SOLFEX Unvented Cylinders for Heat Pumps

Last Updated: May 26, 2017 08:04

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Product Details

SOLFEX energy systems offer a complete range of unvented stainless steel cylinders specifically for heat pump applications providing mains pressure domestic hot water.

Utilising an already well established stainless steel unvented hot water cylinder, this product has been developed to maximise the lower temperatures available from the heat pump.

The heat exchanger consists of a multi-pass corrugated stainless steel tube in parallel to reduce the pressure loss whilst maximising the heat exchange. Many medium to large heat pumps need heat exchangers in the store that will cope with the higher flow rates associated with primary temperatures that are typically 50˚C or 60˚C.

Due to the fact that many heat pumps will not raise the stored water temperature to 60˚C, which is necessary to prevent the growth of legionella, the SOLFEX range of cylinders are supplied with an immersion heater and a thermostat.

Features & Benefits

Special Features

  • The latest and highest quality Duplex Stainless Steel

  • 25 year guarantee.

  • Fast reheat rate from its purpose designed low resistance coil.

  • One of the highest insulation ratings on offer today.

  • Supplied with all the necessary connections including a dry thermostat pocket.

Duplex Stainless Steel

The latest high specification Duplex stainless steel resists all forms of corrosion including crevice and stress whilst its high mechanical strength gives it durability. The very latest automated welding procedures along with full post weld treatments guarantee welds that are as strong as the metal. All cylinders are factory pressure tested to a full 12 bar which is four times the normal working pressure.

Corrugated Stainless Steel Coil

Solfex cylinders use a high heat transfer corrugated tube heat exchanger to give a 20% faster recovery than plain tube. It is also lighter and stronger than plain tube making the vessel the lightest and easiest to handle on site.

Heat Loss

All Solfex cylinders are manufactured using the very latest HCFC free EnviroFoam insulation. This has an Ozone Depletion Potential (ODP) of zero and an industry leading Global Warming Potential (GWP) of 0.7. Tests show that the 50mm of EnviroFoam insulation injected into the case and covering both domes achieves astonishingly low levels of heat loss, which ensures it is fully compliant with 2010 Part L requirements for both new build and replacement cylinders.

Quality Standard

All Solfex cylinders are manufactured in accordance with BS EN 12897 the specification for unvented water storage vessels. The cylinders have been tested by NSF-WRc and WRAS, and found to comply with Building Regulations G3 and Water Regulations.

In performance, it complies with the requirements of BS EN 806-1 to 5 and meets the NHBC criteria for domestic properties. Our manufacturing partner also operates a quality management system audited and accepted by the BSI in accordance with BS EN ISO 9001:2008.

Cylinders are supplied with:

  • Combination inlet group incorporating pressure reducing valve, strainer, check valve, balance cold take off point, expansion relief valve and expansion vessel connection points.

  • Potable expansion vessels c/w flexible hose and wall bracket

  • Tundish

  • Dual control thermostat and combined overheat thermostat (x2)

  • Two port (28mm) zone valve for primary circuit

  • Wiring junction box for primary system

Model Selection Guide

Number of Bedrooms in propertyModel

Technical Specification

Energy efficiency classBCCCD
Heat Loss (w)54657585118
Capacity (l)180210250300400
Volume heated by IH (l)158199238279372
Weight empty / full (kg)33 / 21338 / 24843 / 29358 / 35862 / 462
Pressure regulating valve setting (bar)33333
Expansion relief valve setting (bar)
Temperature setting (P&T Valve, °C)9595959595
Pressure setting (P&T Valve, bar)
Expansion vessel size (l)182424352 x 24
Expansion vessel initial charge pressure (bar)33333
Height (mm)13051493174319902030
Diameter (mm)550550550550630
Hot supply (mm)13521540179020352080
P&T valve (mm)10471235148517311784
22mm secondary return (mm)-1127137715771577
28mm primary flow (mm)10431230125012701660
HP Control thermostat (mm)440494577677668
28mm primary return (mm)273260280300330
Cold feed (mm)259258258258285
3kW immersion heater (mm)217217217217245
Overheat thermostat (mm)440494577677668
Heat exchanger surface area (m2)2.53334
Heat exchanger thermal rating (kW)16.7417.9115.9313.1818.87
Heat exchanger pressure loss (bar)0.040.0320.0320.0320.07
Heat up time from 15°C to 50°C18.0220.4731.5742.537.1
Avg DHW temp. (°C)46.9546.7748.4442.0647.32