Bramco

Hi, Just about to mount the PV panels on a ground mount which consists of 16 metre long galvanised poles hammered into the ground with the structure attached above. A very similar arrangement to the one @billt showed in @ProDave's post from 2018 The question is, given the amount of steel in the ground, do I need an earth rod? Simon

Our UFH is ground floor only, so we put electric UFH and electric towel rails in the upstairs bathrooms. The electric UFH is set to 19 and has only occasionally come on at night during the really cold spells. The towel rails haven't been on at all - so probably and expensive option - but they do look nice.... Simon

Hi Mike, For this type of application, I reckon if you just used them without calibrating, then you wouldn't know the difference. If you were using them to measure something that needed an exact temperature, then it would be necessary. For a central heating/cooling application, you're deciding on a setpoint according to how the house/room feels. if c above is 0.2 or 0.3 out, then your heating/cooling would kick in a bit higher or lower temperature and you'd adjust the setpoint accordingly. Accuracy is great but maybe a bit of overkill for this application? Simon

I'm no expert, but I think a lot of them are simply a switch, so the switch is closed to indicate a call for heat, i.e. NO. Also, there's normally only 2 wires going from the thermostat to the heating wiring centre, so you wouldn't be able to get both the NO and NC signal to the centre. Wireless thermostats might be a way of doing what you suggest.

18 B20s? if so they don't need calibration but you do need a microcontroller based system to read the them. I was planning to put in some tubes but didn't get round to it - so we'll see if actually need to run the UFH in cooling mode - although I can't see how you can do this with standard thermostats - they want to heat, not cool - so you'd have to have a separate system that could switch off the thermostat control and introduce a cooling control - you won't get your standard ASHP engineer or plumber specc'ing that for you. Simon

Welcome to the club!!! It's worth asking the architect if all of it is really necessary - can it be pared down to the absolute minimum. There's tendency with this stuff as we found out, to massively over-specify it. It's timber frame must go everywhere surely!!!! We got ours down to a reasonably sensible minimum - but the first ideas were crazy. Simon

Surely, they can simply set the ASHP to Heating only? Although, I guess they have trained their teams to do an 'install' which would always include the plumbing to the DHW tank coil. Simon

IKEA do 800, as well as 400 and I think there are units with pull out internals narrower than that. Check out the on-line configuration tool. If you want 600 tall units at either end, with a sink in counter height units with wall units above, then you will need cover panels as you switch from full height to the middle section. From memory, these are 18mm and would need to be accommodated. Simon

I'm guessing you asked a company with the term 'renewables' on their web site. Today's double glazing salesmen. Our coolenergy was £5.2k installed - the UFH buffer tank and DHW tank were installed by our main contractors plumber. With the BUS £5k grant it cost us £200. We had to make sure that the electrical connections were in place - these were done by our main contractors electrician. Simon

Two! 60cm -> https://www.ikea.com/gb/en/p/foerdelaktig-induction-hob-integrated-extractor-ikea-500-black-50534854/ 80cm -> https://www.ikea.com/gb/en/p/foerdelaktig-induction-hob-integrated-extractor-ikea-700-black-90534852/ But prices have gone up since we bought ours last year - now a 1/3 of the Elica....

Everyone to their own - it's a weird world where 4x the price means status. I'll bet you're a B&O status person as well....

Same with the IKEA one - you could have 4 IKEA ones in your kitchen for the price of the Elica! Bramco

Thanks - will look into this to see if I can force longer runs on the odd occasion that the thermostats take over control! Simon

Another option Adam that I've considered is to add a delay timer into the thermostat circuits. These are the kind of things that keep a bathroom fan running when you've turned off the light. Although we've mostly overcome the cycling caused by the thermostats turning on and off too much/quickly with the way we're scheduling them if we had a delay time in the circuit, then it would prevent the call for heat being switched off by the thermostat after a few minutes. For your situation, you could maybe lower the target temperature and make sure with the delay that the ASHP runs for at least say 30 minutes. So ensuring the HP runs more efficiently. Simon

We run ours differently as well. And our system is slightly different - a larger buffer tank and no auto-balancing actuators (there's a recent thread on whether these are actually useful for ASHPs with UFH). The other main difference is that our UFH loops are incorporated in the insulated slab - so probably our system is slower to heat up and cool down than UFH in screed. We have 12 loops and 3 zones with Tado thermostats - and just like you @Adam2 the thermostats tend to cycle on and off which means the ASHP cycles too much. We've solved this more by chance than good management. We're on Octopus Go, so we scheduled the thermostats to 22 degs from 00:30 to 04:30 on the 7p tariff. This was fine in the autumn and I could see from some monitoring of the various temperatures that the ASHP runs continuously for 4 hours and the slab is loaded with heat. As things got colder, I added another scheduled period from 15:00 to 19:00 again at 22 deg. This didn't cause cycling most of the time - the exceptions were on sunny days where we get a lot of heat into the house from the large south facing windows. Obviously also, when it's really cold the HP goes through it's defrost cycles, so doesn't run continuously. When the thermostats aren't scheduled for 22 degs, they're in frost protection, so no chance that there will be a call for heat. I should add that we use solar PV and the 7p tariff for DHW, so the ASHP is on Heating only. So basically, we've almost got round the fact that the thermostats are less than ideal with a HP through scheduling things. I would really like though to have a much wider window between the call for heat and the thermostats saying they are up to heat. One idea from another forum would be to use the wiring to the thermostats as the wiring for DS18B20 temperature sensors hooked up to a suitable microcontroller and have that switch the call for heat to the wiring centre. It could even be done with wireless temperature sensors like the Sonoff ones (there are plenty of other makes) which are pretty cheap. Obviously this isn't an off the shelf solution but should be quite easy to implement. Simon

That looks like the manual that can be downloaded from their web page. Also, what's the installer password - that's something I've not been able to get out of them... Simon

There already is one - with all the theory -> https://docs.openenergymonitor.org/pv-diversion/introduction/choosing-an-energy-diverter.html I've had the software for the MartinR version running for several years. You do need to make the SSR board but it's not rocket science. Simon

But do they? Our flow temperature at the moment is 29deg and the return temperature is 26deg - what would an auto balancing actuator do? Turn off? If so, then we'd stop trickling heat into our insulated slab which wouldn't be great. Which was why the original question - are they intended for applications where the emitters lose heat rapidly, i.e. radiators or UFH in screed. Maybe being thick but I can't see how they would work with an insulated slab where heat is lost very slowly to the house and basically you want to keep it at or around the same temperature most of the time. Simon

Would auto balancing actuators work with an insulated slab? Or conversely, do they only work with radiators and UFH in screed, both of which lose heat quickly. With our system with an insulated slab, the feed and return temperatures from the manifold are only about 3deg apart. The slab stays warm, which is the whole idea and gets topped up at scheduled times during the day. The thermostats are turned up higher than the real target, so that they call for heat all the time and don't cycle which means the ASHP runs continuously and doesn't cycle. At the moment while it's cold outside, the schedule is twice a day for 4 hours each time. When it's warmer, it's only once a day. Simon

Do the PVGIS calculations for several angles of incidence. For us in the midlands, the annual production doesn't vary very much between say 30deg and 45deg but the winter output is far higher the more upright the panels are. We're expecting to export a lot of our summer output (no battery yet) but want to maximise output in the winter when we won't be exporting - so for us the more vertical the better within the window of roughly similar annual output. Ours will be a 12 panel array, in line, so no worries about shading between arrays. Simon

We had Nationwide, the coolenergy MCS installers do ours. We already had the cylinders in place for DHW and UFH buffer, so the costs were just for the ASHP and install. Came out a tad over the £5k grant that Nationwide applied for, for us. So net net a no cost addition to the build. Prices have gone up since then and I still haven't seen the MCS documentation a few months after the install. Roughly speaking, and from memory, this was about £3k for the pump, therefore about £2k for the install, which would include the materials. Our pump is the smaller one, the iVT9. We had to provide the mains supply to the pump and an additional cable and cat5 cable to the controller (there were a few issues there but that's another story). The install took a day, the plumber flat out, the sparky spent a lot of time in the van... From memory, the plumber from the main contractor took about a day to plumb the DHW tank and UFH buffer tank in. And for UFH, you'd need a sparky for the wiring centre, immersions etc. So nowhere near the daft 'double glazing salesman' style quotes that 'renewable energy' companies quote. The tag 'renewable energy' on a suppliers web site should be a red flag to anyone concerned about not being ripped off. Simon

That one went back - it was on hire. A new one arrived when the main contractor took over from the TF Co. I say new, it had seen better days!! But yes, the other trades all used it. Simon

We had to provide birdcage scaffolding for our TF Co for the vaulted rooms. Our scaffolder brought a movable tower which they used both on the ground floor and on the 1st floor. Towers are easier for them to move around as the need arises. But I'd check that that is OK with the TF Co 1st. Simon PS Should add that we had a full spec for the scaffolding from the TF Co.

We've just installed an IKEA kitchen with one of their induction hobs - it's our first induction hob but can't fault it, on boost it boils water incredibly quickly. The only down side was that we had to pass on our Spring saucepans that we'd had for 40 years to our son as they wouldn't work - not enough steel in the base, they were a steel/copper sandwich construction. Finding new pans turned out to be a pain. I think IKEA do 2 widths of hobs, one standard sized and the other 200mm wider. When we bought ours, the only option was the wider one and I think we would have gone for this one if there had been the choice. Simon

Renewable energy companies are the new double glazing salesmen...... Lot's of sucking of teeth etc. If it's new build make sure that you get the Boiler Upgrade Scheme £5k - sounds crazy but it does apply to self builds as well as replacing existing boilers. We had our main contractors do the insulated slab and the DHW tank and UFH buffer tank - both with double immersions. Only after that did we install the ASHP and that was basically because it cost us £200 with the BUS grant. So do all the heat loss analysis etc. and only put in what is absolutely necessary. MVHR is, as Conor said completely separate - you should be able to find an MVHR expert in the area and I'll bet they'll be a lot cheaper than your chaps that can do it all. Simon