Evening all. Ok, here's a thing. Way back, about 2004 or thereabouts, I happened to be living in a flat in a big city. A far cry from my current rural location, but even then, I was always on the hunt for ways to save energy. My energy costs back then were horrendous at almost five pounds a week and I began looking at ways to save money on my bills.
Most of which I had forgotten about until a chance conversation today with an old neighbour of mine from back then. He reminded me of all the crazy DIY stuff we used to do to make life more comfortable and save a few quid.
So, following a bit of a trip down memory lane, here's an idea that we played with back then, and he is still using today to help with the bills. He says they make even more of a difference now than back then, so I'll pass it on.
Stratification is very often an issue in enclosed spaces without much in the way of ventilation. Hot air rises and cold air sinks, so unless you have a window or vent open or some way of circulating air around the room, the air nearer the ceiling tends to be rather warmer than the air at floor level. Your thermostat is usually half way up the wall, so if you call for 18°C at the stat, you could be a couple of degrees lower at floor level, and a couple of degrees warmer at ceiling level. Now, if you have a reversible ceiling fan, job's a good'un. Run it in reverse, or winter mode at a slow speed and you will push a little of the warmest air back down again. An extra few watt hours running a fan, recirculating warmer air around the room might save you a little more on your heating bill.
Neither of us had that option, but I was an electronics engineer and he was a plumber, so between us we put our heads and our junk piles together and came up with a few prototypes, a couple of which worked really well. In fact, the Mk3 version of our 'heat pipe' is still working in his flat nearly two decades later.
So imagine a room about 3m, or almost ten feet high. In two opposite corners of the room, a drainpipe. Just like the downpipe you would find on your guttering. Doesn't matter if it's round or square, we tried both to reasonably equal effect. A 90° elbow on each end, making the pipe look like a very tall letter 'c'. Now, fitted in line with the pipe, near the floor end was a small ultra-quiet, low powered DC fan from a box of my computer spares. A bit of cutting and shutting and a few dabs of epoxy resin, and you now have a fanned duct. Powering the 12v fan from a small 5v power supply (or even a USB cable plugged into a nearby USB charger or even a PC) runs it slower, and almost completely silently.
Ticking away on incredibly small amounts of power, a couple of these circulated warmer air from ceiling level, down the pipe, out at floor level and meant we could either knock the heating down a degree or two or just have the timer turn the heating off a little earlier. Reduced stratification, circulating air effectively and saving a few quid off the heating bills because all the heat wasn't just warming up the ceiling.
Ok, rough as a badger's backside as we used second-hand 'scrap' (the square was part white, part brown and the round was black, white and grey) but it worked.
The Mk2 was a little more refined. In as much as my mate's girlfriend was a bit of a one for matching decor, that is. The Mk2 was made up with fresh 'bought in' white square section with mitred and solvent welded joins to make it look more clean of line, and then offcuts of his living room wallpapers glued into position, and even the border included. It blended into a corner and almost looked like it belonged.
Well, the Mk3 cost a little more, but was a thing of beauty. Instead of using square or round section rainwater downpipe, we used Manrose (other brands are available) rectangular section tumble drier ducting with a rectangular to round adapter on each end. Into one of the joiners, we fitted two 50mm computer fans with the airflow working in opposite directions. One fan circulated warm air down from ceiling to floor in winter, and the other ran in the opposite direction for summer use, taking cooler air from floor level and circulating it around.
A very cheap and simple differential temperature controller measured the air temperature at ceiling and floor level and controlled either fan according to season, reducing flow rate and shutting off as you had the air temperatures nicely balanced.
And that Mk3 is still working in his flat today. The only difference is that his units are powered by USB from a double gang 13A socket with a built in USB charger.
I just mooched the Screwfix website and ebay today, and reckon I could knock up a 'replica' Mk3 for just under £25. My mate says he runs the heating for an hour less in the evening and the stat down a couple of degrees so he's thinking about £2 to £3 a week off his bills at current prices, but November has been a bit mild so he's not really used the heating that much.