All Postings (92)


Taking stock! Physics

Subversive? Physics?

My Philosophy!

Scripts Beget Scripts


Theoretical Physics. A Hobby.

Self-Referential Poetry

Silent Online Writing

'Are You Still Doing PKI?'

My Philosophy (?)

Impact of physics on my life

Not much happened in 2015




Farewell Posting ...

Hacking away...

Web Project - Status

We Interrupt ...

Poetry from Poetry


Life and Work

Definition: 'Subversive'

2014 in Books

Physics Postings

Engineering Postings

True Expert


2014 - a Good Year

Physics or Engineering?

Engineering Links

What Is Art?



Google's Poetic Talents

Certificates and Heat Pumps

Nr. 5: A Mind-Altering Experience

Technet postings


Pink Spaceship

radices = Roots!

IT Postings

Web Projects

Life, the Universe, and Everything

Uh-oh, No Posting in March

PKI Resources

PKI Issues

Subversive Work

Spam Poetry

A Career 'in Science'


On the Shoulders of Subversive Giants

Search Term Poetry

Facebook Art

2013 in Books


Explain, Evaluate, Utilize


About Life-Form Elke Stangl

elkement and This Site

No. 3: Internet Apocalypso


Newsletter Resurrection


For Free

Subversive Yearly Report

Is My Life a Cliché?

Indulging in Cliché

Torture Turning Trivia

Intermittent Netizen

Knowledge Worker...


Physics on the Fringe

Graduation Speech

The Element is Back!


Physics Links


Not Funny

Calendar and Magic


In Need of a Deflector

About to Change

A Nerd's Awakening

For the Sake of Knowledge


Profession Or True Calling?

No. 2: On Self-Reference

I Have No Clue About Art



The End

No. 1: On Subversion at Large


Emergency Exit

Modern Networker


The Scary Part

Exploring the Work Space


Instead of a CV

Favorite Books


Elke was here

Postings tagged with 'Heat Pump', listed in descending order by creation date. All Postings shown.

Heat Pump System and Renewable Energy

(elkement. Last changed: 2015-11-07. Created: 2015-02-04. Tags: Postings, Blogging, Resources, Links, Engineering, Heat Pump. German Version.)

I blog about anything heat-pump-related, in particular about our system. In addition, I am interested in thermodynamics, heat pumps and heating systems in general - and their integration with the smart grid and related security concerns. These are my postings about our 'ice-storage-/solar-' powered system specifically and postings on closely related subjects like the power grid, renewable energy and sustainable living.

Hydraulic schema of our system

Physics, Science, Engineering, and a Lot of Fun

(elkement. Last changed: 2015-02-04. Created: 2014-12-17. Tags: Physics, Engineering, Science, Heat Pump, Simulations, Career, Life, Work. German Version.)

I am running a small engineering consultancy together with my husband. Following Star Trek terminology, he is Chief Engineer, and I am Science Officer.

In overly correct legalese, my job titles according to our business licences are 1) Consulting Engineer in Applied Physics and 2) IT Consultant.

We specialize in planning of heat pump systems with unconventional heat sources, that is a combination of an underground water tank and an unglazed solar collector. 'IT' means: playing with control units and data monitorin.

Solar collector for harvesting energy from ambient air.

As we run a German blog focused on this system and I also devote a 'sub-division' of my English blog to it, I use this site ( mainly for consolidating resources and links - in the same way as I curate security / PKI related links. Perhaps these link dumps will not be very useful for anybody but myself.

I once was a laser physicist and a materials scientists - my specialties having been high-temperature superconductors, laser-materials processing with Excimer lasers, and the microstructure of stainless steel. Then I turned to IT security, IT infrastructure and IT management for more than 10 years.

In 2012 I felt the urge to reconnect with my roots as a scientist and engineer, and we started working on our own heat pump research project in stealth mode. It turned to a second 'branch' of our two-person business. There are connections between my different fields of expertise - IT security and heat pumps - like: the security of the smart grid, 'hacking critical infrastructure', monitoring and control systems. Even the data we gather with our pilot setup have turned into 'big data' that require analysis and management.

So I am actually more of an engineer than a physicist. But I am still very interested in theoretical physics as sort of a mental exercise, and I indulge in reading textbooks as hobby. In 2013 I had focussed on (re-) learning quantum field theory.

Since 2014 I am mainly blogging on down-to-earth classical mechanics or thermodynamics, and I enjoy doing cross-checks and back-of-the-envelope calculations on my blog.

Simplified simulation of ice in the water tank in different years.

Last change: Updated dead link to Austrian statistics on fuels and heating systems.

Heat pumps

Heat pump usage in different countries and history of heat pumps

Unusual heat sources

Sizing heat pumps - I am trying to learn the terminology of standards commonly applied in English-speaking countries:

Power grid and availability

Power generation

Hydro power plants

In Sweden the world's largest pumped hydro storage plant might be built:

  • See bottom of page 30 of this research paper:
    Besides the official estimations there are some discussions [28b] about building pumping capacity between the lakes Vänern and Vättern in Southern Sweden. The difference in altitude is 44 meters between these lakes.?
  • ... and the last page of this presentation:
    Possible future? Mariestads Kraftverks AB & others 50 km tunnel between the lakes Vänern & Vättern Cost: 250 billion SEK. Installed capacity: 50000 MW .

Free long-term weather data

Inputdaten für eigene Simulationen.

Germany and Austria.


  • Climate data for the last decades. The navigation is something you need to get used to (Pick: Cities, Climate, Climate Robot...). Therefore I start with Ice Days for Vienna. It is a bit weird that available data seem to depend on the choice of the language (less data for Vienna in English).

Extreme Weather

The winter 1962/63 was the coldest since 250 years in Europe (German article: Winter 1962/63 in Europa. Englisch article: Winter of 1962–63 in the United Kingdom).
More data from a talk / slides avaiable at the website of the Royal Meteorological Society: The bitter winter of 1962/63 - this winter was unusually mild in Canada and Greenland (p.17)

Could such a winter ever happen again? "The 1963 winter is well within the population of other cold winters that have been experienced in this country ... It is not necessary therefore to seek some very special cause in order to explain it." – H.C. Shellard , Meteorological Magazine , 1968  (p.21 of PDF)

Different heating systems

Statistics for Austria: Heating 2003 to 2012 by fuels used and heating system (in Austria). Less than 15% of (primary) heating systems are stoves, and they have been on a decline in the last decade.

Units, heat values, energy costs

Tools for converting units

Heat values

Properties of water (for comparing the energy stored in a water / ice tank)

Costs of energy - international

Monitoring, Control, IT

Metering and monitoring electrical power consumption

  • Smart meters with data loggers and/or various interface for attaching loggers - to be installed behind the official smart meter:
  • Parsing an online monitoring website is perhaps the most universal 'real-time protocol' in case not other interfaces are available. E.g. by using Powershell, I tested with the local website of a Fronius Symo inverter and their web portal One option: Start an InternetExplorer.Application comobject and identify the html containing the interesting value per its ID (getElementById).

Manuals of data loggers by Technische Alternative Gmbh (for control units UVR1611, UVR16x2)


  • Bus topology. Note that UVR1611 is automatically terminated by default.

Heating with computers

Computers installed in private homes provide their computing power to cloud services - while heating those homes.

Basics (Physics) - Mechanics, Electrodynamics

The Feynman Lectures of Physics

  • Volume 1: Mainly mechanics, radiation and heat.
  • Volume 2: Mainly electromagnetism and matter

Unglazed solar collector - part of the heat source of our heat pump system

... an odd combination probably.

But I have a penchant for combining anything. For me IT security, physics, and engineering are all connected naturally, and not only through my biography.

The communication between devices making up the internet of things need to be secured. Publicy Key Infrastructures may provide X.509 certificates needed to do this.

Physics provides one the one hand the underpinning of engineering, on the other hand mathematical methods used in physics can be applied to all kinds of complex systems. There is some truth to this satirical explanation of the relation between Feynman diagrams, certificate validation, and hydraulic designs..

But philosophical musings aside, on a daily basis I simply like to play with technology: Exploring how applications and systems use digital certificates and how they can or can't be 'hacked'. How to build ('hack') a technical solution using off-the-shelf components? How to develop a simulations tool from so-called simple 'Office software'?

Tinkering, Science, and (Not) Sharing It (2017-09-17 11:06:44)
I stumbled upon this research paper called PVC polyhedra: We describe how to construct a dodecahedron, tetrahedron, cube, and octahedron out of pvc pipes using standard fittings. … In particular, if we take a connector that takes three pipes each …

Simulations: Levels of Consciousness (2017-08-17 10:41:54)
In a recent post I showed these results of simulations for our heat pump system: I focused on the technical details – this post will be more philosophical. What is a ‘simulation’ – opposed to simplified calculations of monthly or …

Heat Transport: What I Wrote So Far. (2017-07-14 09:15:49)
Don’t worry, The Subversive Elkement will publish the usual silly summer posting soon! Now am just tying up loose ends. In the next months I will keep writing about heat transport: Detailed simulations versus maverick’s rules of thumb, numerical solutions …

Simulating Peak Ice (2017-05-02 08:43:17)
This year ice in the tank was finally melted between March 5 to March 10 – as ‘visual inspection’ showed. Level sensor Mr. Bubble was confused during the melting phase; thus it was an interesting exercise to compare simulations to …

Mr. Bubble Was Confused. A Cliffhanger. (2017-04-08 11:06:20)
This year we experienced a record-breaking January in Austria – the coldest since 30 years. Our heat pump system produced 14m3 of ice in the underground tank. The volume of ice is measured by Mr. Bubble, the winner of The …

Where to Find What? (2017-03-18 15:20:13)
I have confessed on this blog that I have Mr. Monk DVDs for a reason. We like to categorize, tag, painstakingly re-organize, and re-use. This is reflected in our Innovations in Agriculture … … as well as in my periodical …

Ice Storage Hierarchy of Needs (2017-02-22 17:30:10)
Data Kraken – the tentacled tangled pieces of software for data analysis – has a secret theoretical sibling, an older one: Before we built our heat source from a cellar, I developed numerical simulations of the future heat pump system. …

Earth, Air, Water, and Ice. (2017-02-05 11:48:33)
In my attempts at Ice Storage Heat Source popularization I have been facing one big challenge: How can you – succinctly, using pictures – answer questions like: How much energy does the collector harvest? or What’s the contribution of ground? …

Frozen Herbs and Latent Energy Storage (2017-01-20 13:48:10)
… having studied one subject, we immediately have a great deal of direct and precise knowledge … of another. —Richard Feynman Feynman referred to different phenomena that can be described by equations of the same appearance: Learning how to calculate …

My Data Kraken – a Shapeshifter (2016-12-22 10:53:56)
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 …

And Now for Something Completely Different: Rotation Heat Pump! (2016-11-03 09:55:35)
Heat pumps for space heating are all very similar: Refrigerant evaporates, pressure is increased by a scroll compressor, refrigerant condenses, pressure is reduced in an expansion value. *yawn* The question is: Can a compression heat pump be built in a …

Same Procedure as Every Autumn: New Data for the Heat Pump System (2016-10-21 09:49:11)
October – time for updating documentation of the heat pump system again! Consolidated data are available in this PDF document. In the last season there were no special experiments – like last year’s Ice Storage Challenge or using the wood …

Re-Visiting Carnot’s Theorem (2016-09-18 10:09:51)
The proof by contradiction used in physics textbooks is one of those arguments that appear surprising, then self-evident, then deceptive in its simplicity. You – or maybe only: I – cannot resist turning it over and over in your head …

Hacking My Heat Pump – Part 2: Logging Energy Values (2016-08-24 09:52:12)
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: …

Hacking My Heat Pump – Part 1: CAN Bus Testing with UVR1611 (2016-08-03 10:04:39)
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 …

Photovoltaic Generator and Heat Pump: Daily Power Generation and Consumption (2016-06-01 12:21:02)
You can generate electrical power at home but you cannot manufacture your own natural gas, oil, or wood. (I exempt the minority of people owning forestry). This is often an argument for the combination of heat pump and photovoltaic generator. …

Everything as a Service (2016-05-19 13:57:08)
Three years ago I found a research paper that proposed a combination of distributed computing and heating as a service: A cloud provider company like Google or Amazon would install computers in users’ homes – as black-boxes providing heat to …

Alien Energy (2016-04-15 17:03:12)
I am sure it protects us not only from lightning but also from alien attacks and EMP guns … So I wrote about our lightning protection, installed together with our photovoltaic generator. Now our PV generator is operational for 11 …

No, You Cannot ‘Power Your Home’ by One Hour of Cycling Daily (2016-02-07 15:45:30)
In the past days different versions of an article had popped up in my social media streams again and again – claiming that you could power your home for 24 hours by cycling for one hour. Regular readers know that …

Temperature Waves and Geothermal Energy (2016-01-22 11:04:48)
Nearly all of renewable energy exploited today is, in a sense, solar energy. Photovoltaic cells convert solar radiation into electricity, solar thermal collectors heat hot water. Plants need solar power for photosynthesis, for ‘creating biomass’. The motion of water and …

How Does It Work? (The Heat Pump System, That Is) (2016-01-07 11:13:05)
Over the holidays I stayed away from social media, read quantum physics textbooks instead, and The Chief Engineer and I mulled over the fundamental questions of life, the universe and everything. Such as: How to explain our heat pump system? …

Half a Year of Solar Power and Smart Metering (2015-12-07 11:11:53)
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 …

Peter von Rittinger’s Steam Pump (AKA: The First Heat Pump) (2015-11-24 09:51:42)
Peter von Rittinger’s biography reads like a success story created by a Victorian novelist, and his invention was a text-book example of innovation triggered by scarcity ( Bio DE / EN). Born 1811, he was poor and became an orphan …

The Impact of Ambient Temperature on the Output Power of Solar Panels (2015-11-13 09:21:38)
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 …

Economics of the Solar Air Collector (2015-10-14 11:43:21)
In the previous post I gave an overview of our recently compiled data for the heat pump system. The figure below, showing the seasonal performance factor and daily energy balances, gave rise to an interesting question: In February the solar …

Heat Pump System Data: Three Seasons 2012 – 2015 (2015-09-29 17:23:33)
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, …

Having Survived the Hottest July Ever (Thanks, Natural Cooling!) (2015-08-11 09:27:07)
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 …

Solar Energy, Batteries, and Autonomy (2015-07-15 14:00:27)
This is the third post in my series on our photovoltaic generator. It had been a part of previous post with the data for the first month, but I cut and saved it as the other post was so long …

Solar Power: Some Data for the First Month. (2015-06-17 12:04:07)
On May 4, 2015, we started up our photovoltaic generator. Here are some numbers and plots for the first month – and what I plan to do next. Our generator has a rated power of 4,77 kWp (kilowatt peak), one …

An Efficiency Greater Than 1? (2015-06-01 08:41:32)
No, my next project is not building a Perpetuum Mobile. Sometimes I mull upon definitions of performance indicators. It seems straight-forward that the efficiency of a wood log or oil burner is smaller than 1 – if combustion is not …

Two Weeks After Lift-Off (2015-05-18 10:27:44)
After a little delay our photovoltaic generator went online – we had been waiting for the delivery of this sophisticated addition to our office decoration: People on G+ had very cool suggestions, such as a rotating alien-fighting device throwing darts. …

How to Evaluate a Heat Pump’s Performance? (2015-04-21 14:00:52)
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 …

Ice Storage Challenge: High Score! (2015-04-01 09:31:38)
Released from ice are brook and river By the quickening glance of the gracious Spring; The colors of hope to the valley cling, And weak old Winter himself must shiver, Withdrawn to the mountains, a crownless king. These are the …

We Have Come a Long Way: Rooftop Solar Power Now! (2015-03-23 23:12:13)
We had considered it already a few years ago – when we decided to live and work in the middle of a dusty and noisy construction site for a few months: The upper part of the roof is inclined by …

Data Logging with UVR1611 – FAQ (2015-03-18 15:10:40)
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 …

The Ice Storage Challenge (2015-03-08 12:41:11)
The more we enjoyed our spring-like winter, the more we were worried if we will ever see much ice in our underground water tank this heating season. So we did what I had announced – we switched off the solar …

“An Unprecedented Test for Europe’s Electricity System” (2015-02-27 15:56:31)
And we will not be able to contribute – by a hair. We have just ordered our photovoltaic generator, and installation is planned for April. It is the (partial) Solar Eclipse on March 20 that made Europe’s Transmission System Operators …

A Sublime Transition (2015-02-14 13:51:01)
Don’t expect anything philosophical or career-change-related. I am talking about water and its phase transition to ice because … …the fact that a process so common and important as water freezing is not fully resolved and understood, is astonishing. (Source) …

More Ice? Exploring Spacetime of Climate and Weather. (2015-01-28 14:58:07)
I have become obsessed with comparing climate data for different regions in the world and in different years (space + time). Finally I have found the tool I was looking for; now I can compare average Ice Days quickly – days …

Personal Risk Assessment (2015-01-22 12:47:53)
We all do risk management intuitively – when we decide on uploading our data to the cloud where the NSA may spy on us. Or when we install heating systems that depend on electrical energy. The previous post triggered an …

We Want Ice! (2015-01-15 17:14:50)
We haven’t seen much of it this winter yet. I am talking both about the ice you would expect in winter and about the one created from extracting heat from a water tank – our heat pump system‘s heat source. …

Cistern-Based Heat Pump – Research Done in 1993 (2014-12-14 21:54:52)
One of the most recent search terms on this blog was: ‘cistern for water source heat pump’. I wanted to double-check and searched for this phrase myself. This was the first Google Search result: Cistern-Based Water-Source Heat Pump System Design …

“Being Creative with What Is Available” (2014-11-27 11:11:00)
This is a quote from Simon Dale’s website who has built several eco-friendly ‘Hobbit’ houses. It reminded me of the cave house built into lava bubbles by Lanzarote’s most famous artist César Manrique: Being creative with what is available has …

Google and Heating Systems (2) (2014-11-15 16:24:46)
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 …

A 1970s Pioneer in Self-Sufficient Living (2014-11-08 12:53:56)
Living in southern France, Jean Pain developed a self-sustaining ecosystem in the 1970s that supplied his home with 100% of the energy needed. He built a 50 tons compost mound from chipped wood – brushwood that had to be cleaned out to lower the …

Pumped Heat from the Tunnel (2014-10-04 14:04:17)
The idea to use a reservoir of water as a heat pump’s heat source is not new. But now and then somebody dares to do it again in a more spectacular way. Provided governmental agencies give you permit, lakes or …

Biology / Chemistry Challenge or: Should We Really Blame the Dead Frog? (2014-09-28 10:28:28)
We often say we operate in Leonardo da Vinci Renaissance Mode – given our odd ‘portfolio of diverse services’. But as much as the Chief Engineer does not like to work with mortar, cement, or any other slimy substances I …

Big Data, Big Plastic Worms, and How to Utilize Your Cellar (2014-09-07 15:03:41)
Our heat pump system will soon commence its third heating season. The amount of measurement data collected so far has exceeded the capabilities of the software I had once developed; so I crafted a new application based on a real database server. Now you …

What Learning about Feynman’s Path Integrals Was Good for (2014-07-03 14:08:07)
I have gone to great lengths on this blog in order to explain how and why a degree in physics prepares you for seemingly different careers, or at least does not hurt. But it would have been so simple. I …

Art from Plastic and Wood (2014-05-31 09:52:18)
After the musings on Life, the Universe and Everything you deserve a break – and a post with not too much verbiage. I am borrowing some images from a series of posts the Chief Engineer is currently running on our …

Measurement Data for Our Heat Pump System – Finally Translated Documentation (2014-04-13 17:12:04)
In an earlier post  I said Although we have very innovative, and if I may say so, geeky / nerdy customers it is rather unlikely that we will plan heat pump systems in Australia via sending checklists or doing ‘remote …

Lost in Translation – an Overdue Update (2014-02-20 14:01:48)
In this post I try something new: I will keep it short. This is actually an update long overdue. Months ago I have written a post on how to control the four elements that is how to harvest energy from …

Greatest Innovation Ever (2013-09-04 15:01:28)
I like Top Something Lists, in particular the hilarious variety. In a more serious state of mind I wondered what a list of the top inventions or top innovations of humankind might comprise. (Nitpickers, I don’t care about distinguishing ‘innovation’ …

Welcome to the Real World! (2013-08-14 19:01:28)
Warning: This is a disturbing post – despite the allusion to The Matrix in the title it is – really – about the real world only. Hardly any geekiness included. In order to compensate for that I will craft a …

Controlling the Four Elements. Or: Why Heat Pumps Are Cool. (2013-02-26 21:41:24)
Despite my attempts to post mainly geeky and weird stuff peppered with (very often not down-to-earth) physics, I got involved in some serious discussions on renewable energy, sustainability, heat pumps, and the pleasures of Building Your Own Stuff. So I …

Trading in IT Security for Heat Pumps? Seriously? (2013-01-22 18:45:21)
Astute analysts of science, technology and the world at large noticed that my resume reads like a character from The Big Bang Theory. After all, an important tag used with this blog is cliché, and I am dead serious about theory and …

The First Heat Pump Ever Was Built in Austria (2012-12-10 17:46:49)
I have confessed recently that I am from Austria. So the patriot in me wants to entertain her readers with the story of a milestone in the history of engineering thermodynamics – set by an Austrian! The development of the …

Why Do Heat Pumps Pump Energy so Easily? (2012-05-10 14:22:28)
I know my posts are usually walls of text, but I am trying to improve! In his landmark physics course, the Feynman Lectures on Physics, Richard Feynman tries to explain what an explanation in physics actually is. You can always understand …

Personal website of Elke Stangl, Zagersdorf, Austria, c/o punktwissen.
elkement [at] subversiv [dot] at. Contact and Legal Notice