marshian

good tool - I should have borrowed this one sooner

Just because of continuity (and a bump for a question unanswered) The diverter only actually stops the flow past the first two columns Here's the rad in situ And here's the thermal image

Got to do a borrow of the work FLIR camera - once I got my head round the fact that the heat scale very much relates to the difference between the coldest part of the image and the warmest part of the image........ So in the case of the image below the big wall being red is warmer than the area in yellow so heat being leaked Boiler Plume management kit shows up well in white

I have the Nuaire version (with heater) I bought the heated version as I wasn't sure of the impact of cold air on house temps in the winter and thought I'd be better having it and not needing it than not having it and needing it (the difference in cost was pretty minimal) I thought I had the heater disabled but that little cold snap in November caught me out - we were on holiday and the CH was on very low - pretty clear something was driving the additional consumption and it turned out to be the PIV heater Normal daily electricity usage when the house is un occupied is 5.5 kWh. This jumped to 9.0 kW when we had the cold snap so the heater impact was 4.5kWh per day (or an additional £1.12 per day) The PIV unit has been running all winter on speed 2 (so consumption of 5W) - that does a good job in AC terms and the air under the outlet might be a little cold you can't feel that a few feet away and it's nicely dropping the humidity in the house when running (scheduled times). It (heater) is now turned off / unplugged.............

I originally had just a drain on either the flow or the return - Found that when I needed to modify the pipework under the floor there was still a lot of water in the pipes so fitted drain points to both. Added bonus was I could run an air line to one from my garage and use a low pressure air feed to scavenge the water out of the pipes. The rads all drain fine it's just the circuit I want to clear out. I've got to modify the pipes again this summer to improve the circuit (simplify and get rid of a 15mm piggy back circuit when I added another radiator and get rid of a couple of compression fittings that were used as drain points before I put the external drain points in)

@seanblee Any updates sir?

I debated ASHP but decided to stick with a gas boiler so current boiler is Viessmann 100-W Heat only (16kW with Weather comp and DHWP - range rated to 4.5 kW for Space heating) I was merely posting to support the statement you made that historical energy usage can be a good guide to sizing of ASHP provided you are heating in the same way - ie low and slow rather than scheduled

I used the heat engineer software to calculate my heat loss (at -2.4 Deg C) Heat Engineer software suggested that my heat loss is 4.93 kWh - but I did make a couple of mistakes in the process which when I spotted them I back calculated the difference and got to 4.7 kWh However I have also been measuring my gas usage v HDD (Heating Degree Days) for nearly 3 years however until Dec 2024 I heated to a schedule rather than 24/7 which compared favorably to the heat loss calc because of the periods where heat loss is reduced due to a lower internal house temperature so my kWh/HDD was 3.5 to 3.8 Moving to 24/7 heating with a weather compensated flow temp has increased the kWh/HDD figure to 4.2 to 4.6 If a HDD value of 20 is a good fit for 24 hrs at -2.4 deg C (pretty sure it is) then my heat loss is between 3.5 and 3.75 kWh

Pictures of what I did and where I was working in this thread if it helps any

75mm PIR I had to do it from under the floor due to tiled surfaces and 25mm oak planks

Actually yes comfort was the biggest benefit - to a point where Mrs Alien wasn't happy if the living room was below 21 and I was happy with anything above 18 Now it's 19.5 to 20.5 and she's happy with room comfort (this means she can find something else to whine about which is not so great!)

None - we still heated to the same temp - just got there quicker on scheduled heating slots and didn't drop off a cliff as soon as the heating went off. Looking at data from before insulation at similar OAT (around zero Deg C) All the main ground floor rooms we would lose about 0.7 to 0.5 deg C per hour After insulation around 0.25 to 0.20 deg C per hour So taking one room as an example heating went off at 10pm at 20 Deg C room temp you could pretty much expect it to be around 13 deg at 8am next morning After insulation you could expect it to be around 18 deg C Takes a lot less energy and time to get a room from 18 to 20 than it does from 13 to 20

3 years ago I would have agreed with you and said insulating under the floor was a lot of work for little gain I was very wrong - in my house it made a massive difference and along with a few other improvements halved my energy usage for space heating

Yes - just remember HW needs are occupancy driven I don't think the ATAG goes down to 3kW I agree 30kW is too much 16kW would be plenty You are on a journey - you haven't got to the destination yet. My previous boiler I based the choice on existing boiler was a glow worm - it had been very reliable so get another Old boiler was ~15 kW non condensing (single glazed wooden windows - 30mm of loft insulation - T11 rads and no CWI) - house had been extended so new boiler 24kW with a 10kW min Totally unsuitable for a property that now had SUDG, CWI and 70mm of loft insulation I spent about 6 mths working out what boiler I should get this time......... If your heat loss is 6kW at -2 deg c that situation is maybe 10 days out of 365 - rest of the winter it's going to be 4kWh at 5 deg C so I'd want a min modulation of 4kWh but 6kWh wouldn't be terrible.

No probs but you didn't learn enough 😉 It only matters that the return is as low as possible - as discussed elsewhere if you have a room temp of 20 deg and a flow temp of 35 deg you are never going to see a delta T of 20 deg c We aren't buying boilers 2 x bigger than necessary - some (not all) gas engineers have just been lazy and thrown bigger boilers at the wall rather than do the required calcs because it was easy and required no thought One that can modulate down to as low as possible and is sized to meet the house heating demand plus HW requirements A good rule of thumb is to always try to get boiler manufacturers own controls and avoid 3rd party controls - the manufacturers controls are designed to work with the boiler and maximise the efficiency of the boiler 3rd party controls can be good but most are fancy on/off controls which are dumb (even when labelled as "smart")

Where does the 4.5 come from??

Well it’s new first for me - I’ve actually listened to a sound clip of someones toilet What an amazing time to be alive On a serious note sounds like an air emmitance valve being activated - you get a oomph type reverb as a slug of water causes a vacuum and pulls it open

Ahhh Now I've got it - Thank you @John Carroll

Absolutely Because then it's OK to put your children in there I'd walk away - you'll have the same issue if you leave it as it is when you come to sell it

OK totally with it until the last bit 88.8 = 90 - 1.2 from the first part What I can't get in my head is how the 8.29 % is calculated Sorry but I like to understand the math behind numbers (it's an OCD thing)

Phase I completed So area covered = 1.5 m x 6.1 m - Yes I know it doesn't show insulation or boarding but it's all done Now I'm on to Phase II (opposite side of the loft) Boards are temporary just so I could lie down and roll out the insulation between the I-Beams Next section requires me to lift the additional insulation I laid over the top of the layer between the trusses which will be a pain as it's all odds and sods

Not unlike CWI, spray foam loft insulation etc etc Anytime the Government hoses around taxpayers money the sharks will circle to cream off the top as much as they reasonably can

Mind Blown!!!! I'm going to read that a few times now...... OAT durng the test was 4.1 Deg C

I got very close to that with my workings but it's a mile away from the expected chart position based on a ~25 - 26 deg return temp I am however bloody amazed at 612 grms of condensate in just over an hour running at close to min modulation

Now posted