Jeremy Harris

FWIW, I did indeed follow the MIs and connect both heat exchangers inside the UniQ in parallel. On the house side there was still only a single 22mm cold water in and 22mm hot water out, though, not the tangle of pipework that some hot water systems seem to need.

A cord is 128ft³ of wood: https://en.wikipedia.org/wiki/Cord_(unit) I'm pretty sure it may have originated around the time that wood fired steam transport (railroads and steamers) were cutting down millions of trees for fuel along their routes. There was a US TV programme on back in the 1960s about a river boat (I think it was on the Mississippi) , and they seemed to always be stopping to pick up cords of wood for fuel.

I've installed two of these, a Sunamp PV (essentially the same as far as connections go) and a Sunamp Uniq eHW 9. The hardest part by far is transporting the UniQ to its final resting place. Our 9 kWh model weighs around 155kg, so although it's not that big it should be a multi-person handling job (I struggled a lot, but got it upstairs and installed on my own - never again). Plumbing is dead easy for the electrically heated models, just a mains cold water pipe in and a hot water pipe out (both 22mm). The indirectly heated models (heated by a boiler) need four pipes connecting, a flow and return to the boiler indirect circuit and the same cold water in and hot water out as the electric units. Electrically, there is a control box that has a sensor cable that runs from the UniQ to screw terminals in the box. There are two basic versions of the control box (with some variations) and the electrically heated models need an always on low power mains power feed to the box, a high power feed (if using a PV diverter to heat water from excess PV generation this comes from the PV diverter unit, Immersun, Apollo or whatever) and a cable out to the electric heating element in the unit. For the non-electrically heated models then the control box only has low power mains, plus control connections to call for heat from the boiler, etc. Commissioning is really just turning on the water (plus filling the boiler loop for boiler heated models) and checking for leaks. Turning the power on and checking that the control box internal status indicators are OK, then letting the unit charge up for a time and checking that it's delivering hot water. Maybe half an hour of work plus another hour or two waiting for the unit to charge to test the hot water. Doesn't take any special skills, I'm not a plumber and found the things dead easy to connect up, commission and test.

Yes, it would. With a platform that was just set so that the thing could be picked up and lifted to below waist height to hook it on to the fixing rail the job would be pretty easy. I sold my platform to our plasterers, after we'd finished decorating, as it was taking up too much space in the garage and I didn't think I'd need it again... I think I've cracked how to do this now, using two ladders and a rope either end of the unit, so that I can lift each end separately. That should stop it twisting and allow me to lift each end up to hook the the thing into the rail that's screwed to the wall. It just hooks on to this rail, so needs to be lifted about half an inch higher, one end at a time, hooked on, then lowered slightly, repeating this for the hook at the other end.

I'd really love to do this, but the front of the unit ends up about 18" away from the wall (it needs an air flow space behind it), and the path is only about 3ft wide (can't easily make it wider because of the retaining wall and stuff on it). With hindsight I should have arranged things differently and not had the path so close to the house, but it would be a major exercise now to change the path and other stuff. Having said that, I've just come in for a cold drink, after my second (failed) go at hoisting the thing up. I can lift it OK, just can't get it hooked on to the wall brackets. I need a bit of thinking time to work out a way to get it into place. I reckon I need to make a lifting bar or frame to help hold the thing level as I hoist it, as it's heavier at one end than the other. so wants to tilt and then that seems to make it want to twist. I'll get there in the end...

Can I also suggest that if buying salt in bulk you have a think about where to store it. I bought 60 packs, which is a half pallet load (works out at about £4.50/pack). 60 packs didn't sound like a lot when I ordered it, but when it arrived and I had to shift just under half a tonne of salt upstairs and stack it in our under eaves storage space I began to realise just how much it was (around 5 years worth).

And, it seems, immortal : https://en.wikipedia.org/wiki/Electrocution The next thing you know a new religion will have sprung up about you. Might last a few thousand years, if the last reported person to rise from the dead is anything to go by...

Very glad to hear you're OK, @Patrick, and that no one else was hurt. At the end of the day that's really what matters. Thanks for having the courage to post this tale, too, as there is a fair chance that it may well make someone else think twice before trying something similar, so (hopefully) preventing a future accident. A few years ago we had a large beech tree taken down in the corner of our garden at the old house. It wasn't our tree, but was right on our boundary. It was diseased, and potentially dangerous, so had to come down. There was no way it could be felled, so it was taken down from the top, in sections, with a chap swinging around on the end of a wire from a very big crane. Scary as hell to watch, but it did mean that the way each bit of the tree that came down was carefully controlled. Must have cost a fair bit, though.

Yes, it's a small Toshiba unit, to make the bedroom a bit cooler, as the heat pump in the MVHR isn't that effective at cooling upstairs, even with an increased flow rate to the bedroom. Downstairs is fine, rarely gets over 22°C, thanks to the floor cooling from the ASHP. I really wish I'd thought about this earlier, and made provision for fitting the thing, as it's a PITA trying to run pipes etc around now the house is finished and being lived in. This afternoon's job is to rig up a hoist to get the outdoor unit (weighs 23kg) up high on to the rear wall of the house (well above head height, as it's over a path). I feel the need to get my climbing ropes and kit out yet again...

It'd probably be fine, given the growth in renewable generation and the number of solar farms being built. Also, it doesn't take much solar panel area to provide enough power to offset the use of air conditioning. The air con unit I'm part-way through installing has more capacity than I think we need (~2.5 kW output) but only draws about 800 W maximum from the grid. A pretty small array of around 6 panels on the roof would be more than enough to offset this. Also, fitting solar panels on the roof reduces solar gain a bit, by around 16% to 18% for the area covered by the panels, maybe more if the panels are spaced above the roof, like the way the Land Rover Safari roof works (always thought this was a great idea for cars). Any power generated by the panels means less heat available to be conducted through the roof into the house.

The choice probably comes down to a couple of factors in the end: 1. Are you happy with a bit of tinkering in order to get a bargain price? If so, hunt around for one of the badge-engineered units that's being sold off cheaply - they all seem to be good value, based on the experience of people here. 2. If you want a hands-off install, and don't want to tinker, then go with whatever big name brand your local (reliable) installers normally supply and fit, as long as you're happy with what you've seen of their service and the way the unit runs and is controlled. Pretty much any of the big name inverter controlled units will be quiet if run well within its maximum rating. Equally, pretty much any of the big name inverter controlled units may be noisy when run close to maximum output. For example, our Glowworm badged Carrier isn't supposed to be one of the quietest units around, but it happens to run very quietly indeed for us, as it never really gets asked to run anywhere near maximum capacity. You can stand next to it when it's running during the day and not realise it's on without looking at the front to see if the fan is going around. The same unit installed somewhere where it was being run hard much of the time might be considered a bit noisy. BTW, I'm pretty sure that Nibe units use Copeland compressors. Nothing wrong with that, Copeland are a well respected company that supply compressors for lots of brands, including Carrier.

I think one issue is that there really isn't very much to choose between any of the big-name inverter controlled ASHP manufacturers in terms of performance. They will all probably perform pretty much exactly the same, so any differences are likely to be related to things like how easy their controls are to install/use. There's a massive amount of badge-engineering, plus the use of a limited range of key components used by several manufacturers, which also makes comparisons challenging. For example, Carrier (the company that invented the things originally) supply major parts, or sell badge-engineered versions of their products, to loads of different companies. Our Glowworm ASHP is really a Carrier with a Glowworm badge on the front, and the same goes for Kingspan units, and others. The small Toshiba unit I've just bought is really a Carrier too, I've just found out. Likewise, Panasonic sell their inverter controlled compressors to loads of other manufacturers, including some no-name Chinese stuff. Pretty much any of the big name brands, Mitsubishi, Daikin, LG, Carrier, Panasonic, Toshiba, Samsung, Hitachi etc, are likely to be pretty much of a muchness, I think. Best bet might be to look to see if you can find any information about which brands have good support locally, as it seems that many suppliers stick to one or two brands, on the basis that they've built up a relationship with them.

We're using about one pack of salt blocks every 4 to 6 weeks, just two of us in the house. I buy salt by the half pallet load for around £4.50 per pack, so the running cost is around £50 a year or thereabouts. (A half pallet load is several years worth, 60 packs)

TÜV can be as flawed as any other body that comes under commercial pressure, though, I have personal experience of a TÜV approval body in the Netherlands effectively handing out Type Approval certificates for cash. The certificates in question were for safety equipment for use onboard commercial shipping.

That looks pretty dire for just 13 months use. Makes me wish I'd taken our old Sunamp PV heating element out after three years to see what it looked like. Harvey softeners are pretty slim and look fairly neat. We have one and it seems to work very well. They are sold under a few different names, as I think Harvey has licenced the core technology. We have this model: https://www.uk-water-softeners.co.uk/product/dimensions/

The foundation for ours is wide, 2m at it's widest, but it misses the rear of the house foundation by about 400mm, and we still have around 1.6m of space around the back of the house. Had we gone for a battered back block wall (Stepoc or similar) then it was going to end up a lot wider at the base, and make it really difficult to get enough space for access around the back of the house. Our 215 hollow block wall is vertical, and "only" 430mm deep at the base, and 215mm of that is under our neighbours garden. The top of our wall, where it forms the boundary with our neighbour, is only 215mm wide. As the side of it facing the neighbour's garden is the boundary line, we've only lost the 215mm thickness of the hollow blocks, plus 15mm or so of render, between the boundary and the house.

Most of it, but not all, and that's with solar reflective film on the outside of the windows (which also cuts down winter solar gain a lot). In terms of money spent, we probably still spend more on cooling than heating.

For us, winter heating is virtually negligible, less than £100. The electricity we use for cooling is easily three or four times that we use for winter heating, even though most of it comes from the PV system.

Looks very similar to the foundation blocks pioneered by Walter Segal. @Ed Davies has used this method for the foundations of his self-build, I believe.

I think the best approach is to read up all you can about building best practice and spend as much time as possible on site to catch anything that goes awry early, when it's easier to put right.

SSE (the supplier, not SSE the DNO, they are a different company) were very specific and insisted that I had a signed off installation before they would fit the meter. Bit chicken and egg, because I couldn't do the live tests to sign off the installation until after SSE had fitted the meter. Our temporary installation consisted of an isolator switch and a small waterproof consumer unit that had a 16 A commando on the side, for site power. You also have to have an earth electrode and RCD/RCBO for the temporary supply, as they will not connect the meter until you do. SSE (the supplier in our case, could be anyone you choose) would not fit a meter to just an isolator switch on it's own. No idea why not, especially as the meter they ended up fitting had an isolator and accessible consumer-side tails terminals built in. Best to just fit in with what they normally do, I found, even if it did mean having two sessions for installing and testing the temporary site supply.

For retaining walls, all SE's in the UK are supposed to just follow Eurocode 7. It's not hard to use; I did a couple of designs myself using it, before I realised that I had to use an SE in order to get the thing signed off, or use one of the prefabricated block systems and get the sign off via their design services. The snag I found with the block systems was the cost and the room most of them took up. For us they were all more expensive and a lot thicker than the reinforced 215mm hollow block wall we ended up using, plus the block wall was a lot thinner, so gave us more useful room at the back of the house. Our SE was very good, and only charged us £300 + VAT for a full drawings package, specs, steel cutting list etc.

You must have a signed off temporary installation for the electricity supplier (not the DNO) to be able to install a meter. The sequence is usually this: Install empty meter cabinet (anyone can do this). Install a temporary site supply, which at it's simplest can be an isolator switch (optional but a good idea), small consumer unit with RCD/RCBO/MCB protection as required for any connected circuits, plus the site supply outlets, as required. Any electrician (Part P required for England and Wales) can do this, but it needs two visits, one to do the install and dead checks, another to do the live checks after connection. Get DNO to install a supply (has to be done by the DNO). Get a supplier of your choice to install the meter and connect it to both the incoming fuse and to the isolator switch or site supply consumer unit. Get your electrician to complete the live testing and issue an installation certificate.

Don't just vent it into the loft space, as you will get a lot of condensation inside the loft, which will drip down everywhere (ask how I know this...). Run the duct out to either the eaves or the gable and then to a terminal outside. Often there is room under the soffit to fit a terminal, saves going through the gable wall. You can get roof fitted vents, but they are a bit more hassle to install, depending on the sort of roofing.

I agree with @PeterStarck, we have an all-timber house, with vaulted ceilings upstairs, and don't have problems with movement. The only area where we get any odd noises is from the bamboo flooring on the upper floor. I bonded this down, with expansion spaces around the edges, but for some reason this flooring does make odd noises as it warms up and cools down. I don't think it's anything to do with the the frame or floor construction itself, though.