Key Features

Solahart Commercial Solar Water Heaters combine our proven solar collectors with a centralised heat store to extract the sun’s free energy and hold it ready for use. Highly efficient heat exchangers transfer the stored energy to the water supply to meet your hot water requirements on demand. A range of booster options ensures a continuous hot water supply regardless of the demand or weather.

This combination of storage and controlled heat transfer allows the system to quickly deliver large volumes of water at a consistent supply temperature. Each system is specifically customised to best meet your requirements and existing infrastructure. The flexibility of the Solahart HS Series ensures it can be connected as a solar pre-heater to immediately reduce the running costs of almost any existing hot water plant with minimal disruption to the installation. Alternatively, the system can be tailored for new building projects or as a complete replacement for old, inefficient water heaters.

  •  Complete over-temperature protection
  •  Engineered specifically for your requirements
  •  Highly efficient use of available solar energy
  •  Scalable and expandable to meet demands of over 1,000lt/day

Delivery Skid Specifications

Model SD200 SD400 SD600 SD800
Nominal Capacity kW 200 400 600 800
Parameters for Nominal Capacity Rating
Primary Side (non-potable)
Inlet Temp °C 80 80 80 80
Flow Rate L/min 48 114 144 186
Pressure Drop kPa 24 47 36 36
Secondary Side (potable)
Inlet/Outlet Temp °C 15/65 15/65 15/65 15/65
Flow Rate L/min 57 115 172 223
Pressure Drop kPa 37 47 51 48
Dimensions H x W x D mm 1364 x 761 x 700
Weight Kg 130 138  147 156
Pipe Connections Primary Circuit BSPF RP1¼ 
Pipe Connections Secondary Circuit   50mm Flange Type E
Max Operating Pressure Primary Circuit kPa 900*
Max Operating Pressure Secondary Circuit kPa 1000*
Electrical Supply   230-240V 50/60Hz Hard Wired By Electrician
Min Circuit Size Amps 10
Standard Model   Single pump
Deluxe Model   Dual head pump


Storage Tank Dimensions and Technical Data Carbon and Stainless Steel

Model ST1000 ST2000 ST3000 ST4000 ST5000
Construction   Stainless Steel / Carbon Steel 
Corrosion Protection

Stainless Steel

Carbon Steel

316 Stainless steel

Carbon Steel - Exterior with rust-protection coating  - Interior with corrosion inhibitor

Insulation (supplied loose) –

Indoor installation

Outdoor installation



100mm Polyethylene insulation w/ PVC outer cover

100mm Polythylene insulation w/bonded aluminium cladding

Storage Volume Litres 920 2055 2960 3820 5180
Top Element Flange Boost Volume Litres 304 678 977 1261 1709
Diameter (without insulation) mm 800 1100 1250 1400 1600
Diameter (with insulation) mm 1000 1300 1450 1600 1800
Height (without insulation) mm 2200 2565 2845 2918 3128
Height (with insulation) mm 2200 2565 2845 2918 3128
Dry Weight (without insulation) SS/carbon steel kg 136 /115 245 /245 330/334 455 /455 660 /535
Wet Weight (without insulation) SS/carbon steel kg 1056 /1035 2300 /2300 3290/3294 4275/4275 6022 /5715
T&PR Valve Setting SS/carbon steel kPa 850/500 850/500 850/500 850/500 850/500
Expansion Control Valve (ECV) setting SS/carbon steel kPa 700/NA 700/NA 700/NA 700/NA 700/NA
Maximum Water Supply Pressure            
without ECV fitted SS/carbon steel kPa  680/400 680/400 680/400 680/400 680/400
with ECV fitted SS/carbon steel kPa 550/NA 550/NA 550/NA 550/NA 550/NA
Max Operating Temperature °C 90 90 90 90 90
Quantity of Solahart Solar Collectors   08-12 12-24 24-36 30-48 36-60
Solar Collector Apperture m2 15.2-22.8 22.8-45.6 45.6-68.4 57-91.2 68.4-114
Gasket Material   EPDM


 Storage Tank
Model Numbering
S T 1000 C 6 ALU
  Solahart Tank Nominal capacity 1000,
2000,3000, 4000,
5000 litres
Tank Material
C = Carbon Steel
(6 bar)
N = Stainless Steel
(9 bar)
Max operating Pressure (of tank)
 6 = 6 bar 
9 = 9 bar
Cladding type
ALU = Aluminium


Solar Pump Skid Specifications

Model SP013 SP015 SP033 SP035 SP055 SP103 SP153
Number of Collectors BT Up to 8 8 -16 16 - 24 16 - 24 28 - 40 40 - 90 90 - 150

Maximum Height

m 20 40 20 40 40 40 40
Dimensions H x W x D mm  941 x 684 x 700      
Weight kg 75 75 80 80 90 182 189
Pipe Connections Inlet
Pipe Connections Outlet
RP1 ¼ RP2
Enclosure Rating   IP55
Electrical Supply   230-240V 50/60Hz Hard Wired by Electrician 380-480V 50/60Hz Hard Wired by Electrician  
Max Current Amps 10 15
Min Circuit Size Amps 16  20


 Storage Tank Skid
 Model Numbering

S P 013 C D 1 0
  Solahart Pump Skid

Pump Model

eg Grundfos

Pump Body

C = Cast Iron

D = Deluxe with data
logging and BMS

S = Standard

1 = 1 Phase

3 = 3 Phase

No meaning





How The HS Series System Works

Central Heat Store

The Central Heat Store, contains the heat transfer fluid and acts like a thermal battery storing heat energy from the sun ready for use as required. This fluid is heated by circulation through Solahart’s proven high performance solar collectors during the day and is stored to provide the energy source to instantaneously heat the cold potable water supply in the highly efficient heat exchanger Delivery Skid.

The Solahart HS Series storage tanks offer the perfect combination of performance, long life and flexibility. The tanks are available in 1000, 2000, 3000, 4000 and 5000 litre sizes and can be supplied with 100mm insulation with either a PVC jacket for indoor installations or bonded aluminium cladding suitable for outdoor installation. The tanks are available in carbon steel with 5 bar operating pressure for indirect heating (supplied with corrosion inhibitor) or 316L stainless steel with 8.5 bar operating pressure for potable water applications. Carbon steel tanks are supplied with corrosion inhibitor. Multiple tanks can be interconnected to meet demands exceeding 5000 litres or utilise banks of smaller tanks instead of one larger tank to better utilise available plant room space and provide redundancy.

Solar Pump Skid

The fully engineered Solar Pump Skid controls all solar functions along with the 3 way valves and booster operation. Deluxe models also incorporate BMS run/fail and data logging capability whilst standard models provide a lower cost alternative where data logging is not required. All switch gear is located within an IP55 powder coated enclosure and the frame is fully welded steel construction and hot dip galvanised for superior corrosion resistance.

A pair of Grundfos CME variable speed cast iron pumps are incorporated to provide duty/standby redundancy. The controller regulates the speed of the solar pump to optimise the flow rate through the solar collectors. This helps to optimise system efficiency, reduce energy use, and also reduce possible frequent starting and stopping of the pump.

Heat Exchange Delivery Skid

To precisely regulate the hot water outlet temperature to the building, the Delivery Skid’s intelligent control system varies the rate of energy transfer from the central heat store. This means the fluid in the storage tanks can be stored at a higher temperature than the required potable water temperature allowing for an increase in energy storage density and efficiency. On days when available solar energy input exceeds the hot water demand, surplus energy can be banked for later use rather than wasted.

The Delivery Skid features a pair of completely integrated high-efficiency stainless steel plate heat exchangers. This allows for a high energy transfer with low pressure drop and a low temperature difference between the transfer fluid and the potable water circuits.

The efficiency of the Delivery Skid design makes it ideally suited for solar thermal applications and / or other low-temperature heating systems (a transfer fluid temperature of 50°C is sufficient to heat the fresh water up to 45°C). The Delivery Skid’s are available in sizes with instantaneous output of 200, 400, 600 and 800kW. Multiple units can be manifolded together to provide greater output if required. Any sized Delivery Skid can be paired with any storage tank capacity combination for maximum flexibility and system optimisation.

Drainback for Energy Efficiency and Over Temperature and Frost Protection

To optimise performance, the Solahart Commercial Solar Water Heaters use the proven drain back principle where the heat transfer fluid drains back into the heat store at times when there is insufficient solar gain, or when the fluid is at its maximum set service temperature, to prevent overheating. This also provides protection against freezing.

The system incorporates an automatically controlled pump, which is activated by a smart controller that can be integrated into most building management systems. Drainback is effected by a patented automatic diverter valve which dramatically increases system reliability. Drainback negates the need for heat dissipitation equipment which is typically required for fully flooded solar systems.

Booster Options

A variety of options exist to ensure constant hot water supply at times of low solar radiation or high hot water demand. We can supply and incorporate boosting solutions with electric, gas, or heat pump options, by either boost‑heating the fluid in the central heat store, or boosting the potable water output from the heat exchanger modules to the required service temperature.

Using our highly efficient Heat Pumps as a booster option complements the operating cost savings and environmental benefits of the solar collector system. By combining Heat Pump technology in conjunction with solar collectors (a hybrid solution) some powerful synergies can be gained.

Solahart’s Commercial Heat Pump range is designed with the volume user in mind. Up to 300kW output means almost any demand can be met. Our commercial Heat Pumps typically have a Co-efficient of Performance (COP) of around 4.0*, which means that more than 75% of the energy used to produce hot water is energy free from the sun. Naturally, the hotter the conditions the better the performance.

Solahart Commercial Solar Water Heating Solutions








* COP of 4.0 is achieved at 20ºC and 60% RH


HS Series Commercial Brochure: Download

Case Studies

HS Series

Saddiyat Island: Download

New York University: Download

Other Commerical Solar Hot Water Projects

Costa Verde Hotel: Download

Middleburg Mine: Download