Automatic anti-freeze system for solar water heaters

Patent · Tue Jan 18 04:00:00 EST 1983

OSTI ID:6492020

Bonnet, A

A protection device for automatically draining the water contained in a solar energy water heater in case of frost is a frost detector disposed externally of the heater, and includes a heat exchanger formed of a material having a good heat conductivity, preferably metal, secured to a small container filled with water through a bond having a good heat conductivity, and means responsive to a difference between the physical properties of water and ice, notably a variation in the density, and, therefore, a variation in volume and a variation in the electric resistivity. When the outdoor temperature has fallen below the water freezing point in this frost detector, the small volume of water contained in the small container is transformed into ice, and this icing is utilized for producing an electric signal controlling the draining of the heater. Conversely, when the temperature rises from a water icing value to an ice melting value, another signal is produced which differs from the former and causes the heater to be filled automatically with water to be utilized.

• Assignee: EDB-83-066226
• Patent Number(s): US 4368724
• OSTI ID: 6492020
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140907* -- Solar Thermal Utilization-- Water Heating
141000 -- Solar Collectors & Concentrators
APPLIANCES
AUTOMATION
DESIGN
DETECTION
DRAIN-DOWN SYSTEMS
EQUIPMENT
FREEZE PROTECTION
FROST
HEAT EXCHANGERS
HEATERS
ICE
SOLAR COLLECTORS
SOLAR EQUIPMENT
SOLAR WATER HEATERS
WATER HEATERS