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A home page with brief technical information, images, some conceptual detail and relevant links has been placed on the web page: http://home.iprimus.com.au/fredb19/solarhouse/house01.htm
Below is an updated copy of the Fact Sheet originally developed and printed to hand to visitors on Solarhouse Day, 11 September 2005. We had a total of 130 visitors who were passionate about passive solar design - and we enjoyed their interest.
SOLAR HOUSE DAY
PREAMBLE
We apologize for those
areas and parts of our building on our property that are still under
construction or are being modified.
INTRODUCTION
We will point out those
major areas we consider topical and interesting and suggest you inspect at
your leisure. Of course, these
comments may only scratch the surface of your interest, so please feel free
to look further and ask questions. We
will be pleased to try and answer any questions you have.
GENERAL DESIGN
FEATURES
The total house design concept is for a passive solar, very comfortable, single bedroom (with study) house on one side, and a “guest wing” of two additional bedrooms (which is largely unused for most of the year) on the other side. This reduces housework and cleaning.
We have attempted to design lighting such that it is not only energy efficient, but also very unobtrusive. We do not like glaring lights. Most of the lights are hidden, recessed or task-specific, to reduce glare but provide appropriate levels of light where it is required. Much of the lighting is computer controlled so that movement around the house at night causes lights to switch on, or dim up and down, as you walk around the house – no switching needed. All lighting is ether low energy flourescent or LED.
We have also achieved a feeling of openness, consistent with room privacy without the need for doors. This is due to carefully positioned walls, floor layout, movement thoroughfares and garden courtyards.
We have endeavoured to achieve a very light and airy atmosphere with a lot of natural light and extremely good cross-flow summer ventilation where required. Along with these design features we have achieved a very enjoyable ability to “see the sky” no matter where we are in the house.
The house has been designed to give us a “relaxing area’, a “living area”, a “working area”, and a “sleeping area”. These areas have subtle differences in décor and simple furnishings. We have tried to keep an unobtrusive ambience, practical positioning and very easy maintenance.
We do not have exposed external beams, horizontal galvanized sheeting or large quantities of external horizontal stained timber etc. (current fashion which we believe to be a very high maintenance and cleaning nightmare). Our seamless soffits are easy to clean, and they do not harbour spiderwebs.
We have installed internal ceiling to floor blinds on all the glass areas so that on the few nights each year when it is very cold, we can lower these blinds and reduce the chill penetration through the glass. These blinds have been hidden in slots in the ceiling and are not visible unless lowered.
In the kitchen and relaxing area we have installed floating wooden floors to provide a very comfortable, springy, walking surface that reduces fatigue (especially useful in the kitchen area). These floors are insulated to prevent sound transmission.
We have installed a large number of carefully placed louvres which provide good, controlled ventilation in summer, even when it may be very windy and raining, and we have installed substantial eaves which helps in summer climate and wet weather control.
We have built a cool shadehouse, planted out with subtropical and tropical plants, along the entire southern side of the house, and installed many tall louvred windows which can be opened onto this area when required to promote cool airflow in summer.
The main bedroom has no 240 Volt electrical wiring at the bedhead, thus reducing potential health damaging electromagnetic fields around the bed. All switching is data based and bedhead lights are 12 volt (with associated very low intensity electromagnetic fields).
The house is ‘smart-wired’ (using Clipsal C-Bus system) for electrical, video and data. All wiring circuits are individually laid and terminated at a central switchboard and every 240 volt electrical circuit is on a dedicated safety switch (RCD). Data and video cabling is terminated at central patch-panels so that data, communications and video distribution can be designed and switched where required in every room.
A sophisticated security alarm system has been integrated into the C-Bus wiring and Clipsal Homeminder computerized house management system. This system is logged by computer and keeps track of all movement and timing in the household buildings. These systems integrate with the C-Bus electrically controlled systems, are programmable and automatically alert, or can be controlled, via telephone.
Microprocessor based security alarm detectors are dual element infra-red and microwave based devices with excellent false alarm prevention. These devices act as presence detectors when home, and carry out automatic toilet fan extraction and relevant light switching and dimming at night based on occupant movement.
All kitchen, bathroom and toilet exhaust ventilation is exhausted outside above the roof (not into ceiling spaces). Toilets are fitted with odour-vac systems with imperceptible but very effective exhaust flow via the toilet bowl.
Built-in furniture has been designed to promote spaciousness to maintain an uncluttered and ‘open-space’ effect. The minimalist, low-line and suspended design furniture enhances the open and spacious environment.
The dark, vitrified Italian tiles along a ‘virtual hallway’ absorb winter solar energy but are shaded and remain cool in summer. A ‘drop-down’ timber ceiling above the tiled ‘virtual hallway’ provides the illusion of a separate hallway, yet allows a large, open room area to enhance spaciousness.
The main bedroom has been
designed to be integral with an adjacent courtyard which provides privacy
and a spacious ‘outdoors’ outlook.
The en-suite is single shower, single hand basin as we believe the
current trend to provide a “his-and-hers” double setup does nothing but
ensure double the amount of cleaning for something that is used for just a
few minutes each day.
The house is fitted with two
rain water tanks, totalling 50,000 litres, supplying all household water via
a solar powered constant-flow pressure pump.
Town water is available at the switch of a valve if required.
Lawns and gardens are automatically watered from a Bore Pump (solar powered of course!) and computer controlled based on (Homeminder management system interface) monitored soil moisture content, actual rainfall and time-of-day/Council restriction parameters which are programmed into the systems.
The driveway has ‘Grass Tiles’ installed, and ‘Sir Walter’ soft buffalo grass planted over. This reduces sweeping and hosing – clean up is a simple mow with a catcher. The grass is shade, sun and drought tolerant.
A 330 litre Beasley stainless
steel hot water system with two solar absorber panels has been installed
and computer monitored for temperature and boosting (if required – a very
rare event).
PASSIVE SOLAR DESIGN FEATURES
Note the orientation of the
house which aligns the long side of the house facing north.
The design of the large, north facing glassed areas, allows maximum
solar energy penetration and absorption during winter to provide free
heating. The house design and
this orientation effectively prevents the penetration of sunlight during
summer, so the house stays cool all summer.
In order to maintain a nice view over the canal (directly due east) large, picture windows have been installed, but this in turn gives us early morning sun which is unwanted in summer. To alleviate this problem the computerized electrical and household management system (Clipsal C-Bus and Homeminder) program lowers external blinds on the eastern windows at sunrise every morning to prevent solar energy entering the house. The blinds are partially “see-through” with a 95% UV blockout. They are currently programmed to retract automatically after the eastern sun no longer impinges on the eastern windows.
The motorized awning is manually adjusted by remote control to more efficiently manage sun penetration in winter and to adjust for summer shading near patio if required. The awning has automatic wind monitoring and retraction if it is too windy.
Note the clerestory windows
along the top of the house. These
windows provide solar energy penetration in winter which heats the rammed
earth wall along the southern side of the house by absorption of solar thermal
energy. The angle of the roof
over these windows is exactly the angle of the sun at
Note the dark roof cladding color on the steep section of roof over the clerestory windows. This not only reduces annoying reflection into our neighbours house, but the double-insulated, dark colorbond sheeting gets very hot in summer and this encourages the hot air to rise rapidly from the surface of the steeply angled sheeting, and thus create a thermal gradient induced air flow, which in turn, encourages air flow through the house, up and out of the clerestory windows. In addition, although our house has a high roof line, the angle of this roof ensures the neighbours on the southern side do not have their yard shaded during winter.
The remainder of the roofing is a very light grey (reduces heat absorption in summer) thus reducing ceiling void temperatures.
All ceilings are double insulated with bulk 125mm R3.5 insulation on ceilings and roof cladding is insulated with 50mm foil backed blanket.
Many of the walls are built with rammed earth. These 300mm thick walls provide a beautiful, naturally textured finish that does not require additional painting or rendering, and they have enormous thermal inertia. All walls not constructed with rammed earth have been fully sound-proofed and thermally insulated.
Computer controlled external motorized blinds, motorized awning (with remote manual functionality) and internal ceiling-to-floor blinds enable maximum solar energy penetration when required, exclusion of this energy penetration in the warmer months and effective insulation of glass surfaces in winter if it is very cold.
The high-point roof area has been designed to accommodate a very large (1100mm diameter), low speed, silent fan to aid in summer ventilation if required. This computer controlled fan pulls air through open external windows and exhausts hot air out over the roof line.
The house does not have, or
need, air conditioning or heating.
The solar system was designed to be ‘revenue neutral’ (ie, export energy income would cover all Energex charges). Our aim was to set up a solar system where we would never again have to pay an electricity bill. It even covers our Ambulance Levy charges!
The solar energy system
design was based on meeting the needs of a modern, well equipped house with
high technology control, electrical, data and video/sound systems, and
fitted out with the latest in efficient household whitegoods components.
We ensured that all
lighting, whitegoods and control strategies were installed to maximize
energy efficiency.
Considerable effort was placed on reducing ‘phantom loads’ by load control, programming and automatic control procedures.
The solar battery bank provides seamless uninterruptible power to the house (no blackouts or brownouts). It is capable of running the house for 5 days without sun or Energex backup.
Much of the house
electrical fit-out and automatic computer control systems are in
contradistinction to the normal, minimal solar powered design principles.
However, we believe that by careful design, programming and the
utilization of efficient products we have made a good compromise and have
ended up with a superbly comfortable and very energy efficient household
system.
Lightning and Surge
Suppression
= 10.85 kWH/day
= 6.57 kWH/day
= 14319 kWH
= 17.42kWH/day
Average household
energy use per day
= 8.43 kWH/day
Total energy exported
= 7394 kWH
= 8.99 kWH/day
Total dollar income
(from Energex) for exported electrical energy (at $0.08/kWH):
Average income per day
= $0.2759/day
Smaller solar systems can be designed that do have a payback period
of 5 to 10 years, but they do not meet the demanding criteria we required
for our household.
New technology Concentrated Photo Voltaic (CPV) panels coming on to the market during 2007 and capable of running a system the size we have here will likely have a payback period of less than 5 years.
Please feel free to contact us if you wish. Click on the mail box below if you wish to send us an e-mail message:
This web page is maintained by Fred & Jeanette Birkbeck