SteamyTea

nO eXiT fEe. So free to change. If an offer is too good to be true, it probably is. Why I avoid all this swapping nonsense in a mature marketplace.

I find all this very interesting. I like logging data, and analysing it even more.

Having made air filter, you are going to need a very large area to reduce VOCs, they are not removed the same way as dust. So maybe a sensor and a flap. In fact, cant you fit an ordinary spring loads flap the wrong way around. Though it may rattle a bit if the spring is not strong enough.

You could get a cheap PlantPower particulate sensor, stick it into the MVHR input pipe, then with a bit of code, set a limit for it to turn the MVHR off.

About 10m of trench for every kW So 300m long Trenches can not be tightly packed, so say a 2 m gap between them. and they are about 1 m wide, that area becomes ~ 1000m2 Or about the same as PV (ish). This is not surprising as GSHP are really solar powered, just that the ground is buffering the annual solar input.

And now the area of an ASHP. Or shall we call it no more than 1.5m2

Me too, but it is alright, as I live right by the 3rd word polluted road of 2017/8. I would love to see the time serious data as there is no gas, so possibly it is all the people who burn coal and timber that is the real problem, not people with EURO4,5,6 cars (I missed the opportunity to work on the project a decade ago).

When I was working all this stuff out, I made my own spreadsheet. Seemed to work. Would be interesting to make up a calculator for working out UFH piping, then compare it to LoopCad.

Of dry timber, not sure if the FC table is for that. And just for a giggle, work out the area of land needed, with PV on it, to supply the same energy at the same time of year.

Possibly it. It may be hard to convince people that after being told they need everything less powerful i.e. vacuum cleaners, light builds, kettles, cars; to save the environment, to then come along and say, 'well actually, you need a 10 kW system, so we are fitting a 15 kW one. I think it is up to the manufactures to get this message across, and offer a scaleable system i.e. 4kW increments.

Only on new builds. It does not change existing installations as far as I know.

There is going to be no choice in a few years. https://www.gov.uk/government/speeches/spring-statement-2019-philip-hammonds-speech Still, your old plumber can service old boilers.

No, I am interested in why there is a reluctance to fit them. I think so, and usually undersized, or customers told that an ASHP cannot get the temperature high enough, so they fit gas or oil because It is the same, pumps and pipes valves and distribution manifolds. The emitters (radiators, UFH pipework) may be a different physical size, or spacing, but is hard to design a wet system differently that it already is. I think there is a lot of confusion with terminology, my favourite being the names used to store hotwater, is it a cylinder a thermal store, am unvented cylinder or a vented one, buffer tanks, accumulators (though I think they are to buffer mains waiter pressure), feed and expansion tanks, pumped showers, mains pressure showers. About time some of the plumbers put up some diagrams showing the difference. But when it comes to heating the actual house (space heating), this is where a proper thermal model of the building, and local climate, is needed. Would probably save money on all installations regardless of fuel type.

It may be worth you doing a sketch of your system, bit like a London Underground map (topological). Probably all become clear how it works then.

It may not, if the return temperature is too high, the boiler may cut out as it assumes that the need is satisfied.

Shame they use W for work and power, even if work is intalised.

Can you copy the pages from his books. Be interesting to see how it is explained. I am not sure if an oversize system would overheat a house. The control system should take care of that. It would probably not be very efficient though.

This is the 2020's not Caxton's 14070's. I think I did a bit about phase change materials on this thread:

Yes they must. But we have to put a cost on the externalities to. The servicing issue is a problem at the moment. But it is with some gas boilers, and definitely oil ones, even down here. Generally, ASHPs are reliable and are low maintenance. But you know that from the one you have that heats the water.

Only took a few days for mine to turn up. China warehouse in Southampton probably. I have used an ordinary relay in the past. Just hook the coil up to the switched supply, then sense the contacts closing.

If only this forum had a way to easily direct people to decent static resources. There is a second part to the whole energy, power and temperature bit that is more relevant to heat pumps and that is phase change materials. This is how heat pumps work efficiently, but also gives that looks like a deficiency. As the gas used in the units has a fixed temperature, like all gases, at phase change, this puts an upper limit on how high it can raise the temperature, off say, water. The gasses are chosen to be as high as possible, without causing other problems i.e. extremely high, or low pressure, too large a difference in temperature between liquid and gas states, power need to change the state via the compressor etc, and other things like the need to lubricate moving parts, not so cold that they instantaneously free the moisture out of the air. It is the differences in specific energy capacity, and reversibility, of gasses and liquids that allow heat pumps to run with high efficient. Oddly, combustion can also be thought of as a phase change, from gas to plasma and back to a gas, but not the same gas, it is not easily reversible though, and this causes pollution problems. The efficiency cannot be as high as a heat pump, ever.

Energy is the ability to do work. It can take one of two forms. Potential or kinetic. Those words just mean stored or moving. The unit of energy is the joule [J] and the definition of that, in SI units is kg.m-2.s-2. Power is the actual work done, and is the rate that the energy is being used. The unit is the watt [W] kg.m-2.s-3 or is simpler English, a joule per second j/s. Temperature is a relative value with the 0 point set where there is no kinetic movement within an atom. This is known as 'absolute zero'. Temperature can be thought of as how fast atoms are allowed to move when unimpeded. The hotter they are, the faster they can move. So taking a very simple example, if you have a box with sided each 1 metre long, with lots of smaller cubes in it, 1000 of them, that have a mass of 1 kg each, and you move each smaller cube out of the box and place then on a table 1 metre away, if you disregard friction and gravity, for each mass you move you have used a J of energy. The temperature of the masses has not changed (though the person, or machine doing the work will get warmer. Now if you move each mass at a rate of 1 a second, the power you are moving those masses is 1 W. It will take 1000 seconds to empty the large box and 1 kJ of energy will have been used. For some reason we do not use joule as a unit of energy, we use the kilowatt hour. But that can be easily broken down in derived SI units. kilo = 1000, W = J/s and hour is 3600 seconds. Writing out in long hand. 1000 x 1J.s-1 x 3600s = 0.00027777777777778 kWh.

In what way, operation, design, installation, maintenance?

I is easier than working out the volume. Timber has a specific energy of ~4.5 kWh/kg. Another thing worth looking at is the number of rings showing on logs, that gives a good indication how long it takes to replenish that resource, quite frightening that you can burn a ten year old log in a few minutes. But that is another topic. Without knowing the heat losses of the building, it is hard to work out the cot of any type of heating system. You can do a simplified calculation by working out the U-Value and areas of all the exposed components, then find some local weather data, that will give a fairly good estimate of what is needed. Then you can look at different technologies and how they compare on capital and running costs. Which do you think is more complicated, your gas oven or your fridge? Heat pumps are really very basic and have been around, unchanged, for about 50 years (the first heat pump was about 1940). The only major change is the transition from reciprocating 'piston' compressors to rotary 'scroll' compressors. Though is some CO2 HPs they are going back to reciprocating pumps. The reason for this is that even the 'best' R32 refrigerant gas is still several hundred times worse that CO2. This is legislation driven, not a technology change as such. Heat pumps can use tap water as the refrigerant, but as water is 'the universal solvent' it does not have the longevity desired, though the performance is very good. While a useful basic comparison of technologies, the running costs can vary way too much in individual households i.e. the standard deviation is very great. When looking at the technology side, it is easy to get side tracked by the fuel costs. These vary, and vary greatly around the world. Japan, which has no naturally occurring coal, oil or gas, uses heat pumps. Russia has about 150 year worth of natural gas at current consumption rates, so uses basic technology and they control temperature by opening windows. The running costs do not change the efficiency of a system and can very easily be a distraction when trying to work out the best there is.

Out of interest, could you weigh the logs you burn in a typical day, then we can work out the energy that is used.