News and Events
Renewable technologies working in tandem with conventional boilers
When Craig Hewitt began renovating his new home, he set himself the challenge of combining condensing gas boilers with renewable solar thermal and underfloor heating technologies to bring cost effective, energy efficient hot water and heating in a practical, economical way.
Calling on his experience as owner of Hewitt Plumbing, Craig took the decision to install two Remeha Avanta 30v Heat Only gas boilers. One supplies the heating, the other works in tandem with an array of solar thermal flat connector panels to provide hot water for the house and swimming pool.
“I’ve used the Remeha Avanta on a number of my own contract installations,” said Craig. “I like them, and I know that they offer performance and reliability at the right price. The customers that have had them fitted have always been happy with them. As the project was a complete re-build and redevelopment, I couldn’t afford to waste time worrying about whether or not the boilers were up to the job, so I went with a brand I trust.”
Craig’s slightly unusual decision to use two domestic boilers has resulted in a far more effective and efficient system, as he has no need for expensive mixing valves or controls. Thanks to the small dimensions of the Remeha Avanta, he was able to put two side-by-side to work more effectively and easily in a smaller space than, say, a commercial boiler.
“By choosing to install both boilers, I was able to modulate their outputs to suit their specific roles. For example, because I opted to fit underfloor heating, the boiler that regulates the heating only needs to heat up to 45˚C. Compare this to the hot water, which needs to get to temperatures of about 75-80˚C, and it becomes clear why using one boiler wouldn’t have been the most efficient option.”
Craig had no problem combining the Avanta boiler with the renewable technologies. “The second boiler, which acts as the supplementary/backup heat source for the water, has been set up to give priority to the hot water for the house. It heats the 300l domestic storage vessel rapidly, then it works in tandem with the solar flat plate collectors to heat the 600l storage vessel for the swimming pool.”
The solar thermal package works on a three stage system feeding into three separate cylinders. The first cylinder is dedicated to domestic hot water. The use of relays ensures that this cylinder always has priority for any available solar energy. When the domestic hot water cylinder has reached its set temperature, which happens rapidly during the summer months, the solar energy is diverted to heat the second cylinder which is used to heat the pool. When solar power is at its peak, any excess solar energy is stored in the third tank and is used during non solar generating times.
The result is a beautifully warm house and abundant hot water. With the boilers not switched on all summer for hot water, Craig is reaping the desired benefits of reductions in fuel costs and carbon emissions.
- October 2011