Everything Drolet Tundra - Heatmax...

[TDD11]

The cold snap definitely shortened my current basement wood supply by at least a week or 2. I was home the past 5 days, and found it much easier to maintain 68 by loading the stove every 5-6 hours around the clock, when flue temps got down to around 250°F. I really had a huge bed of coals by Friday though.

I'm glad to see the brutal cold temps subside for now, although I do not care for the >30°F warmup right now. I just got over being sick, and want to go ice fishing

 

[KC Matt]

Oh, so your wood furnace IS hooked up to the house's return air duct then? If so, I would not recommend both furnaces be running at the same time if they share the same return duct.

Yes it is. Otherwise the furnace would be trying to heat outdoor air.

I'm not trying to run both at the same time, I'm trying to make it switch between the two as needed. When the gas furnace comes on, it will be because the wood furnace has died and will either be off or on the low position. I've run the gas furnace while the Tundra was cycling on low and it didn't seem like anything was off though the volume on the supply was noticeably higher. The filter housing on the gas furnace has a cheap manometer type device and it doesn't indicate much restriction on the return side with both running.

I could rig up a heat dump where when the gas furnace is running and the Tundra kicks on, it dumps the heat from the tundra into the garage. In that case the return damper would be open though. As low as the Tundra cfm is, I don't see how it makes a big impact on the gas furnace or vice versa.

 

[JRHAWK9]

Yes it is. Otherwise the furnace would be trying to heat outdoor air.

Sorry, I'm mixing up who's who here. I really need to pay more attention to who I'm replying to..lol

 

[maple1]

Yes it is. Otherwise the furnace would be trying to heat outdoor air.

How so?

 

[KC Matt]

How so?

My furnace is in the garage which has leaky old doors and the door to the house is closed. Without the return air hooked up, it would pull 100% of the air from outside, in addition to freezing the two bedrooms above the garage. The return air is a necessity in my case.

 

[maple1]

Ah, OK. Didn't realize your furnace was outside the envelope.

 

[JRHAWK9]

Has anybody else noticed the Tundra's are no longer on Menard's website?

 

[brenndatomu]

Has anybody else noticed the Tundra's are no longer on Menard's website?

I did. None on display at the local store either. Drolet still lists them as a dealer though...

 

[3fordasho]

I did. None on display at the local store either. Drolet still lists them as a dealer though...

Menards seems to be more interested in pushing the Shelter stuff. Locally no Drolet furnaces in stock since they closed out the original Tundra.
I was always hoping for a good deal on the Heat Pro but not in the cards I suspect.

 

[jacksnipe]

It's not just the Tundra's which work better with a variable speed blower controller, pretty much ALL solid fuel burning furnaces can benefit from one. Your fossil fuel furnace's blower is setup with a certain heat rise, meaning the delta between return air and supply air. The larger this heat rise the more efficient the heat transfer will be, as long as it stays within the specs found on the data tag. When your fossil fuel furnace runs, it's pretty much putting out the same BTU's over the timeframe it's running. So one blower speed works fine for that. Our wood burning furnaces don't, they ramp up and down over the course of a burn cycle. So at the very beginning (cold light) and end of the burn cycle you will have a very small heat rise with a static rpm blower and it will be cycling off/on with very inconsistent and dropping supply temps. Adding a variable speed controller will increase this heat rise by varying blower speed based on heat output and will keep the blower running MUCH longer at the end of the burn with consistent supply temps. This will increase delivered efficiency towards the end of the burn cycle.

I added one to my Kuuma last winter and it DID make a difference, especially at the end of the burn cycle.

Could it be possible to install one of these variable speed controllers on a heat pro furnace installed in a 1900 sq. Ft shop

 

[JRHAWK9]

Could it be possible to install one of these variable speed controllers on a heat pro furnace installed in a 1900 sq. Ft shop

I don't see why not. It's very similar to the Tundra, AFAIK.

 

[jacksnipe]

I don't see why not. It's very similar to the Tundra, AFAIK.

I don't have the slightest idea on how to hook up one of these units to control the blower speeds, The heat pro unit is programmed to run at a certain speed which is imbedded on the factory chip wired to the blower. The blower has a tendency to run & shut off to much during the burn cycle..

 

[motoguy]

It’s discouraging for those of us that might want to move to a furnace to think that we have to become parts chasing electrical engineers just to get these furnaces to function safely and efficiently. It’s not a cost issue if even the kuumas need these upgrades.

We're in the 2nd year of heating using our Kuuma VF100. I LOVE it. Our house is above it's rated sq/f capacity (I think it's rated at about 3500sq/f, we're right around 4k sq/f), with high basement ceilings (~10ft) and tall vaulted ceilings upstairs. So, a little past rated capacity on sq/footage, but likely far above capacity on cubic volume.

We use the Kuuma in conjuction with our existing LP furnace. My Kuuma install is thus far very basic...I plopped it down, and ran the supplied t-stat to it. I also ran a manometer. That's all. I have done none of the tips/tricks to increase efficiency/add output. Things like scavenging heat from the front of the stove for the incoming air supply, relocating plenum t-stat, and others (which I've now forgotten...I'd have to search here to find them). In addition, I'm still burning wood that I cut 3 years ago, before I knew the "preferred" sizing for the Kuuma. They are mostly short (18" or so), and BIG (used to the old smoke dragon I grew up with).

The Kuuma seems to be able to handle about a 45 degree delta on it's own. We like to keep the house at 68, with the LP set at 66. The Kuuma handles all the heating by itself until it's in the low 20's or teens outside. At that point, the LP starts kicking in.

I've not read all the pages of this thread. In fact, the top portion of this page (98) us ALL I've read. I'll go back and skim it, to see if there's useful information (I'm sure there is). However, with a "plop it down, run the wiring to the supplied T-stat, and forget it) installation I have, I'm VERY pleased with the performance of my Kuuma.

 

[motoguy]

I don't think anybody can expect to buy a wood furnace, hook it to a chimney, connect the ducts, light it and be done...if anybody has, they just got lucky IMO...I think that almost all of them require some setup work to be optimized...and some more than others obviously...Kuuma would probably be the one that I would guess would take the least amount of work...normally anyways...

This is essentially what I did with my Kuuma. Plopped it down in place of the old Avalon Arbor stove, raised it up on concrete blocks, and ran the flue to the existing chimney. I added a manometer to accurately set the draft controller. We replaced all our ductboard ducting with metal. I adjusted the pot on the computer to increase firebox temps. Other than that, nada.

After taking a season to "learn" that Avalon Arbor, and being impressed with it's heat output vs volume of wood used, I wanted to move to a furnace. However, I wanted a furnace that was close to set-and-forget. Loading the Avalon, trying to get up to reburn temp quickly, slowly ratcheting down the damper, etc etc was time consuming. A refill (or heaven forbid, a re-start) was a 30 minute to an hour deal. Not conducive to waking up, loading the stove, and heading out the door to work. I wanted something that would work that way, for convenience and so my wife/kids could safely load it.

The computer on the Kuuma effectively handles all those chores for me. I rake the ashes out, empty the pan if necessary, pull the coals forward (push them back about 2" from the front), then load that baby up. Make sure the doors are shut, and I'm outta here.

 

[DoubleB]

Could it be possible to install one of these variable speed controllers on a heat pro furnace installed in a 1900 sq. Ft shop

If I recall, the heat pro has a circuit board that automatically cycles through the 4 blower speeds to maintain temps, meaning that the circuit board has 4 output lines, each connected to one of 4 speed taps on the blower motor. If I'm remembering that correctly, you'd probably have to insert the var spd controller between the slowest speed motor tap and circuit board output. Heck, I'd be far more comfy doing it on a heatpro, since if the controller takes a dive then the heatpro will automatically kick in on speed 2 once the temp probe measures enough temperature. At least that's my understanding of how it could work...

 

[jacksnipe]

It has been done both ways...I personally don't like the speed 1, 2, 3, 4 method because the fan still moves a lot of air on low speed and you will still get the cycling on/off...the speed control that we have been using can keep the blower running at a very low speed for hours on end at the end of the burn...it made a huge difference for me.
You want to take the temp reading from the plenum IMO.

This is where I am at now, I need all of the necessary items needed to get the heat pro set up. Where do I buy all of the req'd items along with part # to start this project. It sounds like we need a fan speed controller along with a 24 volt transformer or an all in one unit. Then tap into the circuit board located on the rear of the furnace. I will have to determine which terminals are for speed 1to 4

 

[JRHAWK9]

If I'm remembering that correctly, you'd probably have to insert the var spd controller between the slowest speed motor tap and circuit board output.

IMO, you don't want to cut the low speed tap on the motor. When the low speed tap receives 65-70V it's REALLY slow and sounds HORRIBLE, at least that's what I saw on my motor when I tried it. I'm cutting the high speed tap and it's much better.

 

[brenndatomu]

IMO, you don't want to cut the low speed tap on the motor. When the low speed tap receives 65-70V it's REALLY slow and sounds HORRIBLE, at least that's what I saw on my motor when I tried it. I'm cutting the high speed tap and it's much better.

Agreed.
I like using speed 3 or 4...it lets the blower "stretch its legs" if the furnace is making enough heat to support that much air flow...

 

[JRHAWK9]

This is essentially what I did with my Kuuma. Plopped it down in place of the old Avalon Arbor stove, raised it up on concrete blocks, and ran the flue to the existing chimney. I added a manometer to accurately set the draft controller. We replaced all our ductboard ducting with metal. I adjusted the pot on the computer to increase firebox temps. Other than that, nada.

It will definitely work just fine like that, however, like with almost everything, one can optimize things for their exact situation. These furnaces come from the factory able to be used in ALL sorts of different scenarios and installation parameters....from exterior/short chimneys to fully insulated ones running inside the house. They have to be setup to work with all situations. Some of us are just taking advantage of our situation.

It's just like running E85 in those factory flex-fuel vehicles. They can run on it, but the vehicle in stock form is FAR from being optimized running on it. They are using the stock fueling, compression and timing curves when all three can be optimized to take advantage of the higher octane E85 has and see better fuel economy and more horsepower.

After taking a season to "learn" that Avalon Arbor, and being impressed with it's heat output vs volume of wood used, I wanted to move to a furnace. However, I wanted a furnace that was close to set-and-forget. Loading the Avalon, trying to get up to reburn temp quickly, slowly ratcheting down the damper, etc etc was time consuming. A refill (or heaven forbid, a re-start) was a 30 minute to an hour deal. Not conducive to waking up, loading the stove, and heading out the door to work. I wanted something that would work that way, for convenience and so my wife/kids could safely load it.

yep, pretty much sums it up. I can go from a stone cold furnace to walking away in under 5 minutes if I need to.

 

[motoguy]

It will definitely work just fine like that, however, like with almost everything, one can optimize things for their exact situation. These furnaces come from the factory able to be used in ALL sorts of different scenarios and installation parameters....from exterior/short chimneys to fully insulated ones running inside the house. They have to be setup to work with all situations. Some of us are just taking advantage of our situation.

It's just like running E85 in those factory flex-fuel vehicles. They can run on it, but the vehicle in stock form is FAR from being optimized running on it. They are using the stock fueling, compression and timing curves when all three can be optimized to take advantage of the higher octane E85 has and see better fuel economy and more horsepower.

Agreed. I intend to make these changes as we work through the basement remodel. It has not been a priority in the past.

yep, pretty much sums it up. I can go from a stone cold furnace to walking away in under 5 minutes if I need to.

Yup. I love it.

 

[DoubleB]

When the low speed tap receives 65-70V it's REALLY slow and sounds HORRIBLE, at least that's what I saw on my motor when I tried it. I'm cutting the high speed tap and it's much better.

Interesting, I used the lowest speed tap and I can't even hear the blower blowing. But I believe you if those were your results.

I like using speed 3 or 4...it lets the blower "stretch its legs" if the furnace is making enough heat to support that much air flow...

For the Tundra1, I can see that. But for the heatpro, the circuit board already kicks into high speeds if the temps start getting warm enough. If you put the var spd controller on speed 2, 3, or 4, I'd worry that the var spd controller couldn't vary the speed once temps start to cool down, because then as temps cool down the circuit board would switch the power to a lower speed tap anyways and bypass the var spd controller. And if you put the var spd controller on low speed, you can always increase the min voltage quite a bit.

But I don't have a heatpro, and I'm not using my var spd on my Tundra anyways, so it's just talk from me.

 

[JRHAWK9]

Interesting, I used the lowest speed tap and I can't even hear the blower blowing. But I believe you if those were your results.

really? even with the high speed tap my blower makes a whew, whew noise when getting down to that 65V area. In my experience, when using the low speed tap, it's pretty much the same as giving the motor like 40V on the high speed tap. Maybe different motors react differently though. The reason I wanted to try the low speed tap was to see how much I could slow down my blower in order to increase the heat rise though the furnace. As soon as the blower turned on using the low speed tap and the controller slowed it down I could tell by the noise the blower was making that is was not going to work. It just seemed like it was turning WAY too slow.

 

[brenndatomu]

For the Tundra1, I can see that. But for the heatpro, the circuit board already kicks into high speeds if the temps start getting warm enough. If you put the var spd controller on speed 2, 3, or 4, I'd worry that the var spd controller couldn't vary the speed once temps start to cool down, because then as temps cool down the circuit board would switch the power to a lower speed tap anyways and bypass the var spd controller. And if you put the var spd controller on low speed, you can always increase the min voltage quite a bit.

Ah, I see where you are going there...makes sense.

 

[Matt78]

code - description - setting
HIAH - high limit alarm - 3000 (default setting)
LoAH - low limit alarm - 255-275
HdAL - deviation high alarm - 3000 (default setting)
LdAL - deviation low alarm - -999 (default setting)
Loc - parameter lock - 808 (unlocks rest of parameters)
AHYS - alarm hysteresis - 100
AOP - alarm output assign - 111 (default setting)
CtrL - control mode - onoF
Act - n/a - rE (default setting)
P - proportion band - 30 (default setting)
I - time of integral - 100 (default setting)
d - time of derivative - 50.0 (default setting)
Ctl - control period - 20 (default setting)
CHYS - control hysteresis - 200
InP - thermocouple type - 5 (selects J-type thermocouple)
Scb - input shift - 0 (default setting)
FILt - pv input filter - 1 (default setting)
Fru - input hz and C or F - 60F (60 hz , F)
SPL - low limit of set value - 0 (default setting)
SPH - upper limit of set value - 1000

3fordasho, I've been experiencing some technical difficulties with my temp control. Hopping you or someone could help. What's been happening is. It's been acting like the wall timer is active all the time. Thinking this was the problem I installed a new timer but no difference. I have control set up like above except the AHYS is at 175. High limit 550 degrees. Low 250 degrees. Right now it always wants to run up to the 550 degree Mark before closing damper. Then opens around 350 degrees. Normally I believe it would open and close at 250 and 440 with timer at zero. Hopefully I explained good enough. Guess I should of wrote my settings down. And where it exactly opened and closed.

 

[3fordasho]

3fordasho, I've been experiencing some technical difficulties with my temp control. Hopping you or someone could help. What's been happening is. It's been acting like the wall timer is active all the time. Thinking this was the problem I installed a new timer but no difference. I have control set up like above except the AHYS is at 175. High limit 550 degrees. Low 250 degrees. Right now it always wants to run up to the 550 degree Mark before closing damper. Then opens around 350 degrees. Normally I believe it would open and close at 250 and 440 with timer at zero. Hopefully I explained good enough. Guess I should of wrote my settings down. And where it exactly opened and closed.

Ok, First thing to check is to make sure everything is wired per the diagram I posted. It does indeed seem that something is closing the thermostat terminals when it should not be. With your current settings the control setting at 550F cuts power to the damper motor at 550F and with a CHYS of 200 will re-establish damper motor power at 350F. It seems this part is working correctly. Now with a Low alarm of 250F, the controller closes the thermostat terminals on the tundra at 250f and with a AHYS of 175 should open again at 425F. But it appears this is not happening until you hit your control setting at 550F and cutting power to the damper motor. So now you have to look for what is holding those thermostat terminals on the tundra closed.. could be a shorted timer/wiring, thermostat (if you have one) calling for heat or shorted thermostat wiring, damper switch on the tundra in the on position, and finally shorted low alarm contacts/wiring on the temp controller itself. All these things (all switches) are wired in parallel with those terminals on the back of the tundra. Begin by disconnecting each of these things one at a time until you find the culprit.


One more thing to check, the temp controller has LEDs below the digital display to indicate control and alarm contact operation. Labelled OP1 and AL1. OP1 should be on until you hit your control setting at 550f, shut off and remain off until temps drop 550-200= 350. AL1 should be on at 250f or less, then shut off at 250F+175=425. If the LEDs are not acting like this you need to check your controller settings.