{"product_id":"oso-accu-a60-60l-stainless-steel-buffer-tank-for-heat-pumps-nanopur-insulation","title":"OSO ACCU A60 60L Stainless Steel Buffer Tank for Heat Pumps | NANOPUR Insulation","description":"\u003cstyle\u003e\n  .oso-buf-wrap{font-family:inherit;color:inherit;line-height:1.7;font-size:16px}\n  .oso-buf-wrap p,.oso-buf-wrap li,.oso-buf-wrap td,.oso-buf-wrap th{font-size:16px!important;line-height:1.7}\n  .oso-buf-wrap h2{font-size:22px!important;font-weight:700;color:#1a3a5c;border-bottom:3px solid #0077b6;padding-bottom:6px;margin:2rem 0 1rem;line-height:1.3}\n  .oso-buf-wrap p{margin:0 0 1rem}\n  .oso-buf-wrap ul{padding-left:1.5rem;margin:0 0 1rem}\n  .oso-buf-wrap ul li{margin-bottom:0.5rem}\n\n  .oso-buf-badge{display:inline-block;font-size:13px!important;font-weight:700;border-radius:4px;padding:2px 10px;margin-right:5px;margin-bottom:4px;vertical-align:middle}\n  .oso-buf-badge.blue{background:#0077b6;color:#fff}\n  .oso-buf-badge.navy{background:#1a3a5c;color:#fff}\n  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.oso-buf-why-box{background:#fff3cd;border:1px solid #ffc107;border-radius:5px;padding:0.9rem 1.1rem;margin:0.8rem 0 1.2rem}\n\n  .oso-buf-spec-table{width:100%;border-collapse:collapse;margin-bottom:1.5rem}\n  .oso-buf-spec-table th{background:#1a3a5c;color:#fff!important;text-align:left;padding:0.7rem 1rem;font-weight:700;font-size:16px!important}\n  .oso-buf-spec-table td{padding:0.6rem 1rem;border-bottom:1px solid #bde0f5;vertical-align:top;font-size:16px!important}\n  .oso-buf-spec-table tr:nth-child(even) td{background:#e0f2fe}\n  .oso-buf-spec-table td:first-child{font-weight:600;color:#111;width:44%}\n\n  .oso-buf-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:0.85rem;margin-bottom:1.2rem}\n  .oso-buf-card{background:#e0f2fe;border:1px solid #90caf9;border-radius:6px;padding:1rem 1.1rem;line-height:1.6}\n  .oso-buf-card strong{display:block;color:#1a3a5c;margin-bottom:0.35rem;font-size:16px!important}\n\n  .oso-buf-faq-item{border-bottom:1px solid #bde0f5;padding:0.9rem 0}\n  .oso-buf-faq-item:last-child{border-bottom:none}\n  .oso-buf-faq-item strong{color:#1a3a5c;font-size:16px!important;display:block;margin-bottom:0.3rem}\n\u003c\/style\u003e\n\u003cdiv class=\"oso-buf-wrap\"\u003e\n\n  \u003c!-- Badge pills --\u003e\n  \u003cdiv style=\"margin-bottom:1rem\"\u003e\n    \u003cspan class=\"oso-buf-badge blue\"\u003eOSO ACCU A60\u003c\/span\u003e\n    \u003cspan class=\"oso-buf-badge navy\"\u003e60 Litres\u003c\/span\u003e\n    \u003cspan class=\"oso-buf-badge green\"\u003eStainless Steel\u003c\/span\u003e\n    \u003cspan class=\"oso-buf-badge grey\"\u003eNANOPUR Insulation\u003c\/span\u003e\n    \u003cspan class=\"oso-buf-badge grey\"\u003eSKU 11009165\u003c\/span\u003e\n  \u003c\/div\u003e\n\n  \u003c!-- Feature strip --\u003e\n  \u003cdiv class=\"oso-buf-feature-strip\"\u003e\n    \u003cdiv class=\"oso-buf-feat\"\u003e\n\u003cdiv class=\"feat-icon\"\u003e🏗️\u003c\/div\u003e\n\u003cdiv class=\"feat-label\"\u003eStainless Steel\u003c\/div\u003e\n\u003cdiv class=\"feat-value\"\u003eEVERLAST™ titanium alloy\u003c\/div\u003e\n\u003c\/div\u003e\n    \u003cdiv class=\"oso-buf-feat\"\u003e\n\u003cdiv class=\"feat-icon\"\u003e🌡️\u003c\/div\u003e\n\u003cdiv class=\"feat-label\"\u003eNANOPUR Insulation\u003c\/div\u003e\n\u003cdiv class=\"feat-value\"\u003eClass-leading heat retention\u003c\/div\u003e\n\u003c\/div\u003e\n    \u003cdiv class=\"oso-buf-feat\"\u003e\n\u003cdiv class=\"feat-icon\"\u003e🔄\u003c\/div\u003e\n\u003cdiv class=\"feat-label\"\u003eDual Connections\u003c\/div\u003e\n\u003cdiv class=\"feat-value\"\u003eFlow + return both sides\u003c\/div\u003e\n\u003c\/div\u003e\n    \u003cdiv class=\"oso-buf-feat\"\u003e\n\u003cdiv class=\"feat-icon\"\u003e🛡️\u003c\/div\u003e\n\u003cdiv class=\"feat-label\"\u003eAnti-Clocking\u003c\/div\u003e\n\u003cdiv class=\"feat-value\"\u003eProtects heat pump\u003c\/div\u003e\n\u003c\/div\u003e\n    \u003cdiv class=\"oso-buf-feat\"\u003e\n\u003cdiv class=\"feat-icon\"\u003e📏\u003c\/div\u003e\n\u003cdiv class=\"feat-label\"\u003eCompact: 60L\u003c\/div\u003e\n\u003cdiv class=\"feat-value\"\u003eØ434 × 741mm\u003c\/div\u003e\n\u003c\/div\u003e\n    \u003cdiv class=\"oso-buf-feat\"\u003e\n\u003cdiv class=\"feat-icon\"\u003e🔩\u003c\/div\u003e\n\u003cdiv class=\"feat-label\"\u003eWall Brackets\u003c\/div\u003e\n\u003cdiv class=\"feat-value\"\u003eIncluded\u003c\/div\u003e\n\u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003c!-- Intro box --\u003e\n  \u003cdiv class=\"oso-buf-intro-box\"\u003e\n    \u003cp\u003e\u003cstrong\u003eOSO ACCU A60 — 60L Stainless Steel Buffer Tank for Heat Pumps (SKU 11009165)\u003c\/strong\u003e — 60L (57L actual volume) stainless steel buffer tank  |  NANOPUR insulation  |  Dual flow\/return connections  |  Hydraulic coupling \u0026amp; balancing  |  Anti-clocking protection  |  Cool storage function  |  G½\" air vent + drain  |  Wall brackets included  |  Ø434 × 741mm  |  18 kg  |  ErP C\u003c\/p\u003e\n  \u003c\/div\u003e\n\n  \u003c!-- Why a buffer tank box --\u003e\n  \u003cdiv class=\"oso-buf-why-box\"\u003e\n    \u003cstrong style=\"color:#856404\"\u003eℹ️ Why does my heat pump need a buffer tank?\u003c\/strong\u003e\n    \u003cp style=\"margin:0.3rem 0 0;color:#5a3a00\"\u003eMost air source heat pumps require a minimum flow rate to operate correctly — without sufficient water volume in the system, the heat pump can \"clock\" (short-cycle on and off repeatedly), which reduces efficiency, increases wear and can shorten compressor life. A buffer tank adds volume to the system so the heat pump always has adequate water to heat, allowing it to run in longer, more efficient cycles. A buffer tank is also essential for \u003cstrong\u003edefrost mode\u003c\/strong\u003e — the tank provides the heat energy the pump needs to defrost its evaporator — and for \u003cstrong\u003ecooling\/heating systems\u003c\/strong\u003e where the buffer stores cooled water during summer operation.\u003c\/p\u003e\n  \u003c\/div\u003e\n\n  \u003cp\u003eThe \u003cstrong\u003eOSO ACCU A60\u003c\/strong\u003e is a 60-litre stainless steel buffer tank designed for use with air source heat pumps and solar thermal systems. Built from OSO's EVERLAST™ titanium-alloyed stainless steel and welded using the ULTRAWELD™ process, it is inherently corrosion-resistant — unlike mild steel buffer tanks, it requires no sacrificial anode and no periodic re-pressurisation of protective coatings. NANOPUR insulation ensures minimal standby heat loss (44W) to keep the buffer volume at the right temperature with minimal energy input.\u003c\/p\u003e\n  \u003cp\u003eThe A60 is the most compact tank in the OSO ACCU range, suited to smaller heat pump installations or where space is limited. Its slimline Ø434mm footprint allows it to fit alongside most domestic heat pump units in standard plant rooms, cupboards or utility spaces. Wall brackets are included, allowing the tank to be mounted on a wall where floor space is at an absolute premium — though it can equally stand on the floor.\u003c\/p\u003e\n\n  \u003ch2\u003eKey Features\u003c\/h2\u003e\n  \u003cdiv class=\"oso-buf-grid\"\u003e\n    \u003cdiv class=\"oso-buf-card\"\u003e\n\u003cstrong\u003eHydraulic Coupling \u0026amp; Balancing\u003c\/strong\u003eActs as a hydraulic separator between the heat pump's primary circuit and the heating distribution circuit — decoupling the two so the heat pump can maintain its minimum flow rate independently of the variable demand from the heating zones.\u003c\/div\u003e\n    \u003cdiv class=\"oso-buf-card\"\u003e\n\u003cstrong\u003eAnti-Clocking Protection\u003c\/strong\u003eAdds essential system volume so the heat pump runs in longer, more efficient cycles rather than short-cycling repeatedly. Protects compressor longevity and keeps COP consistently high.\u003c\/div\u003e\n    \u003cdiv class=\"oso-buf-card\"\u003e\n\u003cstrong\u003eDefrost Mode Heat Reserve\u003c\/strong\u003eProvides the thermal mass the heat pump needs to complete a defrost cycle without drawing energy from the heating distribution circuit — critical for reliable operation in colder ambient conditions.\u003c\/div\u003e\n    \u003cdiv class=\"oso-buf-card\"\u003e\n\u003cstrong\u003eCool Storage Function\u003c\/strong\u003eFor heating-cooling heat pump systems, the buffer tank stores cooled water for space cooling while the heat pump simultaneously heats a DHW cylinder — enabling both functions without conflicting demands on the refrigeration circuit.\u003c\/div\u003e\n    \u003cdiv class=\"oso-buf-card\"\u003e\n\u003cstrong\u003eNANOPUR™ Insulation\u003c\/strong\u003eClass-leading insulation technology with thermal performance far surpassing standard Pentane foam — keeps the buffer volume at temperature with minimal standby losses (44W), reducing the energy cost of maintaining system readiness.\u003c\/div\u003e\n    \u003cdiv class=\"oso-buf-card\"\u003e\n\u003cstrong\u003eEVERLAST™ Stainless Steel \u0026amp; ULTRAWELD™\u003c\/strong\u003eTitanium-alloyed stainless steel provides class-leading corrosion resistance. The ULTRAWELD™ welding system and passivation process ensure a sealed, durable tank construction — over 40% lighter than equivalent enamelled steel tanks.\u003c\/div\u003e\n    \u003cdiv class=\"oso-buf-card\"\u003e\n\u003cstrong\u003eDual Flow\/Return Connections\u003c\/strong\u003eDual sets of flow and return connections on opposite sides of the tank provide flexible connection and installation options for a variety of primary and secondary circuit configurations.\u003c\/div\u003e\n    \u003cdiv class=\"oso-buf-card\"\u003e\n\u003cstrong\u003eWall Brackets \u0026amp; Air Vent Included\u003c\/strong\u003eCorrosion-resistant wall brackets for vertical wall mounting are included. A separate G½\" female connection for an automatic air vent, plus a drain connection, are factory-fitted for installation convenience.\u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n  \u003ctable class=\"oso-buf-spec-table\"\u003e\n    \u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eBrand \/ Range\u003c\/td\u003e\n\u003ctd\u003eOSO Hotwater \/ ACCU\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003eACCU A60\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eSKU \/ Product No.\u003c\/td\u003e\n\u003ctd\u003e11009165\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eActual Volume\u003c\/td\u003e\n\u003ctd\u003e57 litres\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eNominal Capacity\u003c\/td\u003e\n\u003ctd\u003e60 litres\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eEnergy Rating (ErP)\u003c\/td\u003e\n\u003ctd\u003eC\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eStandby Heat Loss\u003c\/td\u003e\n\u003ctd\u003e44W\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eTank Material\u003c\/td\u003e\n\u003ctd\u003eEVERLAST™ titanium-alloyed stainless steel\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eConstruction\u003c\/td\u003e\n\u003ctd\u003eULTRAWELD™ — no enamel, no anode required\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eInsulation\u003c\/td\u003e\n\u003ctd\u003eNANOPUR™\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eDiameter (Ø)\u003c\/td\u003e\n\u003ctd\u003e434mm\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eHeight (H)\u003c\/td\u003e\n\u003ctd\u003e741mm\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eWeight (empty)\u003c\/td\u003e\n\u003ctd\u003e18 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eFreight Volume\u003c\/td\u003e\n\u003ctd\u003e0.18 dm³\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003ePlacement\u003c\/td\u003e\n\u003ctd\u003eFloor-standing (wall-mountable with included brackets)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eFlow\/Return Connections\u003c\/td\u003e\n\u003ctd\u003eDual sets — flexible configuration\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eAir Vent Connection\u003c\/td\u003e\n\u003ctd\u003eG½\" F (separate)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eDrain Connection\u003c\/td\u003e\n\u003ctd\u003eYes — factory fitted\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eSensor Pocket\u003c\/td\u003e\n\u003ctd\u003e1× for 6–8mm sensor\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eWall Brackets\u003c\/td\u003e\n\u003ctd\u003eIncluded (corrosion-resistant)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eTypical Applications\u003c\/td\u003e\n\u003ctd\u003eAir source heat pumps, solar thermal, heating-cooling systems\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/table\u003e\n\n  \u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n  \u003cdiv class=\"oso-buf-faq-item\"\u003e\n\u003cstrong\u003eWhat size buffer tank do I need for my heat pump?\u003c\/strong\u003e\u003cp\u003eThe required buffer volume depends on the heat pump output, the number of heating zones, the minimum flow rate of the heat pump and the minimum on-cycle duration specified by the manufacturer. As a general guide, 20–50 litres per kW of heat pump output is a commonly used rule of thumb, though the correct sizing must be calculated for each installation. For a typical 5–10kW domestic heat pump with 2–3 zones, a 60L buffer is often sufficient; larger systems or fewer zones may require 100L or 200L. Always consult the heat pump manufacturer's guidance or MCS documentation for your specific system.\u003c\/p\u003e\n\u003c\/div\u003e\n  \u003cdiv class=\"oso-buf-faq-item\"\u003e\n\u003cstrong\u003eDoes a buffer tank replace the need for a hot water cylinder?\u003c\/strong\u003e\u003cp\u003eNo. A buffer tank stores heating system water (the circuit fluid) at heating temperatures — it is not a domestic hot water (DHW) cylinder. It is used in the primary heating circuit to stabilise heat pump operation. A separate unvented or vented DHW cylinder (or thermal store) is still required to provide hot water to taps and showers.\u003c\/p\u003e\n\u003c\/div\u003e\n  \u003cdiv class=\"oso-buf-faq-item\"\u003e\n\u003cstrong\u003eCan the OSO ACCU be wall-mounted?\u003c\/strong\u003e\u003cp\u003eYes. The A60 comes with corrosion-resistant wall brackets so it can be mounted vertically on a wall — useful in plant rooms or cupboards where floor space is restricted. The tank can equally stand on the floor; both installations are supported.\u003c\/p\u003e\n\u003c\/div\u003e\n  \u003cdiv class=\"oso-buf-faq-item\"\u003e\n\u003cstrong\u003eIs this tank suitable for underfloor heating systems?\u003c\/strong\u003e\u003cp\u003eYes. The OSO ACCU A60 is suitable for use with heat pumps connected to underfloor heating, radiators, fan coil units or any closed heating distribution system. Its dual flow\/return connections make it compatible with a wide variety of primary\/secondary piping configurations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"OSO Hotwater","offers":[{"title":"Default Title","offer_id":63667142033757,"sku":"ACCU A60","price":430.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0958\/2051\/3629\/files\/OSOACCUA200200LStainlessSteelBufferTankforHeatPumps.webp?v=1772364921","url":"https:\/\/qualityheating.co.uk\/products\/oso-accu-a60-60l-stainless-steel-buffer-tank-for-heat-pumps-nanopur-insulation","provider":"AIZO Quality Heating","version":"1.0","type":"link"}