ProDave

Electricians have been asking for an isolator to be built into all smart meters to provide safe isolation. So they have the physical mechanism to disconnect the output, but still they won't provide an isolation facility. I guess a relay under control of some flaky software would not qualify as safe isolation anyway.

That depends on your salary and credit rartng. I got a pretty low £3200 credit limit but because the only sensible way to transfer the balance is by balance transfer I am limited just to transferring our normal credit card bills as they come in. The transfer window of 60 days might run out before I have transferred up to the credit limit. You can do it as a cash advance, but then a 5% fee applies and it is only 0% for 20 months, so not such a good deal.

Not enough to build a house. I am playing the 0% credit card game Virgin were offering 0% for 29 months a few weeks back. With a 3% balance transfer fee, that works out about 1.25% per year. Once all that is spent SWMBO will be opening one hopefully on a similar deal. If not paid off in full by 29 months we will be looking for another 0% deal to swap them onto. (probably need to look at MBNA then)

I think Jeremy did the calculations and the difference is only a few % in the heat capacity of air over the range we are talking about. so I am sure the HP will run at a better COP just now, but the saving by running it instead on the off peak rate will be greater. Mine topped up the tank today powered by the PV with no import. Mine only comes on after 11AM to maximise the chance of enough PV generation to run it.

But even if you owned a £500K house and wanted to borrow £100K, they would only lend up to what they thought your salary could repay.

That is how the new export payment scheme will work. you first have to get a smart meter then the smart meter will record import and charge it at your normal rate and separately meter export and pay it at the much lower export rate. Currently as far as I know, Octopus are the only ones to introduce this on a trial basis and are paying 5.5p per KWh exported.

That would be good, but it would mean you getting paid at the full retail price for what you export. The export scheme will only pay you at the wholesale rate.

The normal salary multiples will still apply so if your salary is low will that not be your limit?

I think the issue is the previous FIT system may have imposed limits on actual panel capacity when claiming the FIT, but that is gone and any such limits gone with it. We now only have to satisfy G98 (or G99 for larger systems) and unless someone can find to the contrary, I believe that is only concerned with maximum current.

A quick search finds this http://www.ena-eng.org/ENA-Docs/D0C3XTRACT/ENA_EREC_G98_Extract_180902050358.pdf The only talk is of the maximum current being less than or equal to 16A. It does not seem to care how many panels are connected or indeed anything about the technology used, just the maximum current. Unless anyone else finds anything to contradict that I still believe the maximum number of panels is a technical limit of the inverters max voltage and current inputs. It will still limit the output to 3.68KW / 16A

The DNO are concerned about export current. Up to 16A you don't have to notify and they cannot refuse connection. If you are not claiming the small export payment there is no need for MCS involvement either. So subject to the voltage and current input limits on your inverter I cannot see an issue with more panels.

Pleasant 21 degrees, dry, some cloud, here in the Highlands.

Re sizing, First ask your DNO what they will allow you to connect. Up to what is generally referred to as a "4KW" system (actually the inverter output is limited to 16A or about 3.68KW) you can connect without prior notification but you must notify the DNO once you have connected it. This is what we have with 4KW of panels. Above 3.68Kw you need prior approval BEFORE you connect it. Depending on the infrastructure around you they may just say yes or they may hit you with a cost to upgrade the network first. This I am sure is what would happen here. When I submitted the form to notify mine, they initially read it as "4KW" and wrote to me saying as it was over 3.68Kw they would provide me with a quotation to upgrade the network and I must not connect it until the upgrade work has been done. That went away when I provided them with the manufacturers declaration that the inverter does limit the output to 3.68KW Once you know what size the DNO will allow you then look at the roof space and see how much will fit in nicely, and how much you are prepared to pay for. We self use at least 90% of what we generate. In fact the exported amount is so low that I estimate even if we were able to sign up for the 5.5p per KWh export payment we would get less than £10 per year, so totally not worth it. In order to sign up for that you have to use an MCS installer which is generally recognised to push the price up somewhat. If you are not bothered about claiming the paltry export payment then you or any competent electrician can connect it, probably for a lot less than an MCS installer. The key to maximum self usage is to use the big appliances (washing machine, dishwasher and tumble dryer) in the daytime, one at a time. If you are out all day set them on a timer. The other key thing is choose a hot water system with a hot water tank and buy a device that sends excess PV generation to the immersion heater. In the first half of this year my unit has sent 324KWh to the immersion heater. The last thing I do to maximise self usage, is at this time of year I have the ASHP set to heat the hot water after 11AM when there should be enough PV for that to power it on a good day.

Rather than move the existing wall IN by 200mm, amend the plans to build the existing garage wall OUT by 200mm. It will give the step they want, I doubt they will notice what you have done, will give you more space, and is no hardship since you have to build up where the garage door was.

I ran it for about 3 hours, and turned the water temperature down to 16 degrees. There was no sign of condensation on the manifold or any of the pipes entering or leaving the manifold so I assume that means it was okay and there won't be any condensation within the actual floor. In that time the floor surface temperature dropped about 1 degree. I have turned it off now, it is not as warm today and outside is now cooler than inside so I have gone back to "open window" cooling

Running costs will be about equal. except ASHP might be slightly cheaper if you don't have gas at all so no standing charge to pay for that. Install costs won't be far off equal. Remember you will probably save £2K at least just by not having gas connected to the house, so the gas plus A/C install price would need to be £2K less than the ASHP plus water tank plus fan coil option, just to be equal.

Why not? you can have UFH upstairs as well.

I guess this sets the bottom end of the price range then? https://www.alibaba.com/product-detail/House-Home-Villa-cooling-and-heating_60540911211.html?spm=a2700.details.maylikeexp.7.5e07360cQOVJOm

That is why I am specifically looking for a cooling unit, without much luck apart from the huge things meant to go in office ceilings.

Searching "water heat battery" on ebay just lists mostly fancy thermostats and controls. Searching that on a search engine gives lots of links to the Sun Amp hot water systems. Nothing resembling what I want?

We have a portable AC unit, bought years ago in a CPC sale. It is damned noisy and as has been pointed out it is hard to exhaust the hot air without letting outside hot air back in. We do however use it quite a lot as a dehumidifier, for which it is much better suited.

Whilst we are all "enjoying" the present spell of hot weather, many of us are thinking of ways for cooling our houses. Many of us have an air source heat pump that can operate in cooling mode as well as in heating mode. So I would like to look at using mine to cool the bedrooms. What I am looking for therefore is two wall mounted Fan Coil Units (FCU's) one to go on the wall in each of the 2 bedrooms that we use. They need to be wall mounted as one bedroom has a full vaulted ceiling and the other a partial vaulted ceiling. It makes sense to get two identical units so bot can be wall mounted. What I had in mind was something that looks a bit like the inside unit of the air conditioner that @JSHarris has just fitted and detailed in this thread It seems to me that it would be a very simple unit. It would take the chilled flow and return water from the ASHP pass it through a heat exchanger with air passing through that from a fan inside the unit. It needs the minimum of controls, it really just needs a manual fan speed adjustment and control of the fan on or off by a (cooling) room thermostat, probably separate to the FCU. I thought this might be something easy to find and cheap. but 45 minutes on a browser and I am disappointed with how few units seem to be available, how expensive they are, and how over complicated their controls seem to be. So I open it up to the forum to discuss options and try to find a small, simple, basic, cheap FCU to put in each of our bedrooms.

Unfortunately not. All the wood fibre board and render materials were lumped in the price I paid to the builders that built the shell and were not itemised. I paid the plasterer that did the rendering as by that point I was running out of money and had to lay off the builder (amicably thankfully)

Yes. I never found out the cause but the plasterer re did that bit free of charge and it has not blown again.

As you may see on another thread, I have just enabled cooling mode on my LG Therma V ASHP. I probably won't get it done this summer but the longer term plan is to get two fan coil units, one for each of the main bedrooms and connect that into the system to give us cooling in both bedrooms.