Forced Air Wood Furnace that works with Zoning?

[usernametaken]

I am in the later stages of planning a new home build. I am was pretty much locked into LP hydronic radiant with a Tarm Froling S3 Turbo in parallel. However, after getting my first quote, I've managed to give myself a moderate heart attack. I have another HVAC contractor working up a competitive number but in case I need to scale things back, I am researching other, less expensive options. I had considered the Caddy Max (new home has approximately 3400 sq/ft) but after speaking with their tech line, I learned that their unit doesn't play nicely with a zoned system. Our house is to be a simple center hall colonial so 2 zones there. 1st floor and second floor. Then a 3rd zone will be needed for a bonus room over the garage. So, the question is... like the thread title states... are there any quality forced air wood furnaces that will work with a zoned HVAC system? Thanks in advance for any thoughts or advice...

 

[brenndatomu]

I am in the later stages of planning a new home build. I am was pretty much locked into LP hydronic radiant with a Tarm Froling S3 Turbo in parallel. However, after getting my first quote, I've managed to give myself a moderate heart attack. I have another HVAC contractor working up a competitive number but in case I need to scale things back, I am researching other, less expensive options. I had considered the Caddy Max (new home has approximately 3400 sq/ft) but after speaking with their tech line, I learned that their unit doesn't play nicely with a zoned system. Our house is to be a simple center hall colonial so 2 zones there. 1st floor and second floor. Then a 3rd zone will be needed for a bonus room over the garage. So, the question is... like the thread title states... are there any quality forced air wood furnaces that will work with a zoned HVAC system? Thanks in advance for any thoughts or advice...

Why do you really need zones with a wood furnace...you would just let all the zones open up when using the Max, I think that would work fine. But, I disagree with SBI that a Max (or most any wood furnace) would not work with zones...you just need a good HVAC guy to set it all up for you...the main thing would be to make sure that no matter what, there is always a minimum amount of open duct area so Max wouldn't over heat from lack of air flow...seems like a pretty simple issue to sort out.

 

[maple1]

What is the rest of your system going to be?

I think if I was building new, my HVAC system would consist of some mini-splits, and a nice wood stove.

 

[usernametaken]

I think I found my own answer. Instead of radiant I'm going to go with hydro air. That way I can use the central AC ducting for the wood heat by way of heat exchangers and air handlers without the expense and complication of a full on radiant install.

 

[Bad LP]

I think I found my own answer. Instead of radiant I'm going to go with hydro air. That way I can use the central AC ducting for the wood heat by way of heat exchangers and air handlers without the expense and complication of a full on radiant install.

I'm sure you realize it's an apples/oranges comparison. Nothing beats a warm floor in the winter. Tile in high traffic areas wears like iron. Setting the pex into gypcrete has a lot of mass to carry but the down side is it takes a long time to come up if you set back too far.

If my AC system craps the bed I'll put in a heat pump and proper coil for quick recovery and shoulder season use when the radiant really isn't a good option. I did stub my manifold for a water coil in the fan coil unit for the future.

If forced into a corner with one or the other (radiant or fha) I'd go with radiant all day even fossil fueled. I love the radiant that much. Splits are an option as mentioned but I really don't like the look on the wall. I've had split AC system for 25 years.

I like the wood boiler route but it is a big expense added onto the overall HVAC systems that were already installed. IIRC the System 2000 firing rfh in gypcrete and baseboard plus the Thermo Pride central AC was 30K 13 years ago.

 

[usernametaken]

I was never in it for the radiant floor. I just wanted to use the Froling boiler so it went hand in hand. I actually prefer the quick recovery of forced air along with the ability to turn down the system at night for more comfortable sleeping. So, for my needs, forced air was always better. I just hadn't figured how to incorporate that with hot water until today. This also frees me up to do the prefinished hardwood of my choice as many don't play well with radiant. I may still do a loop of radiant in the master bath or kitchen. The flexibility of hot water is a great thing. I know I'm doing a heat exchanger and a Modine type heater in the garage too. Plus a loop to the HW heater.

I think everything is a compromise. Radiant feels the best in the cold of winter but in the spring and fall when it's cold at night and warm during the day, your floor will still be producing heat when your AC kicks on in the afternoon.

 

[brenndatomu]

I love the radiant

Me too...but not enough to fork over all the extra dough $$$

 

[sloeffle]

I am in the later stages of planning a new home build. I am was pretty much locked into LP hydronic radiant with a Tarm Froling S3 Turbo in parallel. However, after getting my first quote, I've managed to give myself a moderate heart attack.

I'm sure you realize that you got a quote for one of the top of the line wood boilers out there ? I'd be interested in what a quote would be for middle of the road boiler. @maple1 can probably point you in the right direction there.

I had considered the Caddy Max (new home has approximately 3400 sq/ft) but after speaking with their tech line, I learned that their unit doesn't play nicely with a zoned system. Our house is to be a simple center hall colonial so 2 zones there. 1st floor and second floor. Then a 3rd zone will be needed for a bonus room over the garage. So, the question is... like the thread title states... are there any quality forced air wood furnaces that will work with a zoned HVAC system? Thanks in advance for any thoughts or advice...

To me this is a yes and no question.

Yes - if you are able to have a dump zone ( basement maybe ) or you can have at least one zone open at all times. Like @brenndatomu said, you might run into ducting issues though. A wood furnace isn't like a heat pump or gas furnace, the heat doesn't stop when you "turn it off". If there a no zones calling for the heat, the wood furnace will still be putting out heat due the fire in the firebox.

No - if your HVAC company is not will creating a dump zone or have at least one zone open at all times.

A lot of HVAC companies don't want to deal with wood furnaces so you might be back to square one before you started. I don't mean to sound like Debbie Downer but that is a common problem that a lot of folks have.

 

[usernametaken]

Oh, I realize that this is the BMW of boilers for sure but the price of the wood boiler was not the excessive part of the quote. That was the one part I was prepped for... I think I have my situation sorted now though. Thanks for the thoughts!

 

[brenndatomu]

Oh, I realize that this is the BMW of boilers for sure but the price of the wood boiler was not the excessive part of the quote. That was the one part I was prepped for... I think I have my situation sorted now though. Thanks for the thoughts!

I'd say with just about any boiler setup, the boiler itself is only half the cost...and depending on what you have in mind for the type of heat emmiters, and how elaborate it will be, maybe more like 25% of the total cost. (as you already found out)
A full radiant install is probably about the most expensive setup too...so yeah, I bet your estimate did blow you off in the weeds!

 

[usernametaken]

Yep, the complete HVAC system cost more than sticking up the house!

 

[brenndatomu]

Yep, the complete HVAC system cost more than sticking up the house!

[coughs]

 

[sloeffle]

Yep, the complete HVAC system cost more than sticking up the house!

That is nuts. I didn't realize that hydronic heat was that expensive.

Our two furnaces cost almost 20k but we received a 30% rebate from Uncle Sam and money back from our electric co-op to help offset some of the costs. With the rebate from Uncle Sam, the geothermal unit was a little more than a dual fuel ASHP / propane furnace.

 

[usernametaken]

The cost is multifold. First off, it's three separate systems installed at once. AC, traditional LP boiler, and wood boiler. Then add running radiant floor throughout the entire 3400 sq/ft house as well as thermal storage. Lastly add the indirect hot water heater and a good deal of 6" class A chimney for the wood boiler and man... you've got a huge project! There is a MA biomass rebate that will help with the wood portion but that's small cash relative to the entire install.

 

[sloeffle]

Now I can see how that would get really expensive really quick.

When I hit the lottery, I'll have a system similar to what you described. I have cold feet all winter and having heated floors sounds great.

 

[brenndatomu]

When I hit the lottery, I'll have a system similar to what you described. I have cold feet all winter and having heated floors sounds great.

Same here...except I don't play the lottery...sooo...guess ima gonna just hafta keep the Kuuma choochin along to keep the floors from freezing. I don't miss the cold floors we had with fuel oil fired FA heat one bit!

 

[usernametaken]

No lottery here either so the radiant is slashed... It will still be pricy but much more reasonable...

 

[sloeffle]

I don't play the lottery either.....HA HA. I guess I use that term to loosely describe "when money is no longer a big deal".

We have an unheated crawl space in part of our house so the floors will never be warm there. Where we have a basement ( wood furnace heats the basement ), the floors do occasionally get warm but not radiant heat warm.

 

[brenndatomu]

the floors do occasionally get warm but not radiant heat warm.

Exactly.
I was at a new years eve party some years back where the whole house had radiant in the floors...and I was in love! I think they were starting to get worried that I was never gonna leave!

 

[Wood1Dennis]

Where we have a basement ( wood furnace heats the basement ), the floors do occasionally get warm but not radiant heat warm.

This is my experience. I have never lived in a home with radiant heat so maybe I don't know what I am missing. But, with the wood furnace in the basement, in the vicinity of the tiled floors in the master bath and in the mudroom/laundry above it, the floors stay comfortable because of the heat that radiates off of the furnace in the basement below them. I have an electric heated floor in the master that runs on a program to warm it in the morning when we get up, but with the heat from the wood furnace, it is usually warmer than the set point and runs very little.

I know its not radiant heat, but the wood furnace fan runs a lot slower than the gas furnace, so even though it is a forced air furnace, the heat is a lot more even, not cyclical like a gas furnace can be.

 

[JRHAWK9]

Where we have a basement ( wood furnace heats the basement ), the floors do occasionally get warm but not radiant heat warm.

Exactly.
I was at a new years eve party some years back where the whole house had radiant in the floors...and I was in love! I think they were starting to get worried that I was never gonna leave!

This is my experience. I have never lived in a home with radiant heat so maybe I don't know what I am missing. But, with the wood furnace in the basement, in the vicinity of the tiled floors in the master bath and in the mudroom/laundry above it, the floors stay comfortable because of the heat that radiates off of the furnace in the basement below them. I have an electric heated floor in the master that runs on a program to warm it in the morning when we get up, but with the heat from the wood furnace, it is usually warmer than the set point and runs very little.

I know its not radiant heat, but the wood furnace fan runs a lot slower than the gas furnace, so even though it is a forced air furnace, the heat is a lot more even, not cyclical like a gas furnace can be.

Same here. I'm sure they are not as warm as they would be with radiant floor heat, but they are warm enough where I have no issues walking around barefoot all winter. Although I also load the Kuuma barefoot a lot of times (and sometimes barely even dressed).