Net Work January 2025
December 8, 2024Net Work February 2025
This month I utilise my wireless weather station to help monitor and banish indoor condensation using a dehumidifier. Readers can also check my live weather data online using the link provided. There’s an update on Britain’s Small Modular Reactor programme as well.
^ The author’s Ecowitt HP2551 weather station was used to check indoor humidity levels using multiple wireless sensors. (Stock image.)
As I pen this month’s column in late 2024, we’ve had a taste of winter with early snowstorms battering parts of the British Isles. In the July 2023 and January 2024 issues of Net Work, I introduced my new internet weather station, a Wi-Fi- enabled system marketed by Ecowitt. The model HP2551 has a crystal-clear 7” TFT display that logs various meteorological metrics on its bright and colourful screen. It generates plenty of data that helps owners to recognise trends and anticipate weather conditions.
The weather station’s 7-in-1 outdoor array (the WS69) measures wind speed, gusts and direction, rainfall, outdoor humidity and temperature, UV index and solar radiation. It must be installed pointing to true North. European models use the reliable and less-crowded 868 Mhz frequency band to transmit data wirelessly.
^ The Ecowitt WN31 indoor sensor detects temperature and humidity, and has an at-a-glance LCD. DIP switches select one of eight channels.
^ Inside an Ecowitt WN31Temperature/ humidity sensor. UK model operates on 868MHz.
A single WH32 sensor is included that reads indoor temperature, humidity and atmospheric pressure, and up to eight wireless sensors can be added as your enthusiasm grows. In my case, this would prove very handy as I’m trying to tackle a condensation problem this wintertime, possibly caused by insufficient ventilation or insulation in the home. Since condensation is caused by warm, moist air hitting cold surfaces, I set up several Ecowitt WN31 temperature/ humidity sensors around the house to keep track of ambient humidity levels indoors.
AI with everything
^ I chose the Ebac 3650e 18L ‘smart’ model to solve a wintertime humidity problem in the house.
^ There is no humidistat on this model, instead a ‘Smart AI’ sensor just operates the dehumidifier when it needs to.
The British brand Ebac manufactures dehumidifiers designed especially for the British climate. Some models use a sophisticated and unique ‘Smart control AI’ sensor instead of a basic humidistat that only measures relative humidity (RH), though ‘Smart’ here does not imply internet connectivity. Ebac says their ‘smart’ approach is superior for British weather as there’s never an optimum RH figure anyway, because RH changes when the weather changes.
The relationship between Relative Humidity, Vapour Pressure and Saturation Vapour Pressure is:
RH% = VP/SVP x 100
As the SVP increases with temperature, the RH decreases when the vapour pressure is constant. A very good explanation of the terminology will be found at https://www.chemguide.co.uk/physical/phaseeqia/vapourpress.html
I chose the Ebac 3650e 18L ‘smart’ model (ie it extracts up to 18 litres per day), bought online direct from the makers at https://ebac.com/dehumidifiers/range (Online buying tip: hold back until special discount offers appear; direct sales also attract an extended 4 year warranty.)
Moist air tends to rise, so the dehumidifier is plugged in permanently upstairs. Keeping internal doors ajar improves air circulation. The appliance then becomes the coldest spot in the house, where humid air is forced to condense before being collected in a tub, emptied daily. Alternatively, water can drain externally through a small pipe.
Initially I was astonished to see some 3 litres of water extracted every day before it settled down over the course of a few weeks. Continuously operating the Ebac costs about 45p a day, my Ketotek power meter shows (see Net Work, January 2024), and indoor humidity has fallen to 45-50% or so regardless of the weather. Best of all, the condensation problem has disappeared completely.
After 18 months of operation, I’m also pleased to say that the Ecowitt weather station still performs flawlessly. I’ve had no issues at all with sensor communications, even though the outdoor array is 30 metres or more away, and the console is located well inside the house with quite a few brick walls intervening.
Net Work’s weather station
^ Here’s my weather station array in the east of England and I hope readers’ will enjoy checking and comparing weather conditions over time.
I’m now pleased to offer readers an opportunity to view some of my own live data on Ecowitt’s servers, by visiting the special link at https://www.ecowitt.net/home/share?authorize=1HJ565 . The URL is valid for up to one year and may change over time. (Email me if the URL has failed.)
One UK website worth checking is https://weatherspares.co.uk and Amazon has a selection of Ecowitt products as well as dehumidifiers. AliExpress also lists many Ecowitt products, noting that prices exclude VAT.
Next, I’ll try uploading data direct to the UK Meteorological Office Weather Observation Website (Met. Office WOW) at https://wow.metoffice.gov.uk – but that’s a project for the winter holidays!
Gloomy outlook
Britain’s anti-cyclonic weather in early November saw a period of some 10 days or more with absolutely no sun, little wind and low cloud – a dunkelflaute. At such times, to keep the lights on we rely on storage battery farms, nuclear, biomass and fossil fuels, overseas interconnects and some hydro-electricity to top it up. The highly informative website https://grid.iamkate.com designed by Kate Morley shows admirably the status of the National Grid as it edges perilously close to 100% during peak periods.
Data provided from the last ten years is insightful, as it also shows how energy costs of £35 per MWh in 2020 increased five-fold in 2022. International Energy Agency (IEA) statistics show that the UK now has easily the most expensive industrial energy costs anywhere in the Western world, 4.5 times higher than Norway’s, for example.
Delayed reaction
Sixty years ago, Britain’s forward-looking Government placed its bets on the wrong horse, backing the development of its own Advanced Gas-cooled Reactors (AGRs) to replace first-generation Magnox reactors, while the rest of the world was opting for Pressurised Water Reactors (PWRs) instead.
Fourteen AGRs were then built after 1963, all of them used exclusively in the UK. Buoyed by the arrival of North Sea ‘natural’ gas, the famous 1990 ‘Creature Comforts’ TV adverts (shown in full at https://www.youtube.com/watch?v=fBJ6pixLHtc ) implored us to use as much of this bounteous energy as we could!
In January 2022 I first described the prospect of the country adopting Small Modular Reactors to fill Britain’s energy gap. For financial reasons, Japan’s Hitachi and Toshiba had previously pulled out of building nuclear power plants in Britain, adding to Britain’s power generation shortfall. Hitachi’s former sites in Wales have since been purchased by Great British Nuclear (GBN) as part of its future growth plans.
SMRs are nuclear power plants that can be assembled on-site using major pre-built elements that can be transported by road. In 2022 SMRs were still a decade away, and a Government ‘competition’ would be held to produce a short-list of contractors that the UK would support in developing them. There was much flag-waving from Rolls-Royce, but foreign rivals were eager to offer SMRs too.
France’s EDF withdrew early from the race, followed by America’s NuScale. The ‘competition’ finalists have now been announced as Rolls-Royce, GE-Hitachi, Holtec and Westinghouse. Holtec Britain is already heavily involved with Britain’s nuclear construction programme and chose Doncaster in South Yorkshire as the site for a new SMR factory. Some 70% of components would be UK-sourced. The world-famous Sheffield Forgemasters steelworks, now owned by the Ministry of Defence, is just up the road and produces highly specialised castings for the nuclear sector.
^ 
^ A rendering of Holtec’s proposed SMR-300 nuclear reactor site.
To encourage us to reduce energy consumption, the energy providers’ Demand Flexibility Service offers consumers with smart meters a rebate to encourage them to use power-hungry appliances such as washing machines during off-peak periods. This will shift demand on the electricity supply during so-called ‘DFS events’, when the supply operators struggle to match electricity demand with supply. It’s probably only a matter of time before ‘Event’ messages pop up on smart meter displays or via SMS, so consumer behaviour may well be manipulated that way too.
Astonishingly, we now learn how windfarm generators are actually over-producing at times, and are actually being paid to “shed the load”.
Hidden deeply in some small print from the electricity system operators is a caveat, though: “Using electrical goods overnight can create increased risk of an incident. We advise all consumers to follow the guidance offered by organisations such as the [campaigning charity] Electrical Safety First [https://www.electricalsafetyfirst.org.uk/guidance/safety-around-the-home] and where possible to avoid using their electrical appliances overnight.”
In the meantime, let’s hope that the country doesn’t suffer from any more dunkelflaute and enjoys more sonnenschein instead!
As always, you can drop me a line at alan@epemag.net