Here we find ourselves down a rural unmarked lane in Kent, the site of a large barn conversion.
It comprises a two storey hallway, and many original features.
Much of the house is already underfloor heated, using an L&K system with around 14 separately controlled zones.
What makes this system unusual is the various heat sources used to create the heating and hot water. There’s two fuel burning stoves, some solar thermal on the rooftop, and a Rayburn solid fuel stove.
This was all installed by the present owners, who were almost singlehandedly responsible for the design and execution around 14 years ago. They made a very professional job, too.
Being 14 years younger at the time, the idea of using renewable energy was attractive, and their location had plentiful supplies of timber for the stoves.
Now the honeymoon of chopping logs, drying them out and moving them into the house was beginning to pall. The solar panels, whilst creating around 50% of their hot water requirements over the year, only save around 7.5% of the annual energy bill, because heating is responsible for around 85%.
They had even installed a separate electric boiler a few years ago, but this had been ruinously expensive to run. No surprises there; at the time of writing (January 2020) electricity is over double the cost of oil. Or gas.
Our customer had used a thermal store to amalgamate all the different energy sources, and provide hot water. The store had seen better days, and was a basic type with a coil rather than a plate heat exchanger, and this was giving a poor performance.
Our customer had seen a Heritage cooker at a friend’s house, and wanted an oil fired one for their house.
We designed a new system that used a Heritage cooker, complete with a internal 30Kw boiler, to replace the Rayburn stove and the various other heat sources.
We swapped out the thermal store for a solar compatible Fabdec Self Sustaining 3S unvented cylinder. This immediately and visibly improved the hot and cold water performance compared to the thermal store.
The Fabdec cylinder, from the inventors of Megaflo, incorporates the latest technology to recharge it’s own air gap. Expansion vessels are no longer required, and unlike the Megaflo, there’s no airgap that need periodically recharging.
We had to order a unique cylinder for this job; it was the first Fabdec 3S solar compatible cylinder to be fitted.
The cooker was a Heritage standard Duette. it comprises a cast iron frame with modern pressure jet burners inside. For a heat store oil fired cooker, it is quiet, and very fast to warm up.
It has a digital timer so it can be ready when you get home, typical warm up from cold to cooking is less than half an hour. Read this and weep, AGA owners. PS: If you have an oil fired AGA, get this, if you turn the Heritage off, it will come on again!
This particular Heritage has two full sized ovens, plus a boiler inside. The functionality of the boiler is completely separate to the cooker. The only things they share are the flue and the casing.
A new bunded steel oil tank was installed outside, there was a lake nearby so no chances were taken with the tank specification. Steel oil tank degrade gracefully, leaving the owner with plenty of warning when their lives are nearly up. Plastic moulded tanks give little warning of impending failure, and are also easily damaged by air rifles, and collateral damage from attempted oil theft.
Heritage Cookers are based in Liskeard, Cornwall.
We’ve got a fair bit of experience with them; I installed ours back in 2004, and it is still used every day.