Thermal Stores
My house is in a rather cold spot in England, I measured it at around 860feet above sea level, it’s in the North and it’s on the edge of the Pennines. It can get windy here, it can get very windy indeed just ask what used to be my garage roof. It can get snowy, when other parts of the country are breaking into fine weather I can appear with my truck covered in inches of icy snow.
What we need is some way of heating this place and some way of keeping it warm once it gets warm.
Heating represents a problem when there’s no gas supply up here and I have little money to burn. The oil fired system works well, but not great, but it does have a few down points, it’s expensive and it does have a tendency to go walkies.
I needed a new way of looking at heating, something modern and cheap to run, something that could take advantage of the oil but something green too, something that could use renewables.
The heating system would need multiple sources of heat but I wasn’t interested in employing complex and expensive switching systems that would move from one heat source to another with clunky bad technology I needed something that would sit at the heart of the system that work seamlessly with all the sources of heat I had at my disposal.
The Heart
The thermal store/bank.
What’s a thermal store I hear you say, well a thermal store is just what it says on the tin, the thermal store stores heat, it provides a way that heat produced through unreliable sources can be used at a later date. I need a system as I mentioned that would cater to a plethora of heat sources but as I’m in and out and I don’t have the time to light a fire every morning I need something that I can just switch on that doesn’t necessitate the convenience but the expense of oil.
The thermal store (sometimes called a bank) is a big cylinder that holds a large amount of water, typically 300 litres and upwards, there are some enormous ones on the market but these usually cater to the needs of farms or estates. This water reservoir stores the heat to be released later, they are incredibly insulated and being such a large volume they lose very little heat over protracted periods.
What’s clever about a store is that you plug in all your heat sources in your house. The store employs heat exchangers in the form of coiled pipework running through the water to transfer heat to the water making it a bit heat battery. I have a multi-fuel burner, an oil condensing boiler and the potential for a couple of thermal solar cells (note here that thermal solar is nothing to do with photo-votaic solar cells that churn out volts, the thermal solar cells churn out hot water).
The beauty of this is that in winter is I can use my multi-fuel stove to heat the water rather than the oil and when I want access to this hot water it is available at any time I want. If the heat in the store should go below a predetermined temperature then the oil boiler will cut in and heat it up and should the oil run out there’s even an electric immersion heater in the store that can cut in – this could have proved useful when my oil mysteriously went missing.
In summer you can use thermal solar to heat the water, again the oil provides a convenient backup with the immersion heater as a brace for the oil’s belt. Get enough thermal cells and it will heat a full store up to melting point on a hot day, this means that you won’t pay a penny for heating over the summer.
Another useful string to the store’s bow is what heating devices you can plug into it. You can plug your full radiator system into it, you can plug your underfloor heating into it, your domestic hot water works by running your mains water supply through an external plate heat exchanger (this is done deliberately as if this heat exchanger lime silts up – this is the one that would – then it is simple to disassemble and clean, make sure that your store has an external plate heat exchanger for domestic hot water) a great advantage to this is that your hot water is at mains pressure and not a trickle that relies on the gravity from your hot water tank.
It is such a flexible system and will be on full test on this site once it is fitted. I’m hoping my heating will go down to a fraction of what it’s been funding oil to heat my house and the houses of other less honest people.
Remember too that you’re not just limited to the sources I’m going to be using, you can also input pellet burning systems, ground heat recovery systems, get creative and run a pipe through a pile of manure, see what heat you can squeeze out of sh….. manure.
There are plenty of good sites out there too offering lots of advice on buying a store, the first thing to seek out is a ready reckoner to figure out the litreage of the tank you’ll need. This calculator should take into consideration the size and heat lossiness of your house.
My advice though:
Hunt around, there are plenty of thermal stores out there and don’t think that expensive necessarily means best.
Make sure that the one you get is made of stainless steel and not just mild steel.
Make sure it has an external heat exchanger for your domestic hot water.
Get the size right, don’t be tempted to go toooo big.
I like the fact that the header tank for mine is made of metal and not plastic.
Check to see how well support supports. I got to know Matt at HTG and no question was too much trouble, some other companies could barely respond with a quotation let alone do support.
Do your research, hunt around and find out what other peoples experiences were, it makes sense when you’re paying thousands of pounds
The thermal solar will have to go on hold for the moment, I really don’t have the money to do it at the moment and it will be brilliant though once I do get it in.
Watch this space.