Is wood that's too dry actually bad?

[NE_Chris]

I built an epic wood shed with a clear polycarbonate roof to keep my firewood super dry and warm. When I tested it with a moisture meter, I got readings of 3% to 7% moisture in the wood (mostly oak, hickory and maple). I was told that was too dry (with 15% to 20% being optimal), and might be why my new fireplace insert is burning TOO COOL--can't get it up to even 500 degrees on the door surface). I had thought that dryer wood simply burns more efficiently, so that the potential problem is that it burns too hot and fast and could damage your stove if you are not careful. I actually split my pieces a bit on the large size to counteract that. So, first question is whether my low temperature problem could be due to my wood being too dry (does not make sense to me), and my bigger question is in general if it really is a problem if wood is too dry--assuming you don't overheat your stove using it.

 

[begreen]

When testing, did you split the thicker splits in half and then test on the freshly exposed face of the inner wood? 3-7% is extremely hard to achieve even commercially.

And yes, that would be too dry.

What insert is this in? Does it have a stainless steel chimney liner? If so, how tall is this liner?

 

[Poindexter]

I have accidentally kilned some of my cordwood down to 8%, and yes it is a problem for modern stoves.

I agree with begreen, do crack a split open and then stick your pins in parallel to the grain on the freshly split face a few places and let us know what you find.

I did talk at some length with one of the stove mfr executives, user name here is BKVP. Nationwide, folks that get their cordwood split, stacked off the ground and top covered can generally get to about 20%MC if they wait long enough. If you stare at enough maps and charts, and limit yourself to looking at areas of the USA where people might really need to use woodstoves you too will find 18-22%MC is about all anyone can plan on without some kind of (polycarbonate) assist.

What I recall @BKVP telling me was the break point for most modern stoves is going to be around 12% MC. Above that (my stove runs best around 14-15% MC) the stove will run hot and fast (yes please) but still safely, and settle into the performance the mfr expects in the 16-20%MC range, with up to 22% allowable. Also IIRC from BKVP, when you start burning fuel under 12% you can easily get into burning too hot and too fast and damage your stove.

The one year I had a bunch to burn at 8% was too much trouble, I haven't painted myself into that corner ever again. I was having to vacuum off the face of my combustor every week or so, brush the fluffy bits out of the chimney pipe right regular, it sucked.

If your wood seasoning process can return product under 13%MC it is not a problem you will be willing to deal with year after year. I tend to open my kilns around 12% MC in late summer and let the fuel glide back up towards 15% before freeze up.

I will also tag @Woodsplitter67 , his kilns are capable of making crispy critter cordwood also.

 

[NE_Chris]

When testing, did you split the thicker splits in half and then test on the freshly exposed face of the inner wood? 3-7% is extremely hard to achieve even commercially.

And yes, that would be too dry.

What insert is this in? Does it have a stainless steel chimney liner? If so, how tall is this liner?

It’s a Pacific Energy Alderlea T5 and it has a stainless steel liner. Not sure exactly how tall, but it’s fairly tall. My last stove, a Hearthstone Heritage, had no problem getting enough draft.

One other difference is that the PE insert does not have a fresh air intake like my Hearthstone did. It was supposed to support it, but Pacific Energy lied in their product information and even in their manual. When I wrote to them to ask about the discrepancy, they just ignored me. So I’m not too happy with PE now.

 

[PA. Woodsman]

A few months ago I got some really dry wood off a porch of someone I know from work and thought it would burn good being so dry like you thought. It had had bugs in it as there were holes and sawdust was pouring out from it but I figured I'd use it and have found that it is good when I have the fire going already, trying to start a fire with the smaller kindling like pieces it doesn't work very well, so I'm just using it up as the fire is going and then it works okay. I don't know what the MC is of it but it has to be in the single digits I'm sure.

Live and learn I guess....

 

[begreen]

It’s a Pacific Energy Alderlea T5 and it has a stainless steel liner. Not sure exactly how tall, but it’s fairly tall. My last stove, a Hearthstone Heritage, had no problem getting enough draft.

One other difference is that the PE insert does not have a fresh air intake like my Hearthstone did. It was supposed to support it, but Pacific Energy lied in their product information and even in their manual. When I wrote to them to ask about the discrepancy, they just ignored me. So I’m not too happy with PE now.

The Alderlea T5 LE and the Super LE inserts both have an outside air supply option. This is covered in detail in the manual on page 18.

If the liner is over 25' tall then it is likely the draft is very strong. In this case, sealing off the boost air intake port can notably improve control.

 

[NE_Chris]

The Alderlea T5 LE and the Super LE inserts both have an outside air supply option. This is covered in detail in the manual on page 18.

If the liner is over 25' tall then it is likely the draft is very strong. In this case, sealing off the boost air intake port can notably improve control.

Thank you for the additional comments.

The Alderlea T5 insert I received claims to have an outside air option, but it is a lie. Claim is that just sealing around the surround and having air come in from the clean out would work. But the opening on the back bottom of the stove, the back of the stove, and the area around the flue pipe are all open to each other (can shine a flashlight between them all) and there is a 6” wide opening in front of the flue pipe to the air stream from the blowers. So, the front and back and bottom of the stove are all open to each other even when the front plates and surround are sealed.

I’m having difficulty getting the stove hot enough, not with it getting too hot.

 

[begreen]

The convection plenum is sealed and not open to the fireplace interior.

What temperature is the stove at and where is it being read? Is there a block-off plate in the damper area? How tall is the liner on the stove?

 

[NE_Chris]

The convection plenum is sealed and not open to the fireplace interior.

What temperature is the stove at and where is it being read? Is there a block-off plate in the damper area? How tall is the liner on the stove?

What I am saying is that this is not true. If I were to push air from the fresh air supply in the basement up through the clean out, it would come out the front of the stove where the blower discharge the air! Now this particular unit I have may well have been manufactured wrongly (two welds were missed on it, which was not a good sign), but the front and back of the combustion box enclosure are not separated from one another.

Again. I don’t know the exact height of the chimney, but it’s probably just over 20 feet, with a plate sealing it on top, and 6” mineral fiber packed around the stainless steel flue pipe where the fireplace damper originally was. Chimney goes from 1st floor where the stove is, through 2nd floor and then about 4 feet past the peak of the roof.

I can only get the stove up to a maximum of under 475 F no mater what I do, and over 400 is difficult. And that is measured both with a stove thermometer and a high quality IR temp gun on the middle of the bottom of the cast iron door (both devices agree on temp).