Temp

Basically the boiler puts hot water into the buffer and UFH takes it out. The boiler ON time depends on how long it takes to fill the buffer tank. The boiler OFF time is determined by how fast the UFH empties the buffer. The two times added together give the cycle time. If I've done my sums right a 29KW boiler would make about 0.35L/S or 20L/min with a 20C uplift. So it would take about 5min to raise a 100L buffer tank by 20C (ignoring any draw by the UFH at the same time). To calculate how long the UFH would take to empty the buffer you need to know the power the UFH draws but we already know its less than the minimum the boiler can deliver (10KW?). 10kW is about 0.12L/S or 7.1L/min with a 20C drop between flow and return. So the UFH should take at least 100/7= 14min to empty the buffer. So the cycle time should be around 5min ON and 14min OFF. However the useable capacity of a 100L store probably isn't 100L. It probably depends on the position of any stats on the tank. I'm sure things aren't quite that simple in practice so you should get the buffer tank sized by someone providing a warranty. Eg Heating Engineer. All I have is O-Level physics and some back of the envelope calculations.

2 port vs 4 port buffer tanks.. https://blog.heatspring.com/2-pipe-versus-4-pipe-buffer-tank-configurations/ Apparently the 2 port set up is more efficient as hot water only flows into it when needed not all the time.

I think in Scotland you need a Road Opening Permit.. https://www.gov.uk/road-opening-permit-scotland Just one councils view on this... https://www.scotborders.gov.uk/info/20031/roads_and_pavements/744/road_permits My guess is the process for getting one will require you to provide info on the contractors qualifications and insurance. In England I think they are meant to have £2m public liability insurance?

One possibility might be to fit smaller jets in the burner or even a smaller burner? Would need to talk to the boiler manufacturer. We fitted smaller jets in our oil boiler but oil boilers don't modulate like gas boilers, they run flat out all the time making cycling even more an issue. We did it because Grant said it improved efficiency a few % as well as reducing Max power. On a modulating gas boiler I don't know if smaller jets reduce the minimum power or just the maximum? Reducing the max power could impact the DHW flow rate.

It sounds like your diagnosis is correct. Does the UFH appear to be working OK otherwise? I've heard of some builders making silly mistakes such as using airated screed which inadvertently insulates the floor loops a bit. That would cause return temperatures to be too high and shut down the mixer. If you have to fit a buffer tank you can probably get away with a simple buffer tank (eg not one that splits the system). The main issue will be getting the sizing right. Some references suggest 10L per kW of boiler output, but they say that's not the minimum power but the "start up power" which presumably is higher. That would give a tank of perhaps 10*10kW=100L? Too small and it won't lengthen the cycling enough, too large is less an issue but it will leak more heat than necessary.

What temperature is the manifold mixer set to? If its very low then increasing it _might_ help a bit. Note there is usually a limit/safety stat on the manifold as well as the mixer. The safety stat is usually set to something like 50C or lower for some floor coverings that might be damaged by high temperatures (Karndean?). The mixer must be set lower than the safety stat. Short cycling reduces efficiency, a bit like stop start driving a car. Its worse for an oil boiler than a gas boiler. I was concerned our oil boiler would short cycle and so intended to put a buffer tank between boiler and UFH. In the end we opted for a thermal store which buffers DHW as well as CH. Heat banks are just a variant on the theme. More after Dr Who!

On my outbuilding (timber frame, tiled roof, oak clad) on clay I... Removed about 12" of soil and compacted the ground with a wacker plate. Laid 6" of hardcore (compacted in two layers) then a thin layer of sand (compacted) about 1ft bigger than finished building all round. Staked 6" shuttering using rebar stakes (dimensions of slab slightly smaller than finished building so water dripping off cladding would fall outside the slab not on the top of it). Just about remembered to add a length of mdpe pipe for electrics to come up through slab later. Laid membrane into shuttering (prevents water draining out of the concrete). Filled with 6" readymix concrete and levelled to top of shuttering using a long length of 4*2 (the levelling part was physically hard work). I didn't have trees to worry about but if I had then would have added mesh raised up 3" before the concrete pour. It would have been easy to add a trench around the edge to make it deeper for block walls. Perhaps make trench wide enough to get the Wacker plate into it?

I was also considering making one. The holders are normally designed for 10"*2.5" carts but there are "jumbo" versions which are 10"*4.5" and double length 20"*2.5" both of which should have less resistance to the flow.. You could also use two in parallel to boost flow rates. Example Pair of jumbo carts but these are in series.. https://www.finerfilters.co.uk/finerfilters-10-jumbo-high-flow-double-water-filter-housing.html?gclid=CjwKCAiAjMHwBRAVEiwAzdLWGInx_E8xNuP2QWESQWLjyT4U34xkTcn-z_OkEJy3LD7bNA7lyMnwehoCq8kQAvD_BwE Haven't yet found a jumbo size refillable cart but haven't looked hard as other projects are going to keep me busy for quite a while. Some water filter holders have/haven't got brass thread inserts which seems to affect the price a lot.

Interesting use of ball bearings for bushing. I used skateboard ballbearings on another project and found they pressed into my PLA prints really well. Think they have a slight bevel on the edges which help.

Google found NHBC.. http://nhbccampaigns.co.uk/landingpages/techzone/previous_versions/2006/Part6/section4/sitework.htm Section 6.4

Think this cistern is just 96mm from back of cistern to front of wall (80mm cistern and 16mm for the plasterboard and tiles).. https://www.ukbathroomstore.co.uk/pura-cc100-super-slim-concealed-insulated-pneumatic-cistern?dfw_tracker=34263-CC100&gclid=CjwKCAiA6bvwBRBbEiwAUER6Jf7NtV2SrNHriTpCeWY-DxudR5Y6VTUaSbPbvDy3hX9HQYJU1_QCLxoCsv8QAvD_BwE So a 110mm waste pipe would be the limiting factor eg back of pipe to front of wall could in theory be 110+16mm = 125mm? Would have to be a floor mounted WC and horizontal studs only. Getting a bit carried away here :-)

Think the shortest wall hung is around 480mm so add 145mm and you get 625mm.

With short projection pans check the seat will stay up. Some may need low profile seat and cover?

Usually the cistern and pan connector/bend are similar depths. If you find a really narrow concealed cistern then.. Gberit have a pretty short right angle bend/pan connector they use on some of their frames... https://www.tapsempire.co.uk/product/geberit-hdpe-bend-with-connector-for-wall-wc/?gclid=CjwKCAiA6bvwBRBbEiwAUER6JS-hK4K4TgfYTUUF4UnumZIJx615fJ76S1f_4Wr2oNw9bIl69gmHwBoCPpIQAvD_BwE

I don't know if that's correct but.. If the wavelength depends on the molecular/mechanical properties it shouldnt be surprising that that water and ice have different lines because they have different mechanical properties. https://en.m.wikipedia.org/wiki/Absorption_spectroscopy

Just had similar answer from a son. Some absorption lines depend the "electronic" structure and others the "molecular" structure of the gas. The electronic structure is all about electron orbitals (the "fixed" gaps between orbitals leads to absorption lines having fixed wavelengths). The molecular structure is its vibrational and rotational properties/modes. This video covers lines caused by the electronic structure..

Do you mean how does matter such as the surface of the earth convert visible light to infra red? Think that's mostly to do with temperature and the way photons work. The energy a photon has is determined by its frequency or equivalently it's wavelength. The sun is literally white hot (radiates in the visible spectrum). The surface of the earth is colder so energy it radiates is mostly in the infrared spectrum. If you heat up some steel the light it emits starts as infra red and changes to visible light as its temperature increases. https://en.m.wikipedia.org/wiki/Photon_energy

Think that partly confuses energy and temperature. Capturing less energy does not necessarily mean a smaller temperature rise. It means a smaller _rate_ of temperature rise. Temperatures keep rising until there is no net inflow of energy. It's actually the relationship between the surface temperature and the energy lost into space that needs to be considered. Eg how big an increase in surface temperature is required to increases the energy lost to space and restore net zero energy flows?

Make sure your electrician knows the same set of symbols.

Our shower tray has drainage grooves which makes it hard to get a plunger to seal. On day I might print a plastic widget to fill them in but meanwhile a ring of wet dish cloth used as a crude washer seems to improve things.

And brush the glue on. Running the bottle along can be too hit and miss.

C02 levels have certainly been higher in the past but the sun wasn't as bright then and apparently that makes a big difference.. https://skepticalscience.com/co2-higher-in-past.htm A winter duvet is fine in winter but summer is arriving and even a few blankets will be too much.

We have a mix of spreader plates (under oak floor) and pipe in screed (under stone and tile). Both work ok but the spreader plate system warms up faster from cold. What matters more is: 1) How much insulation you can put under it and what's going over it? Put as much as possible under it. If I was building again I would aim for >150mm and 200+ wouldn't be unreasonable. Some people lay 18mm Chipboard and put 14mm engineered wood on top. It would be better to just to use 21mm engineered wood on its own. Chipboard and carpet? Keep the TOG of underlay and carpet to 2.0-2.5 in total. Special underlay exists. Hessian backed carpet is better than foam rubber. 2) how well your house is insulated overall? At the end of the day your bill depends mainly on how much energy the house looses and the fuel used (gas, oil, electric, ASHP etc) 3) and if you both go to work? If house is empty during the day a faster response time may be better. That way you don't spend ages putting heat into a floor only for it to come out when you aren't there. 4) it there much solar gain? If sun comes out can the heating system respond fast enough to the increased solar gain?

Welcome to the forum. Personally I fear we maybe heading for a recession and might find in a year or two it's harder to get a new one. Do you have help available? Some building jobs are two man or even three. Most people find the planning department very slow. Took me over a year to get our planning permission through. Sometimes we heard nothing for a few weeks then discovered the person had left the council and had to wait for a new one to be recruited. Don't be tempted to start any work on site until you have the CIL exemption paperwork in order or you can loose the exemption altogether and have to pay it. One document lost in the post on the way to the council can cost a fortune. Make sure they receive anything you send.

Sorry I only did O-level chemistry. Came across Schrödinger's equation doing electronics a long time ago. Google says water vapour (reasonable simple molecule) has at least 37,000 absorption lines so how the maths works im not sure.