Pictured above - the frame for the Solar Thermal tubes.
Pictured above - the bottom of the ST frame showing the lower caps that support the tubes.
Pictured above - the old DHWC prior to removal.
Pictured above - the Airing Cupboard after the old DHWC was removed.
Pictured above - our installer fixing in the last of the Solar Collector Tubes.
Pictured above - a close-up of the bottom of the collector tubes.
Pictured above - the Solar Thermal Tubes in position as seen from the ground.
The Solar Thermal ("ST" or "Solar Hot Water") installer turned up a bit later on the first Wednesday. Unfortunately the Gledhill twin-coil hot water cylinder wasn't ready yet but the installer was able to fit everything else. He soon had the tube frame mounted on the roof. These are mounted differently from the PV system as they are smaller, lighter and fitted closer to the roof surface. The PV system is heavier and mounted a couple of inches off the surface so that cooling air can flow underneath. PV works better when cool whilst ST likes to get really hot (of course). Hence small holes are drilled directly through the roof tiles and then long screws are screwed directly into the roof rafters. Rubber washes protect the tiles from breakage.
Next came the internal work. A pumping station is mounted on the attic wall on the opposite side to the PV Inverter. This all worked out quite well as electricity and water don't really mix very well! Thankfully the layout of the house meant that the garage and consumer board are at the western end whilst the hot water tank is at the eastern end of the roof space. There was no vying for limited space - there was plenty. An expansion tank is mounted on one rafter. Flexible tubing is laid out between pump and roof. More tubes go from pump station down under the loft insulation through to the airing cupboard.
Due to the delay with the Gledhill tank we had to wait another week before the installer could come back to finish the job. In that week the tubes themselves couldn't be put in place so the scaffolding had to remain in place.
Finally the tank turned up after some comic comings and goings. It had been delivered to the installer's head office in Slough rather than our home. Gledhill had turned up at our home expecting to collect a cylinder they had never delivered. Apparently the original cylinder wasn't correct. It didn't have a sensor pocket for the DHWC temperature sensor for the KWB Easyfire. The survey should have picked this up but the surveyor was an electrician not a plumber. He had no interest in the ST system's requirements and only took a photo of the Hot Water Cylinder. It really pays to have a proper survey done by your installer. By 'proper' we mean thorough! It didn't result in much inconvenience for us really as the time restriction was on the LCBP Grant. Since that as related only to the PV installation then we were perfectly happy to accept a small delay.
The installing company were very good in bending over backwards to get us all of the right paperwork so we could complete the grant application. However we think the old adage is true - "more haste, less speed"!
After the right tank turned up we soon found our old domestic hot water cylinder sitting on the front lawn. The swap over was completed in under a day so there was no inconvenience of having no hot water or heating. The water is off for a few hours obviously but it was of no great inconvenience. You fill up your bath with water and flush the toilet with a bucket! If you have a bit of "Blitz spirit" then this is just part of the fun.
The old hot water cylinder was in a poor state. It was only fitted by the previous home owners back in 2003. It was heavy with lime scale as this is a hard water area and they had no water softener fitted. We had our water softener fitted after the KWB went in so this damage is now unlikely. The new cylinder has a 170 litre capacity. The old one had only a 100 litre capacity. The lime scale probably accounted for a lot of that so we easily doubled our hot water capacity. This now stops us from running out of hot water after a couple of showers. A really big help around the home!
The only downside was the loss of space in the airing cupboard. The new cylinder was taller and thinner. It mean we lost half a shelf. Later on we managed to reconstruct a partial-shelf from bits of left-over shelves to give us a bit more storage space there. Due to the limited width of the tank there is more space in front of it. You can stack quite a few shoe boxes there. So we will probably find some small shelving units that will fit well.
The only significant set back during the install was the flood of water after the new tank was connected. This lead to an embarrassing near-panic by the installer who feared he had not connected something properly. We quickly ran around the house and put down some blankets, plastic sheet and buckets to catch the drips downstairs. Thankfully no damage was done.
The problem was quickly located to the hole at the top of the cylinder where the Domestic Hot Water Cylinder normally slots. The installer had decided to use the immersion heater electrical spur for the Pump Station so he elected to specify a tank with no immersion heating element. All well and good but Gledhill didn't supply the cap to go over the hole. This would have been quickly rectified if they had not covered the hole up with a plastic over-wrap that had been taped in place permanently. Once ripped off the problem was obvious. The installer popped out to buy a tank cap and all was then well. However, red-faces all round and an eternally apologetic installer resulted.
Despite this we felt it was Gledhill's fault and didn't blame the installer who, otherwise, did a superb job. It was just unfortunate. We were lucky that no damage resulted as the problem was spotted quickly and the water switched off before too much over-flowed.
This incident did waste a bit of time but the installer made up for it and everything then slotted neatly into place. Soon it was back to the roof to put in the evacuated tube solar collectors. These do not actually have any fluids flowing through them that are connected to the hot water cylinder. The heat transfer glycol fluid, that takes the heat down to the hot water cylinder, only flows through the top part of the ST frame. It extracts the heat from the very top of the tube. Inside the tube is a long thin element which absorbs the heat and conducts it to the end of the tube. This makes the entire assembly easy to install. It is easy to add or remove the tubes. We were even supplied with a spare!
Before the installer left he showed us how to operate the system control panel that is mounted in the airing cupboard. This delightful box of tricks gives a clear visual read out of tank temperature. You can set the desired temperature to whatever you wish. There is also a "holiday mode" which you can use to prevent the system over-heating if you are not using the hot water for several weeks. It all gave us a great feeling of having a system we were fully in control of.
Our system is a 20 tube ETZ2580 BE Solar System. The tubes are 1.8m long giving a 1.87m2 aperture.
By the late summer the glycol in the system had vanished and we had to get BritishEco back to refill and recommission the system. Various theories were forwarded on why this happened and we still await a follow-up visit in 2011 to perform other minor rectifications. We suspect that the roof sensor doesn't read correctly but the installer disagrees. They wish to fit a valve to stop reverse siphoning.
Pictured above - the Solar Pump Station in the attic
Pictured above - the piping from Pump Station to Solar Collectors
Pictured above - the top-right-hand side of the ST frame showing the pipe mounting.
Pictured above - the left hand-side of the ST frame sowing how close it is to the PV panels (left)
Pictured above - the old cylinder and the new.
Pictured above - the new cylinder in the Airing Cupboard.
Pictured above - the Tubes being secured.
Pictured above - the airing cupboard after all the pipes were re-insulated and the shelves replaced.