SteamyTea

Just had a quick look on the Panasonic PV site, their Evervolt module has a temperature coefficient of 0.26%/°C. This, I assume, uses the STC so that will be based on a temperature of 25°C.

With your fingers, oh

I thought the same until someone pointed out that they are fairly low powered.

I would like that sort of challenge, beats cooking 2,000 meals, in 4 days. In this much space (not my mess, was out doing the washing up).

There is a loss of efficiency as temperatures rise, but there is also a rise in power as solar radiation rises. Part of the reason for this is the standard test measure. Temperature and radiation levels are picked i.e 25⁰C and 1000 W/m². Then efficiencies changes are based around these. We should really use the Kelvin scale for temperature. In practice, power output is a bit misleading, PV often produces relatively small amounts of power, relative to the input, but does it for a long time. Today in Penzance, I will get 16 hours and 21 minutes of 'normal' daylight, but even though it is sunny, very few PV modules are reacting in 2 axis to take full advantage of this. Most will be fixed in altitude and azimuth by the building design and orientation, so may not get as much direct beam sunlight on them as imagined, and because it is a clear day, there will be less diffused light. This is why optimal yield days are often in the late spring and early autumn, but that is very weather and building orientation dependant. This is often used as 'proof' that a rise in temperature is very bad for PV production. Not always the case. Like a lot of things, it is not as simple as it first seems.

There is a reason it is abbreviated to MAD. I usual filter out the odd readings by putting limits in place, though this was the problem with collecting data about the Ozone layer over the Antarctic. But that would have been picked up soon if they had used standard deviation of the mean. Lesson learnt, do both. All depends if the important part is the tails or the central tendency.

Welcome Was there not a couple of Boys that were on GD that converted a water tower, they used to frequent eBuild or the 'other place' when they were building.

I bought some of these a while back. They are genuine ones and work fine. https://www.ebay.co.uk/itm/162692252714

If you do not have a reversible heat pump you will need to buy a small Air2Air heat pump and somehow plumb it into the air ducts of the MVHR. You can get cheap A2A for a few hundred quid and they can also heat the place up. https://www.ebay.co.uk/itm/323974879488

Not sure why you think you need very good accuracy or precision. All you are really after is relative differences. Relative difference is just looking at the deviation from the mean. So that can be done easily in software, post collection. Having said that, it is worth doing a quick calibration just to establish that all sensors are within a sensible range. Precion and accuracy https://en.m.wikipedia.org/wiki/Accuracy_and_precision

I think this is the safety net I did a nail technicians course for a laugh about 22 years ago (long story why I did it). Was pretty easy.

There is always a silent p in swimming pool. Trouble is, you to it off the top diving board.

I have a yellow stripe for swimming a width of the swimming pool. Think I got a red one for doing a length

A few of us have code that can run a simple temperature and RH data logger. £30 will get all the parts you need. Here is some very basic code for a RPi, it created daily, time stamped files. #!/usr/bin/python #imports necessary libaries import os, time, datetime #load drivers os.system('modprobe w1-gpio') os.system('modprobe w1-therm') while True: #Sort out the time format dt = datetime.datetime.now() runday = dt.day dt.day == runday #sensor 1 tfile = open("/sys/bus/w1/devices/28-0306979462ca/w1_slave") text1 = tfile.read() tfile.close() temperature_data1 = text1.split()[-1] temperature1 = float(temperature_data1[2:]) temperature1 = temperature1 / 1000 #sensor 2 tfile = open("/sys/bus/w1/devices/28-031097946bbc/w1_slave") text2 = tfile.read() tfile.close() temperature_data2 = text2.split()[-1] temperature2 = float(temperature_data2[2:]) temperature2 = temperature2 / 1000 #sensor 3 tfile = open("/sys/bus/w1/devices/28-030197941c13/w1_slave") text3 = tfile.read() tfile.close() temperature_data3 = text3.split()[-1] temperature3 = float(temperature_data3[2:]) temperature3 = temperature3 / 1000 #sensor 4 tfile = open("/sys/bus/w1/devices/28-03149794263a/w1_slave") text4 = tfile.read() tfile.close() temperature_data4 = text4.split()[-1] temperature4 = float(temperature_data4[2:]) temperature4 = temperature4 / 1000 #opens and reads the time ts = time.time() #sets time to UTC and dd/mm/yyyy hh:mm:ss format UTC = datetime.datetime.utcfromtimestamp(ts).strftime('%d/%m/%Y %H:%M:%S') logfile = '/home/pi/monitoring/data/1wire-%s-%s-%s.csv' % (dt.day, dt.month, dt.year) #creates and opens or appends data to file tfile = open(logfile, "a") #writes to data file tfile.write("%s"%UTC + ",%s"%temperature1 + ",%s"%temperature2 + ",%s"%temperature3 + ",%s"%temperature4 + '\n') #closes data file tfile.close #sleeps for (n) seconds until next reading time.sleep(25)

Ian @Dave Jones is just trolling, he does it a lot.

I suspect that the outside air temperature is so high that without active cooling you are going to struggle. My house, when there is no heating on, is usually about 3°C higher than the outside temperature during the winter. During the summer is is usually cooler than the outside air (though 24°C would be a treat down here). So I suspect you are getting incidental gains i.e. cooking, washing, entertainment systems and people, plus if your MVHR is not well insulated, that is heating up in the loft.

I would worry more about Folliculitis more than the waste water. It is very often caused by spa baths. Worse job I ever had was cleaning the DE filter at the Sheffield YMCA. I have no idea what those young men got up to.

first things first, what has the outside temperature been?

Would that have been in one of the coldest winters down here, with a unique weather pattern.

Yes and no. The CoP will drop below 1 while the defrost cycle is happening (and this does depend on where it draws an elevated temperature from), but once it has defrosted it is back to running at a higher CoP. They are designed to do this. I can wreck the fuel consumption, and the maximum speed of my car, just stick it is first gear, floor the accelerator, and watch the unburnt hydrocarbons pour out the exhaust. It does not make my car useless, or incapable of being operated as intended.

Bang away

That is enough to still be corrupted if the wind blows just slightly from the East.

Yes it is, but they say Cornwall starts at the three rivers. Tamar, Tavy and Torridge.

"Near Holsworthy in Cornwall" @joe90 is your neighbour then. Glad to see you got the cream tea the right way around.

I wonder about the fire risk with a wall full of lard. I think, assuming that insulation is fitted correctly, airtightness is the important one, even without MVHR. It is also the sort of thing that anyone can do, it is not a skilled job, just a bit of training and understanding why it is important. Off to work now.