Evacuated solar tubes is a water heating system, developed for northern European countries to heat hot water tanks using passive solar energy.
In a nutshell.
Evacuated tubes, commonly known as solar tubes, are the most efficient of the more traditional flat-plate panels.
Installing this solar energy system will enhance your traditional heating system and bring it up to modern 'building regulation' standards too. This works throughout all four seasons to a lesser or greater degree.
The science bit.
The evacuated tube system heat-up due to the sun's short-wave radiation output converting to long-wave radiation.
Specifications.
Heat-pipe tubes or direct-flow tubes. Temperature: 40-80° Celcius (104-176° Fahrenheit). Standard pressure: 3 bar.
Alternatively, we suggest installing PV solar panels working alongside a heating converter to heat water using your excess electricity.
"Solar heating adoption has grown each year. There are an estimated 240,000 homes with a solar heating system in the UK currently."
Evacuated tubes work alongside your boiler
The basic principle of solar heating can be used to decontaminate water in a plastic bottle to make it safer to drink.
Today, with the advantage of modern manufactured technology, we can use this same principle to heat domestic hot water.
Evacuated tubes are super-efficient vacuum tubes that retain heat from the radiation that hit our roofs every day of the year.
This type of system is so efficient that restrictions to temperatures of 85 degrees Celsius are applied. The collecting glass tubes trap and store radiation waves passively, and it's this ability that makes them ideal for northern European climates.
Evacuated solar tubes work alongside a conventional boiler and significantly increase the lifespan by reducing its use annually.
Now, this is where it gets interesting. A solar tube system installed today will still be providing significant savings for the next three decades.
I was originally impressed by how well evacuated tubes worked in the UK climate.
A significant factor in a system's performance is how well-insulated the tank and pipes are. Solar-ready hot water tanks can be fitted to increase the overall performance of the system too.
There are an estimated 220,000 homes with solar heating panels in the UK currently.
This latest research demonstrates that homes with solar heating panels can benefit as household's understand how to use it to its best advantage.
Exciting times ahead.
Questions about evacuated solar tubes
Roof orientation?
Most homes are suitable. If you have an S/SE/SW or east/west facing roof space, then great. Your internal plumbing needs to be checked for compatibility too.
A solar tube system heats up due to the sun's short-wave radiation output converting to long-wave radiation. This process creates heat.
The variable speed controller circulates based on temperatures within the panel.
The pump circulates a Glycol solution through the hot collector and back-down through a heat exchanger.
The system automatically shuts down when not in use, or when the collector temperature is lower than the cylinder.
Do evacuated tubes work consistently in the UK climate?
Evacuated tubes are the most efficient solar heating technology, but not as useful as PV-heating converters.
The
UK receives 60% of the sun's radiation compared with the equator. Each
square metre of the UK receives between 900 to 1,300 kWh annually. All can
be captured and diverted into your hot water tank with evacuated tubes.
Evacuated tubes use a thermos flask principle that allows each vacuum tube to get hot regardless of external air temperature.
What about Combi boilers?
Combi boilers aren't possible in most cases. We would need to re-install a hot water tank. Most homes with Combi's won't have the space to install a hot water tank.
Can I install evacuated tubes myself?
In most cases no. However, if you're Part P electrical accredited, then it
may be possible to install in a DIY
capacity.
Older 'copper' hot water tanks run exceptionally inefficiently, especially after many years of use. Limescale will reduce performance even further.
When installing evacuated tubes, it's essential to establish a modern more efficient tank to get the most out of your system.
Will it contribute towards my central heating?
We would need to check your management system is suitable. In most cases, evacuated tubes can contribute to your central heating via underfloor heating.
How long will it take to install?
Only a few hours in most cases.
Do I require planning permission?
Listed buildings, conservation area homes, national parks may require permission. Please consult with your local planning officer.
Do evacuated tubes work on cloudy days?
This question depends on the density of the cloud. In average cloud density, solar panels use passive energy. With dense cloud cover, probably not.
Can you upgrade my hot-water tank?
Does your tank has an unused twin-coil? In most cases, we update the hot water tank to allow a secondary connection to the evacuated tube system.
How much CO2 will my system save?
Around half a tonne each year, but this is dependent on how much hot water gets used and how you heat the water at present.
Check your roof orientation
