Monthly Archives: August 2010

Earth Tubes with Heat Recovery

Fresh air comes in

The earth tempering and heat recovery system with earth tubes and a heat recovery ventilator, for my office.

The earth tubes are buried in the ground and bring fresh air into the fan unit in the basement.  I used two 4″ pipes not only because that is easier to obtain and install, but because two small tubes give more surface area to transfer heat from the earth,  than say one 6″ or 8″ pipe, with the same ventilation rate.

I planted peppermint around the intakes, it probably does not do much to make air smell fresh but it cannot hurt…

Heat Recovery Ventilator

The fan unit in the basement takes air out of the room and transfers it past the incoming air via a heat exchanger so they can exchange heating or cooling.  there are four ducts which makes it a bit confusing.  One of the ducts on the right is not insulated because that takes the exhausted air directly outside, no need to preserve its heat.

The system works better in the winter to temper the cold incoming air since the outgoing air is considerable warmer, and the earth pre-warms the outdoor air so that the final air that enters the space is nearly up to the indoor temperature.

In the hot summer weather the benefits work against each other to some extent.  But it is still fresh air.


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Small Houses – Oldest House, Newest House

Too small for Building Inspectiion

In North Carolina recently, I saw examples of a house that is too small to come under the building code.   Any house smaller than 12′ x 12′ in plan (I do not know anything about the height..) does not have to conform to the building codes.  So an enterprising designer at Earthaven Ecovillage is producing these 11.5’x 11.5′ little cabins, with sleeping loft and full range of dwelling functions.  Sign of the times / sign of the future?

Meanwhile the remains of an incredibly old residence have been found.  Guess what – it was the same size….

LONDON – Archaeologists have uncovered the site of Britain’s oldest house, the waterside home of nomad hunters dating back about 11,000 years.

The dwelling, which has lake views, a thatched roof and very original features, predates the country’s famous Stonehenge monument by around 6,000 years and was built at a time when Britain was still connected to continental Europe.

Teams from the University of York and the University of Manchester working at the site believe the circular shaped home was built in about 8,500 B.C. next to an ancient lake at Star Carr, near Scarborough, in northeastern England.

Discoveries made at the site suggest the house was about 3.5 meters wide (11 feet, 6 inches), constructed of timber posts and likely had a roof of thatched reeds. The site was probably inhabited for between 200 and 500 years, and there were possibly several homes built at the site.

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