation, as then both blowers are running on low speed. I also have wired up a fail-safe in case the speed control stops working. In this case I have a second 200° snap switch installed in my plenum. If plenum temps ever get that high and that snap switch ever closes, it will take power away from the speed control and send it to the low speed winding of the wood furnace blower.

View attachment 222945

Here's my 3 RIB's wired up as shown above.

Here's what this setup does.

Wood furnace blower motor is speed controlled via the high speed tap only when ALL of the following are true.
- Primary low limit temp in wood furnace plenum is met
- LP or AC blower is off
- Emergency secondary snap switch temp in wood furnace plenum NOT met

Wood furnace's low speed winding is supplied 120V when one or the other, or both of the following are true AND the primary low limit temp in wood furnace plenum is met:
- LP blower is on
- Secondary emergency snap temp in wood furnace plenum is met.

I have the secondary emergency snap disk temp set at 180° (the maximum this particular snap switch goes up to).

 

[TL002]

I am in the market for an add-on wood burning stove as a secondary heat source. My goal is to use as a stand alone system using existing duct system.

I currently have a heat pump with LP furnace as an auxiliary. Our house is 2400 sq., mainly on the first floor. Second floor is smaller. I am wondering what will be an ideal wood burning furnace for my house. I read a lot about Tundra, posted a couple years back. Is it still a good buy? I have no HVAC experience. Appreciate any input.

 

[KC Matt]

Those are the same relays I use except yours appear to be the 20a while the ones I use are 10a. They are super convenient because they have 3 coils and can be used with 120vac 24vac or 24vdc. The reason my above diagram shows SPDT even where I could use SPST is that with just 1 spare relay, I have my whole system covered in an emergency.

If you get a chance, JRHAWK9, take a look at my schematic and see if you find flaws that prevent it from doing my stated goal. It's almost spring and this system probably won't be installed for a couple weeks so it may not run until next year.

 

[JRHAWK9]

Yeah, I emailed Functional Devices and they recommended using the larger one to power a blower motor. I'm using the smaller 10A one to control my powered damper. It's a RIBU1C. I should have used that smaller one to control the speed controller too, as I think I'm going to order a U1C and swap it out. I don't need that big thing just to power a speed controller! I can use the spare larger one for a backup.

I'm not totally following what you want to do and, like you mentioned, everybody's setup is soooo different. This makes it hard to fully grasp what you want done and how to do it. I know a couple years ago I asked a master electrician to look over something and he never got back to me. I'm guessing he didn't want to "OK" it not knowing anything about it. Plus I need my diagrams looking like a pre-schooler did it in order to follow them. I follow them easier when I see all connections, etc.

 

[STIHLY DAN]

Here's my 3 RIB's wired up as shown above.

Here's what this setup does.

Wood furnace blower motor is speed controlled via the high speed tap only when ALL of the following are true.
- Primary low limit snap temp in wood furnace plenum is met
- LP or AC blower is off
- Emergency secondary snap switch temp in wood furnace plenun NOT met

Wood furnace's low speed winding is supplied 120V when one or the other, or both of the following are true AND the primary low limit snap temp in wood furnace plenum is met:
- LP blower is on
- Secondary emergency snap temp in wood furnace plenum is met.

I have the secondary emergency snap disk temp set at 180° (the maximum this particular snap switch goes up to).

View attachment 223285

Thats a good looking setup. Especially the speed controller. If the manufacturers steal the design we should get the royalties. LOL..

 

[JRHAWK9]

Thats a good looking setup. Especially the speed controller. If the manufacturers steal the design we should get the royalties. LOL..

I couldn't ask for a better functioning controls setup. I really like how it turned out.