Solid State Ventilator



I designed an air circulation system [1,2] for our tiny cottage that uses no moving parts. Think of it as a solid-state fan. It is driven by thermo-siphoning through the block wall behind the wood stove and chimney where the sun also shines. The hotter the wall, from wood burning or passive solar gain, the faster the air flows.

Until now the system had remained closed and the temperature differential between the floor and the top of the cottage 11′ above was typically about 10°F, sometimes more. This made the kid’s loft rather warm, often reaching 78°F which is to hot for comfort for us hot blooded Vermonters – we melt.

Will jack hammered open the base of the three air tubes this weekend which allowed the air circulation system to begin operating. The temperature differential between the floor and ceiling is now just a couple of degrees. Pretty impressive for a system that uses no electricity to power the circulation.

The air pipes in the ventilator have their lower openings at three different heights in three different rooms. The lowest one pulls air from the lowest point of the cottage in the fire wood bin under the stove. This causes air to flow past the wood continually drying it. Otherwise we might get air stagnation and some mold there. The next one up pulls air from the master bedroom floor. This catches the coldest air from our toes and lifts it up past the warm masonry to the ceiling. The third tube sucks air midway up the kitchen wall, 180° away from the bedroom vent.

Currently the ventilation system is not hooked up to our earth air pipes. When I make that connection it should further increase the efficiency of the system. I like to test things slowly so I can observe how each component works before connecting them.

I like simple systems. They take longer to think about and design but in the long run they save time and resources. No electricity. No maintenance. No whirring fan noise. Nothing to break down. I will admit that I designed the system so I can add energy efficient computer style fans if it didn’t work out the way I wanted. Always have a backup plan!

Outdoors: 31°F/30°F Cloudy, Drifting snowflakes
Farm House: 59°F/55°F First pillar form placed
Tiny Cottage: 66°F/65°F

Father & Son


Big’Un & Archimedes

Big’Un, on the left, is the son of Archimedes and Big Pig. I was working on setting up the greenhouse pillar forms when I saw them posing so nicely. I walked over to the crest of the hill to snap this photo. Then I saw why they were looking down towards the road…

Oops, not the case – see here Turns out Archimedes is Big’Un’s step-father of sorts.


How it’s hanging…

Spot had noticed I left the gate open when I brought in the pillar forms for the greenhouse concrete pour. He was headed down the hill at a good clip to check it out.

Outdoors: 37°F/31°F Cloudy, drifting snowflakes
Farm House: 59°F/54°F GH1 Pillar bases set, 1 round bale to north
Tiny Cottage: 68°F/65°F

Mystery Photo – Hexagon


Hexagon on Snow

Hmm… What magic am I up to now, building hexagons on the snow… The wagon and large dog will give you a sense of scale. Leave guesses in the comments… The answer will appear in a post next week.

By the way, if you don’t want the EPA gaining Title V regulatory control over your home, wood stove, livestock, gardens, fields, apartment, etc please go read about the EPA power grab.

Outdoors: 31°F/29°F Cloudy, Drifting snowflakes
Farm House: 59°F/55°F GH1 Pillar forms raised
Tiny Cottage: 66°F/64°F

Dancing Tractor – Greenhouse Wall Pour


Pouring Greenhouse Concrete Kneewalls

About a week ago we poured the concrete kneewalls of the greenhouse as shown in the video above. We are now preparing to pour the roof pillars. The snow is deep already. Yesterday morning we got another 10″ on top of the 4″ or so already on the ground. Fortunately it has compacted down some.

As mentioned before the ready mix concrete truck can’t get close enough to the construction site to deliver the concrete. Our solution was to build a chute that we’ve been using to deliver the concrete down hill from the upper pond level where the whey tank road ends. The concrete flows down, with much pushing of rakes and hoes, into the half cubic-yard bucket of our tractor. I then dump each load, slightly less than half a cubic-yard in practice, into the form work.

The pour went amazingly well. Nine yards of concrete in under three hours by three adults (Walter, Holly & Will) and one eleven year old (Ben). It snowed almost the whole time we were pouring the concrete – not hard but a warning of the solid week of daily snows that was to come.

We did have one blowout which we’ll fix in the next pour. I’ll discuss the problem and solution in another post. Nothing disastrous.

The movie above is a trimmed and sped up five fold – we don’t really zip around that fast! Some notes on setting a camera up to record:

  1. Lock the focus on infinity;
  2. Lock the white balance;
  3. Put it somewhere where curious piglets won’t play with it!

Outdoors: 33°F/31°F Mostly Cloudy, Snow Flurries
Farm House: 59°F/55°F
Tiny Cottage: 68°F/66°F