{"id":41509,"date":"2026-01-04T21:27:35","date_gmt":"2026-01-04T21:27:35","guid":{"rendered":"https:\/\/valve-atlas.com\/?p=41509"},"modified":"2026-04-26T00:57:03","modified_gmt":"2026-04-26T00:57:03","slug":"delta-p-noise-hvac-piping","status":"publish","type":"post","link":"https:\/\/valve-atlas.com\/fr_ca\/2026\/01\/04\/delta-p-noise-hvac-piping\/","title":{"rendered":"Pourquoi l&#039;augmentation de \u0394P provoque-t-elle des bourdonnements\/sifflements dans les tuyauteries de CVC ?"},"content":{"rendered":"<div style=\"font-family: system-ui,-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif; line-height:1.6; color:#111827; background:#ffffff; padding:16px 0;\">\n<p><!-- TITLE --><\/p>\n<h1 style=\"font-size:2rem; color:#0A336C; margin-top:0;\">\nPourquoi l&#039;augmentation de \u0394P provoque-t-elle des bourdonnements\/sifflements dans les tuyauteries de CVC ?<br \/>\n<\/h1>\n<p style=\"font-size:0.95rem; color:#4b5563; margin-top:0.3rem;\">\nBuzzing, whistling or high-pitched noise in hydronic HVAC systems is one of the most common<br \/>\n<strong>field complaints<\/strong> in both new and existing buildings.<br \/>\nThis article explains the mechanical reason behind it:<br \/>\n<strong>excessive differential pressure (\u0394P)<\/strong> across valves, fittings and terminal devices.\n<\/p>\n<p><!-- QUICK NAV --><\/p>\n<div style=\"border:1px solid #e5e7eb; background:#f9fafb; padding:12px 14px; border-radius:6px; font-size:0.9rem; margin-tops:12px;\">\n<strong style=\"color:#0A336C;\">Related technical guides (ValveAtlas):<\/strong><\/p>\n<ul style=\"margin:8px 0 0 18px; padding:0;\">\n<li><a style=\"color:#0A336C; text-decoration:none;\" href=\"\/pressure-drop-in-valves-cv-kv\/\">Pressure Drop in Valves: Why It Matters (Cv\/Kv Explained)<\/a><\/li>\n<li><a style=\"color:#0A336C; text-decoration:none;\" href=\"\/swing-check-valve-pump-discharge\/\">Pourquoi les clapets anti-retour \u00e0 battant peuvent poser probl\u00e8me au niveau du refoulement des pompes<\/a><\/li>\n<li><a style=\"color:#0A336C; text-decoration:none;\" href=\"\/pressure-reducing-valves-prv-explained\/\">Pressure Reducing Valves (PRV) Explained: How They Work<\/a><\/li>\n<li><a style=\"color:#0A336C; text-decoration:none;\" href=\"\/grooved-vs-welded-vs-flanged-piping-toronto\/\">Grooved vs Welded vs Flanged Piping: Time, Cost, and Modification (Toronto Scenario)<\/a><\/li>\n<\/ul>\n<\/div>\n<hr style=\"margin:1.5rem 0;\" \/>\n<p><!-- 1 --><\/p>\n<h2 style=\"font-size:1.4rem; color:#111827;\">\n1. What Is \u0394P in a Hydronic System?<br \/>\n<\/h2>\n<p style=\"font-size:0.9rem; color:#4b5563;\">\n\u0394P (differential pressure) is the pressure difference between two points in a piping system.<br \/>\nIn hydronic HVAC applications, it typically appears across:\n<\/p>\n<ul style=\"font-size:0.9rem; color:#4b5563;\">\n<li>Control valves and PICVs<\/li>\n<li>vannes d&#039;\u00e9quilibrage<\/li>\n<li>Strainers and filters<\/li>\n<li>Terminal units (fan coils, AHUs, radiators)<\/li>\n<li>Check valves<\/li>\n<\/ul>\n<p style=\"font-size:0.9rem; color:#4b5563;\">\nEvery component needs a certain \u0394P to operate correctly.<br \/>\nProblems begin when the available \u0394P is<br \/>\n<strong>much higher than the component was designed for<\/strong>.<br \/>\nIf you want the sizing logic behind this, see<br \/>\n<a style=\"color:#0A336C; text-decoration:none;\" href=\"\/pressure-drop-in-valves-cv-kv\/\">Cv\/Kv &amp; valve pressure drop basics<\/a>.\n<\/p>\n<p><!-- 2 --><\/p>\n<h2 style=\"font-size:1.4rem; color:#111827; margin-top:1.8rem;\">\n2. Why High \u0394P Creates Noise<br \/>\n<\/h2>\n<p style=\"font-size:0.9rem; color:#4b5563;\">\nWhen \u0394P increases, velocity through valve ports and restrictions also increases.<br \/>\nThis leads to several noise-generating mechanisms:\n<\/p>\n<ul style=\"font-size:0.9rem; color:#4b5563;\">\n<li><strong>High-velocity jetting<\/strong> through partially closed valve seats<\/li>\n<li><strong>Turbulence<\/strong> downstream of control elements<\/li>\n<li><strong>Vibration<\/strong> of valve internals (disc, plug, stem)<\/li>\n<li><strong>Flow-induced resonance<\/strong> in piping and fittings<\/li>\n<\/ul>\n<p style=\"font-size:0.9rem; color:#4b5563;\">\nThe result is the familiar <em>buzzing<\/em>, <em>whistling<\/em> ou <em>hissing<\/em> sound<br \/>\noften reported by occupants or facility staff.\n<\/p>\n<p><!-- CALLOUT --><\/p>\n<div style=\"border-left:3px solid #F97316; background:#fff7ec; padding:10px 14px; margin-top:1rem; font-size:0.88rem;\">\n<strong>Field observation:<\/strong><br \/>\nNoise complaints usually increase after partial load operation begins \u2014 for example when VFD control is enabled,<br \/>\nzones close, or terminal valves modulate. This is also where proper \u0394P control strategies matter most.\n<\/div>\n<p><!-- 3 --><\/p>\n<h2 style=\"font-size:1.4rem; color:#111827; margin-top:1.8rem;\">\n3. Common Situations That Push \u0394P Too High<br \/>\n<\/h2>\n<table style=\"border-collapse:collapse; width:100%; font-size:0.9rem; margin-top:10px;\">\n<thead>\n<tr style=\"background:#eef3f8;\">\n<th style=\"text-align:left; padding:6px 8px;\">Situation<\/th>\n<th style=\"text-align:left; padding:6px 8px;\">Typical Result<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border-bottom:1px solid #eee; padding:6px 8px;\">Oversized pump \/ aggressive VFD setpoint<\/td>\n<td style=\"border-bottom:1px solid #eee; padding:6px 8px;\">Excess \u0394P at part load \u2192 valve noise<\/td>\n<\/tr>\n<tr>\n<td style=\"border-bottom:1px solid #eee; padding:6px 8px;\">No differential pressure control valve<\/td>\n<td style=\"border-bottom:1px solid #eee; padding:6px 8px;\">Terminal valves see too much available head<\/td>\n<\/tr>\n<tr>\n<td style=\"border-bottom:1px solid #eee; padding:6px 8px;\">Poor balancing \/ branches short-circuit<\/td>\n<td style=\"border-bottom:1px solid #eee; padding:6px 8px;\">Some zones get high \u0394P \u2192 whistling at valves<\/td>\n<\/tr>\n<tr>\n<td style=\"border-bottom:1px solid #eee; padding:6px 8px;\">Clogged strainers<\/td>\n<td style=\"border-bottom:1px solid #eee; padding:6px 8px;\">Local turbulence + flow noise (sometimes \u201cscreaming\u201d)<\/td>\n<\/tr>\n<tr>\n<td style=\"padding:6px 8px;\">Check valve flutter \/ wrong selection<\/td>\n<td style=\"padding:6px 8px;\">Disc vibration, rattling or buzzing (esp. near pumps)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p style=\"font-size:0.9rem; color:#4b5563; margin-top:10px;\">\nFor pump-related noise and check valve stability, see:<br \/>\n<a style=\"color:#0A336C; text-decoration:none;\" href=\"\/swing-check-valve-pump-discharge\/\">Clapets anti-retour \u00e0 battant sur le refoulement de la pompe<\/a>.\n<\/p>\n<p><!-- 4 --><\/p>\n<h2 style=\"font-size:1.4rem; color:#111827; margin-top:1.8rem;\">\n4. Why Noise Often Appears at Part Load<br \/>\n<\/h2>\n<p style=\"font-size:0.9rem; color:#4b5563;\">\nWhen flow demand drops but pump head remains high:\n<\/p>\n<ul style=\"font-size:0.9rem; color:#4b5563;\">\n<li>Control valves throttle harder<\/li>\n<li>Local \u0394P across valve seats increases<\/li>\n<li>Velocity and turbulence rise sharply<\/li>\n<\/ul>\n<p style=\"font-size:0.9rem; color:#4b5563;\">\nIn other words, the system becomes <strong>hydraulically aggressive<\/strong> at low load \u2014 exactly when buildings operate most of the year.\n<\/p>\n<p><!-- 5 --><\/p>\n<h2 style=\"font-size:1.4rem; color:#111827; margin-top:1.8rem;\">\n5. Practical Ways to Reduce \u0394P-Related Noise<br \/>\n<\/h2>\n<ul style=\"font-size:0.9rem; color:#4b5563;\">\n<li>Use <strong>differential pressure control valves<\/strong> to cap available \u0394P<\/li>\n<li>Apply <strong>PICVs<\/strong> where variable-flow is expected<\/li>\n<li>Optimize pump control (setpoints, trimming, VFD tuning)<\/li>\n<li>Verify strainer selection and maintenance (clogging = local \u0394P spikes)<\/li>\n<li>Select check valves designed for stable closure (avoid flutter)<\/li>\n<\/ul>\n<p style=\"font-size:0.9rem; color:#4b5563;\">\nIf your issue is pressure regulation (not only hydronic control), read:<br \/>\n<a style=\"color:#0A336C; text-decoration:none;\" href=\"\/pressure-reducing-valves-prv-explained\/\">Pressure reducing valves (PRVs) explained<\/a>.\n<\/p>\n<p><!-- NOTE --><\/p>\n<div style=\"border:1px solid #e5e7eb; background:#f9fafb; padding:12px 14px; border-radius:6px; font-size:0.88rem; margin-top:1.4rem;\">\n<strong>Important:<\/strong><br \/>\nNoise is rarely \u201cjust an acoustic issue\u201d. It is usually a sign of poor hydraulic control, wasted pumping energy,<br \/>\nand unstable valve operation.\n<\/div>\n<p><!-- 6 --><\/p>\n<h2 style=\"font-size:1.4rem; color:#111827; margin-top:1.8rem;\">\n6. How This Connects to Valve Selection<br \/>\n<\/h2>\n<p style=\"font-size:0.9rem; color:#4b5563;\">\n\u0394P-related noise ties directly to Cv\/Kv sizing, valve authority, and check valve stability.<br \/>\nIf you want the full technical foundation, start here:<br \/>\n<a style=\"color:#0A336C; text-decoration:none;\" href=\"\/pressure-drop-in-valves-cv-kv\/\">Pressure Drop in Valves (Cv\/Kv explained)<\/a>.\n<\/p>\n<p><!-- CTA --><\/p>\n<div style=\"margin-top:1.6rem; border-left:3px solid #0A336C; background:#eff6ff; padding:10px 14px; font-size:0.9rem;\">\n<strong style=\"color:#0A336C;\">Next recommended read:<\/strong><br \/>\n<a style=\"color:#0A336C; text-decoration:none; font-weight:600;\" href=\"\/pressure-drop-in-valves-cv-kv\/\">Pressure Drop in Valves: Why It Matters (Cv\/Kv Explained)<\/a>\n<\/div>\n<p><!-- DISCLAIMER --><\/p>\n<div style=\"margin-top:1.6rem; font-size:0.85rem; color:#6b7280;\">\nThis article is based on field observations and standard hydronic design principles.<br \/>\nIt is intended for engineering guidance and troubleshooting, not as a substitute for project-specific design review.\n<\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Pourquoi une augmentation de la diff\u00e9rence de pression (\u0394P) provoque-t-elle des bourdonnements\/sifflements dans les canalisations de CVC\u00a0? Les bourdonnements, sifflements ou bruits aigus dans les syst\u00e8mes de chauffage, ventilation et climatisation (CVC) hydroniques constituent l\u2019une des plaintes les plus fr\u00e9quentes sur le terrain, tant dans les b\u00e2timents neufs qu\u2019existants. Cet article explique la cause m\u00e9canique de ce ph\u00e9nom\u00e8ne\u00a0: une pression diff\u00e9rentielle (\u0394P) excessive au niveau des vannes, des raccords et des terminaux. Guides techniques associ\u00e9s\u2026<\/p>","protected":false},"author":1,"featured_media":40749,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"content-type":"","iawp_total_views":4,"footnotes":""},"categories":[175],"tags":[224,220,221,222,223,225],"class_list":["post-41509","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydronic-hvac-engineering","tag-control-valves","tag-delta-p","tag-hvac-noise","tag-hydronic-systems","tag-pressure-drop","tag-variable-flow-systems","category-175","description-off"],"acf":[],"_links":{"self":[{"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/posts\/41509","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/comments?post=41509"}],"version-history":[{"count":2,"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/posts\/41509\/revisions"}],"predecessor-version":[{"id":41511,"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/posts\/41509\/revisions\/41511"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/media\/40749"}],"wp:attachment":[{"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/media?parent=41509"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/categories?post=41509"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/tags?post=41509"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}