SteamyTea

You can get a 300 W PV module for £135 on eBay. That is 1.6m2 of coverage. B&Q will sell you, for £1000, a rooflight that is 1.5m2 of coverage. How cheap do you want PV to become?

Regardless of the heating system, heat losses and maximum heat demand will be the same. You can't fool nature. The reason that the government is pushing heat pumps is that they are the only practical way to supply thermal energy to home in a low CO2 emissions manner. This is because we are cleaning up our electricity generation. This is expensive, hugely expensive, but in the last decade we have reduced that sector emissions 5 fold. There is an alternative to use resistance heating, like we did between the 1960's and the late 1980's. This would mean we would have to add a lot more generation capacity. This is possibly cheaper, in the short term, than retrofitting heating systems. But there is a land issue. The UK does not like having wind turbines and solar farms on its land. We have convinced ourselves that only the best farming land will be used for this, will kill every bird within a mile of a turbine and the glare from a solar farm will give every child cataracts. It is all bollocks of course, but perception is more important than fact. So it is basically down to us to upgrade our homes. If your roof is suitable for PV, add it. It is cheap to self install and could probably do 70% of your DHW needs (with some diverter trickery) Airtightness and insulation really need to be considered together. External wall insulation is usually the most cost effective and will (should) improve airtightness. It is like putting a windproof winter jacket on. There will always be areas that air can bypass this that may have to be address after the installation. This may well be hard to get at area i.e. between loft space and the rooms below. These can possibly be addressed when fitting PV as scaffolding will be on site. Ideally you would convert your roof void to a warm roof system, then mechanically ventilate your house. This is expensive. So go down a layer and make the interface between room ceilings and loft space airtight, then ventilate the rest of the house. Some internal insulation may be useful. The ground floor is a large area, that is usually connected to the ground, which is cold. Insulating the floor will help a lot. This is not always easy as door and ceiling heights are important, as is the first step on the staircase. Digging up the existing floor, adding in 200mm of insulation, screen and UFH pipework is not really a viable option. But 20mm of insulation will help. Now back to ventilation. You have probably read that systems with heat recovery are not effective unless the ACH are below 3. I have never calculated this, but it intuitively make sense. So get the airtightness sorted out. It is more important than having a wall U-Value of 0.1 W.m-2.K-1. Fitting MVHR is a bit disruptive as it usually requires boxing in some pipework between floors. This does depend on the house layout. Through the wall systems are available, but they are not as efficient as proper systems, but are cheaper. Ditch any thoughts of a log burner. All these do is add CO2 to the atmosphere (what we are trying to avoid), put holes in your walls and roof (what we are trying to avoid), fill the house and street with particulates (there is new WHO guidance on this), cost a lot to run and smell. Fitting an ASHP is probably the easiest option if you have room for radiators (really convectors), but plinth heater can help in tight spaces. All these are, are fan heaters, with the heat coming from hot water, rather than an electrical element. I have no idea how noisy they are in a domestic setting, only experienced them in offices, where I never noticed them. The main thing is to not be tricked into thinking that there is some wonder technology that will sort it all out, cost less to install, have zero running costs and the government will pay for it all, and reduce your income tax to 10p. So if you hear the terms Far Infra Red, Reflective, Nano, Eco, Sustainable, Multifoil, Easy, or other such nonsense, laugh at them and walk away. Yes

Isn't that about 60% greater than building regs suggest?

We used to sell HP heaters for swimming pools in the 1980s. Nothing new. They worked well. The Jubilee Pool in Penzance got a load of cash ~£1.8m (£540m was my money) to have a geothermal heating system fitted. While drilling they hit problems. So abandoned drilling to 450m (I think) and started pumping up some warmed water ~30°C and put it though a Water to Water Heat Pump. This heats a small area of the pool, a few square metres, not the whole pool. What narks me is that this is a seawater pool, so part of the warm Atlantic Ocean is constantly pumped in and out of the main pool. I suggested that using the Atlantic as the heat source would be a lot cheaper, especially as there is a company in Cornwall that already makes sea W2WHPs. My estimate was £300k to do this. But forgot the council was involved, and hippies.

λ Sheep wool = 0.039 W.m-1.K-1 How many sheep would you need if you wanted to have a U-Value of 0.15 W.m2.K-1 R = l / λ Where l = thickness in metres U = 1 / R I have no idea what the thickness of a fleece is, or the area, or how much is lost after cleaning, treating and processing into batts. But after listening to this: https://www.bbc.co.uk/programmes/b093hdkw I may go out and kiss a goat.

I read the book, can't see how it would help.

So it is near saturation point. When close to that it tends to feel damp. Rainfall tends not to increase RH in itself, it is the evaporation and condensing of the water vapour that does that.

How you actually 'feel' is related to temperature and humidity. Where in the country are you?

And pound coins

That is basically what they did with the MCS. It could be argued about the level of training to bring a pipe fitter up to the standard of a real engineer. That usually takes 3 years at university.

One way of not getting them installed I guess.

That is because, like Cornwall, it was never invaded by the Romans.

I would like a system like that, but I can't see an easy way to administer it i.e. if the installer goes bankrupt, who then pays. What is, generally a known known, is the energy usage of a house. It is in the gas bill. There may be slight differences due to occupancy and internal temperature, but generally not huge. So half the verification of a heat loss survey is already done. Few current heating companies will bother to double check their numbers against known data. I also think that we need to loose the term 'Heating Engineer'. That is a description anyone can use, it means nothing now.

Yes, and that is what science is based on. The way he stubbornly refused to concede, in the face of overwhelming evidence, and then have a Damascian conversion is what irks me. Whether I like it or not, he had a huge influence before 2006 and would have been better of saying nothing, but he carried in saying he was not convinced it was happening. If anyone is interested, here is the IPCC's Physical Science Summary for Policy Makers.

Yes, there are going to be disappointed people. Why we need a decent program to educate. I frequently hear the Betamax vs VHS argument put forward. Not a good argument, they both worked, the problem was, in part, that Betamax was a closed format, VHS an open format. Was more to do with marketing than technology.

BREXIT language is kicking in already. I think I am going to invest in a company that makes metric to imperial adapters.

Was this the same David Attenborough that was not convinced that anthropogenic climate change was real until about 15 years ago? Now he is making a living from emotionally blackmailing the general population.

Sturdy girl that Karen who was driving the Rangerover. She could have just picked up the protestors, one under each arm, and carried them away.

Is there anything, from an energy transfer point of view, to not have larger pipework?

Would hate to think i mine was made by Cornishmen.

You can use an IR thermometer if your aim is good.

My house is a similar size to the OPs flat (48m2). I do my laundry at night, and I sleep though it. How much do you think you use during the day? I work evenings, only use a couple of kWh during the day, and often less. 80% of my energy is at the night rate.

Almost there then. https://www.engineeringtoolbox.com/heat-recovery-efficiency-d_201.html

Yes it will. The majority will be generated via renewables and some new nuclear. This should not come as a shock to anyone, it has been discussed, like Climate Change, for years. The people that need to do the work, not small builders and householder, but the infrastructure providers, know what to do, how to do it, and when it has to be done. None of this is an idea that popped into Boris Johnson's head last night. I also heard them talking about fuel poverty on the radio earlier. This really does need a proper definition. Many people still work on 10% of a household's wage. This is a nonsense number and was plucked from thin air I suspect. I am going to claim that most households are in 'vacation poverty', 'transport poverty' and 'gambling, fags and booze poverty'. I base that on nothing that prejudice and ignorance. But as a nation we are certainly suffering from 'educational poverty'.

Are they talking about doing proper heat load calculations? And why the (expletive deleted) are you listening to Radio 2. That is for people that are stuck in the past.