JohnMo

Why pay for system when you already have one for free. Clip pipes to insulation and screed over done. Way more effective, run low and slow, use the depth of screed as a big buffer for the heat. Had a system similar to Wunda, was cr*p, high flow temp required to get any output. Disconnected it in the end. Hook up to a heat pump - no pumps or mixers, single zone, set weather compensation, cheap and effective to run. You get cooling for free.

Under a mortgage, you will be one the keeper of the land and property not really the owner, the mortgage own it in reality, don't pay your mortgage the mortgage company evicts you. Not until you become mortgage free, that you really own it.

I would speak to a decent plasterer. We did up an 1830 house, it had similar damaged cornice and lathe and plaster ceilings. He remoulded the cornice in place and made good everything with the correct materials. Once painted, you couldn't find where he had done any work.

If you aren't really that happy move on to the next house, no point buying a house then fretting over it's safety. You obviously have concerns, enough to for you write about them. Plenty of other houses out there.

All of a sudden we have moved from our cold weather into hot, so flicked the heat pump back into cool mode for awhile yesterday, as the house was starting to get a bit toasty. Over a period of 2.5hrs we pulled 12.5kWh of heat out the house floor and summer house using 2kWh of solar energy. The fan coil decreased summer house by 5 degrees in 2 hrs. Similarly the house temp dropped a similar amount but with a 15 min lag over the fan coil. Cooling in house is via UFH loops only.

Mine are only 200W elements so ok for towels, but not really heating the room, just adding a little heat. But bigger wattage are available. They come with a tee piece to dual fuel. But mine are just electric. I use a Termo TTIR, thermostat and timer.

Convert to dual fuel with Termo One thermostatic heat element

If was doing it again I would do water UFH at 100mm centres in bathrooms AND electric. Water supplies the bulk of the heating in winter, the electric makes the floor feel warm if you want

Just look at a datasheet, they even say they are rubbish, when you apply your airflow rates. Think from memory a typical 200m2 house is going to get a kW of cooling if you are lucky. I was getting a CoP of about 7 doing floor cooling and a fan coil, doing a a cool battery you need to flow at lower temps and CoP is likely to be nearer 4. So rubbish output and higher running costs, what is there to like.

Ours is 70mm thick wood, then the 90mm Frametherm 32 mineral wood (not 140mm) in the walls and plasterboard, 200mm of EPS70 and YBS SuperQuilt in roof and I think 200mm of EPS70 in the floor. We have a fan coil for heating and cooling. But yes it can get hot, because it's angled for the views and the glazed end gets the full sun.

You don't really need to be inside inside. Getting data out of a metal box maybe problematic. Somewhere close ish is fine, I was using Shelly add on to monitor at one point. You need to use either a thermo well or heat conductor paste and aluminium foil tape if externally on the pipe. The only issue is logging data intervals can be quite wide, so ok with a few measured data points. You also really need the electric data and temperatures time point to coincide to get reliable data points.

You need a decent method of cross ventilation, so air is allowed to come in the dry rooms and is sucked out of all wet rooms. Extract - dMEV fans cost almost nothing to run, Greenwood ones come up on eBay quite often for not much money they will react to rising humidity. MEV is a central unit if you have easy access to run ducts. Supply - You have two options retrofit trickle vents to dry room (not wet rooms) windows or through wall. Through wall humidity activated vent something like this https://www.bpdstore.co.uk/glidevale-fresh-99h-humidity-sensitive-wall-ventilator/p/231 Their trickle vents https://www.bpdstore.co.uk/glidevale-energy-saver-humidity-sensitive-trickle-ventilator/p/182 Other makes and models are available. So you need an air inlet in all dry rooms, bedroom, lounge etc An extract fan in all wet rooms, bathrooms, utility, kitchen etc. The fans run at a very low flow rate 24/7.

We did 140mm (I think) mineral wool. With a small building you are getting diminishing returns quite quickly. We only need a kW to heat even when minus lots outside. Adding more wall insulation wouldn't have changed that much.

You actually have volumisers not really a buffer. A2 valve isn't really needed. If A1 closes the flow entering FCU is stopped and so is reverse flow. Why will condensation be an issue, just pump the water around in cooling mode above dew point which will give you plenty of cooling power from the fan coils and no condensation issues. With a heat pump you have a minimum flow requirement, it is very unlikely you will get through a single radiator. My 6kW is 9L/min minimum flow not sure you will squeeze that through a bathroom radiator. From your info on the other thread your heat load is around 2kW, but you are planning 11 radiators and 4 FCUs - seems a lot, plus two volumisers. Think some simplification is needed somewhere. You're well insulated and you really don't need heat in every space or under every window to heat up drafts, that may exist in a more normal house.

So almost operating as a single zone really. Hence no issues.

I did indeed. But then even more reason not to zone. Heat pump you really have too options no zones and super simple, or a big buffer (never a small one), additional pumps to buy and run and zones with controls. I am down the simple route and now only have a switch to change over from heating and cooling and a diverter valve for the cylinder heating to CH change over.

Run a low temp system, then there is no hot air being blown, just air a few degrees warmer than the room. That gets my vote also. It's simple it works, others will come along and say you can't get it to work, but it does. The biggest issue you will have is a strong likelihood of the boiler short cycling if you do zone. This will increase gas consumption dramatically. Ours used double the expected amount of gas, when I had zones. Do the system so everything is a similar design temperature and get rid of any mixers or additional pumps. Big output boiler, low demand of 2.2kW, even lower at 7 degs. I assume the output min should be closer to 5 or 6kW. If that's the case you need a minimum of around 50L engaged water volume at all times to keep the boiler happy and not short cycle. That should give you about 8 to 10 min run time for the boiler.

If only radiators or a single zone of UFH is asking for don't you get a lot of cycling of the boiler. So it runs a short period locked out for 10 mins repeat. I halved our gas bills by getting rid of zones

Making it complicated instead of simple. Been there got the tee shirt, paid the super high bills. Then went to boiler controlling everything halved my gas bills.

If you go on heat geek, they don't bother insulting pipes within the heated envelope, as heat is not wasted. Only exception is hot water cylinder heating pipes, as these would add to summer heating, so should be insulated.

You can get them from Cool Energy, often sell on eBay at reduced prices

The answer is 2m then. He has to certify. Connection to boiler yes copper, I would do all the main connections on the cylinder in copper also. Are you doing proper Viessmann install. With priority demand hot water and weather compensation? So without mixers or additional pumps? If you haven't bought your cylinder, get a heat pump one, with a 3m² coil. Your flow temp will drop and your recovery really quick.

Not tried it, not sure if you intend to use it with a heat pump? Output could be rubbish at low flow temps. Our summer house has a fan coil, at the moment it is just getting circulation water from the house, and the odd blip of heat at night from the heat pump and seems to keep the summer house temp quite even between 19 and 20. Circulation temp is around 21 degs, so just using the floor as a big buffer.

Your issue is, if it was used for real, you could have the pipe backup the fluid flow, the result hot water spilling out the tundish. Let us know if the valve fixes the issue.

Radiator heat output calculator, yellow cells is what to alter, use a dT between flow and return of 5. Radiator Heat Output Calculator (1).xlsx