SteamyTea

Probably been thought of, and as it is not a main stream, well published feature, probably just not worth it. Easy and quick to take, what may be just half a kWh (about 10p), and pump it around till the unit drips.

Yes, basically means junking all the existing control system. May be easier to make it work on a non inverter one. I have often wondered how hard it would be to put a speed controller on the fan, I am not sure how much difference it would actually make. One of those 'retirement project'.

Then maybe the idea Joe, Dave and myself had could be worth a revisit. Should only need three Temp and RH sensors, external temp/RH, heat exchanger temp, and after heat exchanger temp/RH. When I was heat exchanger, I mean the radiator that the air gets blown though. Then a dew point predication algorithm that has a built in offset i.e. 3% above dewpoint, or 1 K above dew point, that turns the refrigerant pump off, but keeps the fan going to blow out moisture as it would not be 100% perfect. Then after a set time, it turns it all back on again.

I think the problem is, they do not frost up enough to have to worry about it. It is only us that want to extract the last 2% efficiency out of them.

But you are still using DHW, which is possibly your largest, continuous draw on power. It was an exceptionally cold and damp spell last year mind. I suspect the air was dryer this time as it was a North East wind, not a North West one.

Yes, it needs to happen a proper amount before frosting, not as it happens, that is then too late. Do you remember if we discussed it here, it on eBuild, I can't be bothered to look.

@joe90 and myself discussed this at length a few years back. We wondered if there was a way to sense the conditions that would cause frosting i.e RH and temperatures, then stop the ASHP for a set time i.e. half an hour. But as Joe90 found out it took 4 years before his ASHP frosted up last winter. Has it done it again in the last few days @joe90, I am still up country were it snows and freezes.

This topic has got me thinking a about having a hot buffer. Generally, the day tend to start cooler than they finish, e.g. the first 3 hours are, on average cooler than the last 3 hours. There are obvious exception to this i.e. a warm weather front moving in. Now if you start with a buffer that is at the slab temperature, pump some energy in until it gets to maximum operating temperature, then start to reheat the slab, while at the same time still putting energy into the buffer when needed, you will end the day with a buffer hotter than it needs to be. So maybe the answer is to stop adding energy to the buffer at set time, and just let the slab draw what it can. This could be made very sophisticated with rate of change comparators, but I think maybe a simple thermal lockout is all that is needed i.e. @7PM if buffer is at max temp, stop adding heat to it, if @7PM buffer is not at max temp, reheat for 30 minutes, then check again.

Or use supplientary heating for those extreme days.

I have never really seen the advantage of an overcomplicated system like this. Tidal stream turbines are simple, and work, and they are always in the same position that you leave them. There are a limited number of places this sort of technology can be installed. You need relatively shallow water, with a greater depth and therefore volume, either side. Then not in an area with large mammals and fish, not in a busy shipping area, though shipping tends to avoid tidal races, not is a fishing, or potting area, somewhere that is not disturbed by large waves, you don't want suspended sand or silt either. If we are to develop tidal power, tidal lagoons are probably the best available technology at the moment. People should learn lessons from Wave Hub.

Not having a variable tariff on the gas is an advantage, one less variable to match up. But there have been times when variable electrical tariffs have been below the price of gas, maybe not at the moment, but there will be in the future. So this is where you use a HA system to not use gas but use the PV or the cheaper than gas electricity.

Surely you do. If you can use your PV instead of gas then you are better off. Smart Metering is means to be more than just remote meter reading.

Yes you do as that is power, not energy.

Take a simple scenario of adding your server as the only load to the grid. It just draws in the 1.2 kW. Now if you fit a grid tied 1 kW PV system, all the power that produces will go to the closest load, your server. Grid imports will be reduced in direct proportion. So while the DNO needs to be told, this is a safety matter, you will never be exporting. Now with a small system, most of the time it will not produce the nameplate power, that is just the way daylight works with PV. So it is usual to oversize the module arrays so that the mean generation is closer to the load, so maybe a 2.5 kW system would be better. You can run the numbers though PVGIS and see what comes out. There will be optimal sizes, both performance and financial for your needs, even allowing for exporting unused generation. But the setting up will be cheap and simple. No need for load sensing switched and spikey changeovers. But first, is there anyway you can reduce the server load, the heat given off would heat my house nicely. Maybe I should build one and rent it out, except I can only get 5 mb connect speeds.

1 yes. 2 reasonably wide within ideal flow and return range. 3 a coil will hydraulically separate the ASHP from the rest. 4 I think a 2 port is really a volumiser and goes in series with a pipe, 4 port goes in parallel. Go 4 port. 5 don't know but would have thought so. No need to go via the buffer for DHW, but I think you know that from your earlier comment. 6 I think it depends on which way around it is plumbed, which would make it more of a thermal store. It also depends on how fast the discharge and recharge rates are i.e power out v power in. 7 no Idea, but I would have thought so. 8 I don't really know much about the nuts and bolts of installations, and I know that some things can seem counterintuitive in plumbing. Space heating and DWH are different things, at different temperatures and at different times. The more they can be separated the better in my opinion.

I did a PM course at university. The lecturer seemed to be only half a page I front, and relied on us, older students to fill in gaps. Only new thing I learnt was not to use MS Project.

This is an interesting problem as usually we are looking to thermally isolate elements, not join them together. Underlay also needs to deaden sound and allow some 'bounce' underfoot. So I thought I would look at two common materials, rubber and cellular rubber. These have thermal conductivities of 0.13 and 0.045 W.m-1.K-1 respectively. Now assuming that the underlay is only 6 mm thick, then: Rubber 0.006 [m] / 0.13 [ W.m-1.K-1] = 0.0462 [R = m2.K.W-1] 1 / 0.0462 [R] = 21.65 [U = W.m-2.K-1] Cellular rubber 0.006 [m] / 0.045 [ W.m-1.K-1] = 0.133 [R = m2.K.W-1] 1 / 0.133 [R] = 7.52 [U = W.m-2.K-1] So cellular rubber will be 3 times more insulating.

Is that the right type of cylinder for your future needs? I don't know the cylinder, but isn't it for solar thermal, not photovoltaics?

Usually a race to the bottom is a bad thing. But not here.

Isn't that why people post their code up to Github?

Computer is mashed. Did you really think I would say what it really means: Computer is Microsoft

CIM

Is the interrupt the wife coming in, and how do you handle it?

Yes well, we all know how that muscle got developed. So with all this knowledge, turning the lights on and setting the heating would be a doddle. I expect to see a working example by Friday noon.

Nor do I. There are about 25 trillion blood cells, so even if they could be in only 1 of 4 places, it would take longer than the age of the universe to count them. P versus NP But some simpleton Physicist have made a major breakthrough in the Riemann Hypothesis.