Flat plate vs. evacuated tube solar hot water collectors

 

Solar hot water has come a long way in the last decade, particularly with the introduction of evacuated tube collectors that are rapidly becoming the preferred option over flat plate systems. If you're not sure of the difference between the two in terms of how they work, read our brief guide to solar hot water systems

 

flat panel vs. evacuated tube collectors

 

The latest is certainly not always the greatest, so which is actually better - a flat plate solar hot water system or one that uses evacuated tube collectors? While evacuated tube technology is more of an investment, the benefits certainly outweigh the cost. Any additional cost may also be offset by solar hot water rebates!

 

Evacuated tube collector based systems:

 

  • Capture sunlight better as they have a greater surface area exposed to the sun at any time
  • Are more efficient in transferring heat - up to 163% demonstrated in Australian conditions!
  • Can be used in subzero temperatures
  • Are durable and if a tube should be broken, it can be easily and cheaply replaced.
  • Provide excellent performance in overcast conditions
  • Require a smaller roof area than comparable flat plate collectors
  • Do not have the same level of corrosion problems as flat plate collectors

 

Get a solar hot water quote today!

 

Collector efficiency comparisons

 

The results below speak for themselves as to the improved efficiency of evacuated tube technology over flat plate collector solar hot water systems.

 

The following figures demonstrate efficiencies of collectors when heating water from ambient temperature to 75 degrees Celcius - data provided by Hills Solar. Flate Plate Collector efficiency testing was performed at National Solar Test Facility Canada.



Sydney, New South Wales

 

Flat plate vs. evacuated tube efficiency for Sydney, New South Wales

 

Winter: Based upon solar insolation of 426W/m2 and an ambient temperature of 13.1degrees Celsius in Sydney, the Hills Esteem evacuated tube solar collector is on Average 104% more efficient per m2 of aperture compared to flat plate solar collector.**

 

Summer: Based upon solar insolation of 840W/m2 and an ambient temperature of 21.3 degrees Celsius in Sydney, the Hills Esteem evacuated tube solar collector is on Average 50.5% more efficient per m2 of aperture.**

 

** Data taken from Hills Solar report on collector efficiencies - download full report including testing criteria (380kb PDF)

 

Melbourne, Victoria

 

Flat plate vs. evacuated tube efficiency for Melbourne, Victoria

 

Winter: Based upon solar insolation of 296W/m2 and an ambient temperature of 9.9 degrees Celsius in Melbourne, the Hills Esteem evacuated tube solar collector is on Average 163.5% more efficient per m2 of aperture over the flat plate solar collector.**

 

Summer: Based upon solar insolation of 861W/m2 and an ambient temperature of 19.8 degrees Celsius in Melbourne, the Hills Esteem evacuated tube solar collector is on average 51.5% more efficient..**

 

** Data taken from Hills Solar report on collector efficiencies - download full report including testing criteria (380kb PDF)

 

Brisbane, Queensland

 

Flat plate vs. evacuated tube efficiency for Brisbane, Queensland

 

Winter: Based upon solar insolation of 546W/m2 and an ambient temperature of 17.8 degrees Celsius in Brisbane, the Hills Esteem evacuated tube solar collector is on average 81% more efficient per m2 of aperture compared to the flat plate solar collector.**

 

Summer: Based upon solar insolation of 828W/m2 and an ambient temperature of 25.2 degrees Celsius in Brisbane, the Hills Esteem evacuated tube solar collector is on Average 54% more efficient.**

 

** Data taken from Hills Solar report on collector efficiencies - download full report including testing criteria (380kb PDF)

 

Adelaide, South Australia

 

Flat plate vs. evacuated tube efficiency for Adelaide, South Australia

 

Winter: Based upon solar insolation of 452W/m2 and an ambient temperature of 10.9degrees Celsius in Adelaide, the Hills Esteem evacuated tube solar collector is on Average 132% more efficient per m2 of aperture than the flat plate solar collector.**



Summer: Based upon solar insolation of 953W/m2 and an ambient temperature of 22.1degrees Celsius in Adelaide, the Hills Esteem evacuated tube solar collector is on Average 52% more efficient.**

 

** Data taken from Hills Solar report on collector efficiencies - download full report including testing criteria (380kb PDF)

 

A correctly installed solar hot water system can start saving you money straight away, while doing your bit towards a smaller carbon footprint. Contact us today via email or on 133-SUN and speak to our friendly, knowledgeable team for advice on a system to suit your needs.