In my last post I described how a heat store works but nothing about its installation. This was thought unnecessary as that’s the plumber’s job and is no more than pulling out the old stuff and routing a few more pipes etc. Unfortunately with a slightly bigger tank than expected ( due to a tripartite combination of errors between myself, plumber and supplier) the airing cupboard door had to be removed and I will have to fit another one. I had thought this would be necessary from the very outset. Unfortunately the fitting of such a large new tank led to delays and an extra day’s work. By the end of the second day we all a bit tired and so when I raised the question of the anti-corrosion additive the advice was that all I needed to do was add a half a litre of the stuff.
Fine I thought, I will trot off and get some. Unfortunately the smallest quantity was 4 litres at £20. This put me on warning so a call to the supplier soon showed that I had a problem. The requirement for a tank of our size was that 6% of additive was needed. A quick calculation showed that this came out at 15 litres. After a stunned silence the supplier said the installer should have put this in and if I bought it I could deduct £80 from the final bill. I am tempted to deduct a charge for the following labour as well, but on the basis that no experience is a wasted experience, I shall delude myself into thinking that value was had.
The next problem was to make room for this extra liquid while not reducing the 6%. Firstly I siphoned out the contents of the small header tank. Since there was only about 2 inches of clearance bailing it out or pushing down a bucket so that the ovewrflow di its job, was not on. The siphon worked well but the amount removed was about four litres out. The next move was to fit a hose pipe to the drain tap and measure a drain off of about 4 litres. All these moves were intended to keep the waste of hot water ( at 56c by the end of the day) to a minimum. This worked well.
The next stage was to deliver the 15 litres to the header tank Enter the mad DIY boffin. The sensible method would be to decant about a litre at a time by means of a squeezee lemonade bottle but the scientific solutions was the fix a small pump to the Black and Decker Drill and hey presto 15 litres are delivered without difficulty. For this purpose I needed the hep of the reasonable woman. The first attempt failed as I had connected the inlet and outlet spigots the wrong way round. Result, loads of bubbles in the fluid which should have been speeding its way aloft. A quick, but splashy interlude, resulted in nothing. Tried to prime the pump; same result.
The next suggestion was to take a hose pipe upstairs and get gravity on our side. Assurances to the reasonable woman that the stair carpet would be safe and that there would be no more splashy intervals failed. The reasonable woman suggested the squeezee bottle solution and produced 2 such bottles but only 750 cls. However, 18 or so deliveries later the header tank was filled with the protective fluid and the spare litre was delivered to the back boiler header tank upstairs.
Mad DIY boffin was then put on mopping duties while reasonable woman retired to the lounge to watch one of her detective dramas. Shimples.
Showing posts with label Solar Panels. Show all posts
Showing posts with label Solar Panels. Show all posts
Friday, 16 October 2009
Thursday, 15 October 2009
Heat Store Story: the tale of the vented heat store tank with a solar panel, back boiler and Economy 7 immersion heaters
For a number of reasons our solar panel of some five years decided to stop working. I will not bore you with the details but, among a number of things, this was due to the micro bore pipes which take hot water to our immersion tank getting blocked. Along side this, our plumbing system was originally designed to handle a trickle supply of water from a spring two fields away. Because the spring was only a few feet higher than the location of the header tank the head of water in the house was probably not more than 12 inches above the highest tap in the bathroom. Running the hot water for a bath was therefore a slow job and even slower should someone want hot water downstairs.
To get the solar panel running again and avoid another blockage we would either have to install a water softener or convert to an indirect system whereby the hot water from the panel was confined to a coil and thus kept separate from the water in the immersion tank which was being drawn off for domestic hot water. The other solution was to have a heat store tank. This would have the same effect but by a different method, with the added bonus that all the hot water throughout the house would be at mains pressure and the space taken up by the header tank above the stairwell would be available for storage..
Although I had seen heat store tanks at various NEC exhibitions I had never picked up an explanatory leaflet nor found a sales rep capable of explaining how they worked. This is fairly simple once the basics are grasped. A conventional immersion tank has an electric element like a giant kettle that heats the water.. The hot water in the tank is drawn on when a tap is turned on and is replaced from below by cold water from a header tank. It is the height of that header tanks water which pushes the hot water round the hot water circuit. Unfortunately each batch of hot water as it is heated up will deposit lime scale and other minerals into the tank. Some of the chemicals will corrode the tank and other bits of the pipes. The local water might be treated by adding lime to bring the acidity down but whatever the chemistry there is always a danger that this constant process can corrode the electric element first. Once removed, we discovered that our old tank, fitted 20 years ago, was already leaking.
When the mains water eventually gets pushed through a solar panel from such a system further deposits can be left behind after the high temperatures reached in this ‘roof top boiler’ and so the risk of blockages. With direct systems such as the SolarTwin the softer the water the lower the risk of blockages. This system pumps water directly into the top of a conventional immersion tank and avoids the need for a replacement tank, anti-freeze solutions or a separately powered electric pump as a PV panel is built in for this purpose.
It would seem our local water is rather acid but has lime added to it but it probably varies. The theory goes that for a solar panel that is heating constantly replenished mains water of this type deposits will soon occur if high running temperatures are achieved. The same happens with the constantly heated new water in the tank as well.
As we found that we had no room for a water softener and we were fed up with a slow supply of hot water we opted for a heat store tank. This retains the same water all the time and will only change if it gets so hot the water expands to the point that it returns to its own nearby header tank and the water is thus replenished. Even here the amount of new water entering the tank is small. It is this water, stored in a highly insulated and extra large tank, some five feet tall or more, which heats up and cools as heat is put in and heat taken away. That transfer of heat is brought about by a coiled pipe passing through the heat store tank containing water at mains pressure. The miracle of the system is that the heat store is sufficiently hot and the coil sufficiently long to achieve an instant heating of the mains water passing through the coil which never comes into contact with the column of permanent water in the heat store. Result, hot water at mains pressure at a temperature you can select by a special valve that will mix some mains cold water into the mains pressure hot water when it exceeds the required temperature, usually about 60c but lower temperatures will be ok for hand washing and a or showers. As no cold water enters the heat store it is cooled down much slower than a conventional tank and hence is more efficient. The system makes a shower easier to install because with hot and cold water both at the same pressure all that is needed is a mixer shower valve and you have a power shower depending on what pressure of supply you choose.. Even in the bathroom you can make sure your mixer is thermostatically controlled so you won’t be trapped in a scalding shower ever again. As the meerkat sayeth, ‘shimples!’
To get the solar panel running again and avoid another blockage we would either have to install a water softener or convert to an indirect system whereby the hot water from the panel was confined to a coil and thus kept separate from the water in the immersion tank which was being drawn off for domestic hot water. The other solution was to have a heat store tank. This would have the same effect but by a different method, with the added bonus that all the hot water throughout the house would be at mains pressure and the space taken up by the header tank above the stairwell would be available for storage..
Although I had seen heat store tanks at various NEC exhibitions I had never picked up an explanatory leaflet nor found a sales rep capable of explaining how they worked. This is fairly simple once the basics are grasped. A conventional immersion tank has an electric element like a giant kettle that heats the water.. The hot water in the tank is drawn on when a tap is turned on and is replaced from below by cold water from a header tank. It is the height of that header tanks water which pushes the hot water round the hot water circuit. Unfortunately each batch of hot water as it is heated up will deposit lime scale and other minerals into the tank. Some of the chemicals will corrode the tank and other bits of the pipes. The local water might be treated by adding lime to bring the acidity down but whatever the chemistry there is always a danger that this constant process can corrode the electric element first. Once removed, we discovered that our old tank, fitted 20 years ago, was already leaking.
When the mains water eventually gets pushed through a solar panel from such a system further deposits can be left behind after the high temperatures reached in this ‘roof top boiler’ and so the risk of blockages. With direct systems such as the SolarTwin the softer the water the lower the risk of blockages. This system pumps water directly into the top of a conventional immersion tank and avoids the need for a replacement tank, anti-freeze solutions or a separately powered electric pump as a PV panel is built in for this purpose.
It would seem our local water is rather acid but has lime added to it but it probably varies. The theory goes that for a solar panel that is heating constantly replenished mains water of this type deposits will soon occur if high running temperatures are achieved. The same happens with the constantly heated new water in the tank as well.
As we found that we had no room for a water softener and we were fed up with a slow supply of hot water we opted for a heat store tank. This retains the same water all the time and will only change if it gets so hot the water expands to the point that it returns to its own nearby header tank and the water is thus replenished. Even here the amount of new water entering the tank is small. It is this water, stored in a highly insulated and extra large tank, some five feet tall or more, which heats up and cools as heat is put in and heat taken away. That transfer of heat is brought about by a coiled pipe passing through the heat store tank containing water at mains pressure. The miracle of the system is that the heat store is sufficiently hot and the coil sufficiently long to achieve an instant heating of the mains water passing through the coil which never comes into contact with the column of permanent water in the heat store. Result, hot water at mains pressure at a temperature you can select by a special valve that will mix some mains cold water into the mains pressure hot water when it exceeds the required temperature, usually about 60c but lower temperatures will be ok for hand washing and a or showers. As no cold water enters the heat store it is cooled down much slower than a conventional tank and hence is more efficient. The system makes a shower easier to install because with hot and cold water both at the same pressure all that is needed is a mixer shower valve and you have a power shower depending on what pressure of supply you choose.. Even in the bathroom you can make sure your mixer is thermostatically controlled so you won’t be trapped in a scalding shower ever again. As the meerkat sayeth, ‘shimples!’
Tuesday, 19 May 2009
Blog Trailers
If you have stumbled upon this site I thought you might like to know what will be happening here in the near future. This might encourage you to follow the site, to share it with others and to comment.
With the Mr Speaker controversy moving on. Did the Queen have something to say? Will Mr Martin resign his seat and cause a Glasgow bye-election. PM won’t want that. Watch this space for comment
The last fortnight has been filled with constitutional drama and has given the politics side of this blog to gravitate towards Westminster and in the nature of things that will happen from time to time, especially with a year of electioneering stating up. AS my recent blog emphasised the European Elections could be a useful starting point for the General Election. Although the PM can usually decide when to ask the Queen for a general Election, the five year life span of a Parliament now boxes him in and as time goes by his options narrow. So lots of fun to come.
In the meantime why not look out for some of the following blackhilltales. The list does not show an exact the order in which they will appear:
Hay Festival at Hay-on-Wye: Why Not?
Visits to local towns and markets
The joys of insulating old properties and rural poverty
Travails with the Energy Saving
Time to Update the Solar Panel
World Premier of our new folk song: details may follow, if not too embarrassing. Sorry.
Country Pubs
Fixed Penalty Fines in a not so supermarket
Occasional series: Watch out its Wildlife!
Occasional series :Briefing Notes for Debaters.
You will have noticed that articles are a bit long for a blog. Some effort will be made to keep some down to 300 words while others that need a bit of room will be not go much beyond 600 words.
And there will be more articles but various DIY jobs are getting rather urgent.
With the Mr Speaker controversy moving on. Did the Queen have something to say? Will Mr Martin resign his seat and cause a Glasgow bye-election. PM won’t want that. Watch this space for comment
The last fortnight has been filled with constitutional drama and has given the politics side of this blog to gravitate towards Westminster and in the nature of things that will happen from time to time, especially with a year of electioneering stating up. AS my recent blog emphasised the European Elections could be a useful starting point for the General Election. Although the PM can usually decide when to ask the Queen for a general Election, the five year life span of a Parliament now boxes him in and as time goes by his options narrow. So lots of fun to come.
In the meantime why not look out for some of the following blackhilltales. The list does not show an exact the order in which they will appear:
Hay Festival at Hay-on-Wye: Why Not?
Visits to local towns and markets
The joys of insulating old properties and rural poverty
Travails with the Energy Saving
Time to Update the Solar Panel
World Premier of our new folk song: details may follow, if not too embarrassing. Sorry.
Country Pubs
Fixed Penalty Fines in a not so supermarket
Occasional series: Watch out its Wildlife!
Occasional series :Briefing Notes for Debaters.
You will have noticed that articles are a bit long for a blog. Some effort will be made to keep some down to 300 words while others that need a bit of room will be not go much beyond 600 words.
And there will be more articles but various DIY jobs are getting rather urgent.
Subscribe to:
Posts (Atom)