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 […]Read More 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 […]Read More 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! […]Read More The Heat Source Paradox
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 […]Read More Cooling Potential
I found this comprehensive research report: Energy Use in the Australian Residential Sector 1986–2020 (June 2008) (several PDFs for download, click the link Energy Use… to display them) There are many interesting results – and the level of detail is impressive: The authors modelled the energy used per appliance type, by e.g. factoring in how […]Read More Simulating Life-Forms (2): Cooling Energy
Recently I presented the usual update of our system’s and measurement data documentation.The PDF document contains consolidated numbers for each year and month of operations: It is finally time to tackle the fundamental questions: What id the impact of the size of the solar/air collector? or What is the typical output power of the collector? […]Read More The Collector Size Paradox
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 […]Read More Data for the Heat Pump System: Heating Season 2016-2017