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?

Cooling Potential

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

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.

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

Simulations: Levels of Consciousness

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 yearly average temperatures or energies? The latter are provided by tools used by governmental agencies … Continue reading Simulations: Levels of Consciousness

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.

Ice Storage Hierarchy of Needs

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. Today this simulation tool comprises e.g. a model of our control system, real-live weather data, … Continue reading Ice Storage Hierarchy of Needs

Earth, Air, Water, and Ice.

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? or Why do you need a collector if the monthly performance factor just drops a … Continue reading Earth, Air, Water, and Ice.

Frozen Herbs and Latent Energy Storage

... 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 the distribution of electrical charges gives you the skills to simulate also the flow of … Continue reading Frozen Herbs and Latent Energy Storage