Jeremy Harris

For a small extension then the process is really pretty straightforward. Check the planning portal site, here: https://www.planningportal.co.uk/info/200234/home_improvement_projects as it has a fairly easy to follow guide that takes you through the process step by step. If you don't understand some of the questions, ask here and we'll help to guide you through it.

We're really impressed with our very first generation, pre-production, SunampPV. It's performance is really very good indeed, and most impressively the heat losses from it are negligible - the case doesn't even feel warm when it's fully charged. It's made a tremendous difference to the temperature in our services room. When we had a thermal store in there it used to get exceptionally hot, hot enough to damage the oak door, and that was with loads of additional insulation around the store to try and stop it wasting heat. Now the services room is barely warmer than the rest of the house, and that's all down to the very low heat losses from the SunampPV. Bearing in mind that our SunampPV is "old technology" compared to the current versions; we were most definitely early adopters (I think the first on here to get one). I have no doubt that the performance has improved a great deal since our unit was made, which bodes well for anyone thinking of getting one now.

Yes, the panel wires are always live in daylight, and as they are wired in series in each string you can get quite high voltages at the ends of the strings. However, the inter-panel connectors are designed to be hard to accidentally touch the live part, and a fault may well be physically obvious. The most common faults are pulled apart connectors, where something has physically dislodged them, and burned out connectors, usually where the internal crimp to the cable wasn't made properly. The latter usually shows as heat damage to the outside of the plastic part of the connector. Less common faults can be an interconnect ribbon within a panel failing, which usually means replacing the panel. Take a meter up with you, capable of reading several hundred volts DC, and check the panel voltages at the connectors as you go. That way you should be able to trace where the fault is in the string. Because your working on live DC, albeit isolated from earth, a pair of insulated gloves would be a good idea.

I've just looked at our ground works breakdown of cost, at 2013 prices. We had two service trenches crossing single track lanes, one carrying a power cable the other carrying the effluent discharge from our treatment plant. The cost breakdown from our contractor's QS is: Effluent drain road crossing - Mill Lane Excavate trench across road. £216.00 Allow for reinstatement. £900.00 110mm effluent outlet pipe. £77.76 Pea gravel bed and surround to pipe. £117.29 Test foul drainage. £90.00 Electricity main road crossing - Mary Barter's Lane Excavate service trench 1000 deep in road. £252.00 Allow for reinstatement. £1,050.00 150mm rigi-duct. £67.79 Draw-cord. £7.14 On top of this I paid the council for a licence to dig across these two highways that cost around £500. That fee included the council coming out to inspect the road surface reinstatement standard late in the afternoon of the day the work was carried out. I'm not sure of the road widths, at a guess I'd say around 4 to 5m long trenches were dug across each.

Prices are different down here, but probably higher than where you are. Here are some guide prices from down here: Brickies are between £150 and £180/day, excluding their labourer Electricians between £170 and £200/day, reasonable joiner is around £180 to £200/day Plumber at least £200/day, often way more; I've seen some close on £300/day Decorators around £150 to £160/day (just basic gloss and emulsion stuff) General builders vary a hell of a lot. I know a reasonably competent basic general builder who's around £160/day, but only really any good for basic stuff, and at the other end I know an outstandingly good chap that's £220 a day, but is worth every penny. Labourers vary a fair bit too. I can get young lads with strength and stamina but little knowledge for around £60/day (cash in hand) or pretty good, experienced labourers for between £80 and £110/day (the latter for a good worker who can be trusted to dig trenches to the correct spec, mix muck exactly how the brickie wants it, etc).

Depends on how much heating the house needs. For us, RHI would have paid a bit over £80 a year for 7 years. The additional cost of having an MCS approved ASHP install was around 25 times greater than this, so it would have cost a great deal more to have an MCS (and hence RHI) approved installation than we would ever have got back. The same is usually the case for any new build, even one just built to building regs, as the RHI scheme really only makes sense if the house has a high heating requirement, so mainly applies to older, less thermally efficient, homes.

Yesterday I pushed the button on buying two, 2 gang switches and two receivers, to replace the (really crappy) Byron/Homeeasy remote switches we already have. I'm hoping that the Quinetic stuff will be more reliable, and also hoping that the test you did with the dimming switches and the ordinary receiver works. I don't like the idea of having the switch directions reverse if there's a power cut, and the option to just push on and push off seems an attractive one to me. I shall report back on how well they work once they've arrived and are wired in. I still don't understand why the Byron/Homeeasy ones are so crap, but I've tried replacing switches and receivers to no avail, they barely function at all with the receivers mounted up behind the ceiling and the transmitted mounted on the walls around 2 to 3m away.

Simplifying the tariff structure and introducing variable tariff rates based on grid demand/wholesale spot market prices seem to be mutually exclusive. Mind you, nothing would surprise me anymore with any proposed edict from government; they have shown time and time again that they just do not understand how markets work, and frequently blunder around interfering and having the opposite effect to that they intended. The chaotic and complex pricing structures we have for energy, telecoms etc, are all a direct consequence of a government desire to give us all more freedom of choice...

There is only one benefit to suppliers from fitting smart meters, and that is so that they can introduce flexible on-demand tariff changes, to remove the risk they carry at the moment from having to guess what the mean spot market wholesale cost will be for up to a year ahead when setting tariff rates. Right now the wholesale cost of electricity varies half hourly from a negative price per kWh in low demand, high generation, periods, to well over 20p/kWh during peak demand periods. The suppliers want to introduce variable tariffs to suppliers, using the smart meter and it's internal house display, to both set the meter tariff at any time and tell the customer what it is. This sounds reasonable until you look at how customers are going to be able to compare suppliers. With tariffs changing on the fly there will be no way to easily tell if one supplier is offering better value than any other.

The energy companies will have a big problem if they try that. The chap that came out to do the site survey to install a "free" car charging point told me I couldn't have one because there was no mobile phone signal. During the course of the conversation he revealed that this also meant I couldn't have a smart meter (not that I wanted one) as with no phone signal they can't function. There's talk of adopting power line signalling I believe, to get around the problem of areas that have no mobile phone coverage, but I've not seen any sign that they intend to roll this out.

@AndyT, I may be better asking this directly of Sunamp, but I was one of the very early adopters, and have one of the very first Sunamp PVs. Part of the deal was that Sunamp wanted to have the option to examine the cells/heat exchangers after a time to see if using softened water had any impact; they were going to send me two replacement cells so I could swap them over and send the old cells back for examination. I've had an ongoing problem with sporadic over-temperature trips on the resettable thermal trip on the heater block (my unit has the very early firmware that I believe doesn't have a run-on period to reduce heat-soak) and I've already had to replace the thermal trip in an attempt to cure the problem (it hasn't fixed it - it still trips once every couple of months or so). It seems that the newer unit has completely removed these issues, and as I have been contemplating getting some add-on cells to increase the capacity of our Sunamp PV, I'm wondering if it might be worth changing it for a new unit?

Happened to one of our bedroom windows, about 6 months or so after it was fitted. The inner pane of the triple glazing cracked just like that. Munster came out and replaced it under warranty with no hassle and it's been fine since. The window faces east, so only sees the sun in the morning. The glazing unit was a Saint Gobain 3G argon filled unit, with a relatively wide gap between panes of 20mm (it was a 4-20-4-20-4 unit).

Interesting incident yesterday related to decrement delay (i.e. the combination of heat capacity and thermal conductivity of a structure). A neighbour called by, and as it was so hot outside (around 30 deg C) I asked her in (it was around 22 deg C indoors). She immediately remarked on how much cooler our all-timber house is inside then her 1980's built bungalow. She had just come from visiting the Rectory (a big stone built building) and reckoned out house felt even cooler inside than that. Just goes to show that having a house that stays cool in summer and warm in winter isn't related to the mass of the building material used at all, just the thermal properties of the materials and the way they are arranged. We have no masonry in our house structure at all, just a 100mm thick concrete pass slab floor internally.

Welcome back! I agree with @jack, I think you hold the record for taking the longest time to find us all after Ebuild closed down!

The ones that look nicest in my view are the slim section flush LED panel lights, like these: https://www.brightlightz.co.uk/12-watt-frosted-round-led-ceiling-light-office-panel Alternatively, ordinary 12 V MR16 downlighter fittings work fine with pretty much any 12 V MR16 LED lamp, like these: https://www.ledhut.co.uk/spot-lights/mr16-led-bulbs.html?fq[base_type]=MR16 Worth looking around, though. I made a test unit up so I could compare different MR16 LEDs and wrote a short test report, attached. MR16 LED test data.pdf

That test has confirmed that it's the string at fault, not the inverter. @SteamyTea is dead right, this isn't unusual and they can be a pain to get at, as the connectors are under the panels on the roof.

There's no internal fuse on any duds that I've done an autopsy on. The particular problem with GU10 LEDs is that the driver circuit is in the base and runs warm. GU10 fittings designed for use with halogen lights are designed to keep the heat in, as halogen lights are more efficient when run very hot. LED lights hate heat so need a fitting that will allow heat to escape, especially from the base, where the driver circuit is. What then happens is that the base runs hot and over time components start to fail. The electrolytic capacity on the input smoothing side is especially intolerant to heat and it's life will be drastically shortened by running hot (this it the reason why it's much better to fit PV inverters is a very cool location - keeping they capacitors cools significantly extends their life). Once the input capacity fails, then there's a god chance that there will be a chain of failure of other components in the using, leading to the catastrophic failure you have seen. To stop this happening again, make for the GU10 filltings are well ventilated and allow the base of the lamp to receive some cooling. If run cool their life with be significantly extended. As a final note, I don't like GU10 base LEDs for this specific reason - they cram a constant current driver down into the narrow base and will fit into lights that were designed to run hot with halogen lamps. MR16 12 V lamps look the same from the front, but have the advantage that the driver is remotely mounted, so can be fitted somewhere in the ceiling void where it will get some cooling.

@ProDaves and @Declan52s suggestion of using an inner structural timber frame gets my vote. You can include insulation within the timber frame, resolve all the issues with things being out of true and still preserve the external appearance. What's more, even if you used low decrement delay foam insulation internally, to minimise the loss of room space, the overall decrement delay factor would still be high due to the high heat capacity outer skin.

I can see the potential for a new gadget here. Get some thin neodymium magnets and sew them to the back of work gloves. You could stow screws, nails, screwdriver bits etc to them, plus, if you drop a nail, screw, etc you just put your hand down and the magnets pick it up. I have loads of spare magnets around and may try it out to see how it works...

It doesn't look as if the DC connections unplug, but there should be a pair of DC isolator switches fitted, one for each string, so that the system can be made safe. These are usually fitted right next to the inverter, but don't seem to be in your case. The usual type fitted are quarter turn rotary switches, with a yellow or white case and red knob. These isolate the DC from the panel strings so allowing the inverter to be replaced, and I thought they were a mandatory requirement. The four wires going in to the bottom are the cables from the two strings a positive and negative for each, and MPPT1 and MPPT2 should be marked inside next to the terminals, or on the underside of the cover, perhaps. Because you have to access the terminals by removing that cover, the instructions on it need to be followed, to turn off both the DC and AC isolator switches. Often the inverter AC isolator switch will be fitted right next to the generation meter and consumer unit connection.

I've got a feeling that the indicated MPPT voltage floats up when a string goes open circuit, from internal leakage, but you might be right. Swapping the strings over on the inverter should prove it one way or the other though.

The room terminals don't usually have filters, and the main problem area with MVHR is the intake filter, where air is drawn in from outside before going through the heat exchanger.

Looks like one string of panels has gone open circuit. Most likely culprit will be a connector in that string I think. The only easy way to tell is to get up on the roof and have a look at the connectors. There can be problems if connectors aren't crimped to the cables correctly, leading to overheating and an open circuit, but equally it could be something as simple as a connector that's somehow been subjected to strain and just come unplugged - I've heard of that happening when people have poked around trying to clear birds nests from underneath panels. As a test, you can turn off the DC isolators and then swap over the DC inputs on the inverter (they should just plug in). If you then turn the DC isolators back on and the fault shifts to MPPT 2 you know that it's the panel string that is at fault, not the inverter. FWIW, my money is on a duff connection on the string feeding MPPT 1.

I'd have to agree with @ProDave, with no insulation under the screed/slab it will waste more heat than it delivers to the room. As a guide. underfloor heating needs better underfloor insulation than normal heating, because the floor surface will be a fair bit warmer, so accelerating the rate of heat loss downwards to the ground or undercroft.

It's fine, but EPS needs to be about 50% thicker to get the same insulation value. Sometimes you can get EPS at a better price overall, and if you have the space to fit the extra depth, then EPS is fine.