--- title: "Hydraulic Circuit Requirements – Part 2: A Closer Look at Optimisation and Efficiency" description: Optimise and enhance your hydraulic systems with expert insights on temperature differences, flow rates and efficiency from Swegon's Cooling and Heating Product Manager, Stefan Lay. image: https://blog.swegon.com/hubfs/Swegon%20UKI/LinkedIn%20Article%20Template%20(11).jpg --- [![](https://www.swegon.com/Static/img/logo.svg?v=3)](https://www.swegon.com/uk/) Menu - [Solutions & services](https://www.swegon.com/uk/solutions-and-services/) - [Products>](https://www.swegon.com/uk/products/) - [References & Insights](https://www.swegon.com/uk/references-and-insights/) - [Support & Software](https://www.swegon.com/uk/support/) - [Sustainability](https://www.swegon.com/uk/sustainability/) - [Why Swegon?](https://www.swegon.com/uk/why-swegon/) - [Product Search](https://www.swegon.com/uk/product-search-result/) - [Document Search](https://www.swegon.com/uk/support/find-documents/) - [Careers](https://www.swegon.com/uk/careers/) - United Kingdom - [Contact](https://www.swegon.com/uk/contact/) ## Choose a market [Or visit our global site](https://www.swegon.com) - [Belgium - French](https://www.swegon.com/fr-be/) - [Belgium - Dutch](https://www.swegon.com/nl-be/) - [Denmark](https://www.swegon.com/da/) - [Finland](https://www.swegon.com/fi/) - [France](https://www.swegon.com/fr/) - [Italy](https://www.swegon.com/it/) - [Germany](https://www.swegon.com/de/) - [Norway](https://www.swegon.com/no/) - [Poland](https://www.swegon.com/pl/) - [Spain](https://www.swegon.com/es/) - [Sweden](https://www.swegon.com/sv/) - [Switzerland - German](https://www.swegon.com/de-ch/) - [Switzerland - French](https://www.swegon.com/fr-ch/) - [Switzerland - Italian](https://www.swegon.com/it-ch/) - [United Kingdom](https://www.swegon.com/uk/) - [United States](https://www.swegonnorthamerica.com) - [Canada](http://swegonnorthamerica.com/) Explore ## Filter articles ### By topics - [Cooling & Heating (40)](https://blog.swegon.com/uk/tag/cooling-heating) - [Indoor Climate Knowledge (22)](https://blog.swegon.com/uk/tag/indoor-climate-knowledge) - [Air Handling Units (20)](https://blog.swegon.com/uk/tag/air-handling-units) - [Smoke and Fire Dampers (19)](https://blog.swegon.com/uk/tag/smoke-and-fire-dampers) - [Room Units (18)](https://blog.swegon.com/uk/tag/room-units) - [Indoor Climate Knowledge (15)](https://blog.swegon.com/uk/tag/indoor-climate-knowledge) - [Energy Efficiency (13)](https://blog.swegon.com/uk/tag/energy-efficiency) - [News (13)](https://blog.swegon.com/uk/tag/news) - [Tips and Advice (13)](https://blog.swegon.com/uk/tag/tips-and-advice) - [sustainability (13)](https://blog.swegon.com/uk/tag/sustainability) - [Knowledge (11)](https://blog.swegon.com/uk/tag/knowledge) - [Ventilation (10)](https://blog.swegon.com/uk/tag/ventilation) - [Energy Efficiency (8)](https://blog.swegon.com/uk/tag/energy-efficiency) - [Service (7)](https://blog.swegon.com/uk/tag/service) - [Guide (5)](https://blog.swegon.com/uk/tag/guide) - [Humidity (5)](https://blog.swegon.com/uk/tag/humidity) - [Heat pumps (3)](https://blog.swegon.com/uk/tag/heat-pumps) - [BIM (2)](https://blog.swegon.com/uk/tag/bim) - [Diffusion (2)](https://blog.swegon.com/uk/tag/diffusion) - [Services & Connectivity (2)](https://blog.swegon.com/uk/tag/services-connectivity) - [acoustics (2)](https://blog.swegon.com/uk/tag/acoustics) > Fler ### By authors - [![Ajeeb Mohammed](https://blog.swegon.com/hs-fs/hubfs/IMG_20230113_160922.jpg?width=75&name=IMG_20230113_160922.jpg) Ajeeb Mohammed 1](https://blog.swegon.com/uk/author/ajeeb-mohammed) - [![Alberto Ferrandi](https://blog.swegon.com/hs-fs/hubfs/ferrandi.png?width=75&name=ferrandi.png) Alberto Ferrandi 5](https://blog.swegon.com/uk/author/alberto-ferrandi) - [![Alberto Frison](https://blog.swegon.com/hs-fs/hubfs/alberto.jpg?width=75&name=alberto.jpg) Alberto Frison 2](https://blog.swegon.com/uk/author/alberto-frison) - [![Alessandro Lora](https://blog.swegon.com/hs-fs/hubfs/lora.webp?width=75&name=lora.webp) Alessandro Lora 1](https://blog.swegon.com/uk/author/alessandro-lora) - [![Alessandro Lora](https://blog.swegon.com/hs-fs/hubfs/lora.webp?width=75&name=lora.webp) Alessandro Lora 1](https://blog.swegon.com/uk/author/alessandro-lora) - [![Alessandro Pinato](https://blog.swegon.com/hs-fs/hubfs/alessandro.png?width=75&name=alessandro.png) Alessandro Pinato 7](https://blog.swegon.com/uk/author/alessandro-pinato) - [![Anders de Maré](https://blog.swegon.com/hs-fs/hubfs/anders%20de%20mare_1-1.jpg?width=75&name=anders%20de%20mare_1-1.jpg) Anders de Maré 1](https://blog.swegon.com/uk/author/anders-de-maré) - [![Andreas Örje Wellstam](https://blog.swegon.com/hs-fs/hubfs/Finland%20News/Kampanjat,%20uutiskirjeet/Andreas%20%C3%96rje%20Wellstam_S.jpg?width=75&name=Andreas%20%C3%96rje%20Wellstam_S.jpg) Andreas Örje Wellstam 5](https://blog.swegon.com/uk/author/andreas-örje-wellstam) - [![Andrew Collard](https://blog.swegon.com/hs-fs/hubfs/Andrew%20Collard_edited.jpg?width=75&name=Andrew%20Collard_edited.jpg) Andrew Collard 2](https://blog.swegon.com/uk/author/andrew-collard) - [![Andy Bott](https://blog.swegon.com/hs-fs/hubfs/me.jpg?width=75&name=me.jpg) Andy Bott 1](https://blog.swegon.com/uk/author/andy-bott) - [![Andy Dines](https://blog.swegon.com/hs-fs/hubfs/Swegon%20UKI/20260519_095206.jpg?width=75&name=20260519_095206.jpg) Andy Dines 1](https://blog.swegon.com/uk/author/andy-dines) - [![Börje Lehrman](https://blog.swegon.com/hs-fs/hubfs/Blog%20Authors/SE-SV%20-%20PRO%20-%20BACV/B%C3%B6rje_Lehrman.jpg?width=75&name=B%C3%B6rje_Lehrman.jpg) Börje Lehrman 1](https://blog.swegon.com/uk/author/börje-lehrman-1) - [![Carinne Grandjean](https://blog.swegon.com/hs-fs/hubfs/carinneg.webp?width=75&name=carinneg.webp) Carinne Grandjean 1](https://blog.swegon.com/uk/author/carinne-grandjean) - [![Carl-Ola Danielsson](https://blog.swegon.com/hs-fs/hubfs/Blog%20Authors/1494416201_4f37bc2792.jpg?width=75&name=1494416201_4f37bc2792.jpg) Carl-Ola Danielsson 3](https://blog.swegon.com/uk/author/carl-ola-danielsson) - [![Carl-Ola Danielsson](https://blog.swegon.com/hs-fs/hubfs/Carl%20Ola%20Danielsson.png?width=75&name=Carl%20Ola%20Danielsson.png) Carl-Ola Danielsson 3](https://blog.swegon.com/uk/author/carl-ola-danielsson) - [![Caroline Jacobsson](https://blog.swegon.com/hs-fs/hubfs/Blog%20Authors/Caroline%20Jacobsson.jpg?width=75&name=Caroline%20Jacobsson.jpg) Caroline Jacobsson 13](https://blog.swegon.com/uk/author/caroline-jacobsson) - [![Caroline Jacobsson](https://blog.swegon.com/hs-fs/hubfs/Blog%20Authors/Caroline%20Jacobsson.jpg?width=75&name=Caroline%20Jacobsson.jpg) Caroline Jacobsson 13](https://blog.swegon.com/uk/author/caroline-jacobsson) - [![Christoffer Lindström](https://blog.swegon.com/hs-fs/hubfs/Christoffer_blogg.png?width=75&name=Christoffer_blogg.png) Christoffer Lindström 2](https://blog.swegon.com/uk/author/christoffer-lindström) - [![Dan Jones](https://blog.swegon.com/hs-fs/hubfs/dan_jones.jpg?width=75&name=dan_jones.jpg) Dan Jones 2](https://blog.swegon.com/uk/author/dan-jones) - [![Darren Peel](https://blog.swegon.com/hs-fs/hubfs/Darren.jpg?width=75&name=Darren.jpg) Darren Peel 1](https://blog.swegon.com/uk/author/darren-peel) - [![Dave Harding](https://blog.swegon.com/hs-fs/hubfs/dave_harding.jpg?width=75&name=dave_harding.jpg) Dave Harding 2](https://blog.swegon.com/uk/author/david-harding) - [![Dene Kent](https://blog.swegon.com/hs-fs/hubfs/Dene%20Kent%20Swegon.jpg?width=75&name=Dene%20Kent%20Swegon.jpg) Dene Kent 6](https://blog.swegon.com/uk/author/dene-kent) - [![Elvis Kokot](https://blog.swegon.com/hs-fs/hubfs/elviskokot.png?width=75&name=elviskokot.png) Elvis Kokot 1](https://blog.swegon.com/uk/author/elvis-kokot) - [![Fabio Polo](https://blog.swegon.com/hs-fs/hubfs/Fabio%20Polo-1.jpg?width=75&name=Fabio%20Polo-1.jpg) Fabio Polo 7](https://blog.swegon.com/uk/author/fabio-polo) - [![Fabio Polo](https://blog.swegon.com/hs-fs/hubfs/Fabio%20Polo-1.jpg?width=75&name=Fabio%20Polo-1.jpg) Fabio Polo 7](https://blog.swegon.com/uk/author/fabio-polo) - [![Federica Serena](https://blog.swegon.com/hs-fs/hubfs/Serena.webp?width=75&name=Serena.webp) Federica Serena 2](https://blog.swegon.com/uk/author/federica-serena) - [![Francesco Artusi](https://blog.swegon.com/hs-fs/hubfs/Francesco%20Artusi%20CUT.jpg?width=75&name=Francesco%20Artusi%20CUT.jpg) Francesco Artusi 1](https://blog.swegon.com/uk/author/francesco-artusi) - [Frank Schönfelder 2](https://blog.swegon.com/uk/author/frank-schönfelder) - [![François Jouvray](https://blog.swegon.com/hs-fs/hubfs/Fran%C3%A7ois%20Jouvray%20swegon.jpg?width=75&name=Fran%C3%A7ois%20Jouvray%20swegon.jpg) François Jouvray 1](https://blog.swegon.com/uk/author/françois-jouvray) - [![Hannah Finning](https://blog.swegon.com/hs-fs/hubfs/Image%20(5).jpg?width=75&name=Image%20(5).jpg) Hannah Finning 1](https://blog.swegon.com/uk/author/hannah-finning) - [![James Moore](https://blog.swegon.com/hs-fs/hubfs/download.jpg?width=75&name=download.jpg) James Moore 1](https://blog.swegon.com/uk/author/james-moore) - [![Jan Scheuring](https://blog.swegon.com/hs-fs/hubfs/Photo_Jan-1.jpeg?width=75&name=Photo_Jan-1.jpeg) Jan Scheuring 1](https://blog.swegon.com/uk/author/jan-scheuring) - [![Jim Collings](https://blog.swegon.com/hs-fs/hubfs/Swegon%20UKI/Jim%20Collings.jpeg?width=75&name=Jim%20Collings.jpeg) Jim Collings 1](https://blog.swegon.com/uk/author/jim-collings) - [![John Lindblom](https://blog.swegon.com/hs-fs/hubfs/johnl.png?width=75&name=johnl.png) John Lindblom 1](https://blog.swegon.com/uk/author/john-lindblom) - [![John Wibrand](https://blog.swegon.com/hs-fs/hubfs/John%20Wibrand.jpg?width=75&name=John%20Wibrand.jpg) John Wibrand 2](https://blog.swegon.com/uk/author/john-wibrand) - [![John Wibrand](https://blog.swegon.com/hs-fs/hubfs/John%20Wibrand.jpg?width=75&name=John%20Wibrand.jpg) John Wibrand 2](https://blog.swegon.com/uk/author/john-wibrand) - [![Josh Emerson](https://blog.swegon.com/hs-fs/hubfs/Josh_Emerson_Headshot.jpg?width=75&name=Josh_Emerson_Headshot.jpg) Josh Emerson 4](https://blog.swegon.com/uk/author/josh-emerson) - [![Josh Emerson](https://blog.swegon.com/hs-fs/hubfs/Josh_Emerson_Headshot.jpg?width=75&name=Josh_Emerson_Headshot.jpg) Josh Emerson 4](https://blog.swegon.com/uk/author/josh-emerson) - [![Luca Filippetto](https://blog.swegon.com/hs-fs/hubfs/Luca%20Filippetto%20Hubspot.jpg?width=75&name=Luca%20Filippetto%20Hubspot.jpg) Luca Filippetto 2](https://blog.swegon.com/uk/author/luca-filippetto) - [![Luca Zordan](https://blog.swegon.com/hs-fs/hubfs/lucazordan.png?width=75&name=lucazordan.png) Luca Zordan 1](https://blog.swegon.com/uk/author/luca-zordan-1) - [![Magnus Andersson](https://blog.swegon.com/hs-fs/hubfs/magnus%20andersson_550x550%20(1).jpg?width=75&name=magnus%20andersson_550x550%20(1).jpg) Magnus Andersson 1](https://blog.swegon.com/uk/author/magnus-andersson) - [![Malin Höij](https://blog.swegon.com/hs-fs/hubfs/malinh.webp?width=75&name=malinh.webp) Malin Höij 2](https://blog.swegon.com/uk/author/malin-höij) - [![Malin Höij](https://blog.swegon.com/hs-fs/hubfs/malinh.webp?width=75&name=malinh.webp) Malin Höij 2](https://blog.swegon.com/uk/author/malin-höij) - [![Markku Palola](https://blog.swegon.com/hs-fs/hubfs/Blog%20Authors/Markku_Palola_50x83.jpg?width=75&name=Markku_Palola_50x83.jpg) Markku Palola 1](https://blog.swegon.com/uk/author/markku-palola) - [![Markus Schomaker](https://blog.swegon.com/hs-fs/hubfs/Swegon%20UKI/Markus%20Schomaker.jpg?width=75&name=Markus%20Schomaker.jpg) Markus Schomaker 1](https://blog.swegon.com/uk/author/markus-schomaker) - [![Martin Brady](https://blog.swegon.com/hs-fs/hubfs/1569580194632.jpg?width=75&name=1569580194632.jpg) Martin Brady 1](https://blog.swegon.com/uk/author/martin-brady) - [![Martin Ottersten](https://blog.swegon.com/hs-fs/hubfs/Blog%20Authors/Martin_Ottersten.jpg?width=75&name=Martin_Ottersten.jpg) Martin Ottersten 2](https://blog.swegon.com/uk/author/martin-ottersten) - [![Martin Ottersten](https://blog.swegon.com/hs-fs/hubfs/Blog%20Authors/Martin_Ottersten.jpg?width=75&name=Martin_Ottersten.jpg) Martin Ottersten 2](https://blog.swegon.com/uk/author/martin-ottersten) - [![Martin Procter](https://blog.swegon.com/hs-fs/hubfs/MP.jpg?width=75&name=MP.jpg) Martin Procter 2](https://blog.swegon.com/uk/author/martin-procter) - [![Michael Ward](https://blog.swegon.com/hs-fs/hubfs/Michael_Ward_photo.jpg?width=75&name=Michael_Ward_photo.jpg) Michael Ward 1](https://blog.swegon.com/uk/author/michael-ward) - [![Mikael Börjesson](https://blog.swegon.com/hs-fs/hubfs/Blog%20Authors/Mikael%20B%C3%B6rjesson.jpg?width=75&name=Mikael%20B%C3%B6rjesson.jpg) Mikael Börjesson 10](https://blog.swegon.com/uk/author/mikael-börjesson) - [![Mikael Börjesson](https://blog.swegon.com/hs-fs/hubfs/Blog%20Authors/Mikael%20B%C3%B6rjesson.jpg?width=75&name=Mikael%20B%C3%B6rjesson.jpg) Mikael Börjesson 10](https://blog.swegon.com/uk/author/mikael-börjesson) - [![Mike Ward](https://blog.swegon.com/hs-fs/hubfs/Michael_Ward_photo.jpg?width=75&name=Michael_Ward_photo.jpg) Mike Ward 4](https://blog.swegon.com/uk/author/mike-ward) - [![Mirko Sauvan](https://blog.swegon.com/hs-fs/hubfs/Swegon_Mirko%20Sauvan_web_3.jpg?width=75&name=Swegon_Mirko%20Sauvan_web_3.jpg) Mirko Sauvan 2](https://blog.swegon.com/uk/author/mirko-sauvan-1) - [![Morten von Sydow](https://blog.swegon.com/hs-fs/hubfs/Morten.jpg?width=75&name=Morten.jpg) Morten von Sydow 1](https://blog.swegon.com/uk/author/morten-von-sydow) - [![Niklas Jacobsson](https://blog.swegon.com/hs-fs/hubfs/authorniklas.png?width=75&name=authorniklas.png) Niklas Jacobsson 2](https://blog.swegon.com/uk/author/niklas-jacobsson) - [![Owen Crawford](https://blog.swegon.com/hs-fs/hubfs/0%20(1).jpg?width=75&name=0%20(1).jpg) Owen Crawford 1](https://blog.swegon.com/uk/author/owen-crawford) - [![Paola Moschini (Guest author)](https://blog.swegon.com/hs-fs/hubfs/forfattare.png?width=75&name=forfattare.png) Paola Moschini (Guest author) 1](https://blog.swegon.com/uk/author/paola-moschini) - [![Paolo Dalle Fratte](https://blog.swegon.com/hs-fs/hubfs/Paolo%20profile%20image.jpg?width=75&name=Paolo%20profile%20image.jpg) Paolo Dalle Fratte 1](https://blog.swegon.com/uk/author/paolo-dalle-fratte) - [![Per-Åke Ottemark](https://blog.swegon.com/hs-fs/hubfs/1521139778203.jpg?width=75&name=1521139778203.jpg) Per-Åke Ottemark 1](https://blog.swegon.com/uk/author/per-âke-ottemark) - [![Peter Faruqi Nicholas](https://blog.swegon.com/hs-fs/hubfs/Peter%20Faruqi.jpg?width=75&name=Peter%20Faruqi.jpg) Peter Faruqi Nicholas 2](https://blog.swegon.com/uk/author/peter-faruqi-nicholas) - [![Philip Andersson](https://blog.swegon.com/hs-fs/hubfs/Philip_Andersson_pressbild_small_webb.jpg?width=75&name=Philip_Andersson_pressbild_small_webb.jpg) Philip Andersson 1](https://blog.swegon.com/uk/author/philip-andersson) - [![Robert Flaherty](https://blog.swegon.com/hs-fs/hubfs/RF%20photo.jpg?width=75&name=RF%20photo.jpg) Robert Flaherty 1](https://blog.swegon.com/uk/author/robert-flaherty) - [![Robert Siverby](https://blog.swegon.com/hs-fs/hubfs/MicrosoftTeams-image%20(3)-4.png?width=75&name=MicrosoftTeams-image%20(3)-4.png) Robert Siverby 1](https://blog.swegon.com/uk/author/robert-siverby) - [![Ryan Fossey](https://blog.swegon.com/hs-fs/hubfs/Swegon%20UKI/Personal%20photo%201.jpg?width=75&name=Personal%20photo%201.jpg) Ryan Fossey 2](https://blog.swegon.com/uk/author/ryan-fossey) - [![Shannon Jezzard](https://blog.swegon.com/hubfs/1564654168812.jfif) Shannon Jezzard 3](https://blog.swegon.com/uk/author/shannon-jezzard) - [![Stefan Lay](https://blog.swegon.com/hs-fs/hubfs/1517033472060.jpg?width=75&name=1517033472060.jpg) Stefan Lay 6](https://blog.swegon.com/uk/author/stefan-lay) - [![Steve Gore](https://blog.swegon.com/hs-fs/hubfs/1516820800199.jpg?width=75&name=1516820800199.jpg) Steve Gore 10](https://blog.swegon.com/uk/author/steve-gore) - [![Swegon](https://blog.swegon.com/hs-fs/hubfs/LinkedinSwegonlogo-1.jpg?width=75&name=LinkedinSwegonlogo-1.jpg) Swegon 10](https://blog.swegon.com/uk/author/swegon-0) - [Swegon Air Academy 2](https://blog.swegon.com/uk/author/swegon-air-academy) - [Eur Ing Professor Tim Dwyer 2](https://blog.swegon.com/uk/author/tim-dwyer) - [![Timo Schreck](https://blog.swegon.com/hs-fs/hubfs/Timo%20Schreck.jpg?width=75&name=Timo%20Schreck.jpg) Timo Schreck 2](https://blog.swegon.com/uk/author/timo-schreck) - [![Tobias Nordström](https://blog.swegon.com/hs-fs/hubfs/TobiasNordstromPHOTO.jpg?width=75&name=TobiasNordstromPHOTO.jpg) Tobias Nordström 2](https://blog.swegon.com/uk/author/tobias-nordström) - [![Toby Young](https://blog.swegon.com/hs-fs/hubfs/Image2.jpeg?width=75&name=Image2.jpeg) Toby Young 1](https://blog.swegon.com/uk/author/toby-young) - [![Tony Olsson](https://blog.swegon.com/hs-fs/hubfs/Tony%20Olsson.webp?width=75&name=Tony%20Olsson.webp) Tony Olsson 5](https://blog.swegon.com/uk/author/tony-olsson) - [![Tony Olsson](https://blog.swegon.com/hs-fs/hubfs/Tony%20Olsson.webp?width=75&name=Tony%20Olsson.webp) Tony Olsson 5](https://blog.swegon.com/uk/author/tony-olsson) - [![Tony Pettersson](https://blog.swegon.com/hs-fs/hubfs/tonyp.jpg?width=75&name=tonyp.jpg) Tony Pettersson 1](https://blog.swegon.com/uk/author/tony-pettersson) - [![Welat Han](https://blog.swegon.com/hs-fs/hubfs/Welat%20Han.jpg?width=75&name=Welat%20Han.jpg) Welat Han 3](https://blog.swegon.com/uk/author/welat-han) - [![William Lawrance](https://blog.swegon.com/hs-fs/hubfs/William_lawrance.jpg?width=75&name=William_lawrance.jpg) William Lawrance 5](https://blog.swegon.com/uk/author/william-lawrance) - [![William Lawrance](https://blog.swegon.com/hs-fs/hubfs/Blog%20Authors/SE-SV%20-%20PRO%20-%20BACV/William%20Lawrance.jpg?width=75&name=William%20Lawrance.jpg) William Lawrance 5](https://blog.swegon.com/uk/author/william-lawrance) - [![Åsa Norén-Lundh](https://blog.swegon.com/hs-fs/hubfs/A%CC%8Asa%20Nore%CC%81n-Lundh.webp?width=75&name=A%CC%8Asa%20Nore%CC%81n-Lundh.webp) Åsa Norén-Lundh 4](https://blog.swegon.com/uk/author/åsa-norén-lundh) - [![Åsa Norén-Lundh](https://blog.swegon.com/hs-fs/hubfs/Blog%20Authors/SE-SV%20-%20PRO%20-%20BACV/%C3%85sa%20Nor%C3%A9n-Lundh.png?width=75&name=%C3%85sa%20Nor%C3%A9n-Lundh.png) Åsa Norén-Lundh 4](https://blog.swegon.com/uk/author/åsa-norén-lundh) - [![Åsa Norén-Lundh](https://blog.swegon.com/hs-fs/hubfs/AsaLN.jpg?width=75&name=AsaLN.jpg) Åsa Norén-Lundh 1](https://blog.swegon.com/uk/author/åsa-norén-lundh-1) Explore - - - [All About Indoor Climate](https://blog.swegon.com/uk?hsLang=en-gb) Subscribe Share - - - Explore Share Subscribe [« go back](https://blog.swegon.com/uk) # Hydraulic Circuit Requirements – Part 2: A Closer Look at Optimisation and Efficiency [Stefan Lay](https://blog.swegon.com/uk/author/stefan-lay) Aug 20, 2025 Hydraulic Circuit Requirements – Part 2: A Closer Look at Optimisation and Efficiency 6:10 **In the second instalment of this two-part blog series, we take a closer look at how hydraulic systems can be fine-tuned for greater efficiency and long-term performance. With insights from Stefan Lay, UK Cooling and Heating Product Manager at Swegon, this post explores how temperature differences (TDs), flow rates and load conditions interact – and what that means for design choices on site.** **Optimisation** Machines have a minimum and maximum flow field – this means the widest acceptable TD at the slowest flow rate and the narrowest TD at the fastest flow rate. Data published against EN14511 is given at the standard 5°C TD with subsequent flow rates detailed. Be aware that in a fixed flow situation, your expected 5°C TD will only be achievable at full load. For the rest of the year, this TD will depend on how much of the machine needs to operate i.e. if only 50% of the available compressors need to work, expect a 2.5°C TD. You must also consider that as the outdoor temperature increases for heat pumps or decreases for chillers, it is easier for the system to manage the energy requirements and therefore capacities increase meaning the TD varies. Let’s assume a machine with 4 equal sized compressors was selected for 100kW at 45/40 A-5 (OAT) and we want to work out the flow rate needed to achieve a 5°C TD: One parameter required regards the Specific Heat Capacity of the fluid being used. This example includes for pure water, but you would have to adapt accordingly if using a glycol mix. Flow rate = 100kW ÷ 4.2 (Water SHC) ÷ 5°C TD Fixed Flow rate = 4.76l/s Expected TDs based on no. of comps in operation using fixed water flow: 4 comps = 100kW =        4.76l/s x 4.2SHC x 5°C 3 comps = 75kW =          4.76l/s x 4.2SHC x 3.75°C 2 comps = 50kW =          4.76l/s x 4.2SHC x 2.5°C 1 comp = 25kW =             4.76l/s x 4.2SHC x 1.25°C ![Picture1](https://blog.swegon.com/hs-fs/hubfs/Swegon%20UKI/Picture1.jpg?width=491&height=295&name=Picture1.jpg) The same machine but at A7 (OAT) can produce 135kW heat so, using the fixed flow rate from before, our TD changes: TD = 135kW ÷ 4.2 (Water SHC) ÷ 4.76l/s TD = 6.4°C 4 comps = 135kW =                       4.76l/s x 4.2SHC x 6.42°C 3 comps = 101.25kW =                  4.76l/s x 4.2SHC x 4.82°C 2 comps = 67.5kW =                     4.76l/s x 4.2SHC x 3.21°C 1 comp = 33.75kW =                     4.76l/s x 4.2SHC x 1.60°C ![](https://blog.swegon.com/hs-fs/hubfs/image-png-Aug-04-2025-10-18-39-0328-AM.png?width=491&height=295&name=image-png-Aug-04-2025-10-18-39-0328-AM.png) If the flow rate is fixed for 5°C TD at A7 (OAT) operation, the TD at A-5 (OAT) would be reduced: Flow Rate at A7 (OAT) = 135kW ÷ 4.2 ÷ 5°C TD Fixed Flow Rate = 6.42l/s Expected TDs based on no. of comps in operation using fixed water flow: 4 comps = 100kW =                        6.42l/s x 4.2SHC x 3.70°C 3 comps = 75kW =                          6.42l/s x 4.2SHC x 2.78°C 2 comps = 50kW =                          6.42l/s x 4.2SHC x 1.85°C 1 comp = 25kW =                            6.42l/s x 4.2SHC x 0.92°C ![](https://blog.swegon.com/hs-fs/hubfs/image-png-Aug-04-2025-10-19-00-3312-AM.png?width=493&height=260&name=image-png-Aug-04-2025-10-19-00-3312-AM.png) To fix the TD at 5°C, the water flow needs to become variable to match the capacity of the machine. Fixed TD at 5°C for A-5(OAT) = Variable water flow: 100kW =              4.76l/s x 4.2SHC x 5°C 75kW =                3.57l/s x 4.2SHC x 5°C 50kW =                2.38l/s x 4.2SHC x 5°C 25kW =                1.19l/s x 4.2SHC x 5°C ![](https://blog.swegon.com/hs-fs/hubfs/image-png-Aug-04-2025-10-19-09-8547-AM.png?width=491&height=295&name=image-png-Aug-04-2025-10-19-09-8547-AM.png) Our built-in functionality can help simplify this approach using onboard logic which can manage flow either by using system pressures or by directly measuring the TD. Be aware that variable flow systems need to account for the minimum flow requirements of the connected machine to ensure this is not exceeded. The machine should be selected and set to the more favoured outdoor condition which can be considered accurately if “bin” hours for local ambient temperatures are understood. Most selections requested are at design conditions which, if they are ever reached, are never sustained. A more realistic understanding of the actual conditions and any diversification in loads is crucial to avoid oversizing equipment which can lead to operational issues.   **Efficiency** To be able to calculate the efficiency of a machine you need to know its capacity output and electrical energy input in that moment i.e. COP (Heating) or EER (Cooling) = kW Out ÷ kW In. To calculate the kW Out, the following are needed: Water Flow Rate (l/s) x Fluid type (SHC) x Inlet/Outlet Temperature Difference (°C) Operating at 45/40 A7 (OAT) with a fixed 6.42l/s flow rate using pure water: kW Out = 6.42l/s (Measured) x 4.2 (SHC Water) x 5°C (Measured) kW Out = 135kW Let’s assume we have measured 35.8kW Electrical Energy Input to the machine at full load… COP = kW Out ÷ Kw In COP = 135kW at A7 (OAT) ÷ 35.8kW (Measured) COP = 3.77 The efficiency of a heat pump will reduce as the outside air temperature decreases because the machine has to “work harder” to produce the desired output: COP = 100kW at A-5 (OAT) ÷ 35.8kW (Measured) COP = 2.79   **Conclusion** Designing, implementing and operating an efficient and reliable system needs the proper expertise and in Swegon we have the right tools and the right people to support. To better understand system operation / building performance and to find opportunities for optimisation and increased efficiencies, the job shouldn’t stop after installation. In most new build cases, the building itself is not at full use when equipment is commissioned and therefore nowhere near the selected design condition, so it’s best to include remote monitoring which allows you to review operation both historically and in real time, facilitating the possibility to make relevant cost saving adjustments. Topics: - [Cooling & Heating](https://blog.swegon.com/uk/tag/cooling-heating) - - - [![Stefan Lay](https://blog.swegon.com/hs-fs/hubfs/1517033472060.jpg?width=200&name=1517033472060.jpg)](https://blog.swegon.com/uk/author/stefan-lay) [Stefan Lay](https://blog.swegon.com/uk/author/stefan-lay) Stefan Lay is the Product Manager for Cooling and Heating at Swegon UK&I. Boasting over 20 years of experience in a range of roles within the HVAC industry, Stefan looks after our cooling and heating product ranges and system solutions, offering technical knowledge and a great level of industry insight. ## Recommended reading - [Cooling & Heating](https://blog.swegon.com/uk/tag/cooling-heating) - [sustainability](https://blog.swegon.com/uk/tag/sustainability) ### [Luca Filippetto](https://blog.swegon.com/uk/author/luca-filippetto) ## [Our experts explain Europe's adoption of propane as a refrigerant](https://blog.swegon.com/uk/our-experts-explain-europes-adoption-of-propane-as-a-refrigerant-1?hsLang=en-gb) The transition to more sustainable alternatives in the HVAC industry … - [Cooling & Heating](https://blog.swegon.com/uk/tag/cooling-heating) ### [Stefan Lay](https://blog.swegon.com/uk/author/stefan-lay) ## [Free Cooling Potential in UK Climate: Strategies and Pitfalls](https://blog.swegon.com/uk/free-cooling-potential-in-uk-climate-strategies-and-pitfalls?hsLang=en-gb) Free cooling isn’t a new concept, but it’s often underutilised, … - [Cooling & Heating](https://blog.swegon.com/uk/tag/cooling-heating) ### [Fabio Polo](https://blog.swegon.com/uk/author/fabio-polo) ## [How to choose the right chiller](https://blog.swegon.com/uk/how-to-choose-the-right-chiller-1?hsLang=en-gb) There are aspects to consider when choosing the right chiller. A few … Get updates from the blog directly to your inbox. #### Get to know us - [Why Swegon?](https://www.swegon.com/uk/why-swegon/) - [Solutions & services](https://www.swegon.com/uk/solutions-and-services/) - [Products](https://www.swegon.com/uk/products/) - [References & Insights](https://www.swegon.com/uk/references-and-insights/) - [Support & Software](https://www.swegon.com/uk/support/) - [BlueBox Chiller ERP](http://www.blueboxcooling.com/) - [Sustainability](https://www.swegon.com/uk/sustainability/) #### More Swegon - [About us](https://www.swegon.com/uk/about-swegon/) - [Our Brands](https://www.swegon.com/uk/about-swegon/our-brands/) - [Contact](https://www.swegon.com/uk/contact/) - [Careers](https://www.swegon.com/uk/careers/) - [Information for suppliers](https://www.swegon.com/uk/contact/suppliers/) - [Swegon Designer Suite](https://sds.swegon.com/) - [Swegon Air Academy](https://www.swegonairacademy.com/en/) #### Subscribe to our blog [![](https://www.swegon.com/siteassets/logos/swegon-logo-white.svg)](https://www.swegon.com/uk/) Swegon Ltd, 5 Charterpoint Way, Ashby-de-la-Zouch Leicestershire LE65 1NF - [Privacy statement](https://www.swegon.com/uk/privacy-policy/) - [Cookies](https://www.swegon.com/uk/cookies/) - [Processing personal data](https://www.swegon.com/uk/privacy-policy/processing-personal-data/) - [Vulnerability disclosure policy](https://www.swegon.com/uk/vulnerability-disclosure-policy/) - [![Youtube](https://www.swegon.com/Static/img/youtube.svg)](https://www.youtube.com/user/SwegonAB) - [![Linkedin](https://www.swegon.com/Static/img/linkedin.svg)](https://www.linkedin.com/company/swegon-ab/) - [![Facebook](https://www.swegon.com/Static/img/facebook.svg)](https://www.facebook.com/swegongroup)