Our heat pump system uses an underground water tank and a solar/air collector as a heat source. We’ve designed and built this system from scratch ourselves: Theoretical calculations, numerical simulations, building the heat exchangers from off-the-shelf material, testing prototypes, testing components / sensors / heat pumps, optimizing the hydraulic setup of heat sink and heat source, programming the control units, developing software.
I have been the Theory Department of that enterprise, in charge of simulations and data analysis. My blog has been my way of publishing our research.
While we built that system, we also made drastic changes to the way we work: Reducing our air and car miles to nearly zero, and working mainly in remote projects today. This also including heat pump projects!
Every year the International Energy Agency publishes a detailed report on worldwide usage of solar thermal energy. The last one from 2019 is based on data from 2017. Countries are ranked by their installed capacity: Collectors' thermal heating power under standard operating conditions is linked to their area: 0.7 kWth (kilo Watt thermal) per square … Continue reading The Solar Self-Building Movement
I've unlocked a new achievement as a blogger, or a new milestone as a life-form. As a dinosaur telling the same old stories over and over again. I started drafting a blog post, as I always do since a while: I do it in my mind only, twist and turn in for days or weeks … Continue reading Infinite Loop: Theory and Practice Revisited.
This is one of the perennial top search terms for this blog. Anticlimactic answer: Yes, because input and output are determined also by economics, not only by physics. Often readers search for the efficiency of a refrigerator. Its efficiency, the ratio of output and input energies, is greater than 1 because the ambient energy is … Continue reading Can the Efficiency Be Greater Than One?
Why a Carnot process using a Van der Waals gas - or other fluid with uncommon equation of state - also runs at Carnot's efficiency. Textbooks often refer to an ideal gas when introducing Carnot's cycle - it's easy to calculate heat energies and work in this case. Perhaps this might imply that not only must the … Continue reading Consequences of the Second Law of Thermodynamics
It is not a paradox - it is a straight-forward relation between a heat pump system's key data: The lower a heat pump's performance factor is, the smaller the source can be built. I would not write this post, hadn't I found a version of this statement with a positive twist used in an advert! … Continue reading The Heat Source Paradox
Building an ice storage powered heat pump system is a DIY adventure - for a Leonardo da Vinci of plumbing, electrical engineering, carpentry, masonry, and computer technology. But that holistic approach is already demonstrated clearly in our hydraulic schematics. Actually, here it is even more daring and bold: There is Plutonium - Pu - everywhere … Continue reading Things You Find in Your Hydraulic Schematic
I had an interesting discussion about the cooling potential of our heat pump system - in a climate warmer than ours. Recently I've shown data for the past heating season, including also passive cooling performance: After the heating season, tank temperature is limited to 10°C as long as possible - the collector is bypassed in … Continue reading Cooling Potential
I found an incredibly detailed research report by the Australian government – about energy use in private homes, by appliance and purpose. It confirms my reluctance to 'predict' cooling energy as usage of air conditioning depends strongly on life-style choices.
Collector harvest does not change much if we only use half the collector. Perhaps counter-intuitive but explained by the characteristics of heat exchangers connected in series: Especially if one of the heat exchangers (in the tank or collector) is already much superior to the other one, it does not help to optimize the good one further.
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 … Continue reading Data for the Heat Pump System: Heating Season 2016-2017
