Evacuated Tube Solar water heaters

Evacuated Tube Solar water heaters

 – for domestic hot water and hydronic house heating.

 

ultimate solar 40 tube

 

  • Maximum performance – Heat pipe has up to 50% more efficiency than a flat plate collector, and U tube has almost double
  • Works in all climates, including a wintery, overcast day
  • Easy to install – Split system provides solar heating without a storage tank on the roof
  • Instant unlimited mains pressure hot water with either gas or electric boosting
  • Long life materials, maintenance free
  • Designed to withstand extreme frost conditions, using closed loop system.

 

30 tube split system collector

 

What are Evacuated Glass Solar Tubes?

Inside and outside tubes are made from extremely strong borosilicate glass that are fused together to form a vacuum between two tubes.

  1. Outer Tube – Allows the sun’s rays to pass through with minimal reflection
  2. Inner Tube – Special selective coating on the outside of the tube contributes the highest thermal efficiency and good thermal stability
  3. Evacuated Space – Stops heat loss / emission to outside of the glass tube, making these collectors particularly effective during cold and cloudy weather
  4. Selective Surface – Absorbs the maximum solar radiation to convert into heat efficiently
  5. Cylindrical Shape – Sun’s rays are perpendicular to the absorber for most of the day
  6. Fin – Transfers the heat to copper tube without heat loss
  7. Copper Conduction Tube – Passes the heat to the water / fluid inside the copper tube
  8. Barium Layer – Actively absorbs the air to maintain the vacuum between the two tubes

 

Heat pipe tubes

Heat pipe tubes

 

How does it work?

The sun’s rays pass through the outer tube, and perpendicularly strike the absorber surface on the outside of the inner glass tube.

The selective surface absorbs maximum solar radiation and converts it into heat very efficiently.

Because the sunlight is perpendicular to the absorber tubes almost all day, the sun’s energy is absorbed and transferred efficiently.

The insulation formed by the vacuum space between the outer and inner tubes minimises heat loss to the outside, whilst allowing the sun’s energy to reach the copper tube inside the inner glass tube.

 

1. Close-coupled models, tank on the roof with mains pressure coil inside.

These solar water heaters require no pumps or moving parts, and just sit on the roof and get hot.  They are ideal for connecting to a wood stove as they operate at low pressure and will not damage your wood heater.  The tank contains a mains pressure heat exchanger inside that allows you to have hot water at any pressure you like.  These systems are perfect for frost-prone areas as the water inside the evacuated tubes does not freeze.

Two convenient sizes:

300 litre 30-tube solar hot water system showing wood stove connections

300 litre 30-tube solar hot water system connected to a wood stove

 

NS-200WB Slimline solar water heater showing connections position

NS-200WB Slimline solar water heater showing connections position

 

  • Suitable for domestic and small commercial applications
  • Low-pressure stainless tank with a high-pressure heat exchange coil inside
  • “Wet tubes” – the sun’s energy directly heats the water in the tubes.
  • Ideal for connecting wood heaters with wet backs.  You can eliminate electric boosting
  • Extremely flexible boosting options – fit it as a preheater to an existing gas or electric storage tank, thermosiphon into a wood heater underneath, connect it to an instantaneous gas heater, or use the optional 1.5kW electric element.
  • Mounting frames are available for both metal and tile roofs.
  • Suitable for high frost areas
  • 5/10-year manufacturer’s warranty on tanks, frames, and tubes.  (See below)

 

How it works

  • Copper tube internal heat exchanger.
Showing 28-metre internal heat exchanger coil

Showing the internal heat exchanger coil

The close-coupled system uses a 28-metre copper coil to transfer the heat from the water in the low-pressure storage tank to the mains pressure water used in the home.

NS-200WB Slimline showing hot and cold connections

NS-200WB Slimline showing hot and cold connections

 

As the water enters the tank through the mains water supply line, it passes through the heat exchanger and absorbs heat instantly.

  • Low-pressure storage.

Having a low-pressure storage tank with a high-pressure heat exchange has many benefits.

No legionella risk.

Open-vented to safely relieve the pressure from the water expanding due to heat.

Woodfire boosting with ready-made connections.

Lower manufacturing costs.

  • Wet tubes.

This solar water heater uses 1800 x 58mm high-quality evacuated tubes with tri-coating technology.   The “Wet tubes” contain water that is directly heated by the sun and transfers heat straight to water in the storage tank.

  • Pitching frames.

Low-pitch (15 degrees) or high-pitch (40 degrees) frames are available, included in the price.  Please advise your preference.

300 litre frame on tile roof

300-litre low-pitch frame on a tile roof

 

300 litre medium pitch

300-litre high-pitch frame on a flat roof

 

The on-roof system comes with either a 15-degree or a 40-degree pitching frame.  Custom frames are also available.

  • Top-up tank filling kit.

The low-pressure storage tank is kept full using a float valve.  If the tank water level drops due to evaporation, the float lets water enter the tank.   Once the tank is full again, the float rises and shuts the valve, turning off the water. 

  • Boosting.
Showing electric element and thermostat

Showing electric element and thermostat

Every solar hot water system needs boosting in the winter as the days are shorter and the solar radiation is less.   This can be done with a wood fire stove, a 1.5kw or 2.4kw electric element, or an instantaneous gas booster.

  • Sacrificial Anode

Even though the inner tank is made from stainless steel, it is prone to corrosion that will cause eventual failure.  To prevent this all tanks are supplied with a sacrificial anode to protect against corrosion, and this anode will need to be replaced every 1 – 5 years, depending on the water quality in your area.  We recommend annual inspection and service, to ensure a long and reliable life of the cylinder.

 

NS-200WB Slimline solar water heater

NS-200WB Slimline solar water heater showing electrical element and wood stove connections.

 

Close-coupled Systems Size Weight  Prices

July 2023

300-litre stainless steel system with 30 evacuated tubes, 2kw element and thermostat, magnesium anode, 20mm stove connections, and roof frame 2200  x 2490 143 / 471 $3800
200-litre stainless steel system with 20 evacuated tubes, 2kw element and thermostat, magnesium anode, 20mm stove connections, and roof frame 2200 x 1890 117 / 380 $3200
Galvanised roof supports 2.5m 100 x 50 with dampener 2500 x 100 $250
Plumbers installation kit (recommended) $460
Replacement electrical boost element 1.5kw, 2.0, or 2.4kw, with thermostat and fuse $270
Replacement magnesium anode (check every year) $80

Freight cost from Melbourne warehouse not included.  Freight is extra.

Galvanised roof supports

Galvanised roof supports

 

Plumbers installation kit

Plumbers installation kit

 

Sacrificial anode

Sacrificial anode

Warranty Conditions:

All these products are manufactured to high standards, and each product is manually inspected prior to leaving our warehouse and is guaranteed against manufacture faults.

  • Stainless steel tanks are guaranteed against manufacturer’s defects for a period of 5 years from the date of purchase.
  • Solar vacuum tubes are guaranteed against manufacturer’s defects for a period of 10 years from the date of purchase.  This warranty does not cover freight damage, nor thermal shock when the tank is first filled with cold water when the tubes have been heated by the sun.
  • Valves, and the balance of the system, are guaranteed against defects for a period of 12 months from the date of purchase when used within the scope they were designed for.
  • If any of the above is faulty due to a manufacturer.s fault, we will replace or repair, at our choice, the faulty item.

Freight cost is not covered and is paid by the owner, except in the case of DOA, which will be determined by us.

Installation or any workmanship issues are not part of the warranty and cannot be claimed.

 

2. Split-systems, ground-mounted tank, and solar collector on the roof.

Ultimate red circle solar water heater

  • Ideal for domestic and small commercial applications.  There is a large range of tank sizes and models.
  • Evacuated tubes used in a “Split system” heat water as it flows through the top manifold and back to a storage tank.
  • Can be connected to a ground-mounted storage tank with electric or gas boost.
  • Can also be connected (via pump or thermosiphon) to an in-roof tank.
  • “Dry tubes” use the sun’s energy to heat copper heat pipes inside the tubes, which then transfer the heat to water running through the manifold.
  • Suitable for all roof types including tiles.
  • 10-year manufacturer,s warranty on the manifolds, frames, and tubes.

 

Two 30 tube collectors

Two 30 tube collectors

 

Check these convenient sizes:

Exegi Stainless Steel Split System Prices – May 2023
200l stainless vertical tank, 20 evacuated tube collector, 240v pump & controller $4905
300l stainless vertical tank, 30 evacuated tube collector, 240v pump & controller $5962
400l stainless vertical tank, 2 x 20 evacuated tube collectors, 240v pump & controller $7875
500l stainless vertical tank, 2 x 30 evacuated tube collectors, 240v pump & controller $9787
These kits include installation valve kit and 3-probe controller with 75deg top out.  

Freight from Melbourne warehouse not included.  Freight is extra.

 

3. Retrofit kits for existing electric tanks

Evacuated tube collector

  • For domestic and some commercial applications.
  • Evacuated tubes for use in a “Split system” where water is heated as it flows through the manifold and back to a storage tank.
  • Can be connected to a new or existing ground-mounted electric storage tank.
  • Can be connected via pump or thermosiphon (where possible) to a new or existing in-roof tank.
  • “Dry tubes” use the sun’s energy to heat copper rods inside the tubes, which then transfer the heat to water through a heat exchange process.
  • Suitable for all roof types including tiles.
  • Manifolds come with 3/4″ BSP connections at each end.
  • A 10-year manufacturer’s warranty applies to the manifolds, frames, and tubes.  Breakage due to storms or vandalism is not covered.

 

Installing more tubes

Installing evacuated tubes

 

Retrofit Solar Collector, Pumps, and Controllers – May 2023 Dimensions Weight Prices
10 tube collector & frame 2.00 x 1.00 48kg $1039
20 tube collector & frame 2.00 x 1.75 90kg $1617
24 tube collector & frame 2.00 x 2.07 108kg $1848
30 tube collector & frame 2.00 x 2.55 135kg $2156
Replacement glass tubes – 57mm x 1800mm $85
Pump and controller 240v, including sensors $690
Solar-powered 12-volt pump, 20w panel, and controller $695

Solar collectors are supplied with a 0, 15, or 45 degree pitched frame. (Please specify)

Delivery from Melbourne-based supply warehouse not included.  Freight cost is extra.

 

4. Stainless steel solar hot water tanks.

Choosing the right storage tank will determine the life of your solar water heater.

Duplex stainless steel has excellent rust-resistant properties along with double the strength of 316L making it the perfect material for hot water storage tanks.

Inside Exegi stainless water tank

Inside Exegi stainless water tank

These tanks comply with all Australian standards and have the watermark certification to prove it.  The tanks are built using only the finest materials and components, which is why they have a long 5-15 year warranty.

 

solar water heater tanks

 

Stainless Steel Vertical Tank Options

Vertical Stainless Tanks Dimensions mm January 2024
DX0-200  200l – no coil  600 x 1325 $1911
DX0-300  300l – no coil  600x 1560 $2158
DX0-400  400l – no coil  650 x 1810 $2898
DX0-500  500l – no coil  780 x 1828 $3333
DX1-200  200l – one coil  600 x 1325 $2446
DX1-300  300l – one coil  600x 1560 $2839
DX1-400  400l – one coil  650 x 1810 $3534
DX1-500  500l – one coil  780 x 1828 $4075
DX2-200  200l – two coils  600 x 1325 $3043
DX2-300  300l – two coils  600x 1560 $3123
DX2-400  400l – two coils  650 x 1810 $3804
DX2-500  500l – two coils  780 x 1828 $4480
DX2-1000  1000l – two coils $ask
DX2-2000  2000l – two coils $ask
All tanks are supplied with a sacrificial anode
Electrical element and thermostat are available
Optional top coil and bottom coil are available

Freight from Melbourne-based supply warehouse not included.  Freight is extra.

 

5. Automatic Pump Controllers.

 

Novus Temperature controllers for 240-volt pumps.

These controllers will work from any 240-volt supply.  They are ideal replacements for troublesome controllers supplied with imported solar hot water services.

They come already programmed and ready for immediate use.  However, you can manually adjust the switch-on and switch-off temperatures and/or the differential.

12v solar pump controller

12-volt solar pump controller

Price: $395 

For details of the Novus 12-volt controller go here

Novus wiring diagram Sep 2018

Novus 2-page installation and operating manual

 

6. Thermal heat transfer paste

Silicone thermal heat transfer paste

Silicone thermal heat transfer paste

Using heat transfer paste is essential for good heat transfer between the evacuated tube bulbs into the manifold.  Otherwise, the performance of the solar collector will be poor.

$35 per tube

 

7. Top up Tanks.

Essential to keep the fluid level topped up in the solar collector low-pressure circuit, and as a receptacle for unwanted steam or expansion water.

Must be installed at the highest point on the collector circuit.

Top up tank

 

 

Order now, or ask a question:

Queensland:    (07) 5448 8304      qld @ solazone.com.au

Victoria:            (03) 9808 7337      vic @ solazone.com.au

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