Heat pump solar double bottom DHW tank

Heat pump solar double bottom DHW tank

With high performance heat exchangers ...

Inside enamelled tank for central domestic hot water systems, upper heat exchanger with special oversized surface for best heat pump or condensing boiler performance; solar systems can be connected to the second bottom heat exchanger, prepared for auxiliary heating by an electrical element. Available standard sizes 350 and 500 litres.


The use of modern heat pumps in combination with our high performance solar collectors has been a challenge for our constructing engineers. The sophisticated technology guarantees highest gains.

Heat pump application: the heat pump can achieve the best energy performance due to the huge double register in the upper area of the tank. The heat exchanger surfaces are more than sufficient to achieve an adequate coefficient of performance even for the preparation of DHW.

Solar application: the lower tank area consists of a special heat exchanger with additional exchanger surface in the tank’s double bottom. This bottom integrates the usually idle tank area underneath the heat exchanger into the solar heat zone. The solar return line is the lowest connection of the tank. Thus, the DHW is completely heated up to the bottom which guarantees ideal heat efficiency.

Due to its special design the Solarbayer heat pump tank provides for a continuous output and best quality drinking water. Furthermore, the operating costs of the heat pumps are kept low.

The heat pump solar DHW tank offers many advantages for the condensing technology as well. The burner operating time is going to be elongated due to the bigger refueling capacity and at the same time the burner starts are decreased. Condensing boilers prefer low return line temperatures. The enormously vast refueling heat exchanger increases the ΔT between boiler flow line and boiler return line and therefore enables a high boiler efficiency factor.

Take advantage of these benefits
  • double heat exchanger register for the heat pump
  • plain tube solar heat exchanger
  • double tank bottom for highest heat transmission of your solar system
  • perfectly suitable for condensing technology due to the vast upper heat exchanger surface
  • this tank is a high performance DHW tank due to the enormous power of the upper heat exchanger, it even meets the demands of multi-family houses
  • high quality steel S235JR (thick walled, compression proof)
  • internal corrosion protection with double enameling (Made in Germany), two magnesia anodes
  • rigid foam PU insulation, non-removable, insulation protection approx. 50 mm, silver PVC jacket, fire protection classification: B2
  • installation of electric heating element is possible

Successful detail solutions

Technical specifications

Heat pump DHW tank WP   350 500
nominal capacity approx. L 378 422
height with insulation [A] mm 1590 1790
tilted height mm 1765 1945
diameter (incl. non-removable solid foam insulation) [C] mm 750 750
insulation thickness mm 50 50
weight kg 200 240
max. operating pressure bar 10 10
max. operating temperature °C 95 95
max. size of electric heating element (optional) kW 6 6

stand-by heat loss according to EN 12897:2006   350 500
standby heat loss W 88 110
energy efficiency class   C C
efficiency label   PDF PDF

specifications double heat exchanger, top   350 500
heating surface approx. 4,6 5,5
capacity approx. L 22 35
max. operating pressure bar 10 10
max. operating temperature °C 95 95
pressure drop (2 m³/h) mbar 76 87

specifications double bottom heat exchanger, bottom   350 500
heating surface 1,5 1,5
capacity L 14 14
max. operating pressure bar 10 10
max. operating temperature °C 95 95
pressure drop (2 m³/h) mbar 82 82

specifications heat exchanger bottom   350 500
heating surface solar heat exchanger 1,5 1,5
capacity solar heat exchanger (total, incl. double bottom) L 6,4 (14) 6,4 (14)
max. operating pressure solar heat exchanger bar 10 10
max. operating temperature solar heat exchanger °C 110 110
recommended min. collector surface ca. 7 10

specifications output performance   350 500
continuous tap output at 9 kW
(HV 55°C | CW 10°C/HW 45°C)
l/h 740 1150
continuous tap output at 12 kW
(HV 55°C | CW 10°C/HW 45°C)
l/h 815 1300
continuous tap output at 16 kW
(HV 55°C | CW 10°C/HW 45°C)
l/h 943 1550
continuous tap output at 17 kW
(HV 70°C/HR 40°C und CW 10°C/HW 45°C)
l/h 1010 1700
continuous tap output at 27 kW
(HV 70°C/HR 40°C und CW 10°C/HW 45°C)
l/h 1270 2200
continuous tap output at 50 kW
(HV 70°C/HR 40°C und CW 10°C/HW 45°C)
l/h 2050 3780
performance indicator NL at 70/50, double heat exchanger top NL 31 38
performance indicator NL at 70/50, both heat exchangers NL 40,8 45,2

connections with dimensioning   350 500
[1] anodes (2 pcs., 1 ¼″)   top
[2] hot water (Rp 1 ¼″) mm 1390 1590
[3] thermometer (Rp ½″) mm 1300 1515
[4] heating flow (Rp 1 ¼″) mm 1290 1490
[5] tap water sensor 1 (Rp ½″) mm 1190 1390
[6] circulation (Rp 1″) mm 990 1190
[7] tap water sensor 2 (Rp ½″) mm 640 740
[8] heating return (Rp 1 ¼″) mm 540 640
[9] cleaning flange with connection electric heating element (Rp 1 ½″) mm 480 520
[10] solar flow (Rp 1″) mm 405 405
[11] solar sensor (Rp ½″) mm 290 290
[12] cold water (Rp 1 ¼″) mm 190 190
[13] solar return (Rp 1″) mm 100 100

Manufacturing tolerance according to DIN ISO 13920 C
Please take the instructions for installation/start up/maintenance from the relevant operation manuals

Further product informations

Brochure heat storage tanks

heat storage tanks

16-page brochure, DIN A4
PDF-file, 1.2 MB


Manual stratification buffer tank SPS

DHW storage tank

8-page brochure, DIN A5
PDF-file, 0.46 MB