Thursday, July 29, 2010

New Brain for Heat Pump

28 July: I am grateful to Ice Energy for sending up an engineer to swap out the REGO controller in the Heatpump. I had complained many times of frequent over heating of the Hot Water - it seemed that the pasteurisation that should take place about every 3 weeks was happening almost every day. In fact the regular problems that the machine got into were one of main prompts for the long saga of Charging the Earth. We often thought that it was to do with turning it off at night, but we leave it on all night now, using the internal timeclock instead.
   I don't regret for a moment having done the design of the Sunboxes, as I feel that something genuinely useful has been discovered - even if only by accident.
   I was looking through a web page the other day about scientific inventions and advances that were discovered by accident - the most famous being Penicillin, Post-it notes and vulcanised Rubber. I can't claim that sunboxes compete with these, anymore than Sarah Palin can claim to be Shakespeare for inventing 'Refudiate'. But the sunboxes are a bit of a discovery and may be useful one day.
   It has been a great experience working with David Atkins of Ice Energy - a great source of knowledge and ideas. There are few new ideas that he hasn't already tried - Sunboxes were one of them! His research and design skills, his presence at IE, places Ice Energy above any other UK provider of Heat Pumps.
  One small problem - there must be something odd in the algorithm by IVT, but on the very first day, we are still getting temperatures of over 58º. So it's good to know the new REGO isn't faulty, but it is slightly odd in the way it has been programmed. Our soil is so warm now that the heat up is quite quick, even when pushing up to or beyond 58º.

Friday, July 23, 2010

Heat pump demonstration

The central stand is a solar hybrid panel with an
array of sunlamps in front to test out the performance.
22 July: I was invited to a very interesting presentation by Sasie and Christiani-tvet.

The exhibition is of a number of heatpump applications all mounted on free standing castors, so they can be organised in a teaching space, and used for training courses in HP technology.

I am glad to see that my recent research in hybridising HPs is pointing in the right direction. One of the rigs had a panel very like my black collectors, but the front face was PV - and the collectors are intended to stand out in the open, and not be in a glass enclosure. They have to run at lower temperature.
    Mine were originally going to be in the open but I didn't want to, for reasons well explained earlier - the main one being that I didn't want the condensation risk of having large diameter freezing pipes running through the house - with sunboxes, they are not freezing.

    Although the exhibition didn't show an intermediate example, ie panels like my Solar-Focus ones without the PV coating, I immediately recognised what this implied, and it was the first thing I looked at when I arrived (even before the presenter started speaking).  When the the two can work together, it is an outstandingly good direction to take for heat pump technology because the PV works up to 30% more efficiently being cooled down by the glycol. My questions on numerical balance, and on cost went unanswered though. Numerically a house needs 30sqm of PV to only 4-6m of thermal - but a house could still have a mixture. And an integrated PV-glycol panel must be very expensive, and is certainly not yet approved for FiT grid connection in the UK - it is still a prototype. the one shown here works with an adapted airsource HP. I think it is a separated system, i.e. the heat collector is on the left, and the HP is on the right. Most common Air source HPs are 'White Goods', ie, a closed box with inlets and outlets that you use for boiler replacement.

I use my solar sunbox panels with a standard GSHP because it is a good thermal management system and algorithmically adapts to the additional heat source without difficulty - just works more efficiently.

Tuesday, July 20, 2010

Mass production of Sunboxes!

19 July: I have recently been asked to be eco-design advisor for a housing scheme of 80-120 units (depending on configuration) for a town in the south of England. The developer seems fairly convinced by the benefit of eco design - energy saving, but also considered a premium quality helping to market the houses. Eco design also extends to the orientation and layout, of course. And sustainable design also includes social and economic considerations, so the development will be mixed use, including some shops and businesses. There will be emphasis on encouraging cycling and walking and gardening, and less car use. There will be extensive planting of hedgerows, as nature corridors.
  If you are planning a new development, the Ground Source Heatpump makes a lot of sense - compared with fossil fuel burning or air source HP. While excavators are on site, it is far easier to build the trenches for the underground loops, and no need for vertical boreholes - because the plots in a rural housing development will all be big enough for horizontal layouts. With horizontal, there is less risk of long term cooling of the ground.
   There is still a case for smart Sunboxes. If you cluster houses together, you need to inject heat into the ground quicker than the Sun can do so incidentally. Their contribution in winter and equinox is effective as the GSHP can 'ask' for warmth from them before getting it from the ground. Their contribution in summer is valid as the pipes will be deep enough for the delivered heat to be a worthwhile trickle charge, especially as one can programme the thermostat to ensure this.

The houses and apartments will be designed with Sun and energy as a prime consideration in organising the orientation and width of houses and plots:
- There will be 30 sqm or more of south facing roof on each unit, for PV installation, and
- Sunboxes in part of the south facing facade, to augment the GSHP and trickle-charge the ground.
- Even if GSHP is not used, Sunboxes can contribute to the Heat Recovery units, or be replaced by Solar thermal panels.
- Heat recovery ventilation because with very good insulation, the losses through unrecovered ventilation become the greater requirement for heating.
- The larger houses can also have conservatories (sunspaces) which can contribute to house heating, using Heat Recovery.
- Back gardens which contain the loops will also be south facing, but too deeply buried to be dug into by the allotment gardeners.

There are many other criteria we shall be applying, but in the context of Solar Earth Charging, these are of most interest. I will keep the readers up to date with progress. Even if the scheme does not get planning permission, it will be a good exercise to plan the deployment of Sunboxes and GSHP on a large scale. I shall be interested to talk to Ice Energy about installation on a larger scale, volume savings, ideas on grouped ground loops, volume manufacturing of Sunboxes etc.

Night working!

19 July: As I predicted, these Sunboxes continue to work late into the night - tonight they worked until just before 11pm. I have set them to require a temp of over 20ºC in the box, or a temp diff of 5 degs C. They don't work on cold summer days, but that's ok. In the winter they will work frequently but at a lower temperature range because the Heat Pump will be working more frequently, due to the heating load. At this time of year, the GSHP is working less than an hour per day, just for water heating.

Wednesday, July 14, 2010

Holiday gap in PV Readings? No!

13 July: As readers of this Earth Charging blog know, my PV roof is connected to the Internet, so it can publish its performance in realtime (with only an hour or so delay). It bleeps its status to SunnyPortal every 15 mins.
   I have just got back from 10 days holiday in France. Before leaving on the 3rd, I turned off my main broadband router as I wanted to reduce the number of appliances left on all the time, and also didn't want the neighbourhood parking outside my house getting free internet access.
   Unfortunately (although I tried to connect it directly before leaving), the Web Router for the Photovoltaic roof could not find the Internet, so for 10 days in France, I was somewhat in despair seeing zero reports or statistics about the PV. Got back today and after doing a few things (e.g. some weeding in the garden) I turned to the matter of the broadband router. Connected it all up correctly. Nothing had gone to the internet for 10 days.
   Looked at it a few hours later..... wow! The router must have stored all the statistics in some memory, because this evening I found that everything had been sent to SunnyPortal, and broadcast back as the usual set of graphs. We have scored consistently above 14.5 kWh per day during the period, except yesterday and today (Mon and Tue) when it looked more like a couple of days in January. Must have been very cloudy and rainy!

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