SteamyTea

I used to work at the Royal National Institute of Blind People. They spend £100ks on lighting. We just turned them on to full power, and then off when we left. As the old saying goes, 'if you cannot measure it, it is not science'.

Do you have enough height to add insulation on top of the new screed? Thermal losses though a floor are constant, all year round.

The general rule, in the UK's climate, is to stop warmer, humid air, that is inside the building, migrating though the insulation onto the colder surfaces. Depending on the types of insulation used, a vapour control layer is used on the inside, the warmer side, then the insulation, then an air gap for ventilation. The problems start if the cold air, in the air gap, can bypass the insulation. This makes the insulation a lot less effective as it, in effect, reduces the thickness. There are insulations that are called 'Full Fill' that can cope with being damp for a short period of time, @joe90 used it on his walls I think. There are roof system that do the same (warm roof).

Easy to add 150mm of floor insulation onto that sand.

I often drive past the Mitchell and Webber building. Could call in, I am sure they would we willing to tell me just how great it is.

Welcome. Insulation is really very simple. For any given material, it has a thermal conductivity, usually denoted as k or ⲗ. This is amount of power, in watts, that can travel though the material for a given temperature gradient. It is usually expressed as W.m-1.K-1. Dense brick is around 1.3 W.m-1.K-1. Mineral wool around 0.04 W.m-1.K-1. From that you can calculate the R-Value which is just proportioning the k value for the thickness. This gives the derived units of m2.K.W-1. Just a case of dividing the thickness of the material by the k value. So take a 100mm thick brick. 0.1 [m] / 1.3 [W.m-1.K-1] = 0.08 m2.K.W-1 Mineral wool at 50mm 0.05 [m] / 0.04 [ W.m-1.K-1] = 1.25 m2.K.W-1 All that is saying is for the same power transfer, you would can have an area 16 times greater for mineral wool than brick. It is more usual to use U-Value as that is more intuitive. The U-Value is 1 divided by the sum of the R-Values. It has the derived units W.m-2.K-1. U-Value [W.m-2.K-1] = 1 / R0 + R1 So 1 / 0.08 [m2.K.W-1] + 1.25 [m2.K.W-1] = 0.75 W.m-2.K-1 Doubling the thickness of the mineral wool insulation to 100mm. 1 / 0.08 [m2.K.W-1] + 2.5 [m2.K.W-1] = 0.39 W.m-2.K-1 Always worth making the insulation as thick as possible. There is nothing to stop you having insulation thicker on some walls and thinner on others, it all contributes to the overall losses.

Yes. I think you are right.

And the temperature probes wired in right. Also summer bypass not changed to winter. There is also the terminology, which is not that intuitive. I think Exhaust is the air leaving the room, not the room air being expelled out the MVHR unit, though I am never quite sure.

Never again.

Great Crested Newts are their favourite supper.

Where does the hydrogen come from?

What size pencil?

Realistically you are going to have to internally insulate the property, though you may be able to add some external insulation if you do not mind the looks changing. One advantage of adding insulation is that you can also tackle air leakage at the same time. There is the option of digging up the floor and adding 150-200mm of insulation, then under floor heating, but it is messy and expensive. As you already have a heating system, you can at least monitor how much energy it is using. This will inform you as to the sizing of any replacement system is needed. So start taking measurements, internal temperature, external temperature, daily oil usage, electrical usage, kg of timber burned. Which part of Cornwall are you in, it is a long isosceles triangle and the weather can vary along it quite a bit.

Think this one was too fat to get down its burrow.

Linear regression and RMS values.

Was just getting wet when I past Bristol City 3 hours ago.

The Hideous. I am sure I could knock your wife up suitable.

Is it worth asking your bank. They must deal with this all the time.

Or just get a maid, from the Philippines.

Start the search query with site:www.https://forum.buildhub.org.uk Much better than the built in search.

That will be 10 kWp, the peak is for peak. I take it the system is going to be 3 phase and that is why you have 3, 2 kW immersion heaters in your cylinder. I don't know too much about 3 phase systems, but depending on your meter, it may do net metering and you could divert just on one phase and let the other phases export, but the meter will cancel out the imports. May be simpler to buy 3 diverters. The one things to check is that your phases are balanced as well as they can be. That can be quite a challenge.

Not the distance between the generators and the main consuming area though, it is the local substations that are the main areas of losses, though, and inefficient old home appliances. I suspect that more energy is lost though old fridges/freezers, unattended 'entertainment' i.e. TVs on but no one watching, poorly insulated DHW cylinders (which is most of them), security lighting left on unnecessarily, unemptied vacuum cleaners....

It is 4.18 J to raise 1g of water, 1 K. A watt is a joule per second. The joule is the SI unit for energy. This gets 'corrupted' to the kWh, which is 3,600,000 J. Both the joule and the watt are derived units from the SI standards of mass, distance and time. Different materials have different heat capacities and specific heat capacities, the J/kg.K. It is more usual to use specific heat capacities when dealing with fluids, though there are times when just the heat capacity is more useful i.e. evaporation losses. Evaporation, condensation and fusion HCs are often different for the same material. It is what allows a heat pump to work.

Was my first thought. My car has both. One involves opening the window.

Pitifully small. I think the relevant detail is hidden in this spreadsheet. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1131436/RHI_monthly_official_stats_tables_Dec_22.xlsx Sheet S.1 show median costs of installing a kW of ASHP is £980, with lower quartile at £770 and upper quartile at £1710. What that actually covers I have no idea. As a comparison with combustion technology, small biomass is coming in at a median of £590/kW (LQ 480, UP 800)