SteamyTea

MVHR will only contribute to cooling when the external temperature is below the internal temperature. But you still need to change the air. So this may change the rate at which you change the internal air when you need cooling i.e. a lot at night, none during the day. 72W x 500m3 = 36 kW (Ah, that was at 3 ACH, a third of that would be 12 kW) This seems very high to me, so I may have made an error somewhere. Thing is that this is the worse case, and it only happens very infrequently, and then for a relatively short time. Consider you would start cooling well before the temperature reaches your desired maximum, the peak power needed would be smaller. I would have to knock up a spreadsheet to work it out properly. Wall area, but minus window aperture. This is affected by the insulation levels as they slow the passage of heat into the dwelling. Windows can be considered the same as floor area as the light passes though and hits something, and starts to heat that. That implies that it is 8.8 times oversized, which sounds odd. I think you are on the right track to sorting it out, just needs the details filling in.

https://re.jrc.ec.europa.eu/pvg_tools/en/#PVP

To a certain extent it is. And how many people think that spending 5K extra on a kitchen will save them that on not eating out. What is the payback on a £800 bath compared to a £200 bath? Or a £1000 kitchen tap that boils water compared to a £50 one and a tenner for a kettle.

Air loss can be anywhere between 0.3 ACH to 10 ACH. As it is over heating you are interested in, and windows may well be open, work with between 3 to 5 ACH. Air 'hold' around 0.00278 kWh of energy for every cubic metre, for every degree. So if you are changing that air 3 times an hour, that is around 0.009 kW, or 9 W, so relatively small. But at 8°C delta, that is 72W for every cubic metre. Quite a lot. Is SG single glazing or solar gain. If single glazing work on 2 W/m2.K If solar gain, then it is a bit more tricky as this changes during the day, but with noon probably having a lesser affect that 9AM and 3PM. This is because at noon, the sun is hitting the roof more, and the hot air in the roof void is trapped (to a certain extent) and is acting as insulation. When the sun is lower in the sky, it is less powerful, say 800 to 900 W/m2, but is hitting the walls and windows more directly. as a rough estimate, work on 400 to 500 W/m2 as a worse case. Unless you like working with compound angles an want to model the whole day.

You really do need to do some basic thermal modelling. It is not hard, just a case of multiplying the thermal insulation number, the W/m2.K, but the wall, windows, doors, ceiling and floor areas, the m2, by a temperature difference, the K or °C. Then add all those numbers together. Add in some air loss figures, and some solar gain figures (these can be estimated from the external wall and window areas. Air is not a good method to shift energy around, I blowing air into a corridor and hoping it will go into rooms is a bit hopeful. And remember that if the A/C unit is all indoors (like a portable one), switching it on will actually increase the overall temperature.

It may be that the heat pump is not set up to well and the inbuilt resistance heater is on a lot (I am assuming it has one for the legionella cycle). This may be able to be improved with a bit of tinkering. How hot is your hot water? Many on here with heat pumps only run up to 42° to 45°C. Though with only one of you in the house it should not be the major energy usage.

Decent insulation and a timed re-circulation pump would have done it. All hot pipes need to be well insulated. That should have been a warning.

kw, is really kW (1000 watts) and is power, or an instantaneous reading. kWh (1000 watts, for 1 hour), is the energy. 32 kWh a day is still a lot. Do you have a hot water cylinder, with an immersion heater, that is constantly on? Even then, you would have to be using a lot of hot water every day. Is there any chance that there is a wiring problem and you are supplying a neighbour. The easy way to check this is to isolate your house at your consumer unit/'fuse box', and see if there is any movement on your meter. If there is, then you are supplying something else. What do these heat? Where does the power for your sauna come from?

Don't joke about that. Had a very drunk woman that sat in the corner and wee wee'd herself, and a small boy that pissed up the drinks cooler. And, why I think about it, a guy that let go of just about everything at the counter, though he did have an illness. Was still down to me to clean it all up. Still, I am not the local butcher, carnival night a year back, saw two lads weeing though his letter box. Think it may be a comment on his customer service skills though.

That is almost 3.5 kW of power on permanent (assuming your kw is really kWh). Do a meter reading tonight at 8 PM, and another at 8AM, then another one at 8PM. Post up the numbers as something does not seem right.

Come and dump in in my shop, all the other (expletive deleted)ers do.

Actually, if you do not need logging, I have a cheap indoor/outdoor thermometer from Lidl. The outdoor bit is wireless.

If you can run a bit of flex between the tank and the display, then a Raspberry Pi, with a display, can do it.

Pressure tells you very little about the flow rate. I can pump my bike tyre up to 120psi, and my car tyre up to 36psi. The car tyre will still have a larger volume of air in it.

Have you actually checked the flow rate to your house and what you can realistically supply to 4 showers running at the same time? You can reduce the flow rate, 9 litres/minutes is a pretty good shower. Avoid a wood burner, they are horrible, and not as cheap as people think.

Q = k×A×ΔT Where: k is the coefficient of heat transfer of the heating device (W/m²×°C) A is heat transfer surface area of the heating device (m²) ΔT is the temperature difference (°C) You really need to know the room by room thermal losses before you can start to work out radiator types and sizes.

They are still assuming that modern ASHP are the same as ones from 20 years ago. There is a set distance from neighbours windows and doors, but noise will not be a problem. Odd how some government department is encouraging the use of ASHP and others are trying to stop them.

I heard/read, on here I think, that the carbon intensity of grid electricity is dropping for SAP purposes. May be worth checking that out. https://www.cibsejournal.com/general/sap-in-building-regulations/ And do yourself, and everyone else, a favour, forget all about wood burners.

Yes, PV is much more versatile, and reliable. Is there anything you can do the the building fabric to up your SAP? i.e. add an extra inch or two of insulation, triple glaze windows, better doors.

Well I went to their website, but could not find a way to restrict their data collection. So left.

As does CT1

I have kept out of this as I know nothing about it. But, as I like voicing an opinion. If the walls are 2.7m high, how much room is there at the bottom, the width and length. Could you make a slide? Every degree from vertical reduces the downward force. At 30° it will have 87% of the apparent mass, 45° 71% and if you can get to 60°, then half the apparent mass.

That nicely sidesteps the particulates that are in the house that the wood burner is installed in.

Can't do anything about that, except develop a wireless solution, like I currently use. So when your import meter is constantly lit, and your export meter is flashing, you know that you are self generating and exporting. When you are importing and generating, both will flash. Sound like a third meter, with a CT clamp may be needed. Many years ago I rigged up two meters with 7 clamps to work out the flows on a 3 phase PV system, matched the usage, imports and exports very well. As Damon says, not perfect, but pretty good.

Well my CurrentCost, coupled to an RPI is good, shame they don't make them anymore. A few on eBay though. I have seen a project to make one that reads the LED pulses on a meter, that should cope with PV as you can put a sensor on each meter (I assume that the the LED still goes on permanently when exporting.