SteamyTea

I did a small scale experiment on this a decade or so ago. Basically made no difference. An inch of insulation is better. I also did some stuff about painting things different colours. Still up over at the 'other place'.

How to keep your house cool in the heatwave Should you open your windows or close them? Can plants help, and should you get air conditioning? This is your guide to staying cool at home during a heatwave ENVIRONMENT 25 July 2019 By Sam Wong Most UK homes haven’t been designed with heatwaves in mind Rudi Gobbo/getty Scorching hot summers were once rare in the UK, but thanks to global warming, they are now more likely to occur. However, most buildings in the country haven’t been designed with sizzling heat in mind, and many people struggle to keep their homes and offices cool when temperatures get above the mid-20s. So what can you do to improve the situation? Some sources, including the National Health Service website, advise people to keep windows closed. That’s a big mistake, says Sue Roaf at Heriot-Watt University, UK. The main mechanism our bodies have for cooling down is sweating. This works much more effectively if air is moving over our skin. “You need ventilation to actually cool the body down,” says Roaf. That is why a hot room feels much more comfortable with a fan. The NHS website says: “Shut windows and pull down the shades when it’s hotter outside. You can open the windows for ventilation when it’s cooler.” The NHS said its advice is based on the Heatwave Plan for England. But the advice in that document is more nuanced. It says: “Keep windows that are exposed to the sun closed during the day, and open windows at night when the temperature has dropped.” Elsewhere, it says: “Windows and other ventilation openings should not be closed, but their openings reduced when the outdoor air becomes warmer than the air indoors – this should help keep rooms cool whilst allowing adequate ventilation.” In 1995, 739 people died in five days in a heatwave in Chicago. Many of them couldn’t afford air conditioning and didn’t open their windows because they were worried about crime. “This heat is very dangerous,” says Roaf. “If you’ve got an overheating flat or house, go somewhere else.” Go to an air-conditioned shopping centre or cinema, for example, or stay with a friend or relative with a cooler house if possible. If it stays very hot in your bedroom at night, move your mattress to the coolest room in the house. Blocking out light on sun-facing sides of the house can also make a big difference. “Keeping the sunlight out will prevent some 800 watts per square metre coming through the windows,” says Roland Ennos at the University of Hull, UK. The best way is to have shutters fitted on the outside of windows, blocking the light before it gets into the house. If that isn’t possible, closing curtains will help. Read more: Our buildings make this heatwave worse – here’s how to cool them down There are other things you can do to help cool your house in the long run. Growing plants outside your house can help to shade the walls from direct sunlight, once again blocking something like 800 watts per square metre, says Ennos. “Wisteria is great up the south side, as are climbing roses, and reasonably manageable, while ivy on the other sides can help keep the house cool in summer.” In a city like London, green roofs on buildings cool the surrounding area, lowering the peak temperature by around 4°C. Alternatively, you could paint your house white so that the walls reflect more heat, although it will need regular repainting. If a heatwave lasts for many days, even a well-shaded house with thick walls will heat up. At this point, you might be tempted to get air conditioning. From a societal perspective, that’s a terrible idea. Air conditioners shunt hot air outside, making the surrounding neighbourhood warmer by up to 2°C, according to one study. What’s more, they use huge amounts of energy, contributing to the burning of fossil fuels and causing more global warming.

Infrared-reflecting paint can cool buildings even when it is black TECHNOLOGY 24 April 2020 By Layal Liverpool A new paint reflects infrared with a layer of polymer, which helps keep objects cool Jyotirmoy Mandal A two-layered paint that reflects infrared light while maintaining its colour could help keep buildings and vehicles cool under hot sun. This could help reduce energy used in cooling, such as by air conditioners. This coating was developed by Yuan Yang at Columbia University in New York and his colleagues. It consists of a top layer of commercial paint, which provides the colour, and a bottom layer made of a polymer similar to Teflon, which reflects infrared light. Sunlight contains both visible and infrared light but the infrared accounts for the majority of the solar energy, says Yang. When the sun shines on an object coated with this paint, the top layer absorbs certain wavelengths of light, depending on the paint’s colour, while the bottom layer reflects infrared light, preventing the object from heating up. A similar cooling effect can be achieved using white paint or metal mirrors, but Yang says the advantage of this new paint is that it can be any colour desired. Read more: Earthquake-resistant paint could help brick buildings survive tremors Usually black paint absorbs heat, but painting an object with a black version of this new coating kept it about 16°C cooler than when an object painted with commercial black paint was exposed to the same amount of sunlight. In another test, the new paint coating was found to be able to maintain its colour despite being placed in an oven at 60°C for 30 days. Yang says this paint could help save electricity and reduce carbon dioxide emissions. “Solar reflective and thermally emissive surfaces offer a sustainable way to cool objects under sunlight,” says Mingqing Wang at University College London, who was not involved with the work. This could be useful in tropical locations to help keep buildings cool and reduce electricity consumption from air conditioning, as well as to prevent cars, buses and trains from getting too hot, she says. An intriguing next step would be to try and add more functionality to the coating, for instance to enable the energy from the reflected infrared light to be harvested to generate electricity, says Wang. Journal reference: Science Advances, DOI: 10.1126/sciadv.aaz5413 Whitest paint ever reflects 98 per cent of light and could cool homes ENVIRONMENT 15 April 2021 By Matthew Sparkes An infrared camera shows how a sample of the whitest paint (the dark purple square in the middle on the right) cools the board below ambient temperature Purdue University/Joseph Peoples An extremely white paint that reflects 98.1 per cent of sunlight can cool itself by radiating heat into deep space. It could help keep buildings cool, potentially replacing energy-intensive air conditioners. Xiulin Ruan at Purdue University in Indiana and his colleagues previously developed an ultra-reflective paint using calcium carbonate particles that reflected 95.5 per cent of sunlight. They have now improved on that by using barium sulphate particles in a paint that reflects 98.1 per cent of sunlight. This new ultra-white paint absorbs less than half the amount of energy from the sun as the previous paint. Standard commercial white paint absorbs between 10 and 20 per cent of sunlight energy. The amount of sunlight absorbed by the new paint is lower than the amount of energy it radiates through our atmosphere and into deep space, so the material actually becomes cooler than its surroundings. The team plans to carry out experiments with painted tubes carrying water and hopes to create an electricity-free refrigeration effect. The team hopes that the paint can lower global carbon emissions as houses coated in the paint would need less air conditioning. If the paint is used on a 930 square metre roof, the cooling effect could be as high as 10 kilowatts, which the team says is more powerful than a standard air conditioner. Read more: Infrared-reflecting paint can cool buildings even when it is black Ruan says there is a double-pronged positive effect because the paint sends energy away from our planet. “We send the heat to space, we’re not leaving the heat on Earth,” he says. “Traditional air conditioners leave the heat on Earth’s surface, it’s just moved from the inside of your house to the outside.” The team calculated that if 0.5 per cent to 1 per cent of Earth’s surface was covered in this paint, for instance by coating roofs with it, the total effect would reverse global heating to date. The painted surfaces will need to be kept clean of dust and dirt to retain their reflective properties but the team is working on ways to make it shed particulates. Ruan is now working on an even more reflective material but says that there may be diminishing returns. “Pushing to 100 per cent is hard. You will get 19 watts per square metre more cooling benefit, so practically it may not be that attractive given the cost,” he says. Journal reference: ACS Applied Materials & Interfaces, DOI: 10.1021/acsami.1c02368 White roofs can cool cities EARTH 3 February 2010 CITIES can battle the “urban heat island” with paint. Highly reflective white roofs could cool cities by an average of 0.6 °C, according to a global simulation. Dark city surfaces like roofs and roads absorb and radiate heat, leaving cities up to 3 °C hotter than surrounding areas. A team at the US National Center for Atmospheric Research in Boulder, Colorado, combined climate models with a simulation of how temperatures are modified by city landscapes. They found that in a hypothetical world in which cities sported highly reflective white roofs, urban temperatures were on average 0.6 °C cooler than in cities with existing, mostly black roofing materials. In the real world, says lead author Keith Oleson, the benefits might be slightly less as rooftops get covered in dust (Geophysical Research Letters, in press).

Adding PV, or a home made ST system will take some of the energy away.

I do do like your wisdom from the life you have lead.

While it will help, it may not be as good as you think. Surface texture is the important thing, so big difference between matt and shiny, not do great between colours. So may be worth looking at it in more detail. https://www.engineeringtoolbox.com/solar-radiation-absorbed-materials-d_1568.html

Just include that in the mooring fee. Did you say you are a Civil Servant. This is why all departments can't make rules that are fully enforceable.

There will be boat going cheap (instead of chug) because of this. https://www.bbc.com/news/uk-england-beds-bucks-herts-56969793

I am an early riser, so can kill them, dress them, and get them to market, well before the animal loving dog wankers are out.

The trick with a canal boat, especially a narrowboat, is to fit bow and stern thrusters. And then stick 2 fingers up at the traditionalist. Why make life hard. There is also a reduced fee if you have an unpowered boat, or an electric one. So a small electric one (with a genny obviously) and tow a larger unpowered one. And a commercial licence is often cheaper. Properly build GRP is ok on the canals if touring, but if mainly static, it will get hit a lot. Steel and aluminium tend not to fracture so easily. Though a GRP one can be made unsinkable. Two biggest problems, apart from damp and flies, is fresh and waste water. They take up a lot of room.

My sister's cost more than my house. You could make your own as they are pretty basic, structurally.

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)