{"id":4657,"date":"2026-09-11T02:00:00","date_gmt":"2026-09-11T02:00:00","guid":{"rendered":"https:\/\/www.26yc.com\/california-title-24-heat-recovery\/"},"modified":"2026-10-08T23:36:09","modified_gmt":"2026-10-09T06:36:09","slug":"california-title-24-heat-recovery","status":"publish","type":"post","link":"https:\/\/www.26yc.com\/es\/california-title-24-heat-recovery\/","title":{"rendered":"California Title 24 Heat Recovery"},"content":{"rendered":"<p><strong>California Title 24, Part 6<\/strong> (the Building Energy Efficiency Standards) is the most aggressive state energy code in the U.S., and its 2022 edition &mdash; effective 1 January 2023, with a July 2024 Supplement &mdash; puts heat recovery at the center of both nonresidential and multifamily compliance. This article distills the recovery provisions that trigger HRV\/ERV specification in California.<\/p>\n<h2>Nonresidential Exhaust Air Heat Recovery<\/h2>\n<p>The 2022 code adds prescriptive requirements for <strong>exhaust air heat recovery<\/strong> based on climate zone, percent of outdoor air, and annual operating hours (Tables 140.4-J and 140.4-K). It also adds a dedicated <strong>DOAS prescriptive path<\/strong> (&sect;140.4(p)). A key interaction: a cooling system combined with a DOAS that includes exhaust-air heat recovery is exempt from the economizer requirement below 54,000 BTU\/h, whereas a standalone unit needs an economizer above 33,000 BTU\/h.<\/p>\n<table>\n<tr>\n<th>Elemento<\/th>\n<th>Title 24 2022 provision<\/th>\n<\/tr>\n<tr>\n<td>DOAS exhaust-air heat recovery<\/td>\n<td>Prescriptive design path added (&sect;140.4(p))<\/td>\n<\/tr>\n<tr>\n<td>Economizer relief<\/td>\n<td>DOAS + recovery allowed &lt; 54,000 BTU\/h without economizer<\/td>\n<\/tr>\n<tr>\n<td>Exhaust recovery tables<\/td>\n<td>140.4-J (by climate zone \/ % OA), 140.4-K (by operating hours)<\/td>\n<\/tr>\n<tr>\n<td>Filtration<\/td>\n<td>MERV 13 minimum on mechanical ventilation supply (&sect;120.1(c)1)<\/td>\n<\/tr>\n<\/table>\n<h2>Multifamily HRV\/ERV Mandate<\/h2>\n<p>For balanced-ventilation multifamily dwelling units in <strong>Climate Zones 1&ndash;2 and 11&ndash;16<\/strong>, the code prescribes a heat or energy recovery ventilator with a <strong>minimum sensible heat recovery effectiveness of 67%<\/strong> at design conditions. Fan efficacy limits are strict:<\/p>\n<ul>\n<li>Unitary ERV\/HRV: fan efficacy &le; 0.6 W\/cfm (a mandatory 1.0 W\/cfm floor applies in all climate zones).<\/li>\n<li>Central ERV\/HRV (multi-unit): &le; 1.2 W\/cfm, and a <strong>bypass function<\/strong> is required so intake air can bypass the core like an economizer.<\/li>\n<\/ul>\n<h2>Decarbonization Direction<\/h2>\n<p>The 2022 code strengthens the push from gas to heat pumps (&sect;140.4(a)2) and targets net-zero-energy commercial buildings by 2030. Recovery is the demand-reduction step that makes an all-electric, heat-pump strategy affordable. For the cross-jurisdiction picture, see the <a href=\"https:\/\/www.26yc.com\/es\/building-code-heat-recovery-mandate\/\">building code heat recovery mandate<\/a> comparison, and for the federal floor see <a href=\"https:\/\/www.26yc.com\/es\/ashrae-90-1-heat-recovery-requirements\/\">ASHRAE 90.1-2022<\/a> (50% minimum). California&#8217;s 67% sensible floor for multifamily is notably higher than the federal 50% enthalpy floor.<\/p>\n<h2>Sizing Note<\/h2>\n<p>Specify the core and verify pressure drop inside the <a href=\"https:\/\/www.26yc.com\/es\/ahu-selection-calculation\/\">AHU selection calculation<\/a>. Pair a non-rotating <a href=\"https:\/\/www.26yc.com\/es\/membrane-energy-recovery-ventilation\/\">membrane core<\/a> where cross-contamination control matters; otherwise a wheel clears the 67% threshold comfortably &mdash; but watch frost, per <a href=\"https:\/\/www.26yc.com\/es\/energy-recovery-wheel-troubleshooting\/\">energy recovery wheel troubleshooting<\/a>.<\/p>\n<h2>Preguntas frecuentes<\/h2>\n<p><strong>What does Title 24 2022 require for nonresidential exhaust recovery?<\/strong><br \/>Prescriptive exhaust-air heat recovery based on climate zone, percent outdoor air, and operating hours, plus a dedicated DOAS prescriptive path.<\/p>\n<p><strong>What is the multifamily HRV or ERV mandate?<\/strong><br \/>In climate zones 1 to 2 and 11 to 16, a minimum 67% sensible effectiveness at design conditions, with strict fan-efficacy limits and a required bypass function.<\/p>\n<p><strong>How does recovery interact with the economizer rule?<\/strong><br \/>A DOAS with exhaust-air heat recovery is exempt from the economizer below 54,000 BTU\/h, whereas a standalone unit needs one above 33,000 BTU\/h.<\/p>\n<p><strong>How does Title 24 compare to federal 90.1?<\/strong><br \/>California&#039;s 67% multifamily sensible floor is higher than the federal 50% enthalpy floor, and it pushes decarbonization via heat pumps.<\/p>\n<div class=\"yc-related\">\n<h3>Art\u00edculos relacionados<\/h3>\n<ul>\n<li><a href=\"https:\/\/www.26yc.com\/es\/why-bess-pv-inverter-counter-flow-air-to-air\/\" title=\"Why Energy Storage Cabinets and PV Inverters Use Counter-Flow Air-to-Air Heat Exchangers\">Why Energy Storage Cabinets and PV Inverters Use Counter-Flow Air-to-Air Heat Exchangers<\/a><\/li>\n<\/ul>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>California Title 24, Part 6 (the Building Energy Efficiency Standards) is the most aggressive state energy code in the U.S., and its 2022 edition &mdash; effective 1 January 2023, with a July 2024 Supplement &mdash; puts heat recovery at the center of both nonresidential and multifamily compliance. This article distills the recovery provisions that trigger [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[197,241],"tags":[162,214],"class_list":["post-4657","post","type-post","status-publish","format-standard","hentry","category-encyclopedia","category-standards-codes","tag-heat-recovery","tag-standards"],"_links":{"self":[{"href":"https:\/\/www.26yc.com\/es\/wp-json\/wp\/v2\/posts\/4657","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.26yc.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.26yc.com\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.26yc.com\/es\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.26yc.com\/es\/wp-json\/wp\/v2\/comments?post=4657"}],"version-history":[{"count":2,"href":"https:\/\/www.26yc.com\/es\/wp-json\/wp\/v2\/posts\/4657\/revisions"}],"predecessor-version":[{"id":5138,"href":"https:\/\/www.26yc.com\/es\/wp-json\/wp\/v2\/posts\/4657\/revisions\/5138"}],"wp:attachment":[{"href":"https:\/\/www.26yc.com\/es\/wp-json\/wp\/v2\/media?parent=4657"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.26yc.com\/es\/wp-json\/wp\/v2\/categories?post=4657"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.26yc.com\/es\/wp-json\/wp\/v2\/tags?post=4657"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}