Saturday, 2 April 2016

Vents 2

In my original design for the house the sources of ventilation were fanlights on the south facing window wall, protected by the large cowl/overhang from hot sun and rain, and a large fanlight window above the study area's large north facing sliding door access to the light well. However this was deemed, by the planning department, to be inadequate for the size of house. What was proposed was that a large fan unit be installed in place of the north facing vent. This was not acceptable since we are off grid and this would have been a major drain on our power resources. The option that eventually emerged was to install venting shafts in the three main rooms that passed through the earth sheltering and had long horizontal ventilation windows that could be opened from inside the house. These vents were designed to capture the cool air that moves down the mountain side in the evenings. Great so far so good. The planners, however, dictated that these vents must be a certain maximum height above ground level which they insisted was not from the surface of the earth sheltering on the roof but from floor level!! This has resulted in  the top of the vents being barely, 50cm, above the level of the earth sheltering.

In order to be able to open from the inside meant that these long opening windows had to be mounted on the inside surface of the vent. This left a 20cm sill exposed to the outside with only a fly screen for protection from the elements.

As described in an earlier post the windows that were fitted were not locked in place by the fitters and with exceptional wet stormy weather in August water and mud flooded down the hillside and into the house!!

Not wishing to experience this again the fitters were recalled to fit the locking mechanisms and hand controls and generally reseal as necessary.

In October, however, with the windows tightly locked another torrential downpour again produced water running down the inside of the vents into the house. The cause this time of these leaks was that the 20cm wide sills meant that mini lakes formed against each window and the water eventually seeped through the seals and into the house.

I was getting pretty fed up by now and whilst appreciating the experimental design of the house I felt that asking for the windows to be watertight was not too unreasonable.

There were a number of tense meetings between builder, engineer, window supplier and fitter, and myself to try to find a solution. The end result was a proposal to fit "outer" windows/doors to the vent openings that would be opened/closed/locked from outside so that whenever rain threatened I could quite literally batten down the hatches from up on the earth sheltered roof.

An initial water test using a hose directed onto the windows revealed a few hairline gaps around the seal. These were subsequently sealed and so far so good.

But only time will tell.

Roof vent in large room. Note water catching devices.

Preparations for installing the additional window/door on vents.

One nearly done onto the next.

Finishing touches to new vent closure.