Active Closed Loop Solar Water Heating Systems
with Preheat Tank

 
SOLARUSES

There are a variety of situations when a two tank system may be preferred, particularly when integrating with an existing system. Although less efficient, this system easily retrofits to existing systems with a minimum disturbance of the pipework.

 

NOTE: The information presented in this page is for guidance only - no part of this may be used for any agreement, whether express or implied, or to form any contract. THERMO TECHNOLOGIES reserves the right to change specifications and prices without prior notice.

 

There are several ways to connect a two tank system. The traditional method is to have a solar preheat tank, in which the tanks are plumbed in series. Unless there is constant daytime use the pre-heat tank has to be quite large, and standby heat losses in the existing tank are not taken care of by the solar system

.

   
   
       
Advantages
Disadvantages
   

  • Easy to retrofit to existing tank with minimum disturbance of existing pipework
  • Versatile system - the preheat tank can be located away from the conventional tank
  • Useful if the conventional tank is gas or oil fired. Many gas fired DHW tanks have high standby heat losses and will waste solar energy.
  • The tank is usually cold in the morning and ready to receive solar energy.
  • Good control over the system and easily monitored performance.
  • Efficient if the house is occupied through the day. Solar heated water will frequently be drawn into the conventional tank, helping offset standby losses.
  • This solar system can be disassembled easily, leaving the existing system intact, and moved to another location.
  • Solar energy is only heating half of the available storage. If no-one is home through the day the solar heat remains in the preheat tank.
  • A larger pre-heat tank will be necessary than if a tank was added in parallel.
  • Stand-by losses are more than twice those of a single tank system.

   
Contact Thermo Technologies