Can the Efficiency Be Greater Than One?

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?

The Collector Size Paradox

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.

Tinkering, Science, and (Not) Sharing It

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 at 120 degree angles from the others (this is called a โ€œtrue wyeโ€) and we … Continue reading Tinkering, Science, and (Not) Sharing It

Heat Transport: What I Wrote So Far.

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 versus insights from the few things you can solve analytically, and applications to our heat … Continue reading Heat Transport: What I Wrote So Far.

Simulating Peak Ice

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 measurements. Simulations use the measured ambient temperature and solar radiation as an input, data points … Continue reading Simulating Peak Ice

Mr. Bubble Was Confused. A Cliffhanger.

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 Ultimate Level Sensor Casting Show run by the Chief Engineer last year: The classic, analog … Continue reading Mr. Bubble Was Confused. A Cliffhanger.

Cistern-Based Heat Pump – Research Done in 1993

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 ... a research paper that had been available for download at the website of Iowa … Continue reading Cistern-Based Heat Pump – Research Done in 1993