{"product_id":"cozy-heat-o-thru-wall-sauna-stove","title":"Harvia Cozy Heat O Thru-Wall Sauna Stove - 4745010348044","description":"\u003ch2\u003eHarvia Cozy Heat O Thru-Wall Sauna Stove - 4745010348044\u003c\/h2\u003e\n\u003cp\u003eCozy Heat has taken the art of crafting sauna stoves to new heights with elevated craftsmanship and durability. The key component, a 5mm-thick stainless steel flame cutter, ensures exceptional longevity and resilience. Handcrafted in Estonia, where sauna bathing is a cherished tradition, the wood-fired stove delivers mild, long-lasting heat for a truly authentic experience. Designed for pouring water over hot stones, the O TW creates intense, luxurious steam that enhances your sauna session. Featuring a unique through-the-wall design, the O TW allows you to load firewood from outside the sauna, while its circular rim design improves both the stove's aesthetic and heat distribution, creating an efficient and satisfying sauna experience.\u003c\/p\u003e\n\u003ch5\u003eWhat our Experts Think\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli data-section-id=\"4bb5eo\" data-start=\"27\" data-end=\"164\"\u003ePremium \u003cstrong data-start=\"37\" data-end=\"114\"\u003eHarvia Cozy Heat O Thru-Wall wood-burning sauna stove (SKU 4745010348044)\u003c\/strong\u003e designed for authentic Nordic sauna performance\u003c\/li\u003e\n\u003cli data-section-id=\"7b7u1t\" data-start=\"165\" data-end=\"278\"\u003eUnique \u003cstrong data-start=\"174\" data-end=\"209\"\u003ethrough-the-wall firebox system\u003c\/strong\u003e allows safe and convenient firewood loading from outside the sauna\u003c\/li\u003e\n\u003cli data-section-id=\"1ysyvjt\" data-start=\"279\" data-end=\"422\"\u003eHandcrafted in Estonia for \u003cstrong data-start=\"308\" data-end=\"343\"\u003emild, long-lasting radiant heat\u003c\/strong\u003e ideal for extended relaxation sessions \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"15k9ux\" data-start=\"423\" data-end=\"580\"\u003eHigh-efficiency combustion reduces fuel use by \u003cstrong data-start=\"472\" data-end=\"509\"\u003e25–40% compared to similar stoves\u003c\/strong\u003e for improved operating economy \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"12a3bg4\" data-start=\"581\" data-end=\"684\"\u003eProduces \u003cstrong data-start=\"592\" data-end=\"628\"\u003erich, high-quality steam (löyly)\u003c\/strong\u003e when water is poured over the large heated stone mass\u003c\/li\u003e\n\u003cli data-section-id=\"11eubo\" data-start=\"685\" data-end=\"839\"\u003eBuilt with \u003cstrong data-start=\"698\" data-end=\"763\"\u003eheavy-duty steel construction and reinforced 5mm flame cutter\u003c\/strong\u003e for long-term durability and safety \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"o7gnbb\" data-start=\"840\" data-end=\"958\"\u003eEngineered for \u003cstrong data-start=\"857\" data-end=\"909\"\u003ecleaner emissions and improved airflow stability\u003c\/strong\u003e, supporting more efficient burning performance\u003c\/li\u003e\n\u003cli data-section-id=\"1okciok\" data-start=\"959\" data-end=\"1071\"\u003eDesigned for \u003cstrong data-start=\"974\" data-end=\"1042\"\u003emedium to large sauna rooms (approx. 12–18kW depending on setup)\u003c\/strong\u003e with strong heat retention\u003c\/li\u003e\n\u003cli data-section-id=\"1e1n2eu\" data-start=\"1072\" data-end=\"1203\"\u003eIdeal for users wanting a \u003cstrong data-start=\"1100\" data-end=\"1203\"\u003etraditional wood-fired sauna experience with modern convenience and thru-wall loading functionality\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch5\u003eQ\u0026amp;A\u003c\/h5\u003e\n\u003cp data-start=\"79\" data-end=\"348\"\u003e\u003cstrong data-start=\"79\" data-end=\"141\"\u003eQ: What type of sauna heater is the Cozy Heat O Thru-Wall?\u003c\/strong\u003e\u003cbr data-start=\"141\" data-end=\"144\"\u003eA: It is a \u003cstrong data-start=\"155\" data-end=\"215\"\u003ewood-burning sauna stove with a through-the-wall firebox\u003c\/strong\u003e, allowing you to load wood from outside the sauna for cleaner and more convenient operation. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-start=\"350\" data-end=\"584\"\u003e\u003cstrong data-start=\"350\" data-end=\"392\"\u003eQ: What sauna size is it suitable for?\u003c\/strong\u003e\u003cbr data-start=\"392\" data-end=\"395\"\u003eA: The 12kW version is designed for \u003cstrong data-start=\"431\" data-end=\"488\"\u003esmall to medium sauna rooms (approx. 210–423 cu. ft.)\u003c\/strong\u003e, while higher output versions can handle larger spaces. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-start=\"586\" data-end=\"823\"\u003e\u003cstrong data-start=\"586\" data-end=\"642\"\u003eQ: What is the main benefit of the thru-wall design?\u003c\/strong\u003e\u003cbr data-start=\"642\" data-end=\"645\"\u003eA: It lets you \u003cstrong data-start=\"660\" data-end=\"705\"\u003efeed firewood from outside the sauna room\u003c\/strong\u003e, keeping the interior cleaner, cooler, and more comfortable during refueling. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-start=\"825\" data-end=\"1065\"\u003e\u003cstrong data-start=\"825\" data-end=\"866\"\u003eQ: What kind of heat does it produce?\u003c\/strong\u003e\u003cbr data-start=\"866\" data-end=\"869\"\u003eA: It delivers a \u003cstrong data-start=\"886\" data-end=\"921\"\u003emild, long-lasting radiant heat\u003c\/strong\u003e with strong steam (löyly) when water is poured over heated stones, ideal for traditional sauna bathing. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-start=\"1067\" data-end=\"1201\"\u003e\u003cstrong data-start=\"1067\" data-end=\"1102\"\u003eQ: Does it require electricity?\u003c\/strong\u003e\u003cbr data-start=\"1102\" data-end=\"1105\"\u003eA: No. It is a \u003cstrong data-start=\"1120\" data-end=\"1147\"\u003efully wood-fired heater\u003c\/strong\u003e, operating without electricity or digital controls.\u003c\/p\u003e\n\u003cp data-start=\"1203\" data-end=\"1364\"\u003e\u003cstrong data-start=\"1203\" data-end=\"1241\"\u003eQ: How does it create sauna steam?\u003c\/strong\u003e\u003cbr data-start=\"1241\" data-end=\"1244\"\u003eA: Water is poured over \u003cstrong data-start=\"1268\" data-end=\"1288\"\u003ehot sauna stones\u003c\/strong\u003e, producing soft, humid steam that enhances relaxation and heat intensity.\u003c\/p\u003e\n\u003cp data-start=\"1366\" data-end=\"1558\"\u003e\u003cstrong data-start=\"1366\" data-end=\"1400\"\u003eQ: What is the stone capacity?\u003c\/strong\u003e\u003cbr data-start=\"1400\" data-end=\"1403\"\u003eA: It requires about \u003cstrong data-start=\"1424\" data-end=\"1460\"\u003e265 lbs (120 kg) of sauna stones\u003c\/strong\u003e, which helps stabilize heat and produce consistent steam. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-start=\"1560\" data-end=\"1782\"\u003e\u003cstrong data-start=\"1560\" data-end=\"1598\"\u003eQ: What materials is it made from?\u003c\/strong\u003e\u003cbr data-start=\"1598\" data-end=\"1601\"\u003eA: It uses a \u003cstrong data-start=\"1614\" data-end=\"1684\"\u003edurable steel construction with a 5mm stainless steel flame cutter\u003c\/strong\u003e, designed for high heat resistance and long service life.\u003c\/p\u003e\n\u003ch5\u003eMaintenance Tips\u003c\/h5\u003e\n\u003csection class=\"text-token-text-primary w-full focus:outline-none [--shadow-height:45px] has-data-writing-block:pointer-events-none has-data-writing-block:-mt-(--shadow-height) has-data-writing-block:pt-(--shadow-height) [\u0026amp;:has([data-writing-block])\u0026gt;*]:pointer-events-auto [content-visibility:auto] supports-[content-visibility:auto]:[contain-intrinsic-size:auto_100lvh] R6Vx5W_threadScrollVars scroll-mb-[calc(var(--scroll-root-safe-area-inset-bottom,0px)+var(--thread-response-height))] scroll-mt-[calc(var(--header-height)+min(200px,max(70px,20svh)))]\" dir=\"auto\" data-turn-id=\"request-WEB:f7051717-371b-4d73-b829-ae53c5f2d208-63\" data-testid=\"conversation-turn-30\" data-scroll-anchor=\"false\" data-turn=\"assistant\"\u003e\n\u003cdiv class=\"text-base my-auto mx-auto pb-10 [--thread-content-margin:var(--thread-content-margin-xs,calc(var(--spacing)*4))] @w-sm\/main:[--thread-content-margin:var(--thread-content-margin-sm,calc(var(--spacing)*6))] @w-lg\/main:[--thread-content-margin:var(--thread-content-margin-lg,calc(var(--spacing)*16))] px-(--thread-content-margin)\"\u003e\n\u003cdiv class=\"[--thread-content-max-width:40rem] @w-lg\/main:[--thread-content-max-width:48rem] mx-auto max-w-(--thread-content-max-width) flex-1 group\/turn-messages focus-visible:outline-hidden relative flex w-full min-w-0 flex-col agent-turn\"\u003e\n\u003cdiv class=\"flex max-w-full flex-col gap-4 grow\"\u003e\n\u003cdiv data-message-author-role=\"assistant\" data-message-id=\"8d2362cc-b1c1-423e-ba60-30f3808b0e47\" data-turn-start-message=\"true\" dir=\"auto\" data-message-model-slug=\"gpt-5-3-mini\" class=\"min-h-8 text-message relative flex w-full flex-col items-end gap-2 text-start break-words whitespace-normal outline-none keyboard-focused:focus-ring [.text-message+\u0026amp;]:mt-1\" tabindex=\"0\"\u003e\n\u003cdiv class=\"flex w-full flex-col gap-1 empty:hidden\"\u003e\n\u003cdiv class=\"markdown prose dark:prose-invert w-full wrap-break-word light markdown-new-styling\"\u003e\n\u003cul data-start=\"81\" data-end=\"1092\"\u003e\n\u003cli data-section-id=\"16wvf7t\" data-start=\"81\" data-end=\"168\"\u003eRemove ash after every use to maintain strong airflow and clean, efficient burning.\u003c\/li\u003e\n\u003cli data-section-id=\"hytl5x\" data-start=\"169\" data-end=\"261\"\u003eUse only dry, seasoned firewood to reduce soot and prevent creosote buildup in the flue.\u003c\/li\u003e\n\u003cli data-section-id=\"1ncvulw\" data-start=\"262\" data-end=\"380\"\u003eClean chimney and flue regularly to ensure safe draft and prevent blockages. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"1izdsb4\" data-start=\"381\" data-end=\"494\"\u003eRe-stack sauna stones periodically; keep them loosely arranged for proper heat circulation and steam quality.\u003c\/li\u003e\n\u003cli data-section-id=\"1mvoizg\" data-start=\"495\" data-end=\"587\"\u003eReplace cracked or crumbling stones to avoid airflow restriction and overheating issues.\u003c\/li\u003e\n\u003cli data-section-id=\"1hy7tz2\" data-start=\"588\" data-end=\"678\"\u003eInspect thru-wall firebox and loading chamber for soot buildup, warping, or seal wear.\u003c\/li\u003e\n\u003cli data-section-id=\"fn6ypo\" data-start=\"679\" data-end=\"777\"\u003eCheck door seals and joints regularly to prevent air leaks and maintain combustion efficiency.\u003c\/li\u003e\n\u003cli data-section-id=\"1t4u9mg\" data-start=\"778\" data-end=\"869\"\u003eWipe exterior steel surfaces after cooling to prevent rust and maintain finish quality.\u003c\/li\u003e\n\u003cli data-section-id=\"1d4uyn2\" data-start=\"870\" data-end=\"961\"\u003eEnsure sauna room ventilation remains clear for safe combustion and stable heat output.\u003c\/li\u003e\n\u003cli data-section-id=\"1bellnn\" data-start=\"962\" data-end=\"1092\"\u003eSchedule annual chimney inspection and deep cleaning for long-term safety and performance\u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"mt-3 w-full empty:hidden\"\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/section\u003e","brand":"Harvia","offers":[{"title":"Default Title","offer_id":45598864146623,"sku":"4745010348044","price":1342.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0683\/5703\/0079\/files\/cozy-heat-sauna-stove-12-o-tw-front-Edit_0.png?v=1777388126","url":"https:\/\/www.mybackyardzone.com\/products\/cozy-heat-o-thru-wall-sauna-stove","provider":"Your Outdoor Setup Starts Here","version":"1.0","type":"link"}