SteamyTea

A vector is a quantity and a direction.

Or more a case of driving at 50MPH instead of 90MPH. The air resistance goes up with the square of the speed. (Velocity and Speed are different)

Not always. If you lower the mean internal temperature by 1⁰C, you reduce the losses through the walls floors, roof, windows and doors, and the ventilation losses. But you have a colder house. This is not the same as reducing the ASHP, or any other wet heating system flow temperature by 1⁰C. With an ASHP, it may increase efficiency enough to counteract a longer running time. With a condensing boiler, it may mean you get less condensing and loose overall efficiency. Energy (kWh) is Power (kW) X Time (h). We should really calculate in seconds (s), but the numbers soon get s lot of zeros. Just to confuse things, the unit of energy is the joule (J), but there is a direct conversion to kWh. A watt (W) is a joule per second. So a kWh can be described as 1000 watts running for 3600 seconds or 3.6 MJ. Probably notice there is no mention of temperature (T) in the description of power and energy. Temperature difference is the important bit. No temperature difference (0∆T) no energy transfer, so no power used. Called equalibrium. Increase the ∆T and there is an energy flow (Q). If you see the term flow, flux or Q, then you know there is a time element involved. The usual letter for time is t, not to be confused with T for temperature (makes for a gun time in calculous ∆T/∆t). To confuse even more, when dealing with heating systems, surface area (m²) becomes important. This is why a properly installed under floor heating system may run at 28 to 35⁰C. It has a lot of area to distribute the energy over time. It is why, with traditional radiators they are run at a high temperature (up to 70⁰C) to counteract their small surface area. Heating an identical room, well the air in it, takes the same amount of energy. This is due to air needing the same amount of energy to be heated the same amount. This is known as the heat capacity (Cp measured by volume) or the specific heat capacity (SHC measured by mass). Air has a SHC of around 1 kJ/(kg.K). We should really always work with the kelvin scale as it removes odd results when passing 273K, or 0⁰C. Like all basic physics, the concepts are simple, it is the detail that gets confusing. Why I have avoided radiative heating in the calculations. It is the radiative element that can make some rooms feel warmer than the air temperature leads you to believe. Humidity levels can have the same effect. They can both be calculated, as can latent heating affects, but a wall thermostat only measures temperature.

I take it you don't live in that size space. My house is around 50m². Don't leave much space for storage. Hard to find a place to store a bike, a ladder, hobby stuff. Just my book shelves take up 1/30 of my usable space.

Not on the face of it. Would have to look at the spec if the unit and it's control system. But at the moment I am looking at the tide going out, which warms up the town. 12 hours time, the tide will cool the tide down again.

It is because people seem to have trouble grasping the difference between temperature, power and energy. There is still a misconception that lower temperature means lower power, and therefore lower energy by definition. This is wrong. Not many people have an ASPH larger than 12kW. But even small houses often have a 20 kW gas boiler. Now some of that oversizing is to allow DHW to be instantly heated (and that is not a great flow rate). But it does mean that during cold spell, an extra 8kW or so of power is available for space heating.

It is those few times a year when my space heating load doubled. Not much in the scheme of things, but hurts at the time. Heating is off now.

This is the problem I have. With small power loads, it is not worth me fitting an ASHP.

And not poisoning all the newts in your pond.

Physics Specific Heat Capacity of Water = 4.18 kJ.kg-1.K-1 So say you want to heat 200 litres of water from 8°C to 50°C 4.18 [ kJ.kg-1.K-1] X 200 [kg] X (50 - 8) [°C] = 35115 kJ To convert kJ to kWh, multiply by 0.0002777 35115 [kJ] X 0.0002777 = 9.75 kWh Assuming a 2.8 kW immersion heater, to calculate the time taken to heat 9.75 [kWh] / 2.8 [kW] = 3.48 hours Assuming two prices for electricity, E7 at 10p. kWh-1 and Standard at 16p.kWh-1 9.75 [kWh] x 0.1 [£.kWh-1] = 0.975 [£] 9.75 [kWh] x 0.16 [£.kWh-1] = 1.56 [£]

Start with Excel, your existing bills and PVGIS https://re.jrc.ec.europa.eu/pvg_tools/en/#PVP

And E7 DHW system can be installed very cheaply. Cost more to run, but very reliable.

If it is the same model of inverter, you probably don't have to inform them. If different, then yes, they will only need the relevant certificate that comes with it (I can never remember what it is called). They have this for safety reasons, so best to inform them.

Seem to remember that the whole DC side is not earthed. If that is still the case, there is only one place it had go though, the inverter and then the meter.

No. It is illustrative. There will be a system that fits that curve, that is the beauty of physics. The concepts are simple.

Trust in education.

Check with MCS, they should know the answer. Regarding your initial question. Yes, you are unlucky. Put up a lightening rod.

Welcome. Get a good book about physics. The two main areas are material properties and thermodynamics. Both only require basic arithmetic, so no need for a maths book.

I can't remember now, as it was a decade ago. Do generation meters get a MPAN number, and do meter swaps need to be notified to OFGEM. It was a serious offence to misreport the initial meter readings when first installing a system. Easy enough to do a like for like meter or inverter swap as you can isolate the system easily. Just take lots of pictures of where the wires go.

You can ask the DNO to reduce the local voltage at the transformer, then you can export OK. The generation meter problem us interesting, they are just normal meters on single phase. Not sure if they have to be different on 3 phase. Maybe @ProDave knows the answer to that. if your parents are on a normal part of the grid, then they should be OK. What inverters you have as they need to be configured for the UK grid, some cannot be changed by a user after they are installed, they need an installer code.

Better off all round with an induction hob though. Back to my idea of spending money on your existing burner. Are you in a hard water area? Is there a chance that the heat exchanger is scaled up?

Look at it again. As the ∆T increases, the CoP reduces. It has nothing to say about absolute numbers (in fact it is just made up numbers, I could change the chart to fit what you want though). The important thing is that it is sizing and system design that is important, not the underlying technology. A thermal boiler is just a heat engine, just that very little excess energy comes from the air that is drawn in to aid combustion. Though with a condensing boiler, energy, via phase change, is sometimes recovered.

There was an article somewhere that it can devour roadside pollutants. https://www.rhs.org.uk/science/articles/super-cotoneaster But worth a warning that the original NASA report about plants cleaning air was pretty limited in scope, with ambiguous results. But still quoted 32 years later as gospel by some. https://en.wikipedia.org/wiki/NASA_Clean_Air_Study

At the most basic level, any heatpump will loose efficiency as the temperature difference increases. It is also not linear. The idea is that the system has to be designed to work in the most effective temperature range. This is achieved with a combination of system size and refrigerant gasses used. (the CoP is the extra energy from the air or water, not the total energy)

Correct, can't say I have noticed any.