I’m a great fan of this duo. Looking forward to seeing them at The David Hall where I help out, often doing the lighting technician role.
They are performing on Saturday 21^st . The gig starts at 8pm.

I occasionally go to the Acoustic+ gigs at The Cheese & Grain, Frome and am on their mailing list. This is a great place to discover new performers. I’ve never heard of Mark Wynn before but really like his songs. He’s playing at the Cheese and Grain on the 23rd March. Unfortunately the other performers on this month don’t sound so good. The album on his web site is a good listen, I just bought the download. It’s also available as a shared thing so here it is for all of you to enjoy, or even buy your own download copy.

The unexpected element of what was installed for the heating system for my cottage was an external heat exchanger for the solar hot water system. As mentioned in an earlier post this is in place of an extra heat exchange coil in the hot water tank. The reason given for this choice is that Mitsubishi do not sell a prepackaged tank assembly with the extra coil. This is a short sighted omission my Mitsubishi as Kingspan (who provide the tank) make plenty of tanks with the extra coil.
The heat exchanger supplied is the Solasyphon by Willis Renewable Energy Systems. This a thin vertical heat exchanger. I have my doubts about this, so have been taking a close look at the performance. To start with it did not work at all. On a bright day the solar panel got very hot as did the heat exchanger but the hot water tank was not gaining any heat. This I traced to an air lock in the loop of pipe between the Solasyphon and the tank. Ace Energy were called back and they fitted an air bleed valve near the top of the loop. I was surprised this worked, as there was still some pipe work above the air bleed, but it seems to, probably due to a reverse flow forced through the Solasyphon by the Injector Tee when I draw hot water from the system. The injector tee is there to ensure that there is no flow from the cold feed to the tank exit bypassing the tank when hot water is drawn.
The next good test day showed the solar panel not getting as hot, and the tank slowly gaining heat. It was working. However on the following cloudy days the Solasyphon was drawing heat from the hot water tank. This I have traced to the temperature sensor being placed in the wrong place for a system with a Solasyphon.
The solar thermal controller fitted is the Resol DeltaSol BS/4. The installers had placed the temperature sensor in accordance with the Resol instructions, at the bottom of the hot water tank. However this unit is designed for installations with the extra heat exchange coil in the tank. The Solasyphon Instructions show the temperature sensor at the top of the loop between heat exchanger and tank. The result of the temperature sensor being placed too low is that the electric pump between the solar panel and heat exchanger is turned on while the water from solar panel is cooler than that in the Solasyphon, resulting in heat being drawn from the Solasyphon and the convection flow taking hot water from the tank. I’ve been able to work out what’s going on from the temperature displays on the solar thermal controller and two mechanical temperature gauges fitted to the flow and return pipes to the solar panel. The difference between the two gauges tels me which way energy is flowing and gives an idea how much is being transfered.
Ace energy where called back again to discus the problem and fix a minor leak in the central heating circuit. Their guy moved the temperature sensor to the connection for the heat pump coil, about a third of the way up the tank. The system is still taking heat from tank when it is partly cloudy. I have now moved the sensor higher up the tank to an unused port labeled secondary return, about two thirds the way up the tank. The controller is set to switch the pump on when the solar panel is 6°C above the sensor and off when it is 3°C above the sensor. These are the default settings but can easily be changed. Tomorrow should show if this new configuration works, as a partly cloudy day is forecast.
There is a compromise to be found in the location of the sensor that controls the pump. Too high and energy that could be harvested on dull days is lost. Too low and the system runs in reverse heating the solar panel from energy in the hot water tank. Once the system is in this state it tends to stay like that as the solar panel is kept warm from the tank which in turn keeps the pump running as the sensor for the solar panel shows it is hot.
What all this highlights is that the Solasyphon forces the solar panel to run hotter than it would with a tank with the second coil fitted. This results in reduced efficiency as more heat energy is lost to the air around the panel and from the pipework from panel to heat exchanger/tank. This is probably not too great for an evacuated tube system which has very good thermal insulation but could be a problem if you had a flat plate type collector.
I did suggest changing the connection from the top of the Solasyphon to the tank to go to the secondary return port. This would make the configuration closer to a two coil tank. The unknown is how this would affect the convection through the Solasyphon. The guy from Ace Energy said he did consider this, but couldn’t remember why he decided not to use this connection.

I won the cup! It has been awarded for my work creating a new website for the Wessex Strut. Its nothing special, just WordPress with the default theme and a few minor tweaks. The one it replaced was hand crafted HTML and hosted by the Flyer magazine for free. Now it has its own domain and is hosted using borrowed space belonging to our Co-ordinator. The Co-ordinator’s role is a chairman type role. The replacement means it is now much easier to maintain the site, so I have won a cup rewarding me for effort spent making my job easier. In moving to WordPress and issuing all the strut members user-names and passwords I was hoping to get the members to add content themselves. This hasn’t happened much, which is disappointing. I get to keep the bowl for a year. The committee will award it to some one else next year. I do get to engrave my name on it though below the names of previous winners.

I have been subscribed to Google group DIYbio which is forum in which people discuss amateur genetic modification experiments. The perception of genetic engineering has been that this has been solely the domain of large evil corporations like Monsanto. The guys posting to DIYbio want to change this and bring the hacker mentality to GM. This is allowed in the US but even in “the land of the free” they have trouble getting companies to sell private individuals the materials they need. Here in the EU (the land of the bureaucrat) you need to be licensed to do such things. There is a guy in Ireland who has succeeded in getting himself licensed though. My experience of coming in to the field from the outside (my degree is electronics) is that the terminology produces a barrier, but that once you know the terms to use then there is a lot of practical information out there about things you can do in your own kitchen. It’s doesn’t look too difficult to smash up cells to extract DNA. Persuading a bacteria like E.Coli to take in DNA is also kitchen doable. The hard part is selecting bits of DNA from smashed cells. Getting manufactured DNA to put into a cell is also hard and expensive, even if you can get a DNA assembly company to supply you.
So here is the thing. Smashing up random bugs and putting random bits of their DNA into other random bugs is something you could you could work out how to do in your own kitchen with a little research. Working out what you have done afterwards is very hard.
And now to the self harming. I found this youtube video on the DIYbio forum. It’s not about GM but about amateur experiments in implanting electronics inside the human body.

Don’t you get the impression this girl is really into the pain? She is called Lepht Anonym and that link takes you to her blog. She swears quite a bit but it all fits the context perfectively well.

And finally you may have noted that the blog posts and tweets have been a bit sparse recently. That is because I am overloaded with projects at home, see last blog post, work (boring), the last minute rush to get my tax return in (even worse), letting my flat, and helping organise a folk festival. I also have a new woman in my life. This is not of itself time consuming, but it is scrambling my brain. And now back to work as I shouldn’t be spending time doing this.