When your designing a house to be as energy efficient as possible it makes common sense to keep your thermal store within the heated envelope of the house right. So why on earth did I put mine in a wooden shed stuck on the back? Well I gotta admit it’s a question I’ve often asked myself and the truth is I’m glad I did. For a start it weighs almost two tons, containing as it does 1500lts of water and would take up a lot of valuable storage place in the house. Sure it does loose a bit of heat despite being very well insulated but the shed doubles as a store is well insulated and contains a large chest freezer which should be kept somewhere above 10 degrees! Take note of that all you peeps that keep theirs in the garage 
Sure they’ll work at cold temperatures but modern freezers use a lot less power if kept at higher temperatures. It’s a bit counter intuitive but it’s like leaving a fridge door open, it will actually increase the room temperature rather than reduce it cos the compressor has to work harder to try and maintain the fridge interior cold.
So any heat that does escape is not wasted as it, along with the heat from inverters and now a dehumidifier keep the shed nice and warm. This in turn means my Ecocent https://www.earthsaveproducts.com/products/ecocent/ecocent-energy air source heat pump runs more efficiently too.
As you can see the manual quotes 810W input produces 3000W of heat a COP (coefficient of performance) of around 3.5. However this is misleading because it is under ideal conditions and whilst it is achievable, the higher the heat required and the lower heat input will drastically alter this COP. I’ve been unable to find a graph for the Ecocent Energy water heating pump I use but as it is only set to heat the UFH (lower part of the store) to 40degrees from a lower temp of 35degrees. Extracting it’s supply air from the bunker at a relatively mild 10 to 20 degrees it should be quite efficient. It certainly keeps my house toasty. But and it’s a big but, my house is exceptionally well insulated and uses Under Floor Heating that only needs 40 degrees of hot water to keep the house at 20. It simply would not work otherwise. Methinks that an awful lot of people are fitting heat pump heating systems into unsuitable draughty poorly insulated properties 
Sure they can work but only with huge radiators, large pumps and in the dreams of silver tongued salesmen
So it was after the morning jaunt with Bonzo that I found myself in the warmth of my ‘plant room’ der Bunker, named so after the peculiar slit like window on the back wall.
This window being one of several that I found on the Internet that ‘were a bargain’ well they would be wouldn’t they, who on earth needs a window for a pill box Anyway it actually gives more room inside and helps keep the Bunker warm.
It was a nice 17 degrees and the dehumidifier had extracted a couple of litres of water overnight. My plan for the day being to swap around the supplies to my immersion heaters in the store, there are five of them at different heights and I wanted to alter their order of priority.
The top one is for my DHW and is a 3.2kW one used for heating the top of the tank which provides my domestic hot water. This is controlled via a timer in the house if required.
Pressing the button advances the timer from 15 minutes to two hours https://www.ebay.co.uk/itm/253910655223 and it’s very handy ‘off grid’ as I used to leave it switched on all the time and rely on the immersion’s internal thermostat. This was fine until my Son started taking twenty minute showers every day no matter how windy or sunny it was outside
The second immersion is a spare, just in case I come up with a brilliant plan for more free energy and the third in fourth ones are heated by any excess power produced once my batteries are charged. They are also 3.2kW ones acting as dump loads for my system. The final one at the bottom is a 6kW that is ‘hard wired’ into the 12kW generator so it is always kept under at least 50% load when running. Diesel engines being more efficient when under 50 to 70% load and battery charging via a diesel generator being really inefficient in the final ‘absorption phase’ when the generator is only very lightly loaded for several hours.
I could lie to you and tell you all that this was my reason for purchasing a 12kW generator when a 6kW one would do but the truth is very different. Like my Bunker slit windows the generator was a bargain that could not be missed
Anyway the reason why I was swapping immersion elements about was cos I thought one had failed, well it had, the fourth one down didn’t appear to be working. The lowest of the 3.2kw ones being ‘priority 1’ when it came to dumping excess power and at this time of year quite useful for maintaining the UFH part of the store and reducing the amount of time that heat pump runs to warm the house.
So after hours of messing around and finally poking around inside the element with a meter I discovered that the thermostat on the end was faulty. So I bypassed the thermostat and wired the immersion through the timer, figuring that with the the heater being at the bottom of the store and only ever being on for a maximum of two hours it was never going to reach 80degrees 
I then wired the excess power dump to the spare immersion. Thinking about it afterwards I could have just swapped the thermostats over but that’s not how I arrived at the conclusion at the time It took me so long to sort it that I’m gonna leave it well alone for now cos during my quest for a new immersion I found a newer version of my own containing a duel 1kW and 3kW element. Thinking that this would be most advantageous if ever a replacement were needed. I put the idea on the back burner for now and went for another walk with Bonzo.
This being a short perambulation behind the house
Up to the highest rock behind Sonas, just above the ‘puddle’ that once doubled as an emergency water supply for my old house at Number 3.
I’d never even considered that this puddle was anything other than natural but small piles of rocks at its western end look like they have been placed there deliberately. Though I cannot imagine why somebody would do this as it is only a few meters from a good well that supplies my own house.
Wandering back down but still a long way above the township I came across the remnants of an old VHF antennae that once resided on a mast behind my old house. Sure it’s only a light piece of aluminium but even so it must have been some gale of north westerly wind that took it all the way up the hill Probably Henry back in 2016, he fecked my smaller Proven too https://lifeattheendoftheroad.wordpress.com/tag/proven-wt2500-stator/ Henry had far more attitude than Arwen in these parts at least, though I hear there are still thousands without power in parts of Aberdeenshire and Northumberland
How can I make so much washing up
As evening descended early thanks to the thick grey clouds I tried to feed the pigs who are usually waiting at the back gate to come in. Much to my surprise despite the failing light there was no sign of the wee darlings so I fed the dugz instead.
Bonzo doing his customary bounce which considering his reluctance to go up and down stairs or jump in the back of the Land Rover is quite amazing. Molly is old, lame and rarely walks anywhere these days but will jump up or onto anything.
There was still no sign of the ‘Three Amigo’s’ so I started on dinner a grilled mackerel with roast and steamed veg number which created more washing up than Christmas dinner
After demolishing my feast I went back outdoors and managed to feed the ‘dirt stopouts’ and called it a day.
Probably would have done had it been Morse instead 
Life at the end of the road 
