Here's my take on HH with some amateur back-up data.
I use them, and I agree after using them for 3 years there is no way they can season green fresh cut wood in three months. Based on my readings, I don't think they're better than standard ricks or rows, and indeed, as the results of the original posters experiments shows, which I am not refuting here.
So, why do I use them?
Simple, I live on 10 acres of heavy woods. The idiot who built the house didn't knock enough trees down and I have extremely limited space to store my wood that gets sun. I have plenty of wood supply, but no place or very little place on my property that gets sun, let alone wind, all day or even 1/2 of a day, except very few small areas. I keep pulling more trees down as time goes on, but since they're so close to the house, it's a time consuming process, in the interest of safety and the size of these things (usually 70-90' 1-2' diameter red or white oak or maple), I spend half a day rigging cables and pullys and winches and multiple tractors and and trucks as ballast, safety gear to ensure it falls exactly where I want it, so it's a very slow process, for me. So, until I get enough space cleared for row or rick stacking, I use the HH method. Right now I have 2, a 9.5' and a 6', and they get sun the majority of the day. The 6' was split/stacked Mar 2010 (originally in a 10' and then restacked mar 2011 into it's 6'), and the 9.5' Mar 2011.
So, what are my results? Well, I do have a moisture meter, but I've never run controlled experiments. I do take readings however.
My wood is usually dead wood, that said, it's still 45-50% moisture content, to start. I cut and split and stack.
A year and some months later, coming out of the holz, yeah, the inner pieces do seem "wet" if you will, but, that's only surface wetness, not really important and dries up in a day or 2. When I split and take a reading, it's usually in the high 20's. (red/white oak and maple), ok, not so good. The first year I did make make a small row stack and it got low 20's after the same period of time.
But, here's the vexing part, I move from the HH to the big covered front porch I have for easy access from the house on a regular basis to stock my indoor wood rings. My porch holds about 3 face cords. Usually, it's on the porch for about a 3-4 weeks, I stock it up in fall and as each face cord gets burned I bring another face from the holz up to the porch. It gets some wind and western sun in the afternoon. After sitting on the porch for the better part of a month, and then inside for a few days, when I split and take another reading, I get high teens, some low 20's on the bigger splits.
How's that? Well, I've contemplated that for a while. My best theory is, wood pours open up over time, and time alone, wood can never again hold the same amount of moisture it once did after seasoning. In a HH, the pours still open up, but there's not a good place for all that moisture to be released. But after stacking loose on the porch and inside for 3-4+ weeks, that moisture is readily released quickly because the wood pours are already open.
I do think there is something to the draft effect of a HH ,certainly the inner pieces are more surface wet than the outer pieces, but it's not a nasty mold mess inside the HH like I envisioned the first time I built one . But I did measure once with a temp probe, on a nice calm day in the fall, it was 42 ambient outside, the bottom of the stack was 42, and when I got a ladder and put the probe at the top of the stack, it was 45, i retook those measurements several times, and then several more times over the next few months, different ambient, but always the same delta, 3 degrees. Anywhere where there's a temp difference, there's gonna be air moving. Or it could have been just the nature thermal mass of the stack, who knows.
The HH's work for me thus far, I'd prefer row stacking. I will say one additional thing, they are a major conversation piece. When we have people over entertaining in the summer, it is always brought up and talked about, invariably, even if they've been here before and seen them.
Just my $0.02!
Rick
