Modbus Server on Raspberry Pi as Babelfish for UVR16x2

Our main data logger is the Control and Monitoring Interface of the freely programmable controller UVR16x2. There are two pieces of hardware you need for logging – the actual control unit and the logger connected to the controller via the CAN bus. This ‘architecture’ might be due to historical reasons, but I like the separation…

Data for the Heat Pump System: Heating Season 2016-2017

I update the documentation of measurement data [PDF] about twice a year. This post is to provide a quick overview for the past season. The PDF also contains the technical configuration and sizing data. Based on typical questions from an ‘international audience’ I add a summary here plus some ‘cultural’ context: Building: The house is…

My Data Kraken – a Shapeshifter

I wonder if Data Kraken is only used by German speakers who translate our hackneyed Datenkrake – is it a word like eigenvector? Anyway, I need this animal metaphor, despite this post is not about facebook or Google. It’s about my personal Data Kraken – which is a true shapeshifter like all octopuses are. (Because…

Hacking My Heat Pump – Part 2: Logging Energy Values

In the last post, I showed how to use Raspberry Pi as CAN bus logger – using a test bus connected to control unit UVR1611. Now I have connected it to my heat pump’s bus. Credits for software and instructions: juerg5524.ch messpunkt.org SK Pang Special thanks to SK Pang Electronics who provided me with CAN…

Hacking My Heat Pump – Part 1: CAN Bus Testing with UVR1611

In the old times, measuring data manually sometimes meant braving the elements: Now, nearly all measurements are automated: In order to calculate the seasonal performance factor of the heat pump system we have still used the ‘official’ energy reading provided by the heat pump’s display. Can’t this be automated, too? Our Stiebel-Eltron WPF7 basic is…

Half a Year of Solar Power and Smart Metering

Our PV generator and new metering setup is now operational for half a year; this is my next wall of figures. For the first time I am combining data from all our loggers (PV inverter, smart meter for consumption, and heat pump system’s monitoring), and I give a summary on our scrutinizing the building’s electrical…

The Impact of Ambient Temperature on the Output Power of Solar Panels

I have noticed the impact of traversing clouds on solar power output: Immediately after a cloud has passed, power surges to a record value. This can be attributed to the focusing effect of the surrounding clouds and/or cooling of the panels. Comparing data for cloudless days in May and June, I noticed a degradation of…

Heat Pump System Data: Three Seasons 2012 – 2015

We have updated the documentation of monthly and seasonal measurement data – now including also the full season September 2014 to August 2015. The overall Seasonal Performance Factor was 4,4 – despite the slightly lower numbers in February and March, when was the solar collector was off during the Ice Storage Challenge. Edit: I have…

Having Survived the Hottest July Ever (Thanks, Natural Cooling!)

July 2015 was the hottest July ever since meteorological data had been recorded in Austria (since 248 years). We had more than 38°C ambient air temperature at some days; so finally a chance to stress-test our heat pump system’s cooling option. Heating versus cooling mode In space heating ‘winter’ mode, the heat pump extracts heat…

Watching TV Is Dangerous

I am not talking about humans. But TV-sets might threaten other devices in the smart home; this was a recent puzzle submitted by a blog reader. Two unrelated devices / services met on the user’s local computer network: IP-TV provided by a large German telco. a data logger for monitoring the heating system. This user…

How to Evaluate a Heat Pump’s Performance?

The straight-forward way is to read off two energy values at the end of a period – day, month, or season: The electrical energy used by the heat pump and the heating energy delivered. The Seasonal Performance Factor (SPF) is the ratio of these – the factor the input electrical energy is ‘multiplied with’ to…

Data Logging with UVR1611 – FAQ

I have received several questions related to my article on data logging on this blog, or to my postings on monitoring and control on our German blog. Thus I have decided to write the article I would have wanted to read when I once made myself familiar with this. The target audience for this article are…

Google and Heating Systems (2)

I googled our company name. Then I found this: Auftrag means order and the obfuscated parts contain our full company name, the Chief Engineer’s name, the URL of a vendor we ordered material from recently, invoice total, and a comment like The client said we should… The now inaccessible URL had pointed to a comma-separated…