{"id":31153,"date":"2026-07-24T07:36:00","date_gmt":"2026-07-23T23:36:00","guid":{"rendered":"https:\/\/shchimay.com\/how-does-cooling-tower-water-quality-drive-chiller-plant-efficiency-answers-from-shanghai-chimay\/"},"modified":"2026-07-24T07:36:00","modified_gmt":"2026-07-23T23:36:00","slug":"how-does-cooling-tower-water-quality-drive-chiller-plant-efficiency-answers-from-shanghai-chimay","status":"publish","type":"post","link":"https:\/\/shchimay.com\/ru\/how-does-cooling-tower-water-quality-drive-chiller-plant-efficiency-answers-from-shanghai-chimay\/","title":{"rendered":"How Does Cooling-Tower Water Quality Drive Chiller Plant Efficiency? Answers from Shanghai ChiMay"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_50 counter-hierarchy ez-toc-counter ez-toc-light-blue ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/shchimay.com\/ru\/how-does-cooling-tower-water-quality-drive-chiller-plant-efficiency-answers-from-shanghai-chimay\/#How_Does_Cooling-Tower_Water_Quality_Drive_Chiller_Plant_Efficiency_Answers_from_Shanghai_ChiMay\" title=\"How Does Cooling-Tower Water Quality Drive Chiller Plant Efficiency? Answers from Shanghai ChiMay\">How Does Cooling-Tower Water Quality Drive Chiller Plant Efficiency? Answers from Shanghai ChiMay<\/a><ul class='ez-toc-list-level-2'><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/shchimay.com\/ru\/how-does-cooling-tower-water-quality-drive-chiller-plant-efficiency-answers-from-shanghai-chimay\/#Key_Takeaways\" title=\"Key Takeaways\">Key Takeaways<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/shchimay.com\/ru\/how-does-cooling-tower-water-quality-drive-chiller-plant-efficiency-answers-from-shanghai-chimay\/#The_Physics_Fouling_Factor_and_Approach_Temperature\" title=\"The Physics: Fouling Factor and Approach Temperature\">The Physics: Fouling Factor and Approach Temperature<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/shchimay.com\/ru\/how-does-cooling-tower-water-quality-drive-chiller-plant-efficiency-answers-from-shanghai-chimay\/#The_Water-Quality_Levers\" title=\"The Water-Quality Levers\">The Water-Quality Levers<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/shchimay.com\/ru\/how-does-cooling-tower-water-quality-drive-chiller-plant-efficiency-answers-from-shanghai-chimay\/#Quantifying_the_Efficiency_Loss\" title=\"Quantifying the Efficiency Loss\">Quantifying the Efficiency Loss<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/shchimay.com\/ru\/how-does-cooling-tower-water-quality-drive-chiller-plant-efficiency-answers-from-shanghai-chimay\/#Where_Scale_Forms_First\" title=\"Where Scale Forms First\">Where Scale Forms First<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/shchimay.com\/ru\/how-does-cooling-tower-water-quality-drive-chiller-plant-efficiency-answers-from-shanghai-chimay\/#Biofilm_The_Invisible_Efficiency_Thief\" title=\"Biofilm: The Invisible Efficiency Thief\">Biofilm: The Invisible Efficiency Thief<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/shchimay.com\/ru\/how-does-cooling-tower-water-quality-drive-chiller-plant-efficiency-answers-from-shanghai-chimay\/#Corrosion_and_Its_Downstream_Cost\" title=\"Corrosion and Its Downstream Cost\">Corrosion and Its Downstream Cost<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/shchimay.com\/ru\/how-does-cooling-tower-water-quality-drive-chiller-plant-efficiency-answers-from-shanghai-chimay\/#Building_a_Chiller-Plant_Water_Program\" title=\"Building a Chiller-Plant Water Program\">Building a Chiller-Plant Water Program<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/shchimay.com\/ru\/how-does-cooling-tower-water-quality-drive-chiller-plant-efficiency-answers-from-shanghai-chimay\/#Reading_the_Trends_Correctly\" title=\"Reading the Trends Correctly\">Reading the Trends Correctly<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/shchimay.com\/ru\/how-does-cooling-tower-water-quality-drive-chiller-plant-efficiency-answers-from-shanghai-chimay\/#What_%E2%80%9CGood%E2%80%9D_Looks_Like\" title=\"What &ldquo;Good&rdquo; Looks Like\">What &ldquo;Good&rdquo; Looks Like<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/shchimay.com\/ru\/how-does-cooling-tower-water-quality-drive-chiller-plant-efficiency-answers-from-shanghai-chimay\/#Closing_Comment\" title=\"Closing Comment\">Closing Comment<\/a><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h1 id=\"how-does-cooling-tower-water-quality-drive-chiller-plant-efficiency-answers-from-shanghai-chimay\"><span class=\"ez-toc-section\" id=\"How_Does_Cooling-Tower_Water_Quality_Drive_Chiller_Plant_Efficiency_Answers_from_Shanghai_ChiMay\"><\/span>How Does Cooling-Tower Water Quality Drive Chiller Plant Efficiency? Answers from Shanghai ChiMay<span class=\"ez-toc-section-end\"><\/span><\/h1>\n<p>Chiller plants are the most electricity-hungry machines in a modern commercial building or data center. A single 500-ton centrifugal chiller consumes roughly 250\u2013400 kW at full load, and its efficiency\u2014expressed as kW per ton or as COP\u2014swings by 10\u201325% over a season depending on how the cooling tower is run. Water quality is the hidden variable behind that swing. This article, drawn from Shanghai ChiMay commissioning and troubleshooting records, explains the mechanisms and quantifies the loss.<\/p>\n<h2 id=\"key-takeaways\"><span class=\"ez-toc-section\" id=\"Key_Takeaways\"><\/span>Key Takeaways<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ul>\n<li>Every 0.001 inch of scale on condenser tubes adds roughly 3\u20135% to chiller kW\/ton.<\/li>\n<li>Cycles-of-concentration control via inline conductivity is the single largest efficiency lever.<\/li>\n<li>Corrosion products in the condenser water thin tube walls and inflate fouling factor.<\/li>\n<li>Biofilm in the tower fill degrades heat transfer even when the water &ldquo;looks clean.&rdquo;<\/li>\n<li>Field records: chiller plants shifting from timer-based to conductivity-based blowdown recover 6\u201312% annual chiller energy.<\/li>\n<\/ul>\n<h2 id=\"the-physics-fouling-factor-and-approach-temperature\"><span class=\"ez-toc-section\" id=\"The_Physics_Fouling_Factor_and_Approach_Temperature\"><\/span>The Physics: Fouling Factor and Approach Temperature<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Chiller manufacturers rate condenser performance at an assumed fouling factor, typically 0.00025 h\u00b7ft\u00b2\u00b7\u00b0F\/BTU. When actual fouling exceeds that number, condenser refrigerant pressure rises, the compressor works harder, and kW\/ton climbs. A common rule taught in ASHRAE handbooks: for every 1 \u00b0F rise in condenser approach temperature (the difference between refrigerant and leaving water), chiller efficiency drops roughly 1.5\u20132.0%.<\/p>\n<p>Scale, corrosion, and biofilm all raise the fouling factor. Scale is calcareous\u2014calcium carbonate and calcium sulfate\u2014driven by high cycles of concentration or a rising Langelier index. Corrosion in copper tubes produces oxide layers of low thermal conductivity. Biofilm is thin (10\u2013100 \u00b5m) but has a thermal conductivity roughly one-third of water and clings to the tube wall.<\/p>\n<h2 id=\"the-water-quality-levers\"><span class=\"ez-toc-section\" id=\"The_Water-Quality_Levers\"><\/span>The Water-Quality Levers<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>For an operating manager, four measurable water-quality parameters control chiller efficiency:<\/p>\n<p><strong>Conductivity (cycles of concentration).<\/strong> Ideal range depends on make-up chemistry but usually 1,800\u20132,800 \u00b5S\/cm. Above the upper band, scale precipitates. Below it, water is wasted.<\/p>\n<p><strong>pH.<\/strong> Copper is protected by a thin cupric oxide layer that stabilizes around pH 8.3\u20138.7. Below 7.5, copper corrodes fast; above 9.5, brass and yellow-metal alloys pit. A Shanghai ChiMay in-line pH electrode with a double-junction reference lasts 12\u201318 months in this service.<\/p>\n<p><strong>Free residual chlorine.<\/strong> ASHRAE 188 pushes 0.5\u20132.0 ppm free chlorine to control Legionella. Above 2.0 ppm, chlorine attacks copper and stainless steel welds, adding corrosion products.<\/p>\n<p><strong>Turbidity.<\/strong> Suspended solids above 5 NTU deposit on tubes during low-flow hours; the Shanghai ChiMay <a href=\"\/tag\/Turbidity-Tester\" target=\"_blank\"><strong>Turbidity Tester<\/strong><\/a> provides continuous surveillance.<\/p>\n<h2 id=\"quantifying-the-efficiency-loss\"><span class=\"ez-toc-section\" id=\"Quantifying_the_Efficiency_Loss\"><\/span>Quantifying the Efficiency Loss<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Field data from three Shanghai ChiMay-supported chiller plants illustrates the cost of poor water quality:<\/p>\n<table>\n<thead>\n<tr>\n<th>Plant<\/th>\n<th>Load<\/th>\n<th>Poor Water Baseline<\/th>\n<th>After Water-Quality Program<\/th>\n<th>kWh Saved \/ Year<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>4,500-ton office campus (Denver)<\/td>\n<td>Steady<\/td>\n<td>0.62 kW\/ton<\/td>\n<td>0.56 kW\/ton<\/td>\n<td>1.5 million kWh<\/td>\n<\/tr>\n<tr>\n<td>Hospital chiller plant (Cleveland)<\/td>\n<td>Cyclic<\/td>\n<td>0.71 kW\/ton<\/td>\n<td>0.63 kW\/ton<\/td>\n<td>620,000 kWh<\/td>\n<\/tr>\n<tr>\n<td>22 MW data center (Dublin)<\/td>\n<td>24\u00d77<\/td>\n<td>0.48 kW\/ton<\/td>\n<td>0.42 kW\/ton<\/td>\n<td>2.9 million kWh<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>At USD 0.10\u20130.18\/kWh, those savings translate into USD 150,000 to USD 500,000 per year per site. Even at the low end, the payback on a Shanghai ChiMay water-quality monitoring package (<a href=\"\/tag\/Conductivity-Meter\" target=\"_blank\"><strong><a href=\"\/tag\/conductivity-meter\/\" target=\"_blank\"><strong>conductivity meter<\/strong><\/a><\/strong><\/a>, pH electrode, residual chlorine transmitter, and <a href=\"\/tag\/Turbidity-Tester\" target=\"_blank\"><strong>Turbidity Tester<\/strong><\/a>) is under six months.<\/p>\n<h2 id=\"where-scale-forms-first\"><span class=\"ez-toc-section\" id=\"Where_Scale_Forms_First\"><\/span>Where Scale Forms First<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Scale precipitates first at the hottest part of the condenser tube, which is where refrigerant enters. A common site inspection during Shanghai ChiMay troubleshooting is to pull one condenser end cap and look for a whitish ring at the tube entrance. If it exists, the water program is failing to hold saturation index below the calcium carbonate deposition threshold.<\/p>\n<p>The best defensive strategy is cycles-of-concentration control that keeps LSI below +1.5 and Ryznar Stability Index (RSI) above 6.0. Both indices can be calculated in real time by a Shanghai ChiMay controller with the four inputs of pH, conductivity, calcium hardness (from lab), and temperature.<\/p>\n<h2 id=\"biofilm-the-invisible-efficiency-thief\"><span class=\"ez-toc-section\" id=\"Biofilm_The_Invisible_Efficiency_Thief\"><\/span>Biofilm: The Invisible Efficiency Thief<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Biofilm scarcely registers on a visual inspection but adds 15\u201335% to fouling factor once it exceeds 50 \u00b5m thickness. The classic marker of active biofilm is a slow decline in chiller efficiency that reverses within 48 hours after a shock chlorination event. The permanent fix is a chlorine or bromine program held at 0.5\u20132.0 ppm free residual, verified by a Shanghai ChiMay Residual Chlorine Transmitter using amperometric or DPD-colorimetric technology.<\/p>\n<p>Chlorine setpoint alone is not enough. Biofilm shelters bacteria beneath the surface, so periodic biodispersant addition and non-oxidizing biocide alternation (isothiazolone, DBNPA) are standard in Shanghai ChiMay water programs for large plants.<\/p>\n<h2 id=\"corrosion-and-its-downstream-cost\"><span class=\"ez-toc-section\" id=\"Corrosion_and_Its_Downstream_Cost\"><\/span>Corrosion and Its Downstream Cost<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Copper corrodes at 5\u201315 mils per year in uncontrolled cooling water, versus 0.5\u20132 mils per year in well-controlled water. Beyond the direct tube-life impact, corrosion products\u2014cupric oxide flakes, iron oxide colloids\u2014circulate through the loop and deposit on the coolest surfaces. Those deposits then act as scale nucleation sites. Controlling pH, sulfate, and chloride corrosivity is therefore a leverage point that pays back twice.<\/p>\n<p>Shanghai ChiMay in-line pH electrodes with a refillable double-junction reference are the field-preferred choice for chilled water service; their reference junction resists sulfide poisoning from anaerobic bacteria, which shortens single-junction probes to weeks.<\/p>\n<h2 id=\"building-a-chiller-plant-water-program\"><span class=\"ez-toc-section\" id=\"Building_a_Chiller-Plant_Water_Program\"><\/span>Building a Chiller-Plant Water Program<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A robust program has five continuously monitored signals and a monthly lab audit:<\/p>\n<ol>\n<li><strong>Continuous:<\/strong> Conductivity, pH, ORP, free chlorine, turbidity.<\/li>\n<li><strong>Monthly:<\/strong> Total hardness, calcium hardness, alkalinity, sulfate, chloride, iron, copper.<\/li>\n<li><strong>Every six months:<\/strong> Biocide efficacy check via ATP bioluminescence.<\/li>\n<li><strong>Annually:<\/strong> Cooling tower structural inspection and coupon corrosion analysis.<\/li>\n<li><strong>Every three years:<\/strong> Refrigerant-side condenser inspection with eddy-current testing.<\/li>\n<\/ol>\n<p>The Shanghai ChiMay 4-in-1 Multi-Parameter Sensor bundles pH, ORP, DO, and temperature in one head, which fits chiller plants short on wall space or wanting a simpler installation.<\/p>\n<h2 id=\"reading-the-trends-correctly\"><span class=\"ez-toc-section\" id=\"Reading_the_Trends_Correctly\"><\/span>Reading the Trends Correctly<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Efficiency degradation from water quality is not step-change. Operators watching a chiller COP trend over three months see the slow slide: 0.55 kW\/ton in April becomes 0.60 kW\/ton in July, and the reflex is to blame heat wave conditions. Overlaying continuous conductivity, pH, and turbidity trends usually shows the real cause. Shanghai ChiMay engineers routinely export these overlays from the BMS as troubleshooting evidence.<\/p>\n<h2 id=\"what-good-looks-like\"><span class=\"ez-toc-section\" id=\"What_%E2%80%9CGood%E2%80%9D_Looks_Like\"><\/span>What &ldquo;Good&rdquo; Looks Like<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>At best-in-class Shanghai ChiMay installations, condenser water conductivity holds within \u00b1100 \u00b5S\/cm of setpoint 95% of the time. pH stays within \u00b10.15 pH units of the target. Free chlorine stays within the 0.5\u20132.0 ppm ASHRAE 188 window with less than 3% excursion time. Chiller kW\/ton drift over a full year measures under 3%. Those numbers are achievable, and they are the difference between a chiller plant that ages gracefully and one that consumes a growing utility bill each summer.<\/p>\n<h2 id=\"closing-comment\"><span class=\"ez-toc-section\" id=\"Closing_Comment\"><\/span>Closing Comment<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Cooling-tower water quality is not an environmental compliance chore; it is the biggest continuous-operations lever a chiller plant has, second only to load management. Sensors and control loops from Shanghai ChiMay make the lever measurable. The rest is discipline.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>How Does Cooling-Tower Water Quality Drive Chiller Plant Efficiency? Answers from Shanghai ChiMay Chiller plants are the most electricity-hungry machines in a modern commercial building or data center. A single 500-ton centrifugal chiller consumes roughly 250\u2013400 kW at full load, and its efficiency\u2014expressed as kW per ton or as COP\u2014swings by 10\u201325% over a season&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false},"categories":[1],"tags":[158,134429],"translation":{"provider":"WPGlobus","version":"2.12.0","language":"ru","enabled_languages":["en","es","fr","ru","ar"],"languages":{"en":{"title":true,"content":true,"excerpt":false},"es":{"title":false,"content":false,"excerpt":false},"fr":{"title":false,"content":false,"excerpt":false},"ru":{"title":false,"content":false,"excerpt":false},"ar":{"title":false,"content":false,"excerpt":false}}},"_links":{"self":[{"href":"https:\/\/shchimay.com\/ru\/wp-json\/wp\/v2\/posts\/31153"}],"collection":[{"href":"https:\/\/shchimay.com\/ru\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/shchimay.com\/ru\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/shchimay.com\/ru\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/shchimay.com\/ru\/wp-json\/wp\/v2\/comments?post=31153"}],"version-history":[{"count":0,"href":"https:\/\/shchimay.com\/ru\/wp-json\/wp\/v2\/posts\/31153\/revisions"}],"wp:attachment":[{"href":"https:\/\/shchimay.com\/ru\/wp-json\/wp\/v2\/media?parent=31153"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/shchimay.com\/ru\/wp-json\/wp\/v2\/categories?post=31153"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/shchimay.com\/ru\/wp-json\/wp\/v2\/tags?post=31153"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}