SteamyTea

Time over time, I read on here that ASHPs are no good for old houses. Can we stop this nonsense. ASHPs, or any heating system, if it has a too lower power output, will struggle. That is what power means. So rather than say an ASHP will struggle, or is the wrong thing to install, tell the true story. The true story is that it may be cheaper overall to install a gas or oil boiler, or a much larger, or even two, ASHPs. And could everyone stop getting temperature, energy and power confused, they are different thing.

OK, I shall stop offering explanations to your problems, not mine.

Or a quip.

Any chance of starting a new thread about this. I see it mentioned, along with other plans, but don't understand what it means, and too lazy to Google it.

If you are used to a gas or oil burner you would expect that. But this is a heat pump, they are designed to work at below there maximum rated power (a bit like a car is used, not often you drive it at maximum power). The reason for this is it is more efficient i.e. the CoP stays higher, so costs less to run. Now you refuse to let it run for very long, so what you are, in effect doing, it doing a very long car journey, stopping every few minutes, and only using third gear. Then complaint that it takes forever and you have not reached the top speed of the car. I take it that because of your condition, you are currently not allowed to drive, so this analogy my be pointless.

Or not. https://www.gov.uk/guidance/powers-of-entry

Ideally, to get maximum power transfer, the return temperature is half the difference between the store temperature and the input temperature. This gets confusing when the boiler is in condensing mode though, that often sets a minimum temperature. That all sounds a bit confused. Say your input temperature is 70⁰C, the store is at 40⁰C. Half that is 15⁰C, so return should be at 55⁰C. But as the store warms up, say to 50⁰C, the return should be 60⁰C.

I bought, for about a fiver, a current activated switch. Using that you could count the pulses, and if you know the power of the heating element, you will know what is going on. I suspect, but don't know the chemistry that well, heating is limited to stop phase change when it is not needed. The thermal conductivity of the PCM will be different when it is a liquid and when it is a solid, and not just because a liquid can flow. Normally when a PCM changes state, it cannot be easily stopped. SA have got around this somehow, and that somehow may be to do with how the material is 'conditioned' during the heating process.

That is just one of the downside of burning wood to keep warm, it don't take long to use it all up. If we decided to burn every years biomass growth of the entire planet (all plants and animals), we would, at current consumption rates, have about 400 days worth.

Amps [A] times Volts [V] equals watts [W] A watt is a joule [J] per second. A joule is the unit of energy. So 300 [A] x 230 [V] = 69,000 [W] I said that it would run for 2 seconds 69,000 [W] x 2 = 138,000 [Ws or J] As a joule is the the force [mass x acceleration] to move 1 kg 1 metre, I used the force of gravity, 9.81 m.s2 so (and I think I did this step right, but starting to doubt myself now) 138,000 [J] / 9.81 [m.s2] = 14,067 kg.

Does sound as though it is possibly undersized. Or the heating curve is no steep enough i.e. it is only putting in 50% the power it can, when it should be putting in say 90%. It is also possible to be a combination of both i.e a small engined car, stuck in 4th gear, going up a steep hill. It will make it, but it will be slower

I was qualified to fit inverters, really quite simple for a qualified electrician, most will have covered in when they are updating their Part P. If the electrician does not under stand it, find another one. And it can draw a lot more current than that for a second or two before it blows. So let us say it draws 300 A at 230V for 2 seconds, that is the same as a 14 tonne weight resting on your body.

That is the idea, should start to get the rest of the house warmer. And make sure the thermostat is not above the oven. As your system seems to have warmed the place up a bit, all be it slowly, it seems that most of it is working alright. Don't get hung up on the absolute numbers on the thermostat, it is a warm house you are after.

Less than Zoothorn though.

Right, last go. Think of it as a car, one with manual gears. Each gear will have a maximum top speed when the car is running on level ground. Think of that top speed as temperature. Now you can keep the same temperature, but get there faster by using a lower gear i.e. better acceleration. Temperature compensation does this automatically for you (no don't say you don't understand automatic cars and have never driven one, they exist, and work). So when there is a large temperature difference, it in effect uses 'lower gears' to get desired temperature faster. So when you are asked to 'turn the temperature up', there will be a larger temperature difference between inside and outside, the ASHP will 'drop a gear' and endeavour to close that gap as fast as it can. If it fails to show much difference, then the temperature compensation 'curve' may need changing (and don't ask for an explanation, just accept it can be changed). There are a number of reasons that the curve is wrong, mainly these controllers are sold globally and the default settings may be for a totally different climate than the UK (you can claim this is wrong and should not happen, and is bad design, but you are one customer out of millions, and they don't give a flying (expletive deleted) what you think). Turning it up a few degrees for a few hours is going to take that, say 3 hours. You have spent several days, and many collective hours of other peoples time on this. Just give it a go, you may be surprised.

How are you going to power your electrically driven ASHP?

The Horror that is Cornwall. But only the second worse planning office.

Welcome There is the SW, and then the proper SW. I am at the proper end. Wind is one thing to factor in, it saps heat away quite rapidly. But basically you can just about design anything, thermally. Be careful with the Passivhaus figures, some times they are primary energy and not usage energy. I use about 4 MWh/year for everything. Could use 1MWh less if I swapped my resistance heating for a heat pump, or put in PV to heat my water. So yes, ASHP. Thick, well insulated walls, MVHR, spend time on making the place super airtight, initial design helps here, and never be tempted to put in a wood burner.

Yes, and it is painful. But it does keep the beaches clean for the dogs to shit on.

Give Mark Walker at Walker Machinery a call, he will point you in the right direction. 01993 772255 He is just outside Witney. http://www.walkermachinery.co.uk/contact/

We have no shortage either, but the most expensive water in the country. It is not the amount of rainfall, more the storage and treatment. If you live in a very rainy area, and most of the towns are close to the coast, then waste and run off water treatment is very expensive. I think the water targets are base don national averages i.e. average usage and average houses, then a bit taken off, and then 'weighted' for house types i.e. size. I live on my own, but the identical house 4 doors away, there are 4 adults, next to that there is a family of four, then a family of 3, then a single, then me, then a family of 3. Now you cannot have 2.6666 people, so that will be called 3. So the water calculation are possibly based on 3 people in each house of my size and type.

Well it looks to me that you are in for a miserable time with it. Unwilling to get installers back in and unwilling to accept advice, or suggestions, and not even bothering to look up 'difficult terms' on the internet. How much help do you really need, a magic fairy.

Or a simple picture, though suspect a hiding for nothing. Only physics needed is T=temperature and t=time.

Maybe something like this 15 quid special https://www.switchelectronics.co.uk/5v-8-channel-solid-state-relay-board

So these relays are just closing and opening a circuit, they are not actually carrying the motor current. Shall have to see what small SSD there are. I think I have a mechanical relay 'hat' for a RPi somewhere.