SteamyTea

Hard to show drawings over the phone. I did my apprenticeship with an American company, all our drawings had an appropriately sized grid on them. Was easy to reference an area of interest then.

Angle grinder with a metal cutting wheel. Just don't be fearful of it (called being a pussy, which I know you are not). If I get time tomorrow (got a show on this weeks so a lot of driving) I shall make a video of how to do it and how not too. Bit like one of the old Kenny Everett ones.

And finally the wind speed. I had to change the Cornwall location, so picked St. Marys on the Scillies. Eigg has a much better resource, but I am not sure that height the modelling was based on.

And now the sunshine hours and rainfall. The solar resource is pretty good, though the power will be lower for Eigg than Camborne. The rainfall is a bit higher in Eigg, though again, not by much.

I just had a look at the weather data for Tiree (probably not so different from Eigg). I have only looked at the temperature so far and compared it to Camborne. The interesting thing is that if you take the heating period as anything below 12°C (I use 10°C in a slightly improved 1987 minimum building regs house), the heating times are start only 3 weeks earlier than Camborne and and 2 /12 weeks later. I shall now have a look at sunshine hours to see how much generation could be had from a PV system up there. I still think that a single larger turbine would be a cheap way to generate RE power (larger turbines are more efficient, are high up so get higher windspeeds for more time and are cheaper per kWp to install). Here is a chart to be going on with, it shows the median monthly temperature by month from the last 40 years.

So have I. Does that mean I can write a report. Simple pricing structure, 10% of build cost, about the same as an architect, and we know they add value.

I am sure there are some handbooks on how to make napalm and agent orange. Apply a year before application and then show them a lovely picture of what it could be i.e. of what you currently have. When I did my module about the Town and Country Planning Act, I don't remember a single point reference at all. I think this is part of the problem we have with planning the environment. For every rule we have that says we must do something, we have at least one that says it is illegal.

I think you are probably right. Part of the problem is that we are now used to having unlimited electrical energy on demand. Reading some of the comments on that Eigg report shows that a lot of people are missing the point, including the author. Comparing, what is in effect, a stand along system by using the ratio of demand and installed capacity is just wrong. But there are some relatively easy upgrades they can make i.e. more storage (thermal and electrical) and much larger wind turbines.

Here is a picture of MacSalvor's Customer Relations Department. Now how many companies have an effing torpedo in the yard.

You have never been to MacSalvors, if you saw their yard, and some of the stuff they sell, you would not dare ask for a bulk discount. If I remember, I shall take a picture of some of the stuff they keep, then you will see what I mean.

Always worth asking MacSalvors, they usually have some in.

The A30, gets me places really quick.

That is the idea. I don't know individual models well enough, but by the time it has frosted up, it is too late. The Temperature/RH curve is tuned, not the sensor. The idea is to predict, or just sense, when the ambient conditions could cause frosting and then either reduce the ASHP output (lighter load) or switch it off for a period of time. Both would prevent frosting and the associated time or energy to defrost. It may be possible to do this with just one sensor, but without data it is hard to tell. One sensor would, in effect, just be monitoring just the ambient conditions and have, other than the theoretical frosting point (based on dew point), no idea what is happening after that air has passed though the radiator and cooled. The state of the radiator will be dependant on the temperature of the transfer fluid and the flow rate of the coolant.

Ah, Nest. Amazon has already stopped selling it. I can't see any real advantage in knowing the weather hours in advance for an ASHP. You might be able to 'top up a bit more' the day before, but I think they will be small gains in the scheme of things (tomorrows weather will be within 80% of today's. Just that the 80% is not defined too well ). That is why I think a stand alone device is probably the better solution, it should really be built into an ASHP as standard. One of the problems we have on this forum is that we have a higher level of knowledge and realise that there are problems, and we can usually work around them. This is not true of the general public who think that electricity comes from unicorn farts and a hot tap always delivers hot water.

If there was a local, and more importantly, dependable, web based weather service, that had up to the minute data for your location, I would agree. Trouble is there isn't. I have a Met station close to me, but cannot access the live data. I also think the IoT's potential is overstated and very little benefit to be had. And the security is going to be truly dreadful.

So here is a time series chart from yesterday, as long as the ASHP turns off (or reduces power output) before the air after the radiator is above 12.35°C (the highest dew point temperature), then there should be no serious frosting (though the radiator fins may be colder). By finding the sweet spot between the ambient air temperature and the 'exhaust' temperature, it should be possible to run at a higher CoP over a given time period. Obviously there is a minimum desired temperature for any hot water and the ASHP may not be able to deliver that, but that just leaves less of a top up. What it really boils down to is reducing the defrost cycles, but without cycling the ASHP too often during for frosting avoidance.

To a certain extend over sizing is the cure, but then if it does frost up it either takes longer to defrost, or more energy to defrost. The general idea is to sense when defrost may occur, and stop (or slow down) the ASHP. So taking a day like yesterday that was hot and dry, it could run a higher output temperature, today it could not. The tricky bit is getting a decent external Temp-RH curve to work with, and knowing how much that curve can be varied for different conditions.

Yes, and one that we can easily do on here I think. I always like to collect data first as that gives a baseline to work to. I will, and have remembered that I work with someone that has an ASHP. I think the whole estate has them and I know a couple of his neighbours too. Better make up a simple, reliable monitor that can work outside.

Extraordinary claims require extraordinary evidence. So where is that 0.1% figure from and what does it relate to. Isn't that like claiming there is a time and place for antisocial behaviour i.e football matches, Friday night in a rough pub.

I monitor the RH and Temperatures myself. Just a DHT22 and a Raspberry Pi. Easy and cheap to set up. You could try WeatherUnderground to find a local weather station. https://www.wunderground.com/

After a recent conversation with @joe90 about ASHPs frosting up, I have had a few minutes to think about this problem. As usual, data is needed. Does anyone monitor the input and output air temperature and relative humidity of their ASHP? This would be a couple of sensors either side of the radiator and in the airflow. Ideally knowing when the ASHP is on would be useful as well. My thinking of the frosting problem is to monitor the temperature and RH on either side and calculate the dew point temperature. Initially the ASHP could be turned off, for a set period of time, when it reaches the median dew point. This could be offset differently with experience and data for the fine tuning If anyone is at my end of Cornwall I would be willing to set up some logging, but as not many members are down here @bissoejosh being the only one I can think of and have no idea if he has an ASHP, it would be down to others to help me out. So help needed.

Bad news I say, I felt good yesterday and dreadful today.

Has the internal temperature changed? Also, the external RH can change quite rapidly for a seemingly small temperature change. All that is needed is a lot more data

I was pondering this internal RH problem last night. Regardless of whether you have MVHR or not, if your house is hotter than the external temperature, and you are not doing silly things with hot water, then the internal RH will be lower than the external RH. This is because internal RH tracks external RH and for any given mass of water in the air (the AH), the higher the temperature the lower the RH. I seem to remember that there was someone over at the other place who had used lime plaster and had trouble getting it dry (not a surprise with lime plaster, but that is another story). He played with his MVHR and it seemed to make no difference. I offered to measure his RH levels, but he never took me up on it as he was convinced that the problem was the MVHR, so turned it off and just opened the house up. One thought that has just crossed my mind, where is the RH monitor?

Get a decent garden shredder, shred it, bag it and take it to the dump. Burning is not really socially acceptable.