We have been living in the house for nearly two year's. A lot has happened during this time, that I will share with you.
Many Media companies have been to see us and several articles have appeared in publications world wide. In April 2008, The Guardian Newspaper visited the project and an article appeared in The Guardian Paper. The Guardian's film unit visited us also and made a short film at the Zero Carbon House, which can be viewed on their internet site. Log into the Guardian's website and type in "The Zero Carbon House. You will then need to type in Living Off Grid to view. Logon and take a look into our life and the changes we have made to live a carbon emission free existance.
In August of 2008, NBC News Networks visited us and made an item for NBC News for transmission in The United States.
In October of 2008, Korean Television also came to see us and filmed a documentary as a joint production with our BBC, Korean Television and Japanese Television. Many media groups world wide have published articles on our project and we are now linked to a Russian "Heavy Metal" Radio web site, such is the interest in what we are and have achieved.
Additionally during October 2008, a busy month for us with media attention, Scottish Television (STV) made a short film about us, which can be viewed if you logon to STV's website and search for "The 5.30 Show". Search in The 5.30 show for "zero carbon house, shetland" and a short film about us can be viewed.
Two publications in China have published articles on our project and last year I was invited to China, to talk to Chinese architects about our experiences as they are very interested in cutting their emissions. Unfortunately, due to work commitments on our Zero Carbon House project, I was unable to attend the conference.
Many Masters Degree Students worldwide have contacted us regarding our project, as they can use our knowledge and experiences towards their degree project work. We have freely passed on information to assist them. We have also learnt that many schools worldwide, are basing their climate change projects on our house and continuing project. To us, this is very encouraging. Dorothy especially, as a former Primary School Headteacher.
Early in 2008, the front garden was constructed. The dry stone walling was also built, giving us protection from South Westerly and Noth Easterly winds. This improvement has been very successful in protecting our vegetable plot. Further structures have been made from timber, which give additional protection to seedlings. In centuries past, Shetland Crofters used to construct stone walls to give the same kind of protection to their seedlings. All of the seeds which we have used, have been supplied by Thompson and Morgan UK and have produced, delicious, heavy crops for us. Four different types of peas were grown, several types of carrots, cabbages, leeks, onions, lettuce etc.
The Air to Water heat pump.
Due to the considerable benefits of installing Celotex Foam Insulation into the whole of the roof structure and all external walls, we found that we did not need such a large heat pump. Installing a much smaller heat pump has also reduced the energy demand for this device from 6-10 kw to 1.6 kw, which gives us 5kw of heat. This does not need to run all of the time due to another innovation we have built into the project.
Fred Gibson of Shetland Composites, built a 4.200 litre water battery for us with an integrated coil. I will explain this device later. The tank is insulated with 200 mm of Celotex expanded foam. This is the first installation using Celotex insulation for a water battery. If you were to leave it unused it will only lose 0.5 of a degree over 100 hours. The tank is made from GRP and is freestanding on a base at the end of the house. The water battery is connected to the air to water heat pump creating a supply and return circuit. In between this circuit is placed a temperature controlled flow valve. When the signal is sent from the wireless Osma Wavin heating system control box to the flow valve, this opens up the supply for the hot water to enter the house underfloor heating circuit. This has a ground floor area of 180 sq m and has seven zones each one of which can be isolated.
Placed in the water battery is a giant coil. A spur from the cold water main is fed into this and picks up thermal gain from the hot water in the water battery. This is sent to what in ordinary circumstances would be the hot water tank. An external inline water heater switches in when the hot water taps are turned on and heats the water on demand. This works in the same way that a shower works. As a considerable amount of water will always be in the coil picking up more thermal gain, it gives a very efficient use of available resources.
We still have a lot of external work to complete, but as we are now in the throes of the Shetland winter, we are being held back on this work.
Fred Gibson is now taking forward the prototype of the water battery with a major British Academic institution - Oxford University. We are very pleased that this is moving forwards.
Philip our builder, has constructed the first part of the cold frame units which are at the front of the house. The rear wall of these units will support the legs for the front boardwalk and deck with the final front steps being sited at an angle to the front door. This will then give access to all of the doors front and rear on one level.
If you were to run this house from the grid, the monthly total energy cost would be £37.00 Sterling.
Energy For Sustainable Development, our partner in the project, entered the project for an award with Sustain Magazine. The project has been shortlisted against stiff competition, we were told and the awards are being presented at a dinner in London in early March 2009. We are hoping to attend.
It has now been several months since the diary has been updated and several things of interest have happened. We still get large numbers of e-mails asking us about specific areas of the project. The main one which has generated a lot of interest, is the air to water heat pump.
It is quite surprising that to date, so little information is being given out about this very simple technology, which has been available for a long time. We here in the UK, are well behind the times in installing this device. When heat pumps are discussed, it is always the Geo Thermal type that people know about.
In the early 1970s the University of Salford designed and built two houses from Industrial scrap and used second hand refrigerators which they adapted to become heat pumps . The running cost for each house was then £0.50 a week. The article on this project appeared at the time, in The Guardian Newspaper. This was about 1971-1972 and was laughed at by the housing developers and builders, little knowing then that we were on the brink of an energy crisis. During that time we also had a financial crisis to match, which is now dwarfed by the current one.
When we were looking at technologies to incorporate into the project, we thought we would have to use a much larger heat pump unit. As we changed the insulation specification from glass fibre to Celotex insulation foam (which in the process created a sealed house) a smaller heat pump than first thought was required. We also considered the cost of this technology, as we were proposing all those years ago to use the project as an information portal. Cost is a significant element in changing perceptions on which technology to incorporate in a new build or a retro fit. People today, look at costs in a way that was not considered before, in the years of plenty, before the banks took away funding and became owned by the British taxpayer.
Insulation makes a significant contribution to energy reduction. If you look at the new thermos kettles which are now available, you will see that even one of those reduces the amount of energy required. Most heat pumps can cost from 5 to 12 thousand pounds in the UK and we have had e-mails from some very angry people who consider that they have been ripped off, as the heat pump they were sold is too big an appliance for their needs.
Some of the systems we have researched, have a relatively small holding tank for the heated water and losses are incurred when the hot water returns to the tank. The owners of these systems were finding that the heat pump had to be on more frequently than necessary with a smaller unit and in the process was using more expensive energy. We answered this issue, by having what we call the water battery, which is a large thermal heat store. The larger the heat store the more efficient the system becomes.
The cost of energy is now being looked at more closely and also the cost of the technology to provide heating, as most of the cost of peoples energy bills is for heating. You will never get the volumes for expensive heat pumps which are required to reduce the cost. We researched Trianco's 5kw heat pump which would give us the required amount of hot water for a small energy input. Most installations for air to water heat pumps are outside. As we had an under build, we decided to install the heat pump in a protected environment, shielded from the worst of the weather. If you put steel work out side on Shetland, it will corrode. It does not matter how much paint is on the steel, corrosion will take place. Fortunately, the dimensions of the heat pump have enabled us to site it underneath the house. We had to cut an aperture in the wall of the under build to enable the cold exhaust air to escape, as you do not want this to blow back onto the heat pump coil, which could cause a cut out to be activated.
The heat pump was located 500mm away from the wall of the under build and an air tight casing was built around the unit to channel the cold air to the outside. Chicken wire was also built into a frame to impede rodent access. A structure which resembles half a bee hive was then built onto the wall, with a 50mm gap from the ground to enable the cold air to escape. The air tight casing was sealed with waterproof sealant and cold weather foil. The plumbing was connected to the unit and the water battery to create a circuit for supply and return to the water battery to bring the water up to temperature. This is controlled by a controller in the utility room in the house. Additional circuits are in place for supply to the under floor heating via a central manifold which is wireless controlled by thermostats in 7 zones on the ground floor of the house, each zone can be isolated from the others.
Two weeks ago when we had quite high outside temperatures, the unit showed a water battery temperature of 42 degrees centigrade, this is for 4.200 liters. The unit was switched on for 80 minutes and raised the water temperature to 52 degrees. The cost of this heat pump is approx £750.00 sterling, which is a fraction of the cost of some units; and if a heat pump is to be considered as a replacement for a conventional boiler, then most people would consider this cost to be very reasonable.
We have received many e-mails from all over the world asking us how the air to water heat pump works. The heat pump sucks in air to take the heat out of the ambient air temperature. We have discovered that siting the unit in the under build was a good move as the ambient air temperature in the under build in the winter, is within the temperature range of 6- 12 degrees centigrade. This is the ideal temperature range for the device to function. This is also so, when it is minus 5 degrees centigrade outside when you take wind chill into account. You can also site these units in your loft space, as long as it is well insulated and sealed, as it will suck out heat from your house if you do not do it properly.
Air as we no is a gas and has five content components: Nitrogen 78.0482%, Oxegen 20.9463% water vapour 1%, Argon 0.93422% and carbon dioxide 0.03811%. The fan in the unit sucks this into the unit and at the point of the dew point being created, an atom of hydrogen is created, which then produces a small amount of heat. This is replicated millions of times a second. It is amusing that we have such a small unit using hydrogen, as it's energy source. During this process, water is created which is called a condensate. This is in effect distilled water and if collected, could be used for a car battery or for any device needing distilled water eg, a steam iron.
During the recent hot weather we have experienced on Unst and Shetland, which in general has been as hot, if not hotter than the South of France, we noticed that we were generating more heat from passive solar gain than the heat recovery unit which was in Air conditioning mode, could cope with. This was not a fault of the technology, but as a result of the massive amount of installed insulation. I spoke to Gary the MD of Villavent and we came up with the concept of running on occassion the heat pump and introducing the chilled air from the unit through a duct into the intake of the heat recovery ducting, with a by pass duct. This should solve our problem.
The front garden is in it's first year of full production as we built our cold frames, the rear walls of which, will support the boardwalk on the front of the house. We are awaiting the new drawings from our architect Ken, who is very busy at the moment working on the re building of Weston Super Mare pier in Somerset, which was destroyed by fire last year.
When you realize that we are on the same latitude as Anchorage in Alaska, it is amazing what will grow on Unst if you protect the plants. We do however have a rabbit who really likes the cabbages. He or she will have to be re eductated. We have not quite worked out how to do this yet, but we are working on it.
We have had many requests from people all over the world asking if they can come and stay with us. This year we have started to do this in the form of Bed and Breakfast facilities. We had Dave and Frances Hobson from England stay with us, who both used to work on Unst several years ago. They like us, have noticed the changes that have taken place since the early 1980s when we first started to come here. Next month we will have been living on Shetland for 8 years.
We are now working on phase 2 of the project which is the horticultural dimension. We are working with several Universities in the UK who are joining us on this project. We are also looking at incorporating an electric boat into the project, so we can catch fresh fish in the bay.
Five years ago I came into contact with Shanda Lear who with her husband Terry, have established an electric boat company in Los Angeles, California. http://www.learbaylorboats.com
Their boat will run for approx ten hours and will give a 50 mph speed boost if needed. This would be ok in the spring and summer months, but not when we have the severe gales we are subject to in the winter. Plus, it can be charged from a wind turbine.
We have several R & D projects we are working on and I will update these into the diary when we have some concrete results. We are also working on a film/ DVD about climate change with a Canadian media company; and some of the film that we shot on how we built the house will be in the DVD.
We have just installed a GRUNDFOS ALPHA2 circulation
pump for the under floor heating. This is an energy saving pump which is rated at 50w. Circulating the water from the under build into the house heating circuits is only taking 30w.
It is now June 2010 and we have reliable data on the energy consumption of the house. In monetary terms if you were to run a house like this one; the cost from grid consumed electricity would be from £0.83 p per day to £3.28 per day for all house hold usage, heating, lighting, cooking etc.
The insulation we installed from Celotex has proved the point that if you insulate a building well, the pay back is very short.
The Trianco heat pump has been performing extremely well since it was installed and hardly uses any power to keep the 4,200 tiles to a constant temperature of + 50 degrees c to + 55 degrees c. The circulation pump from Grundfos circulates the hot water from the thermal water store or water battery for an energy consumption of 26w to 30 w over a 14 hour period. This is a very efficient circulation pump.
Danfoss supplied the temperature controlled valve which again is doing the job it has been designed to do. This uses no power and is self activating.
We have had a very bad winter on Shetland and the seeds are a good 6-7 weeks behind, e think that the volcano in Iceland also had something to do with the weather patterns on Shetland.
We are still getting a lot of e-mails from all over the world, and to date we have helped over 32 students with their first and masters degrees on sustainable buildings / zero carbon.
We have recently installed two way broadband by satellite with Beyond DSL. This was very simple to install with the satellite finder that came with the hardware. This is working very well. Two Universities are going to use the link to study and monitor hardware in real time. Ref: schematic drawing. It has alays been our intention to come off the traditional land line telephone link with BT. Our current exchange run by BT only gives us a 512kb speed. In remote areas like Unst. you need a much faster link than what is being supplied by BT. It is our intention also to use VOIP for our telephone communications; Voice over the internet protocol.
This will then take us totally out of thr traditional communication link. I think in the not to distant future this will become more widely used.for communications.