Hot water heat pump

A heat pump utilizes the cost-free ambient heat, e.g., from your basement, refrigerators and freezers, clothes dryer, etc.; on farms, the heat source can be barn air.

Solar collectors:

• A solar system is ideal for hot water generation from May to September in Europe. 
• A solar system can cover up to 3/4 of the annual hot water requirement.
• The required collector surface per person varies according to the type of collector:
  • 1.5 m2/person for vacuum collectors 
  • 2 m2/person for flat collectors with selective coating
  • 2.5 m2/person for flat collectors with solar paint coating
• Hot water storage should cover requirements for two days (ca. 100 liters per person). 
• Consult a professional regarding the various collector types on the market. 
• A solar system should also be able to preheat water to increase utilization and the solar harvest.

Electric water heating

The following systems are available for electric water heating:

• Small water heaters with a volume of 5 - 15 liters
  • primarily under-counter models where small quantities of water are needed repeatedly during a day (kitchen sink, bathroom sink) 
• Central electric boilers with volumes of 50 - 500 liters
  • If the mantle is well insulated, the stand-by losses are low.
  • Caution: Observe product declaration.
  • Water temperature is regulated via thermostat (keep under 60° C).
  • Available as wall-mounted, free-standing or flat models.
  • Electric heating rods provide an ideal complement to a solar system to bridge days that are not sunny.
• Demand (instantaneous) water heaters
  • Apply high intense heat to heat the water as it flows through and heats water only as required. 
  • Most of these devices have a small storage tank to assure constant temperature. 
  • Electronically controlled devices automatically adapt the power to the required water quantity and temperature. 
  • Prerequisite for installation: adequate water pressure, adequate capacity of electrical connection (up to 27 kW).

Gas

• Water is heated in combination with a gas central heating system, in a directly heated boiler, or a demand water heater. 
• Gas boilers are available with storage tanks of 100 - 300 liters. Water is heated directly by a gas burner. Multiple withdrawal points can be supplied simultaneously. 
• Gas demand water heaters heat water as it flows through the device; hot water is available anytime without a waiting period. 
• Gas combination water heaters heat the water for the heating system as well as domestic water.