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Endevour

Endeavour is situated 100 metres behind Namaste at the top of Down End (arrow & name on fence)

Descend the steep path beside the house carefully to reach the back garden from which you will be able to look up onto the roof and see the 16 pv panels and also the 30 Philips Fournelle evacuated solar tubes.

The pv panels are rated at 3.76 kWp  and they generate DC which is then changed to AC by two inverters

The evacuated solar tubes contain a volatile liquid which on condensing at the top of the tubes release heat to a closed circuit water system which heats domestic water via its calorifier coil in the hot water cylinder.

 

Endeavour started several decades ago, at which time one waited a year or even more for bricks and hoped they would arrive before VAT, mostly they did.  This was the time of the oil crisis when the price quadrupled overnight and consequently other price rises occurred such as copper and hence electrical wiring.   Window frames were hard to obtain and as  uPVC was in its infancy it seemed wise to stay with proven hot dip galvanised. It was also the time of power shortages and the three day week.

After digging a 30 feet length of foundation with a spade it was apparent that a JCB was needed to carry out the necessary excavation in a reasonable time frame.  Once the foundations had been poured (six readymix truck loads) bricklaying got underway and then more concrete arrived to provide the flooring of the lowest level.  On the uphill side a single thickness wall of brick was laid, painted with bitumenous paint and covered with Bituthene as a barrier to water ingress from the soil, and against this a 9″ thick brick wall was uilt to bring the level up to where it changed to 11″ cavity.  The cavity wall, extending up two storeys, is kept empty delberately.  After consulting BRE documents it was apparent that filling the cavity with insulation could cause bridging, resulting in damp reaching the inner wall and thence into the house.   Keeping the cavity empty allows ventilation, better protection for the wall ties and provision for damp to drain down to the foot of the cavity and exit via the ventilation bricks.

The lowest level is laundry, storage and workshop area and WC; the middle level is lounge, kitchen/dining room, study and one bedroom, bathroom and shower room & WC.  This middle level is brick veneer, single brick width forming the outer wall with a timber frame inner wall structure.  the timber frame was constructed on site from 4″ x 2″ Australian eucalypt which is so hard that holes needed to be drilled before 4″ nails could be driven it make the wall frames.  Internal wall frames, forming rooms, were constructed in the same material and these were filled with fibreglass insulation.  9mm treated plywood sheets were attached to the cavity side of the timber frames and after filling the frames with fibreglass heavy duty polythene sheeting was attached to the inner sides of the frames prior to fixing 12.5mm plasterboard.  Flooring joists are 8″ x 2″ Australian eucalypt and the gaps between joists were filled with fibreglass and fire stops.  Windows other than at the lowest level are double glazed and those in the lounge and South facing dining end are of K glass.

There is an open fire with a wrapround back boiler which via a calorifier heats water for showers and baths as well as three radiators. The main heating system is oil fired and it heats water for showers etc. as well as up to a couple of dozen radiators: because these are aluminium with its exceptionally good thermal properties radiators are normally off and are turned on to the appropriate TRV setting as required; the speed of heating up to temperature is just a minute or two.  One radiator has no TRV so that the pump always has work to do when the boiler is on.  In the kitchen electricity is used for microwave and oven, but bottle gas supplies the four ring hob.

The top floor has three bedrooms, two store rooms, bathroom and WC.  In addition to the hot water cylinder heater by the boiler there is a solar cylinder which has a coil heated via the solar thermal tubes (30 Philips Fournelle) on the South facing roof.  This cylinder also houses the coil from the open fire back boiler.  In summer there is usually sufficient hot water for showers and baths such that the oil fired boiler can be turned off.  In winter the solar tubes and the open fire back boiler will at least preheat the water in the cylinder which can then feed through to the other cylinder heated by the oil fired boiler.

The upper level is again timber frame construction with similar materials and insulation.  The double glazed windows have built in draught excluder rubbers. The roof is mostly tiled over 5″ x 2″ treated softwood timbers with underfelt.  There are dormers to the South and the North and these are decked with tongue and grooved treated softwood covered with low friction building paper and special bitumenous-free felt which allows the (code 4) lead sheets to contract back on cooling after expanding from warming by the sun.  The lead sheets are fixed using copper nails and at their joins they double wrap over mopstick handrail.

The ridge tiles are raised slightly by fine slotted plastic support frames which, with the eaves ventilation, ensure that there is sufficient air movement within the roof space to remove the risk of timbers rotting. The cold water tanks for baths, showers etc. and the top up tanks for solar and open fire back boiler heating need to be well insulated since it is a cold roof regime.  The bedroom ceilings are insulated by laying fibreglass in the spaces between the joists in the roof flooring and in parts then covered with treated chipboard so that the space can be used for storage.

The latest provision is sixteen pv panels of 235W each.  They are connected in two banks of eight to a pair of inverters to change the DC generated to AC.  What is not used in Endeavour is exported to the national grid.  A solar powered decice records daily generation, CO2 saved and information for the last month and the year to date.  It is for this pv system put in by Southern Electric Contracting that HNLC/LCHN has provided a loan, which will be progressively recycled starting in a few days’ time, so that others can borrow for their green scheme.


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