High Wall Supply: Use or Resist the Coanda Effect in Winter? - GreenBuildingAdvisor
Summary
The article discusses the implications of using high wall supply registers in heating systems, focusing on the Coanda effect and its impact on air distribution in winter.
Why It Matters
Understanding the Coanda effect in heating systems is crucial for optimizing indoor comfort and energy efficiency. This article provides insights for homeowners and builders on how to effectively manage air distribution in cold climates, which can lead to better heating performance and reduced energy costs.
Key Takeaways
- The Coanda effect can influence air distribution in heating systems.
- High wall supply registers may lead to stratification if not managed properly.
- Choosing the right type of register can enhance comfort and efficiency in winter.
High Wall Supply: Use or Resist the Coanda Effect in Winter? lmosakow | Posted in General Questions on February 23, 2026 11:21am I’m in Climate Zone 4A with a ducted heat pump system. Supply registers are located high on the wall near the ceiling. Winters are cold; summers are hot and humid. I’m trying to decide which type of register to use, and the key question seems to be how to handle the Coanda effect in heating season. In cooling mode, ceiling attachment makes sense: the cool air hugs the ceiling, gets better throw, then sinks as it slows. But in heating mode, if warm air is supplied along the ceiling, does it stay high due to buoyancy and worsen stratification? If so, it seems preferable to direct air downward in winter to improve mixing at the occupied level. I’m choosing between: – Curve blade registers – primarily throw downward, higher face velocity, stronger jets. – Single deflection registers – adjustable up or down seasonally, but typically lower face velocity and slower jets. With ceiling-adjacent wall supply and heat pump supply temps, is it better in winter to resist ceiling attachment and throw air downward, or still use the Coanda effect for mixing? Why? Thanks! -Luke Answer GBA Detail Library A collection of one thousand construction details organized by climate and house part Search and download construction details Join the leading community of building science experts Become a GBA Prime member and get instant access to the latest developments in gree...
