Traditional mechanical anemometers employ moving parts, which are susceptible to wear and tear, potentially leading to sensor failure. In contrast, ultrasonic wind sensors operate without moving parts, ensuring reliable and stable operation over the long term with minimal maintenance requirements. If you are considering an upgrade from a mechanical anemometer to an ultrasonic one like I did, here you can read my experience including a few hints from the integration into Loxone.
Why I was moving away from mechanical wind sensor
I have been using Windgeber WG 30 wind sensor for almost 10 years; at that time, it was offered as Loxone accessory. It is a simple mechanical device providing frequency of pulses based on the wind speed, connected into Loxone Extension (Digital Input set to frequency measurements). It did not have any wind direction measurement, but knowing just the speed was enough for safety closure of sun awnings or pausing lawn irrigation.
After several years of good service, unfortunately, it started to become more and more noisy. WD-40 always solved this for a short while, but having it mounted on the top of the roof, spraying it regularly started to be annoying and a bit adventurous exercise. And without the necessary lubrication the annoying buzz caused by the vibrations was resonating across the whole attic down to the house. So, one day I said to myself: “Enough”, and started looking for other options. And the ultrasonic weather stations were an obvious choice, as these have no moving parts. To understand the basic principle of how these devices work please look here https://en.wikipedia.org/wiki/Anemometer to the section “Ultrasonic anemometers“.
Ultrasonic options on the market
Initially I was a bit surprised that ultrasonic wind speed sensors have such a high price tag. Mostly these are designed for professional weather stations, sea ships and yachts, not targeting entry level weather enthusiasts. But few exceptions can be found. Here are some alternatives I considered, along with the reasons why I ultimately chose a different option.
Please note that this list may not be exhaustive, as there may be other devices available on the market that I was not aware of at the time of my decision.
1. Tempest Weather System
This was almost my go-to all-in-one solution, which is very interesting. Tempest Features Include: Outdoor temp, humidity, dew point, feels like temp. Wind speed, wind direction, average & gusts and interestingly also lightning activity (strikes and distance up to 25 miles). Even though some reviews mentioned issues with their haptic rainfall measurements, that did not play any role for me. I am still successfully using reliable electrolyte measurement rain sensor and will continue to do so.
A key drawback is the device’s reliance on a small solar panel and battery for power. While sufficient in sunny climates like California, this may not be ideal in regions with limited sunlight, such as those with long winters. Recognizing this limitation, the manufacturer offers a fixed charging mount with an external power booster as an optional solution. But even though you have a fixed cable connection (which I absolutely don’t mind), the data is sent in some proprietary wireless protocol, which requires a base device to receive it. The base device provides your measurements to the Tempest network. It has an API where you can read the values directly, but the maximum refresh rate was 3 seconds (when the device battery is in a good state) even when using local API via UDP messages over port 50222. I confirmed this with Eric from Tempest support. He explained that wind data is reported every 3 seconds, while other data is updated once per minute. This is due to the Tempest being designed as a home product rather than a professional-grade weather station. Finally, there was very limited availability of Tempest outside of US at that time, and the PSU for external power booster was not available at all.
2. SONIC-ANEMO-DVC by LCJ Capteurs
Unlike the previous one, SONIC-ANEMO-DVC is just a simple ultrasonic wind vane-anemometer. It just requires standard 3-30V DC power supply, and it offers DAVIS compatible output: 1 pulse output for the anemometer and 1 potentiometer output for the wind vane. This sounds like the ideal upgrade path from the WG 30, as the pulse connection for wind speed into Loxone would remain unchanged. For wind direction an additional analog input is obviously required.
To get the wind direction however this requires some additional work, because apparently the digital potentiometer for some reason accepts only 5.5V maximum and returns the angle related percentage of the voltage. Not sure why it cannot use the already supplied DC voltage for both. Even though this does not have a heated unit, the manufacture claims temperature operating range from -15 °C (without icing) to + 55°C, with 2Hz output data refresh (with 32 measurements per second) it seemed like an ideal choice. However, with a price 689 EUR + VAT and freight I was not sure.
3. FT Technologies wind sensors
These are very solid-looking units built for extreme conditions, offering heated unit and various versions of output possibilities (4-20mA analog and RS485 digital). The biggest issue for me is the price around 2 400 EUR with shipment from their facility in the UK, which implies customs duty as well.
4. Lambrecht u[sonic]WS
There are multiple versions from this manufacturer. Either just an ultrasonic wind sensor, or WS6 or WS7 weather station. All in very nice aluminum housing with intelligent heating depending on wind speed and wind direction. Again, as you can guess, the price was quite high. The u[sonic] Combined ultrasonic wind sensor costs around 1 989 EUR, u[sonic]WS6 is for about 2 195 EUR and finally u[sonic]WS7 at 2 973 EUR.
So, what was finally my decision? Tough choice! As you can guess, none of the products above. Following a thorough evaluation of different options, I have chosen this as the best fit for my needs:
5. Fengtu WQX7 Ultrasonic Weather Station
I have been contacting few Chinese companies directly asking for their products. I didn’t want to go to any “noname” AliExpress reseller as I was a bit worried about the support. With Fengtu I had a good conversation, and they did not feel bothered even when I told them I want just a single unit. Fengtu offers multiple versions of these ultrasonic weather stations, depending on how many parameters you want to measure. For me the sweet spot considering value for money was the WQX7 Ultrasonic weather station, which measures ambient temperature, ambient humidity, wind speed, wind direction, barometric pressure, rainfall and illumination/global radiation), with minimal data interval being 0.5 second. It is a Modbus unit that can be powered using 12V / 24V and the communication protocol was shared with me on request even before the purchase. The price was 760 EUR + shipping.
I want to emphasize that this is not an endorsement. I purchased the Fengtu WQX7 with my own funds and have not received any compensation for this review. You are free to choose the weather station that best suits your needs and budget.
Having used the Fengtu WQX7 Ultrasonic Weather Station for over half a year, I’m now ready to share my experiences. The journey hasn’t always been smooth sailing, but I am not regretting the purchase at all. Please read my full review of Fengtu WQX7 Ultrasonic Weather Station in a dedicated article if you are interested.
Few things to consider when looking for ultrasonic wind sensor or weather station
Here I have some general guidance in case somebody wants to gown down the same avenue as I did.
- Make sure the protocol, data format/refresh cycle and connection in general fits your purpose. This spans from the battery/solar powered wireless units with wired central hub, to a wired 12V/24V units with given communication standard.
- Is the protocol open and can you access the data from the unit directly or just through some obscure cloud service?
- Do you need to purchase additional devices to read the data?
- What is the data refresh cadence?
- Is it battery / solar powered? Will it survive throughout the year the weather conditions at your location?
- What are the mounting options?
- Look closely at the design of the unit. Perhaps you would want to avoid devices where the ultrasonic sensors/receivers are at the bottom plate. This layout can be susceptible to interference from accumulated water, snow, ice or other debris. To minimize potential issues, I recommend considering models where the sensors are positioned facing downwards minimizing its exposure.
