Back to work

I know I cut off kind of abruptly at the end of last year, but I had it functional enough to heat my house and my wife was strongly urging me to get back to remodeling the inside of the house. I ran it pretty much the way it looked in my last post for the remainder of the winter with few issues. It is early fall now and we have had to kick on the stupid heat pump twice already, so it is time to get back to work on the wood stove. In the plans for this season are rerouting the water lines so that they run a more direct path into my house and building a structure around my stove.
   





  I never got the lines insulated, so they never got buried. That meant that it wasn't a big deal to move them. I decided on a shorter more direct route that would leave less line outside, but would mean I had to cross the living room in the basement with them. That decided I bored two more holes through my foundation and fed the lines through. I  used cpvc pipes to run up the outside of the house and the pex line inside.













 That left insulating the pex on the outside of the house. I had decided last year that instead of buying the outrageously priced ThermoPex I was going to make my own. I bought 4 inch sewer pipe and used that to encase the lines. I first wrapped them in fiberglass insulation that I had cut into strips and secured with duct tape.
 I got all the line wrapped and put in the pipes and the pipes put together.
 

So far they are just laying on top of the ground because I haven't got around the burring them yet. When I posted about doing this on Arborist.com last year I was told that I would have too much heat loss to make this a viable option. However, I don't think that this is going to be an issue because it snowed last night (it has been about 4 weeks since I composed the beginning lines of this post) and when I cam out this morning there was snow touching the pipe. The fact that there wasn't a few inches of bare ground around it like there was on the naked pipe means that I have made quite and improvement.
   

 The final really big piece of my project was to build a building for my stove to go in. My natural aversion to spending money prevented me from just going out and buying one, though I did at least look into it. When a relative had his property bought out by a coal mine he told me that I could use whatever I could get out of an old machine shed I was in luck. I harvested a couple of sections of the side of the building to be the sides of my building. I decided that the easiest configuration to go with would be and A-frame since that wouldn't require me to build a room. At first I tried to do the math on what kind of angle I would need if I knew all the side lengths of a triangle but not any of the angles, but that led me into the territory of trigonometry, which I evidently haven't retained a working knowledge of. After failing to find the angles I decided that I would use hinges so that I could play with the angles, however I couldn't find any laying around.  What I did have laying around was some main drive belts from the Claas combines that I work on. Cutting those into sections with a chainsaw I used them for hinges.

Using them actually worked really well. I not only used the pieces on the top, I also used them to attach the skids at the bottom.  I then put braces towards the top of the frame to hold the angle.

One of the unforeseen benefits of doing this was that when I lifted the section of wall I had into place the flexibility of the belts allowed for certain inconsistencies in my carpentry skills. I attached the wall sections to the frame I had made, trying my best to get everything straight.

After getting the sides put on I decided that I should move it to it's final location before I put the front and back on. It took me three different plans to successfully find a way to pull the building without destroying it. I got it pulled next to the stove and then used my truck to set it over the top. 

I got it in place and secured the tin where nails had come out and where I had replaced the boards. Since it was covered now I put more fiberglass insulation over it to replace the stuff that had been ruined by the weather. 

With all that done I decided to bump my water temps up to 170 degrees from 150. Doing this made the heat coming out of our vents a little hotter and more pleasing. Over the next few weeks I am going to add a front and a back to the building and also an overflow water tank.

More install and some fine-tuning

Lets see, I left off last time with the holes drilled and the exchanger in, so I will start with the inside hook up. Here are the pics. You will see that I have valves to be able to manually shut off the flow to the exchanger and a pressure gauge. I used a mix of cpvc pipe and pex.

I also installed a valve so I could fill my water tank from inside the house.

Also in the top picture you can see a grey box strapped to the pipe. That is my indoor aquastat that breaks the connection from the thermostat in the house to my power hungry heat pump compressor. It kicks the heat pump off when the water temp in the pipe goes above 80 deg.

Here is a picture of my completely uninsulated pex pumping the hot water to the house. I am eventually going to bury it, after I decide how best to insulate it. I am not loosing near as much heat as I thought I would. (Google automatically added the snow when I uploaded it to Google+)

Here is a pic of the top of the wood burner. You will notice I had to add insulation.
When I first hooked this thing up I couldn't keep temps above 120 until I put this insulation on there. Another thing I had to change from my original design was the water return location and the vent location. This all resulted from the fact that I didn't put enough effort into researching what actually goes into designing a hydronic heating system. I ordered 3/4 pex because that was one of the options for the pump I bought and because of the cost savings over 1 inch. I turns out that between my 3/4" lines, the length of the run and the fittings I had a really high head pressure that resulted in very low flow, even though I had a large pump. As a consequence there the water wasn't be circulated through the tank like I thought it would so the water around the burn chamber was boiling and going right out the 2 inch vent above it. To remedy that I took the return line from the back of the tank and put it into the 2 inch fill/vent. I capped the 2 inch vent and instead put a piece of 3/4 inch cpvc in the port where the return had been. The idea being this would cause the water to naturally circulate to the back, it has cut down on water loss.

Another issue I had once I got this thing running was the fact that it was eating MASSIVE amounts of wood. I figured out this was due to the fact that my blower fan ran full blast all the time. I bought a dimmer switch instead of the correct part and it only kind of works, but slowing the fan down saved me a lot of wood and raised the heat in the tank. It will actually go over 150, but it still won't hit 180.

Beginning the Install

We got the wood burner transported to the house and unloaded, so now it is time to start the install. The first thing I did was to install the blower and the aquastat and wire them up. Fun side story... I couldn't wait to try it out until I had filled it up with water, as a consequence I melted the wires running to my aquastat probe. Luckily, though damaged, I can repair it with little trouble.

 

Then the less fun part of drilling the holes through my basement wall to run the lines through. My Dad's concrete bit set has some gaps in it so I my options jumped from a half inch bit to an inch and an eighth. Since I am running 3/4 inch lines I had to go with the bigger one. To use that thing one of us held it steady while the other one used a 2 by 4 as a pry bar to push it forward. Here is a pic of the holes with my had for perspective.

 Finally got the holes drilled then installed the heat exchanger in the duct work right under the furnace. I wanted to put it after the furnace but it wouldn't work out so I had to go below. I am not an HVAC guy so this install is a bit unconventional. To hold the exchanger in place I used 1x4's the I had left over from other projects.

My OWB build.

     I have wanted an outdoor wood stove for several years now, but price has prevented me from committing. While lamenting this fact to a coworker one day he said "why don't you just build your own?" I was intrigued when he told me it was not that hard and that he had built one of his own, and sold when he said he only spent around $2200.
      With that I began to assemble materials. Luckily for me I had access to two tanks already, so that major expense was down. I started with a 250 gallon anhydrous ammonia tank that would be my burn chamber and a 500 gallon propane tank that would be my water jacket.  I started by filling the propane tank full of water to flush out any residual gas and then cut the end out of it at the weld. I did the same thing with the anhydrous tank. I laid the two ends on top of each other and used the smaller as a guide to cut hole for my firebox to poke through. I then put the firebox end aside to use as a door later.

     After that I prepared the smaller tank to go in the larger by welding feet onto the it so it would stay level. In the pic below I am checking fit.

                                           

 I also welded ports closed and made sure everything was air tight. I welded the ring of the larger tank on the smaller one. I then slid them together and welded everything. This is the part that took the longest. I plugged all the ports but one, and attached an air hose to that one. I pressurized it and sprayed soapy water over everything to check for leaks. Then I let the air out welded the suspect areas and did it all over again. It felt like it took forever. Here is a pick of it hoisted up as I am looking for leaks.

After the two tanks were together I welded in the ports I would need in the water jacket. A fill port, suction port, return port, and a port for the aquastat.

My next problem was figuring out how to seal the door. My first plan didn't work out though. I put metal strapping on the the inside of the firebox and fire gasket sandwiched between.

It seemed like a good idea but ended up being too close together to get the door in so I had to cut the outside strapping off. To get the rope gasket to stay on I tied it in a circle and slipped it around the inner strapping. To be sure I got a good seal against the gasket I bent some 1/2 inch round stock in to a circle and welded it to my door. Here is a pic of my dad heating it with a rosebud to relieve the stress.

So with the seal in place the door was ready to go on. It took us two tries to get a design that worked for the hinges. Luckily we have lots of scrap metal laying around. Using some parts from a field cultivator and an old combine we built a hinge heavy enough to support this huge door.

Once I got the door on there I used shims to get it to close correctly and then slathered the hinge in good Cat high temp anti-seize. With the door shutting now I built a hinge out of an old piece of a planter and some teeth from a harrow.

After seeing that other people that built these insulated their doors I took the left over piece of the propane tank cut it down a little and then welded it into my door as an air gap.

To finish out the door I added the tube to mount my blower and a cover to keep the rain off of it. You can see in this picture where I patched a hole after a mid-build design change.

The door was finished so the last major item to be tackled was the chimney. I decided to use a 7 inch fire extinguisher that I had as a chimney, so I cut a 12 by 12 hole through my water jacket and then tried to cut a smidgen over 7 inch hole in the fire box. I failed. The fire box hole was too big. We decided to break out the MIG welder because of the thinness of the fire extinguisher. This meant we had to spend four times as long making sure everything was clean, and that there were no drafts in the shop since this weld would need to be perfect. We also ended up wrapping some half inch round stock around the hole to use as filler. This worked pretty good, we only had one spot that was suspect. In order to clean that spot up dad pulled out his Air-Arc and I cut the imperfections out and re-welded.  I then rolled the tank over and got inside the firebox and welded it there as well.

I then welded the outer portion back on, but due to a lack of the finer points of machine work, I got the hole off and it didn't fit quite right. I just added some filler and welded the gaps. Then came pressure checks and re-welds.

With all the major things done now all I had to do was a little finish work. I am eventually going to add a taller chimney that will sit next to the unit, but until then I need to add a dampener to this one. I did this by taking the end that I had cut off and welding a nut to it and then welding a bolt to a piece of metal that I inserted into two slots cut in the stack. That way I can screw it up and down to adjust draft.

The last thing I did was add a box to put the aquastat controller in.

With everything done that I could get done in the shop it was time to load it up and take it to the house. Here we are loading it on the trailer.

I will post more as I get it installed.