Building a House for the GARN

I didn't give a list of costs, since our project is quite unusual. We have been able to call upon help from friends at Nomaco in the past, so the Imcolock was free. The Rehau pex was also free, again thanks to some very generous friends who have helped out many time before in our project. I do know what this would cost if all products were purchased, and I still would have been able to assemble the needed materials and install for less than a quarter of the usual price for the different pre-insulated brands go for.

The supply and return lines are each in separate sleeves, and the ends are sealed with PUR foam, so are completely waterproof with no air movement. The polyolefin insulation we used gives us an R-value of about 6. Without a consistent air gap I figured the foil radiant barrier wouldn't be worth the effort.

Even though I was not looking forward to messing with big pex and pulling it through the carrier pipe, that turned out to be the easiest part of the job. Cutting the hole in the kitchen basement wall was actually the hardest work, since we couldn't afford to hire a core-drill, and I ended up using our ICS chainsaw to cut a rectangular hole. Spending time deep in a trench with a +100 cc saw burning 25:1 mix left me feeling rather queasy for some time afterwards.

I would have liked to make the boiler room bigger to store more wood, but had to compromise because we feared a bigger addition would not be as aesthetically pleasing in that spot. We decided instead to retain many of the hundreds of crates the limestone veneer came in, and we have been for the last months storing and stacking firewood in one of our nearby pole barns. The firewood is now palletized and we can move it with the forklift or the farm tractor. We should easily be able to store in the boiler room about 2 cords at a time. I think it will be a nice system, since I can go down one of the old roads in the forest carrying empty pallets on the front and back of the tractor, and fill them up as the wood is cut. It is easy to move the pallets around in the boiler room with our pallet jack, so handling should be reduced to the minimum.

ICS has a line of saws called the Redzaw which was brought out only three or four years ago. At that time we were cutting a lot of the limestone for our church and tower here, and needed to make deeper cuts than a typical cut-off saw with 14" wheel could handle, ICS agreed to donate one of their early demonstrator Redzaws with a 14" bar, and they made use of our project in their promotion of the new tool.

At the time I was aware of pricing (now several years out of date) the Redzaw line was about 75% of the cost of a regular duty ICS saw. Since we have handled several million pounds of limestone, and poured a couple thousand yards of concrete, we have found plenty of jobs for this useful tool.

On the topic of bubblewrap, how much R value do you think it adds to an assembly? Obviously I don't know much about how that wrap works, and would be very interested in hearing how it is used by others. I presume you must use reflective tape on the joints.

Just a week before Easter I finally, at long last, got the roof put on the addition to house the new Garn boiler, and last Monday we moved the Garn into place. It turned out to be quite easy to move around with a pallet jack, since it is not nearly as heavy as it looks, although ours (a Garn 1500) is still every bit of 3500 lbs I think.

I have just about assembled all the parts needed to plumb the Garn into our system, as well as build the insulated enclosure around the tank, and will post more photos as the installation proceeds. Hopefully the plumbing and other work will be much quicker than my block-laying was.

After spending much of the spring and summer working in the vineyard and garden, I have finally been able to finish plumbing the Garn into our radiant heating system, and am now building the enclosure to insulate around the tank. We filled it yesterday, and no leaks are apparent, so we will fire it in a couple of days and make sure there are still no leaks before we begin insulating.

Here are a couple photos of the new installation. One shows the hx for the domestic hot water loop, and the other shows the two 1.5" pex lines from the Garn, their transition to copper, and the bypass so we can run the Garn in summer without heating the radiant injection loops.

The Garn is now fully piped and filled, and will be fired this very afternoon. More news to follow.

The hx is from FlatPlate whose instructions show installations in both vertical and horizontal positions. Our water is filtered and treated on the boiler side, and filtered on the domestic side.

I perhaps should have labelled the photos better, but the last pictures show the kitchen basement plumbing, not the Garn enclosure, so the two flues are the backup oil-fired boilers.

Hello Heaterman,

We will probably be turning on the radiant slabs in the fall before they have had a chance to cool down much, but I know you are exactly right about the uselessness of setbacks for such a thermal mass.

Right now, though, we are heating just the hx for the domestic hot water, and finding that about one fire in the Garn each week gives us plenty of hot water, and we may even be using more hot water than usual since it feels free. I will need to do some figuring to tell you better how much hot water is being used. For now all I know for sure is we have fired the Garn until the tank is nearly 200*, and it is still just above 120* a full week later.

Our Garn is well insulated with vermiculite, and framed in with steel studs on two sides, and AAC block on the other two sides, so the heat loss is extremely minimal. One nice thing about the vermiculite is that any mouse who wants to take up residence in the enclosure will think it is in quicksand, so the open top to the insulation is not the problem I thought it would be.