Active Solar Heating

1
Active Solar Heating

• By Syed F. Ahmed

2
Parts of the Active Solar Heater

• Solar systems consist of collectors and
  electricity to distribute the Suns Energy
• The heart of a solar collector is black
• Heat is moved by circulating water, antifreeze,
  and air
• Applications include heating swimming pools,
  domestic hot water usage, ventilation and
  industrial process

3
Types of Active Solar Heating

• Two types
• Liquid
• Air
• Both systems collect solar radiation, then
  distribute and store heat
• If the system does not provide adequate heat then
  a back up heating source is needed

4
Liquid Systems

• Use water, antifreeze, or methyl alcohol
• Components are hydronic collectors, a storage
  tank, pumps, pipes, a heat exchanger, and
  controls
• Liquid Systems of have three operating modes
• Primary mode
• Secondary mode
• Back up mode

5
Storing Heat for Liquid Systems

• Store solar heat in tanks or in the masonry mass
  of a radiant slab system
• Storage tanks require 3.8-7.6 L of water for
  0.093 m? (1 square foot)
• Tanks are usually made of steel, concrete,
  fiberglass-reinforced plastic (FRP), or wood
• Each has its own advantages and disadvantages

6
Distributing Heat for Liquid Systems

• Heat is distributed by radiant slab heaters, a
  central air-forced system, or by using hot water
  baseboards or radiators
• Solar heated water moves through the pipes and
  heats the floor
• This then radiates the room
• Radiant slab heaters are the best for liquid
  systems
• Hot water baseboards and radiators require water
  between (71.1C to 82.2C)

7
Air Systems with Storage

• Air systems uses air as the working fluid for
  collecting heat
• Air systems are composed of collectors, rock bin
  storage fans, ductwork, and controls
• Operates in three modes
• Simplest mode
• Second mode
• Third mode

8
Delivering Heat to Home by the Air System

• For storing heat, an air system delivers hot air
  from the collectors to the storage bin
• The air enters an empty mixing space at the top
  of the bin
• It passes down through the bin where the rocks
  absorb most of the heat
• When storing heat, the top of the bin is usually
  60C and 21.1C
• If the air in the bin is too cool then the back
  system kicks in
• The air delivers warm air from the rock bin to
  the house through ducts