JohnMo

Mine is controlled from a thermostat if there is a requirement to heat the pump runs. The thermostat is set slightly higher than required room temperature, I just located it the hall. With a heat pump, there is a slight disadvantage running rooms with heating off and others on, the internal heat loss between rooms, means a higher flow temp is required for the heated room, so you CoP goes down. It actually becomes as cheap to heat the whole house.

500m2 is a small hotel. Will be full of rooms you never use, bathrooms you never use but have to clean. Hope you are getting a full time cleaner. You should start with a reality check on what you need and what you want - very different. You can quite easily sink £50k into lightning, the same into smart stuff that will be old news by the times it's built.

AVV - automatic vent valve Dot connectors are the connections on the thermal store - these tap in the inhibited fluid in the cylinder. Its just a 160L vented thermal store, with a indirect heating coil (supplemented with a large plate heat exchanger) and DHW coil. DHW water does not enter cylinder directly goes through a coil.

I would keep it simple either A simple immersion timer or an immersion diverter. The advantage of the diverter is if you have 0.1kW it goes to the immersion, nothing more or less - not the full 3kW demand you would get from a simple sunlight sensor.

A schematic of my system. Have a simple combi thermal store (160L) upstream of the combi (with additional insulation to limit heat loss). Immersion heater connected to PV diverter. You need a diverting valve and thermostatic limiting valve on the output of the thermal store DHW coil. This will reduce gas usage and stop un-necessary boiler firing when the cylinder is above about 45 degrees. The cylinder is also being used as the central heating buffer.

Basically you need a buffer. The larger the minimum output of the boiler the bigger the buffer requires to be. But operating as a single zone would help without the buffer. The more zones you have the more likely short cycling will be, if you have TRVs on rads they need to modulate down not be on/off.

Yep, filling my car in litres, calculate consumption in mpg, and distance travelled in miles, while monitoring temperature in degrees C and building a house in millimetres. And paying for things in pounds and pence instead of shilling and Grote's etc.

No I think they have their own network or sits on another similar to a mobile phone.

Oops should of been 1.5 miles. 5' is way to close for comfort.

I tried to get a smart meter, but they failed to get it to connect to the data collection centre. So I now have a dumb smart meter. I am the vast total of 1.5m away from a large village, and they couldn't get it to work, so no hope in a remote area.

Think of a storage heater, but with an air to water heat exchanger instead of and air to air exchange. Idea is pretty simple, would suspect its very heavy, filled with bricks similar to a storage heater. So its really a high density thermal store. Key advantage over water is installed space required is way less. 40kWh sounds great, BUT, if you take away 5kWh for DHW it only leaves 35kWh hours for heating (1.45kW per hour based on 24h) and also depends on the threshold of where in the 40kWh the heat becomes unusable from the store, due the heat exchanger performance and the delta T required. Also if a top up is required during the day - not cheap. According to the manual it looses 15-20% of its charge over 24hrs, which is huge. So 6-8 kWh, which is the equivently of about 3-4 300L cylinders. But 2x300L cylinders would hold about the same energy at 60 degs, with half the heat losses. So if you had space would be better and possibly cheaper run on the same E7 tariff or similar. Also when its cold outside you could charge to higher temperature (to store more energy), in the summer just charge one cylinder for DHW to save money. Something borrowed from another website, the Octopus refers to a heat pump run on the night time tariff.

My flaps work automatically, I cannot select manually (Titon MVHR), but they should only be open when the outside air is warmer than the inside (i.e. summer hot day). Various other thresholds are set like minimum temperatures, the summer by-pass is installed so as not to heat the house when it not needed or would make things uncomfortable.

Go on to sites like the one for FRESH-R and see how they implement MVHR. Very few inlets/outlets. Same thing can be done with MVHR with a little thought. Also look at condition based dMEV. only venting when required by internal humidity levels.

Remember MVHR is ventilation only, it does not provide enough flow to cool the house in summer. You have windows that open to allow cross flow ventilation to provide cooling as much as anything else.

I came from the military with the same definition. However this defined understanding does not exist in many walks of life - building regs included

You want summer by pass off. If it's on the incoming air does not go through the heat exchanger and will just come into the house without being warned by outgoing air. You need both fans on, one is for extract the other for supply air. Hope this helps

No not speaking about CO. Sorry it is a monitor not a sensor, but it is for CO2, also it is not an alarm. The monitor requirement pre dates COVID by 5 years. https://www.gov.scot/publications/carbon-dioxide-monitors-standard-3-14-letter-to-local-authority-verifiers/

If you look in Scottish building regs, they mandate CO2 sensor in the main bedroom, the regs also dictate the functions of the sensor. Other than that, there is nothing that says you must be below an upper threshold. That I am aware of for domestic properties.

I think the problem is although only 1345W that's 32kWh per day. E7 would be 4.5kWh per hour for 7 hours. PV is pretty rubbish in the winter, so I wouldn't bank on anything spare for heating in the winter. But in the summer most of your DHW would be PV heated. Think I would seperate DHW and UFH. Exhaust air heat pump cylinder for DHW, route the air from outside and back outside. Then a Willis x2, most of time only one required. Then batch charge the floor on E7. Or joules do a slightly bigger exhaust air heat pump that can do central heating also.

If your using 5.8kW on a cold day, that is 5.8x24=139kWh per day. So £70 per day at £0.50 per kWh. An electric boiler will give you 1kWh out for each kWh in. Never any better than that. An electric boiler is really just an immersion heater with some control. A heat pump on UFH should get a CoP of 3 or better on the coldest day, so would cost £23 per day instead of £70. A typical heat pump 3kWh out for each kWh in.

You even have to careful about which Freeview box you get, as some don't do all the channel apps, or don't allow you go back in time at all.

They leak air not water, your topic is ventilation, not water leaks. They will be water tight. The T&G, the joints between panel all leak air.

Mine came with a slot below the roof line that could be either filled in or left open, so just left the strips of wood out. But its a bit of a cop out, there should be no humidity being generated, unless you sleep in it, plus they do leak like a sieve generally.

What is your current heating demand? Have you looked at Exhaust Air Heat pump cylinders (heat pump and cylinder in one, such as the Dimplex edel for example. They would be a standalone hot water solution which can also be heated with PV or solar solar thermal.

Heat loss on a -5 day is about 3kW. The issue with short cycling, having to heat up the metal and any water that has cooled while the boiler is off. That all takes energy. In the heat pump most that metal is outside, on boiler I think a lot of heat gets wasted out the exhaust. By getting on top of short cycling and boiler control I have halved my gas consumption. Lots of cycles also mean additional wear and component life reduction.