Open Loop versus Closed Loop

Advantages of a TH Solar Open Loop system:

• Less clutter in the set up, no expansion tanks, extra valves and drains required
• Less maintenance, no ongoing check of system pressure or replacement of circulation fluid
• No problem with overheating, lower maintenance
• Easier cheaper installation
• Better heat transfer
• Cheaper high quality cylinders allow for better solar storage
• TH Solar’s patented collector does not have any small tubes to become blocked.
• TH Solar’s collector is tested to over double the pressure of a mains pressure water cylinder and can be connected directly to any cylinder

 

Advantages of Closed Loop systems

• In very cold alpine areas prone to power failures closed loop systems using antifreeze are freeze resistant
• Some collector systems using “U” tubes can not handle the pressure in a standard mains pressure hot water system and need to use a closed loop system.

 

Disadvantages of Closed Loop systems

• They require monitoring and maintenance of the circulation fluid levels
• In summer conditions the circulation fluid can easily reach boiling point even after taking up the expansion vessel volume. After fluid has boiled off a technician must replace it. If it is not replaced system performance will suffer and pump damage is likely.
• They require more installation time
• In many cases they are simply filled with water. This significantly increases the extent of clogging of tubes and pipes, as minerals tend to collect on pipe walls at higher temperatures.

Positioning of collectors  

Evacuated tubes

• The design of evacuated tubes means that the orientation is not as critical for maximum performance as a flat panel but following the criteria below will produce the best results

 

Orientation

• As close to north as possible +/- 45° acceptable
• Facing more west than east of north is better
• But options are available to mount on east/west roofs or even south facing roofs

 

Shading

• For the best results avoid shading 3 hours either side of midday
• Check for shading impact in winter when the sun is lowest

 

Inclination of collectors

• Panels can be mounted from 0° to 90°
• The optimum angle for all year round performance is the latitude of your location +/- 10°. In Canterbury this is around 40°
• There is not a significant difference if panels are mounted within a further 20° of this
• If panels are steeper performance in winter will be better, if lower then winter performance will not be quite so good
• A frame can be used to adjust the angle to the most suitable for your roof

 

Roof loading

• This is not an issue with pumped systems as each collector only weighs 45kgs
• When installing close-coupled systems the weight of a full cylinder on the roof may mean additional roof strengthening is required. If there is any doubt an engineer should be consulted
• In any case the load should be spread over as many trusses as possible
• The load should be positioned above an area where there are supporting walls below
• Position the tank as close as possible to the main use areas of bathrooms, laundry and kitchen

Solar savings

"The Power of the Future"

Up to 50% of your energy bill is used for water heating

How do you maximise the return from your investment in a solar water heater? 

• Use the best type of panel for your location and climate. Evacuated tubes perform better in New Zealand’s generally cooler and winder weather
• Have as large a storage capacity as you can this allows for maximum storage of solar energy
• As a general rule you should have 1 tube for each 10itres of storage
• Ensure your solar controller allows for easy management of the system and control of auxiliary heating. TH Solar’s advanced controller does all this in one simple to use package.

 

A TH Solar system will save up to 75% of your hot water energy costs 

A TH Solar system will save you money. An investment in a TH Solar hot water system can more than pay for itself and the returns will only continue to grow as energy costs continue to increase.  

A TH Solar system will help you do your part to saving the planet