{"id":7990,"date":"2026-07-24T12:32:14","date_gmt":"2026-07-24T09:32:14","guid":{"rendered":"https:\/\/axinar.com\/blog\/water-heater-apartment-building-solutions"},"modified":"2026-07-24T12:32:14","modified_gmt":"2026-07-24T09:32:14","slug":"water-heater-apartment-building-solutions","status":"publish","type":"post","link":"https:\/\/axinar.com\/en\/blog\/water-heater-apartment-building-solutions","title":{"rendered":"Water Heater in an Apartment Building: Solutions When Solar Won&#8217;t Fit"},"content":{"rendered":"<p>Apartment building in Thessaloniki, 4 floors, 12 apartments. The roof is taken up by other owners&#8217; solar tanks, or has restrictions from the general assembly, or the third-floor tenant simply doesn&#8217;t want to spend 6 months on approvals for a hot water tank. In practice, a solar water heater in an apartment building is <strong>hard<\/strong>, even when it&#8217;s technically feasible.<\/p>\n<h2>What the real options are<\/h2>\n<h3>1. Solar water heater on the roof (classic)<\/h3>\n<p>Requires:<\/p>\n<ul>\n<li>Building assembly approval (majority vote, often 51%)<\/li>\n<li>Free roof space with southern orientation<\/li>\n<li>Piping running from the roof down to the apartment (through a lightwell, mechanical room, or externally)<\/li>\n<li>Waterproofing at roof penetrations<\/li>\n<\/ul>\n<p>In practice: feasible mainly in new-build apartments designed for it, or in older ones with a willing assembly.<\/p>\n<h3>2. Solar on the balcony<\/h3>\n<p>Flat collectors mounted on the balcony railing. Option for west- or south-facing apartments.<\/p>\n<ul>\n<li><strong>Pros:<\/strong> individual system, no assembly approval (for private balconies), no roof penetrations<\/li>\n<li><strong>Cons:<\/strong> aesthetics, lower output because the collector is vertical and small, harder pipe routing<\/li>\n<\/ul>\n<h3>3. <a href=\"\/en\/solbox-info\">AXINAR SolBox<\/a>, PV Panel on the Balcony + Existing Water Heater<\/h3>\n<p>This is <strong>the most practical apartment solution<\/strong>. A 300 to 400W PV panel is placed on the balcony or the facade, connects to the <a href=\"\/en\/solbox-info\"><strong>AXINAR SolBox<\/strong><\/a> (DC controller), and feeds the element of the existing electric water heater.<\/p>\n<ul>\n<li><strong>No general assembly approval required<\/strong> (the panel is inside the apartment envelope)<\/li>\n<li><strong>No utility connection required<\/strong> (does not produce AC for the grid)<\/li>\n<li><strong>No inverter required<\/strong><\/li>\n<li><strong>No plumbing changes<\/strong><\/li>\n<li>Works year-round with reduced output on cloudy days<\/li>\n<\/ul>\n<p>The water heater stays the same. Electricity cost drops significantly, since hot water is 25 to 40% of a household&#8217;s power bill.<\/p>\n<h3>4. Heat pump water heater<\/h3>\n<p>A standalone unit that draws heat from ambient air (or from a non-air-conditioned space) and transfers it to water. Good coefficient of performance (COP ~3), but:<\/p>\n<ul>\n<li>Takes up space (kitchen, bathroom, exterior wall)<\/li>\n<li>Has noise (~50 dB)<\/li>\n<li>Draws power from the grid<\/li>\n<li>Significantly higher purchase cost<\/li>\n<\/ul>\n<h2>Comparison for apartment buildings<\/h2>\n<table>\n<thead>\n<tr>\n<th>Solution<\/th>\n<th>Assembly approval<\/th>\n<th>Work on common areas<\/th>\n<th>Works in clouds<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Solar on the roof<\/td>\n<td>Yes<\/td>\n<td>Yes<\/td>\n<td>With backup element<\/td>\n<\/tr>\n<tr>\n<td>Solar on the balcony<\/td>\n<td>Probably<\/td>\n<td>No<\/td>\n<td>With backup element<\/td>\n<\/tr>\n<tr>\n<td><strong>AXINAR SolBox (PV on balcony + existing water heater)<\/strong><\/td>\n<td><strong>No<\/strong><\/td>\n<td><strong>No<\/strong><\/td>\n<td><strong>Reduced<\/strong><\/td>\n<\/tr>\n<tr>\n<td>Heat pump water heater<\/td>\n<td>No<\/td>\n<td>No<\/td>\n<td>Yes, from grid<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>Practical guidance for apartments<\/h2>\n<h3>If you have a south- or west-facing balcony<\/h3>\n<p>The sun reaches you almost all day. A 400W PV panel laid flat or on a railing bracket, connected to <a href=\"\/en\/solbox-info\">AXINAR SolBox<\/a>, gives enough energy for hot water for a 2 to 3 person household. The panel doesn&#8217;t need exact southern orientation (a 30\u00b0 offset left or right only costs 10 to 15%).<\/p>\n<h3>If you have a north-facing balcony<\/h3>\n<p>Hard for PV. A heat pump water heater is a better fit.<\/p>\n<h3>If you&#8217;re in a penthouse with roof access<\/h3>\n<p>The easiest combination: a PV panel on the roof (small footprint, no piping), DC wiring to the water heater inside the apartment.<\/p>\n<div style=\"border:1px solid rgba(221,43,28,.28);border-radius:10px;padding:22px;margin:26px 0;background:rgba(255,255,255,.02);\">\n<div style=\"margin-bottom:14px;\">\n<div style=\"font-family:'Barlow Condensed', sans-serif;font-size:1.35rem;font-weight:700;line-height:1.15;margin-bottom:2px;color:#ffffff;\">AXINAR SolBox for Apartment Buildings<\/div>\n<div style=\"opacity:.85;font-size:.92rem;color:#ffffff;\">Hot water from PV, without assembly approval<\/div>\n<\/p><\/div>\n<div>\n<p style=\"margin:0 0 12px 0;line-height:1.55;color:#ffffff;\">SolBox works with a balcony PV panel, without grid connection, and without work in the common areas. No general assembly vote required.<\/p>\n<ul style=\"margin:0 0 14px 0;padding-left:20px;color:#ffffff;\">\n<li style=\"margin-bottom:6px;\">Light version for 1 to 2 person apartments<\/li>\n<li style=\"margin-bottom:6px;\">Family version for 3 to 4 people<\/li>\n<li style=\"margin-bottom:6px;\">Installation without touching the plumbing<\/li>\n<li style=\"margin-bottom:6px;\">Works with your existing water heater<\/li>\n<\/ul>\n<p>    <a href=\"\/en\/solbox-info\" style=\"display:inline-block !important;background:#dd2b1c !important;color:#ffffff !important;font-family:Barlow Condensed, sans-serif !important;font-size:.9rem !important;font-weight:700 !important;text-transform:uppercase !important;letter-spacing:1.2px !important;padding:10px 22px !important;border-radius:6px !important;text-decoration:none !important;margin-top:10px;\">Free estimate \u2192<\/a>\n  <\/div>\n<\/div>\n<h2>Request a quote<\/h2>\n<p>Send us a photo of the balcony, orientation, and water heater type. We&#8217;ll suggest the right solution.<\/p>\n<p><a href=\"\/en\/contact\" style=\"display:inline-block !important;background:#dd2b1c !important;color:#ffffff !important;font-family:Barlow Condensed, sans-serif !important;font-size:1rem !important;font-weight:700 !important;text-transform:uppercase !important;letter-spacing:1.5px !important;padding:12px 28px !important;border-radius:8px !important;text-decoration:none !important;margin-top:8px;\">Contact us \u2192<\/a><\/p>\n<hr>\n<p><em>See also: <a href=\"\/en\/blog\/convert-electric-water-heater-to-solar-solbox\">SolBox: Complete guide to converting a water heater<\/a>, <a href=\"\/en\/blog\/water-heater-pv-solar-heat-pump-comparison\">Comparison of PV water heater vs solar vs heat pump<\/a>.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Apartment building in Thessaloniki, 4 floors, 12 apartments. The roof is taken up by other owners&#8217; solar tanks, or has [&hellip;]<\/p>\n","protected":false},"author":16,"featured_media":3689,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_eb_attr":"","site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"rank_math_title":"Water Heater for Apartments: Solutions Without Roof Work | AXINAR","rank_math_description":"Solar water heater won't fit or isn't allowed on your apartment building's roof. See practical PV hot water solutions for apartments, with no work on common areas.","footnotes":""},"categories":[176],"tags":[],"class_list":["post-7990","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"_links":{"self":[{"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/posts\/7990","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/users\/16"}],"replies":[{"embeddable":true,"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/comments?post=7990"}],"version-history":[{"count":0,"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/posts\/7990\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/media\/3689"}],"wp:attachment":[{"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/media?parent=7990"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/categories?post=7990"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/tags?post=7990"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}