All Activity

Update I went to the local councillor with my grievance, the solo building inspector swiftly got in touch with me and arranged to come out. Despite everything, he was alright with me, didnt come with a grudge and allowed me to send pictures for a few outstanding issues. I was also now dealing with him directly rather than someone on a switchboard which was part of the problem in the first place. The completion certificate is now in my possession. Now to get that VAT back

With the roof tile vent you don't need flashings but you need the right vent for your tiles. They have a flexi connector.

When I did some Googling around regarding this I quickly noticed that each local council seems to take a different approach to the process and what requirements they want (probably proportional to the feeling of self-importance the council officer dreams of). I put myself down as the owner and the 'company' doing the work, kept detail to an absolute minimum, and just got an approval email a few days later.

Not sure if we can calculate an EER, we have a heat meter but not sure if it counts backwards..... Gonna add some more fans to the rads and overvolt them a bit to see if we can get some more airflow - I know you can get actual sit on rad units but the fans are less than a quid each compared to about £100 for a unit that will only do about 1/3 the length of a fad and is probably louder too. Currently we are using our second hand heath robinson heat pump - hoping to move to a 'proper' set up but MCS sound rules mean our preferred placement is max 55db that seems to strictly limit the number of 8-10kw units available and the one that seems to be best fit (Grant) does not cool. Does anyone know of any other units that fit the 8-10kw and 55db or less sound power criteria and do cooling? Thanks

Building control have just said fit an in-line roof tile vent. Opinions please!

It of course helps flow if it slopes gown to the outlet but it is tricky to do znc can look untidy. In drizzle the water barely dribbles off a small roof and may even stream back towards the wall, so a clear projection is needed. In a storm, the parabola could be quite a long and flat one. In your drawing above I'd like to see a deeper gutter that is higher so that the water always lands inside. The cheap outlets are a round hole in the bottom. The water flows in like a wier, ie only a few mm deep. The classy ones have a curved outlet, almost a hopper, and flow is very much faster. The price reflects the science and performance, but the dear ones are also sturdier. Btw for a high gutter, I don't allow leaf catchers in the outlet because they need clearing. I catch the leaves at the bottom.

We did at one point very tightly control house temperature and it varied maybe 0.5 Deg. But depending on outside temp etc the way the house temperature actually felt changed, so sometimes you felt warm others cool (I'll put my jumper on). We have relaxed (simplified )that control and just use a room sensor to control everything, our WC curve is 26 to 28 degs, so almost flat. Thick screed (we have) is pretty slow to heat and cool down again. So what happens in our house, in heating season, the UFH generally ends up running at night and spends all day off, down to about freezing and then the heat pump runs for some time during the day also. Colder it gets the longer the run time. Room sensor thermostat set to same temperature 24/7 for heating with a 0.3 hysterisis. We get some undershoot while floor plays catch-up, but we are in bed then so that's fine.

When I designed our house, the plant room was next to the ground floor wet room, so if there was a leak, the water could flow down the shower waste. We also had all the water in one quadrant of the house, so all the pipe runs were relatively short.

I like the simplicity of this very much, and you are probably right that it would work given the lower heat FF output at wider centres (and timber covering). We had originally planned to install only GF loops, the FF loops were later added because of an increase in expected solar gain because we were unable to install planned external blinds on some windows. I think I may be stuck in a mindset that there should be some control to switch off the flow to FF loops just because they were originall excluded. Maybe not 🤔 I agree 👍.

Actuators - no need, then you don't need a buffer. Hitachi, are quite good, but you need additional widgets for cooling AC just do UFH cooling. Maybe find a new installer

If you set as 2x zones. One zone valve for upstairs controlled via a single simple thermostat. But not sure I would bother. Or accept the UFH upstairs output is low anyway with the more open centres on the pipes, just let it run with downstairs as a single zone, and accept the extra water capacity as insurance against short cycling. This would ultimately allow a lower flow temperature overall and better CoP. But you may find you minimum realistic flow temp in mild weather is actually warmer than you really need, in this case use the controller thermostat in a suitable location to act as heating permissions. In mild weather 7 to 10 degs, you find the heat pump only runs a few hours a day. So, one zone, use the main controller thermostat and almost flat WC curve.

I belive gutter capacities are calculated, rather than intuited, including specifications for rainfall amounts to BS EN 12056-3 e.g. https://www.floplast.co.uk/you/diyinstaller https://alugutter.co.uk/pages/gutter-drainage-performance-eaves-gutter-design-bs-en12056-3?srsltid=AfmBOopwXxj1pTu7ASOsX0Hc1K2cJz8FK6ftk4oQ8J6iE5rW0462CgPn

Seems like the research was published in January but a load of AI regurgitation has sprung up about it in the last few days. Original paper https://www.nature.com/articles/s41598-026-35389-6 Not sure, the reference "problematic" LEDs in the study were 3000K so it's already comparing incandescent vs warm white LED. Skimming the article all LED lights roll off at about 670nm but you need about 1000nm+ for the IR spectral component they talk about I've always felt the CTT [colour temperature tuning] is bit of a fad, especially in a domestic setting. But I can see a variant having a large benefit of having WW / IR dual channel emitters, and dynamically increase the amount of IR emitted based on various factors. e.g., more IR in winter when the inhabitants will have exposed to less of it naturally, and also when the loss of lighting efficiency is not so problematic as the IR is at least contributing to useful space-heating.

Just spoke to the installer/supplier on the phone. He spent 10 minutes trying to convince me I needed actuators on the manifold, a buffer tank and a hitachi heat pump instead of Panasonic. And AC as well because passive houses always overheat. He's putting together a price list for all the Panasonic bits sans buffer.

Just spoken to Brendan from MBC on site and he’s reassured us all taping including soil pipe will be done by MBC so we will stick with the one plus AAVs 👍

You make a good point here about wiring two zones back to the heat pump. It just seems unecessary to have a zone-1 valve and sensor at all, because the GF zone 1 valve will always be open so the zone valve is effectively redundant. We will never be running the FF heat without GF heat, but this is of course how Panasonic controllers expect normal people to run their heating with these options. The plan is for the first floor zone to be off most of the time, except maybe for cooling in wetaher like this, but I take your point. This is just an idea at this stage to have an open zone and an independant second zone. I had hoped that this was something more common that would be commented on here 😕 I have a spreadsheet that I put together ages ago, so a person not very sensible at all is responsible for the loops. I have completely forgotten how I arrived at the formulae and numbers but, in theory, we have about 11 W/M2 heat demand per room, and with 200 centres GF and 250 FF that should return 22C GF 20C FF with about 27/22 flow and return. Or something like that. It will be interesting to see if theory and practice are the same 🤔 I'm hopeful that the FF zone will not be used very often for heating and, if so, then mixed circuits are probably unecessary. In theory anyway. In theory the FF loops are primarily for cooling but with insulated screed underneath and engineered timber on top it may be that only the FF bathrooms with tiled floors get the cooling effect 😬

On the inner leaf of the new wall - if you want something to show your builder then LABC publish renovation guidance that covers this including a diagram on page 14...

I allocated MVHR to one 'dry' plant area, and then the client agreed the GF cloak WC didn't need a(nother) shower in it, so we lopped off the end of that room and created a new 'wet plant' area. Both rooms A1 fire protected via the use of cement boards (No More Ply). It is 'wet' because I have put all the "plumbing" paraphernalia in there that is likely to leak (minor or major), by early design. The UFH manifolds are just outside the footprint of this bunded area, but that's the least of 'our' worries; the heating system will only ever leak / puke out the stored volume from being pressurised at 1.5bar, and then it'll stop, maybe a few litres or so max. Odd statement, as you don't have a choice other than to discharge D1>D2>waste (unless you go old school gravity); note you'd still need overflows from the F&E and CWS tanks if so, so are just pushing the problem left to right vs deleting it. Make sure you have a 40mm waste provisioned in this space, even if in abeyance / ends up redundant. I always get this done way ahead of the construction phase, just simplifies things long-term and removes ambiguity for follow on trades if the heavy lifting is done well ahead of their (or my) arrival. Opportunities for value-engineering often go to the wall if these things are engineered 'on the fly', and usually this means compromise / delay / uplift in cost.

Last year on our 6kW heat pump it cycled, depending on load, we averaged around 4 to 5 CoP over the day depending on a few factors doing cooling. This year with a 4kW it can run low and slow, our dT was about 2.5 degs. Yesterday's whole day CoP was 7.3 including standby time/energy. We only cool if there is solar gains, so we have plenty of PV also. So it free. It would almost always get clipped from PV also, if we weren't using it, so it really is free.

And down-sizing the ASHP to allow these long runs at a low deltaT without short cycling, isn't it? Our ASHP is way oversized so will bordering short cycle (5 min runtime, 10min period) when just cooling the slab to ~16deg. I'm still getting COP of 3.5-4. But it's powered from PV - if I could double the COP it would give me about 30p more SEG payments per day on these hottest days.

I'm interested. The regs show ever bigger areas where permeability is poor. On sand they don't seem to acknowledge that the water won't reach the end. So in our case we used perforated pipes heading different directions to spread it.... phase 2 and 3 extensions to the zone, the drawings and calcs got us the approval, but are 'yet' to go in.

Interesting for windowless rooms and I suppose may warrant avoiding specialist solar films on windows? No data on working near a window but I'm guessing that provides way more exposure than a single lamp? Warm leds sit in the same frequency range as cool just with a different distribution so I'd be surprised if that made any difference, but again no data.

Where is your technical drawing showing the location of your airtight layer. is it showing the vcl at ceiling level or roof level. you need to imagine and show the roofer/ builder an image of a continuous line around the whole property with no gaps or breaks in it. from ground floor to roofline a continuous air barrier.

No I am saying heat via immersion. Plate loading as you say just adds complexity you don't need. CoP compared to energy input depends on quite a few variables. CoP isn't always a true measure of energy input as you have to heat pipes, local fabric and cylinder. But with a time of use tariff, what's the point of using the heat pump to heat the cylinder, leave it to concentrate on building heat and cool. Keep DHW simple. But if going down grant route DHW via immersion isn't an allowed option.

The correct terminology is EER for cooling and CoP for heating. In effect I actually get a negative CoP.