JohnMo

You're been watching the freedom heat pump install video's, I watched them yesterday

If the flow rate is increasing at each loop, that would suggest DT would come down, so mean flow temp would increase. The easiest way to get heat in the floor is to just increase flow temp. Instead of making a pump work harder.

Have you worked out your design heat loss. Although the heat pump says it 5kW as it get colder that figure drops. So you need to know your heat loss. Unfortunately that heat pump only has a single flow temp. You would really need to charge the buffer from the heat pump. The ch or cylinder would call for heat from the buffer as they required from the buffer. The heat pump would automatically charge the buffer as needed.

To have the same UFH across two different floor buildups could work badly, as they may or very likely require different flow temperatures to counteract the differing downward heat losses. If you are doing this, you want to think about different manifolds for the different floors, the flow temp for the new floor could be in the high 20s to high 30s, depending on the overall heat loss. The old floor flow could be in the mid to high 40s, and still not heat the room well. I would do as Nick suggests, and I really would not want UFH in an uninsulated floor. It will be a money pit for running costs, perform badly and generally disappoint.

I used 70mm. The only real place mine was exposed was at doorways. Due to strapping the walls out 50mm, plasterboard and skirting. Tiler was a bit surprised, but used a very flexible tile adhesive, we have thick commercial tiles, no issues a year later. The carpet fitter didn't even comment, but I did use a self leveling screed at those doorways. Again no issues.

My be worth doing a calibration, the instructions tell you how to do it. When you do it looks like it takes about 10mins, but in reality it takes about an hour, some of which the flow will be zero.

Would have thought you would simply put an electric meter between the consumer unit and the heat pump? An interface units sounds like a unit that allows one bit of kit to speak or communicate with another. Rather than a read out?

To have a grid connected system you have to completed G98 install certificate. If you don't you need to do it. Then you just use that. Simple

This is what used benn on a summer, single coat so far, looks as good as it went on. Basically a cedar oil at a very good price. It say decking oil, but suitable for anything made of wood. All our cladding and a couple sheds done in it. Dead easy to apply. https://www.ryeoil.co.uk/shop/deckingoil/

It's good you can smell it, means the parts per million is still quite low. As ppm increases your nose cannot detect it, but the concentration is at a level where quite short/medium exposure can kill you or do you no good what so ever. Even after dilution it may have a smell. Concentration (ppm) Symptoms/Effects 0.00011-0.00033 Typical background concentrations 0.01-1.5 Odor threshold (when rotten egg smell is first noticeable to some). Odor becomes more offensive at 3-5 ppm. Above 30 ppm, odor described as sweet or sickeningly sweet. 2-5 Prolonged exposure may cause nausea, tearing of the eyes, headaches or loss of sleep. Airway problems (bronchial constriction) in some asthma patients. 20 Possible fatigue, loss of appetite, headache, irritability, poor memory, dizziness. 50-100 Slight conjunctivitis ("gas eye") and respiratory tract irritation after 1 hour. May cause digestive upset and loss of appetite. 100 Coughing, eye irritation, loss of smell after 2-15 minutes (olfactory fatigue). Altered breathing, drowsiness after 15-30 minutes. Throat irritation after 1 hour. Gradual increase in severity of symptoms over several hours. Death may occur after 48 hours. 100-150 Loss of smell (olfactory fatigue or paralysis). 200-300 Marked conjunctivitis and respiratory tract irritation after 1 hour. Pulmonary edema may occur from prolonged exposure. 500-700 Staggering, collapse in 5 minutes. Serious damage to the eyes in 30 minutes. Death after 30-60 minutes. 700-1000 Rapid unconsciousness, "knockdown" or immediate collapse within 1 to 2 breaths, breathing stops, death within minutes. 1000-2000 Nearly instant death

Seems you may have a huge gap in the insulation called a cat flap. Don't sound that compatible.

Sorry attached the wrong spreadsheet. Have added the Emura 3 details MoreDetailPerformance2.xlsx

You can do by calculation, that is the easiest way. Got the calculation somewhere on my PC, but on my phone now. Down to about -3, double glazed (1.2 U value) actually meet the comfort criteria set by passivhaus because the inert pane, stay above a given temperature. Did all the calcs as part of the house design process, but then went triple glazed anyway. Our roof lights are Passivhaus institute approved and certified. U value is 0.93 https://database.passivehouse.com/en/components/details/skylight/roof-maker-ltd-fixed-flat-1153sk03

I found this on here and have added to it. The micro difference come from the temp set points and outside air temp, some perform well across the board others don't. There is link at the top of spreadsheet, this is where test data comes from, all registered and tested units are there. MoreDetailPerformance Aircon.xlsx

No issue with a single supply terminal. But you need vents to direct the flow through the rooms. You could retrofit something like these https://www.bpdstore.co.uk/glidevale-energy-saver-humidity-sensitive-trickle-ventilator/p/182 You can't get old air out without getting new air in. If you want heat recovery two options MVHR, rip house apart to install. dMVHR, fan unit required in each room, hole in each room through outside wall. Will need power run to each fan. A single unit not that expensive, but several starts to get expensive. Without heat recovery PIV, will replace old with new air, humidity controlled vents will help mitigate heat loss by closing when ventilation is not needed.

Not sure it's anything to do with the buffer. If the trvs are closed the radiator volume is excluded from the heating circuit, so the flow route closed. Then you are trying to dump xxkW through a single radiator and a buffer. Ideally you would reduce the flow temp, the heating would take longer to heat a room, but you Trvs would remain at a more open position as there would be less likely hood of overshoot. The alternative is to balance the system to reduce overall flow through the radiators so you get a larger delta T and radiators give less heat to the room, trv remain open unless you get solar gain. Or do weather comp.

Looked at my boiler this morning 2 degrees outside, and there was white smoke. Not much, just a general stream out the flue. Return temp at that was high 30s. There will always be some water vapour, even if the flue temp was 30, flue gas would hit the cold air, exceed the dew point and water vapour would appear.

It's certainly not going to rot in the short term. Our cladding was on the house for 9 to 12 months before it was coated, with no issues. Wait til you have a nice day or spring. UV strength during the winter is poor - length is day also short.

Cost versus diminished returns. It usually the frame that kills the whole window U value not the triple glazed glass. Passivhaus specs are based on comfort, and inside glass temperature compared to room temp at a given temperature outside. I have triple glazed and it's 2 degrees outside sat right next to a huge glass window, do not feel the cold outside, window is not making me feel cold, ( sucking the heat from me) a single glazed would and a double glazed may also but to a much lesser extent.

Without heat recovery you will loose heat no matter how you ventilate. So basically you have two options without major upheaval PIV, as linked too above. Seems to do what you want, basically it takes fresh filtered air and it blows through the house out open window vents and through any gaps in the building fabric. It has a suitable settings for a 3 bed house. The Other way dMEV, this pulls air out of the building via fans in wet rooms and kitchen. So you need a fan in each of these rooms instead of intermittent fans. You need vents in all other rooms. Fresh air is pulled in the vents and across the rooms to the wet rooms and out of the fan. You can add humidity controlled vents for a low cost, these will limit the ventilation when it's not needed. The link has the brochure and user manual, with the flow rates required etc.

No problem, it does tell a better story

Mine asked for same, told him it was a self install, gave my G98 registration details, he was happy.

Less steam = more condensing. The white steam is water vapour, a condensing boiler condenses the water vapour back to water and collects the latent heat, transfering it the heating system. To get condensing the return temp on a gas boiler needs to be below 56 degs (?). The further below that temp the the greater the condensing effect and more efficient the boiler runs.

That's a big heat input into a small space, take it has little or no insulation?

The mixer always moves excess heat back to the return. You could turn the UFH pump down, so it's taking less from the CH circuit, this would mean less hot water is being returned to the boiler. Just watch the UFH loop flows to make sure your flow is high enough to cope with loop flows. The UFH loop flow rates should really be defined by the loop length, so shouldn't be adjusted except for fine tuning heat put in to a room. Low flow rate on loop, gives a higher differential temp, but this means the 'mean flow temp' is lower, which equates to a lower heat output from the floor.