{"id":13308,"date":"2025-07-16T00:02:37","date_gmt":"2025-07-15T22:02:37","guid":{"rendered":"https:\/\/fotovol.com\/renewable-energy\/aerothermal-for-domestic-hot-water-dhw-the-good-the-bad-and-what-they-dont-tell-you\/"},"modified":"2026-02-20T10:11:29","modified_gmt":"2026-02-20T09:11:29","slug":"aerothermal-for-domestic-hot-water-dhw-the-good-the-bad-and-what-they-dont-tell-you","status":"publish","type":"post","link":"https:\/\/fotovol.com\/en\/renewable-energy\/aerothermal-for-domestic-hot-water-dhw-the-good-the-bad-and-what-they-dont-tell-you\/","title":{"rendered":"Aerothermal for Domestic Hot Water (DHW): The good, the bad and what they don&#8217;t tell you"},"content":{"rendered":"\n<p>Are you thinking of installing an <strong>aerothermal<\/strong> system <strong>for domestic hot water<\/strong>? We tell you everything our customers ask us as certified installers of photovoltaic systems from brands such as <strong>Fronius, SMA, Tesla, SolarEdge, Victron, Kostal or Wallbox<\/strong>. Because yes, aerothermal <strong>can be a great idea<\/strong>, but it <strong>is not always for everyone<\/strong>.  <\/p>\n\n<h2 class=\"wp-block-heading\" id=\"key-factors-when-choosing-photovoltaic-dhw-aerothermics\">Key factors when choosing photovoltaic DHW aerothermics<\/h2>\n\n<ol class=\"wp-block-list\">\n<li><strong>Minimum accumulation volume: 180-200 L<\/strong> for 4 persons.<\/li>\n\n\n\n<li><strong>Compatibility with external solar control signals<\/strong> (e.g., activating the fan heater when there is a surplus).<\/li>\n\n\n\n<li><strong>Installation flexibility<\/strong>: initially operating in <strong>recirculation mode<\/strong> (without outdoor unit) and later adaptable to <strong>outdoor air<\/strong>.<\/li>\n\n\n\n<li><strong>High efficiency (COP \u2265 4.5, class A+++)<\/strong><\/li>\n\n\n\n<li><strong>Low sound level<\/strong> if installed near inhabited areas.<\/li>\n\n\n\n<li><strong>Outdoor temperature range compatible with your local climate (ideal down to -20 \u00baC or -25 \u00baC).<\/strong><\/li>\n\n\n\n<li><strong>Quality components<\/strong> and ease of maintenance (stainless steel tanks are better than enameled ones).<\/li>\n<\/ol>\n\n<h2 class=\"wp-block-heading\" id=\"the-good-thing-about-aerothermics\">The good thing about Aerothermics<\/h2>\n\n<ul class=\"wp-block-list\">\n<li><strong>High energy efficiency<\/strong>: Equipment with COP &gt; 4.5 consumes very little electricity to heat the water.<\/li>\n\n\n\n<li><strong>Ideal for photovoltaic<\/strong>: You can program the fan heater to work when you have solar surpluses \u2192 maximum self-consumption.<\/li>\n\n\n\n<li><strong>Quiet models<\/strong>: There are options with indoor units from 28 dB, almost imperceptible.<\/li>\n\n\n\n<li><strong>Simple installation and maintenance<\/strong>: If you replace an electric boiler, no complex work is required.<\/li>\n\n\n\n<li><strong>Sustainable and gas-free<\/strong>: No combustion or emissions, only electricity (and better if it comes from the sun!).<\/li>\n<\/ul>\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p><strong>Real example:<\/strong><br\/>We recently installed a Panasonic Aquarea in a 4-person household with Fronius panels and Tesla Powerwall battery. The equipment was programmed to activate only when there is a solar surplus. Result: 100% of DHW covered between March and October with free energy.  <\/p>\n<\/blockquote>\n\n<h2 class=\"wp-block-heading\" id=\"we-must-also-know-what-is-wrong-with-aerothermics\">We must also know what is wrong with Aerothermics.<\/h2>\n\n<ul class=\"wp-block-list\">\n<li><strong>High initial investment<\/strong>: Between \u20ac6,000 and \u20ac9,000, although it is amortized in a few years.<\/li>\n\n\n\n<li><strong>Low efficiency with extreme cold<\/strong>: You need a model that works well at -20 \u00baC or below.<\/li>\n\n\n\n<li><strong>Requires space (indoor or outdoor)<\/strong>: Either you have outdoor air available, or you need recirculation mode.<\/li>\n\n\n\n<li><strong>Not all integrate well with photovoltaics<\/strong>: Many models allow it, but you need someone who knows how to integrate it correctly (this is where Fotovol comes in!).<\/li>\n<\/ul>\n\n<h2 class=\"wp-block-heading\" id=\"quick-comparison-dhw-fan-heater-for-4-persons\">Quick comparison: DHW fan heater for 4 persons<\/h2>\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Make \/ Model<\/th><th>Power heating\/cooling<\/th><th>COP<\/th><th>ACS Volume<\/th><th>Noise int\/ext<\/th><th>Min. working temp. <\/th><th>Price approx.<\/th><\/tr><\/thead><tbody><tr><td><strong>Panasonic Aquarea All in One<\/strong><\/td><td>9 \/ 8.2 kW<\/td><td>4.48<\/td><td>185 L<\/td><td>28 \/ 59 dB<\/td><td>-20 \u00baC<\/td><td><strong>5.900 \u20ac<\/strong><\/td><\/tr><tr><td><strong>Mitsubishi Ecodan<\/strong><\/td><td>8.5 \/ 7.5 kW<\/td><td>4.8<\/td><td>200 L<\/td><td>40 \/ 58 dB<\/td><td>-20 \u00baC<\/td><td><strong>6.500 \u20ac<\/strong><\/td><\/tr><tr><td><strong>Vaillant aroTHERM Plus<\/strong><\/td><td>9 \/ 7.5 kW<\/td><td>4.79<\/td><td>185 L<\/td><td>29 \/ 39 dB<\/td><td>-25 \u00baC<\/td><td><strong>8.700 \u20ac<\/strong><\/td><\/tr><tr><td><strong>Hitachi Yutaki S Combi 2.0<\/strong><\/td><td>8 \/ 6.5 kW<\/td><td>4.6<\/td><td>220 L<\/td><td>37 \/ 54 dB<\/td><td>-20 \u00baC<\/td><td><strong>6.200 \u20ac<\/strong><\/td><\/tr><tr><td><strong>Daikin Altherma 3 Supra<\/strong><\/td><td>7.5 \/ 5.35 kW<\/td><td>4.6<\/td><td>180 L<\/td><td>28 \/ 62 dB<\/td><td>-25 \u00baC<\/td><td><strong>6.600 \u20ac<\/strong><\/td><\/tr><\/tbody><\/table><\/figure>\n\n<p><\/p>\n\n<h2 class=\"wp-block-heading\" id=\"why-choose-us-as-an-installer-of-aerothermal-energy\">  Why choose us as an installer of aerothermal energy?<\/h2>\n\n<p>Because <a href=\"https:\/\/fotovol.com\/en\/our-services\/aerothermal\/\" data-type=\"servei\" data-id=\"10750\">wenot only install aerothermal<\/a>, we are also certified experts in the <strong>leading<\/strong> brands <strong>in photovoltaics and storage.<\/strong> That allows us to: <\/p>\n\n<ul class=\"wp-block-list\">\n<li>Coordinate <strong>activation for solar surplus<\/strong> reliably.<\/li>\n\n\n\n<li>Design systems that maximize <strong>self-consumption and efficiency<\/strong>.<\/li>\n\n\n\n<li>Configure everything from <strong>a single interface or app<\/strong> when possible.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Everything you need to know about hot water aerothermal: the best, the worst and how to integrate it with your solar installation. Practical and straightforward information. <\/p>\n","protected":false},"author":7,"featured_media":13294,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[104],"tags":[],"class_list":["post-13308","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-renewable-energy"],"acf":[],"_links":{"self":[{"href":"https:\/\/fotovol.com\/en\/wp-json\/wp\/v2\/posts\/13308","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fotovol.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fotovol.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fotovol.com\/en\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/fotovol.com\/en\/wp-json\/wp\/v2\/comments?post=13308"}],"version-history":[{"count":1,"href":"https:\/\/fotovol.com\/en\/wp-json\/wp\/v2\/posts\/13308\/revisions"}],"predecessor-version":[{"id":17863,"href":"https:\/\/fotovol.com\/en\/wp-json\/wp\/v2\/posts\/13308\/revisions\/17863"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/fotovol.com\/en\/wp-json\/wp\/v2\/media\/13294"}],"wp:attachment":[{"href":"https:\/\/fotovol.com\/en\/wp-json\/wp\/v2\/media?parent=13308"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fotovol.com\/en\/wp-json\/wp\/v2\/categories?post=13308"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fotovol.com\/en\/wp-json\/wp\/v2\/tags?post=13308"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}