! the first wofati - allerton abbey- version 0.7

Notice there are no icicles hanging off the eaves. the thermal buffer is working.

Beautiful photos, Evan!

Paul, per your concerns, I have been thinking of the door weatherproofing...

A doorstop is the strip of wood typically 1/4 inch by 1 inch, nailed to the sides (jams) and top (lintel) of a door frame to stop the door from swinging all the way through the doorway when closed. Typically, thin 1/4 inch wide strips of foam can be attached to the doorstop side facing the door so that when the door is closed, the foam is compressed and the door is sealed weather tight.

I was thinking that a more eco friendly solution than foam might be a very loosely twisted (or braided) thick wool rope glued to the stop, similar to the way fireproof rope is used to seal a wood stove door air tight. Or very thick soft rubber might work. It needs to be something that compresses to half its thickness or smaller to provide the best seal against imperfectly aligned surfaces. The stop also needs to be in the correct position all the way around as well.

You could make a modern style weatherproof threshold by stuffing an old bicycle innertube with some old rags, and nailing it to the threshold in alignment with the door stop (or slightly further toward the door opening side) sticking up slightly above the bottom of the door, so the door compresses and slides over it when closed creating a tight seal. But I don't think this would hold up against foot traffic too well.

In lieu of a modern style weatherproof threshold that uses very durable synthetic rubber, you could extend the wood stop across the threshold. I think for the threshold stop, since it will most likely get stepped on, I would make it much wider so it extends from the door stopping position, all the way to the edge of the threshold (i.e. a board rather than a strip of wood). This will stand up to foot traffic better and should be made of locust or other very hard, rot proof wood.

If you haven't already considered this, you may want to make the stop much thicker than the normal 1/4 inch to provide more surface area for weatherproofing. Perhaps 1 inch by 1 inch.

And you need a good latch that pulls the door tightly closed enough to compress the weatherproofing on the stops. A wooden "dog" similar to the metal dogs used on the hatches of ships might work, and only require a single round hole through the door for the shaft, which might not be too difficult to seal with wool and a cover plate. The dog could be carved so that it gets thicker across its width so the harder you twist it shut, the more tightly it pulls the door to the doorstops. That will give you a little more adjustability than a single position door latch, so you can dog the door tightly against the doorstops, even as the wood door and frame changes shape due to changes in temperature and humidity. If the door is a kiln dried, well sealed (waterproof) dimensionally stable door, this is less of an issue and a single position latch will do fine.

Perhaps I should visit a few of these historic buildings around here and see how they weatherproofed their homes.

Which reminds me, my Grandmother had a long tube of fabric filled with sand that she laid up against the door to stop the wind from blowing between the threshold and door, but that only works when someone is inside to put it in place.

Food for thought. Best of luck!

Brett,

Sounds like something that would be great to have you go over with me while we are both standing there looking it over.

I would like to avoid glue if I can.

The same inexpensive staples used to nail down tar paper to a roof will work in place of glue. Preferably stainless steel, which are pretty common.

I'm busy through Feb, but will touch base then.

Brett Hammond wrote:
Which reminds me, my Grandmother had a long tube of fabric filled with sand that she laid up against the door to stop the wind from blowing between the threshold and door, but that only works when someone is inside to put it in place.

I would think it would work just as well placed against the outside of the door when leaving. One would want to use very dry sand so that on freezing it could still shape itself to the door/frame interface.

This wouldn't work around my house... I have too many people who are more likely to leave the door open, let alone remember to do anything extra after closing the door. That may change if we were living somewhere colder though. It is quite mild here. We have had snow this year (just this past week) which has almost melted again with a daily average of around freezing +2 (from freezing -2 to +5ish). Certainly Our 90 year old who is used to +30C (or more in Manila) is keeping doors closed

Thermal inertia experiment under way.

After 12 days of heating the Abbey to 80+ degrees, we plugged up as many gaps as possible, shut down the stove, and now we're waiting to see what happens.

The heating stage of the experiment burned up almost 1/2 a cord of wood.

Despite stuffing wool into every crack we could find, there were still places where one could feel cold air infiltration. Until the cob is done, it seems that the Abbey will be less insulated than we might like and the experiment may be compromised by this fact.

The thermo-sensors are still recording. After the indoor temperatures drop down to their pre-experiment levels I'll download the data and we'll be able to see some neat graphs.

The real test will of course be after the cob is done and the Abbey goes through a whole year. But perhaps this experiment will be indicative.

evan l pierce wrote:Thermal inertia experiment under way.

After 12 days of heating the Abbey to 80+ degrees, we plugged up as many gaps as possible, shut down the stove, and now we're waiting to see what happens.

The heating stage of the experiment burned up almost 1/2 a cord of wood.

That sounds like a lot as compared to heating a stick build to the same point but that is to be expected.

Despite stuffing wool into every crack we could find, there were still places where one could feel cold air infiltration. Until the cob is done, it seems that the Abbey will be less insulated than we might like and the experiment may be compromised by this fact.

Not from my point of view. A thermal inertia (high mass) design should suffer much less from air leaks than a super insulated box. In fact, part of the reason for using thermal inertia for heating is to be able to live healthier because of the possibility of higher air exchange. What I have seen so far of the data, seems to have proved this is true, though I will wait for the rest of the data before saying more.

The thermo-sensors are still recording. After the indoor temperatures drop down to their pre-experiment levels I'll download the data and we'll be able to see some neat graphs.

The real test will of course be after the cob is done and the Abbey goes through a whole year. But perhaps this experiment will be indicative.

Glad for the recording for sure.

Again from my POV I expect more than one year will be needed to get things to stability, though useful data will likely be available in another year.

My expectation of this experiment with the RMH is that the base temperature (or rest temperature) will have been raised relatively little. This is a lot of mass in that ball of earth which is still not perfectly dry, by the way. If, as I think, the rest temperature has not been raised much by the RMH, that means there is a whole lot of storage in that mass and when the temperature is finally brought to a comfortable level it will stay there through a full winter even with open windows.

As I already stated in another post, I think the Sun provides much more energy than we realize and that the heat put into a patch of ground by the sun during uncovered months is much higher than burning the trees covering the same ground in the same time. (it seems to me I read that burning wood as a source of solar energy is very inefficient)

My advice for anyone else building a high mass, thermal inertia warmed home, is to start preparing the ground at least one year in advance, maybe more. I feel there should be some manual labour involved to speed things up. Passive is the end result it is hoped, but active will help get there sooner.

Another Abbey pic:



Stay tuned, the thermal inertia graphs will be here soon.

Graph from the first (aborted) attempt at the experiment:



Graph from the most recent experiment:



Blue lines represent indoor temp, red represents outdoor temp.

It seemed to me that the mass did warm up a little bit and continued to release heat for a little while afterwards, but I think even the 12 days of heat we pumped into it was miniscule in comparison to the heat of a full summer.

When MUD was located in Missoula's North Side, the greenhouse had a thermal-mass system where the heat generated in the "attic" was pumped below ground through ducting. Unfortunately there was never any data on it's success, but it was understood that it needed about 5 summer's worth of heat pumped beneath the greenhouse to establish a new ground temperature. Like I said, there wasn't any data collection to verify this, but if it is true, WOFATI 0.7 has a long way to go to determine if the temperature of the thermal mass is rising. Perhaps the data collected should be in terms of months, not hours/days.