# Pressure initialization in subdomain **URL:** \ **Category:** Vote for features!\ **Created:** [February 18, 2026, 6:27pm UTC](https://www.simscale.com/forum/t/pressure-initialization-in-subdomain/100776 "2026-02-18T18:27:13Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![GerhardRP](https://www.simscale.com/forum/letter_avatar/gerhardrp/32/5_5575768a8748004e209b776fc1b2916d.png) [@GerhardRP](https://www.simscale.com/forum/u/GerhardRP)\ **Post date:** [February 18, 2026, 6:27pm UTC](https://www.simscale.com/forum/t/pressure-initialization-in-subdomain/100776/1 "2026-02-18T18:27:13Z")
This is not a request for a new feature but just a note on documentation. The page [IInitial Conditions | Simulation Setup | SimScale](https://www.simscale.com/docs/simulation-setup/initial-conditions/) says under subdomain initialization: “ **Fluid Dynamics** #### **Pressure** Pressure initialization accepts global definition only. Please note that the input pressure may be different, depending on the analysis type. For example, an _[incompressible](https://www.simscale.com/docs/analysis-types/incompressible-fluid-flow-analysis/)_ analysis requires gauge pressure, whereas a _[conjugate heat transfer](https://www.simscale.com/docs/analysis-types/conjugate-heat-transfer-analysis/)_ simulation requires the absolute modified pressure.“ I have an incompressible model of a room separated from an inlet buffer volume by a restrictive aperture and I successfully set just the room to a lower pressure with a box geometry primitive. FYI, GerhardRP ---
**Author:** ![RicardoParis](https://www.simscale.com/forum/user_avatar/www.simscale.com/ricardoparis/32/30222_2.png) [@RicardoParis](https://www.simscale.com/forum/u/RicardoParis)\ **Post date:** [February 20, 2026, 1:32pm UTC](https://www.simscale.com/forum/t/pressure-initialization-in-subdomain/100776/2 "2026-02-20T13:32:40Z")
Hi @GerhardRP , Well spotted, the doc has been updated.