Submissions are welcome for the new Special Issue at Energies MDPI where I am guest editor.
Topics: #energyefficiency #HVAC# Sustainability #IEQ #thermalcomfort and many others.
Deadline: April, 27th 2022. https://www.mdpi.com/…/Building_Sustainable_District
Office Building Tenants’ Electricity Use Model for Building Performance Simulations
https://www.mdpi.com/1996-1073/13/21/5541
Large office buildings are responsible for a substantial portion of energy consumption in urban districts. However, thorough assessments regarding the Nordic countries are still lacking. In this paper we analyse the largest dataset to date for a Nordic office building, by considering a case study located in Stockholm, Sweden, that is occupied by nearly a thousand employees. Distinguishing the lighting and occupants’ appliances energy use from heating and cooling, we can estimate the impact of occupancy without any schedule data. A standard frequentist analysis is compared with Bayesian inference, and the according regression formulas are listed in tables that are easy to implement into building performance simulations (BPS). Monthly as well as seasonal correlations are addressed, showing the critical importance of occupancy. A simple method, grounded on the power drain measurements aimed at generating boundary conditions for the BPS, is also introduced; it shows how, for this type of data and number of occupants, no more complexities are needed in order to obtain reliable predictions. For an average year, we overestimate the measured cumulative consumption by only 4.7%. The model can be easily generalised to a variety of datasets.
Keywords: building simulation; office buildings; energy performance; energy modelling; HVAC; analytical modelling; statistical analysis
Our latest paper introduces a tabulated tool that aids in the early design of geothermal systems, by providing estimates of the system’s efficiency according to the chosen energy piles field configuration and heat pump sizing.
Direct link: https://doi.org/10.1016/j.enbuild.2020.110178
The paper can be downloaded FOR FREE for 50 days at this link:
https://www.sciencedirect.com/science/article/pii/S037877882031152X?dgcid=author
Geothermal systems are often employed for both the heating and cooling of sustainable constructions. Energy piles (U-shaped heat exchangers inserted into the foundation piles) are widely included in these installations, whose performance is usually estimated by means of complex, time-consuming simulations already at an early design stage.
Here we propose a simple methodology, where a hand calculation tool provides the condenser yield per pile meter, ground area yield and demand covered by the heat pump by specifying only building heat load and geometric characteristics of the energy piles field. Our tool is tested by assuming 20 years of operation in a hall-type commercial building in a cold climate. A validated IDA-ICE parametric study couples the heat pump evaporator operation with heat transfer processes between energy piles and soil. Various system configurations are considered and thermal storage in the soil is included.
We find that the expected yield is not directly proportional to pile separation, while a smaller extraction power is favoured. Thermal storage in the soil is also confirmed to be critical. Besides our specific quantitative results, our practical guideline is qualitatively general and can be extended to any given building type and climate.
We published a new article! Highlights of the paper, available at https://doi.org/10.1016/j.jobe.2020.101387:
Abstract:
Estimating heat emission losses of heating systems is an important task of energy efficiency assessments in buildings. However, the present international standards do not specify how emission losses should be calculated or measured for different emitter and control system configurations. Aiming to fill this gap, here we propose a method for computing the temperature setpoint variations by addressing the heat distribution throughout a room with space heat emitters. This general and exact procedure enables the calculation of product category-specific setpoint variations for different types of heat emitters, accounting for the overall heat balance in the enclosure and including the cross-correlations of each component. Our method complements the procedure presented in the Standard EN15316-2, making it possible to compute emission losses as product-specific values of setpoint variations instead of tabulated values. As the main finding of the study, the calculation process is defined for a European Reference Room that allows an accurate and transparent evaluation of total setpoint variations. These are computed for specific products from measured vertical stratification and control parameters, by means of an annual IDA ICE simulation model of the reference enclosure. Applying the method to an annual energy performance simulation for an old and a new building in Strasbourg shows that emission losses are compensated by a total setpoint variation of respectively up to 2.00 °C and 1.20 °C, corresponding to an increase in total heating energy usage of up to 22% and 20%.
Our Special Issue with MDPI titled “Energy Performance and Indoor Climate Analysis in Buildings” (18 papers) is available for free download here: https://www.mdpi.com/books/pdfview/book/1828
#Engineering #energy #Sustainability #Science #civilengineering
Our special issue with @MDPIOpenAccess “Energy and Technical Building Systems – Scientific and Technological Advances” (10 papers published) is now fully and freely available in pdf at https://www.mdpi.com/journal/energies/special_issues/energy_and_built_environment #Engineering #energy #energyefficiency #Sustainability #HVAC
“Sabbatical Leave” is the first tale of “The Adventures of Prof. Gideon Longbottom”. The evil researcher hates the world, and particularly his students with their smartphones always at hand. He therefore takes a Sabbatical leave to close himself into a laboratory in the cellar, for designing a weapon of mass destruction…with some (dark) humour.
Quantum Prana: vocals, lyrics, guitar, bass, programmed drums, production.
https://soundcloud.com/quantumprana/sabbatical-leave
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SABBATICAL LEAVE
Walking down the hall, the comedy plays
Students mocking me, “The hatchback will pay”
The rector won’t pay me regards
The faculty has only retards
Walking stick is carrying
My twisted proportions
My forehead is spacious
To accommodate grandeur
Massive head, naughty grin
My asymmetric chin
Showing the wasteland of my hatred for you
BURN! THEM ALL!
Petty dreams end in screams
Fire, your sins
BURN! THEM ALL!
The final resolution
Apocalypse of melted skin
Students check their smartphone
For quantum optics attention is gone
Spoiling little brats, technology
Life upon a display, making them restless
Your ignorance, your blessing
The final resolution
I’m taking my leave
Working in silence
In the cellar
Holding your smartphone
My grin on their display
BURN! THEM ALL!
Makeup and soaring screams
Flaming phones melt your skin
BURN! THEM ALL!
The final resolution
I’m gonna be a superstar!
(My) walking stick in flames
But I won’t care at all
Dancing on your graves
My twisted figure at the shopping mall
Delirium of the senses
The women will be mine
I shall just collect the pieces
Legs oh, will be carbonised
But after all, it will be fair!
Stepping down the stairs, cursing them all
You wonder why my laughing erupts
“That evil man has gone nuts!”
The dawn of my revenge
Sabbatical call
BURN! THEM ALL!
BURN! THEM ALL!
Revenge is nigh!
Sector coupling is a concept referring to the electrification of end-use sectors (e.g. heating and transport); it aims at increasing the share of renewable energy (solar, hydro, geothermal, wind, bioenergy, waste heat…) in these sectors.
In practice, this is a strategy “to provide greater flexibility to the energy system so that decarbonisation can be achieved in a more cost-effective way”.
The EU has committed under the Paris Agreement to make an effort to keep the global temperature rise below 2ºC, and the decarbonisation of the energy system can be crucial to this purpose. Sector coupling then becomes a key player for the EU “policy objective of shifting from our current highly centralised and mainly fossil fuel-based energy system to a more decentralised, energy efficient and renewable energy-based energy system”.
The quoted paragraphs are taken from an official European Parliament document on Sector Coupling, which you can find at the link below. I strongly encourage everybody interested in energy systems to read it (especially those who are critical towards the usage of wind and solar energy…yes, they still do exist!).
https://www.europarl.europa.eu/RegData/etudes/STUD/2018/626091/IPOL_STU(2018)626091_EN.pdf
“Funky Matters” (a play with words) is a song/essay about the discoveries as well as the uncertainties of Particle Physics. Funk and jazz structures and rhythms develop on a metal arrangement, with clean singing and choruses to sing along with (lyrics below).
#nerdmetal
Quantum Prana: Vocals, guitar, bass; lyrics, production
Second Order Effects: Keyboards
Klas Granqvist: Drums
Special thanks to Elisa Mucciarelli and Tatu Hiltunen.
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FUNKY MATTERS
Ancient Greeks figurin’ it all,
Democritos, the atoms, reduction to the call
Fundamental particles, grains of cosmology
Dividing life, by analogy, with our reality
Galilei’s method of induction
(Was) grounded on eye observation
Solitons / got noted / while ridin’ a horse
Newton and Huygens were fighting
Over new tools for understanding
How funky matters / make up the world
Aether was then invented
For light propagation
However the experiments, couldn’t confirm the equation
Einstein eventually, found the solution
Special relativity killed the funky matter
And gave us / Star Trek
Will string theory save us all?
Will we see the curvaton?
Quantum gravity for all!
—————–
CHORUS
Funky matters to all
Come on and join us / at / the / shopping mall
Warping space and time
Enter the quantum loop, and join the ride
—————-
We’re all cool funky matters
Dancing on warping dimensions
We all live under a Calabi-Yau
Supergravity takes the ball
Superpartner of the graviton
Radiative corrections
Are looping in the action
A new bunch of particles was then invented
But nobody has seen them in the Universe
Dark matter remains very dark
Though supersymmetry protects the Higgs
We all need a superpartner!
Will we see the dilaton?
Quantum gravity for all!
—————–
CHORUS 2
Funky matters to all
Come join us / at / the / shopping mall
We’re all cool funky matters
Hunting and searching / the grand unification
—————–
CHORUS 3
We’re all cool funky matters
Particle or wave, (it) doesn’t really matter
Warping space and time
Quantum gravity for all!
A short and coincise presentation I gave in Trondheim (Norway) on 7.11.19, which summarizes the parametric study reported in the conference paper (see the link below).
https://doi.org/10.1088/1755-1315/352/1/012011
Here is the presentation:
https://www.researchgate.net/publication/337111301_Parametric_study_for_the_long_term_energetic_performance_of_geothermal_energy_piles
Releases 