martinwinlow

ie stupidity...

Yes but you said it yourself... *old*... and don't get me started on 'British Industrial Disease' (sitting on laurels and doing precisely nothing to innovate in order to maintain market share).

Well, the price and performance obvs depends on the specific turbine and mount design... eg https://www.ebay.co.uk/itm/163822754038 - an iSTA Breeze 1kW 48V turbine and controller for £730 and if you mount the pole to a suitably strong gable wall the cost of the mount would not exceed a few hundred pounds. This one would produce 300W at 8m/s. So, as you say 7kWh/day but I'd think you could do the same arrangement with a 2kW turbine (noise issues aside) for relatively little more money... and that would give a pretty good payback time - by PV standards at least. In a modern well-insulated house with next to no space heating requirement, that would pretty much take care of your electricity needs (albeit you'd have to add the battery cost to that). But my point was that prices of kit have come down a lot and the cost of electricity has gone up *a lot* in recent years and it just seems a shame that practically no-one is looking at this market - apparently.

You don't need an 'expert'. You *need* someone who knows what they are talking about!... and they are like hen's teeth, sadly. Lots of rather negative sentiment towards wind in this thread and I can see why. It has been traditionally much more expensive than PV in terms of bang for buck but with the advent of good (ie Li-based), cheap batteries and electricity prices trippling (not to mention the same happening to new mains electricity supply costs) I think it's time battery + wind got another look. The other issue is *location*. I'm on a Hebridean island and have access to the data from a 100kW turbine a few hundred metres away. Typically, for the 4 months of winter Nov-Feb, the *average* wind speed here (or at the turbine site) is 8+m/S. That's *average*... for 4 months of the year when electricity use is highest! Even a very modest turbine would make a huge dent in the average households energy use with that much wind on tap - assuming you have the flexibility of storing it n a battery for se when it is needed, not just when the wind is blowing a hooly. A 1kW HAWT would generate 12kW/day easy. Cost? Under £1k (+installation) plus another £4k for a decent chunk of 10kWh battery/5kW inverter/2kW turbine controller, again plus installation (not beyond the realm of competent DIY, of course). But ideally you would want a good-sized PV array for summer, too. 4kWp would do for most people especially if they space/water heat with a heat pump (or wood burner, of course). But, like I say, there just seems to be a complete dearth of users with good experience of small scale wind and the time/inclination to write about it.

It's not in the least pedantic, it's just *correct*!

I know I'm asking a lot but I thought I would ask...! As per the title - I just want a small, self-contained air-to-air heat pump that would mount on one or other side (or both) of an external wall to both supply heat via a built-in heat pump whilst at the same time supplying external fresh air and extracting stale/damp warm air and recovering the heat from it. Anyone got any ideas, please? MW

Just found this on eBay: https://www.ebay.co.uk/itm/394363330368 ... with the potentially interesting feature: "Automation , It allows to make a Scene for this device working with other tuya devices. Set Automation for the Measured Device. For example, If Power or Current Is over the Value, then other tuya device starts to work ."

Well, that gets me half-way there... I just need something that can detect export power greater than 3kW at the point where the turbine feeds the grid (1/4 mile away) that can then interweb a switch on command to the Timeguard (or something a bit more robust, as you say - I could always use the Timeguard to activate a much chunkier contactor...)

Not that I'm aware of... but it warrants further investigation...

...at the moment about 80% of that is going onto the grid (50kW max - any more is burned off in warming the log store, ie wasted)... and the *average* wind speed for the 4 months of last year, here (Nov-Feb) was 8.5m/s...

Well, true but not if you have 3kW or more of export... any less and I'd just stick in a battery. I'm specifically looking for a very simple internet-based (to avoid having to wire stuff together which my be very difficult/expensive to do - particularly if your renewables are a mile away!) system that really is either on or off... I assumed these 'diverters' use some sort of 'power-transforming' system to get around the issue of not having enough power to use a basic immersion element directly (a bit like an MPPT?), hence (no doubt) their high cost... I'm just genning up on them now but, as I say, they are not really what I'm looking for.

I find myself here looking for an immersion heater that can be accessed via the internet for the simple intention of turning it on when my renewables are exporting to the grid thereby allowing *me* to use the energy rather than the grid pay me 1/10th of what its electricity costs *me*... I appreciate the MyEnergi Eddie (probs others too) does this but it's quite a complex and expensive bit of kit for what is a very simple situation. Ideally the device I'm looking for would have an internet-linked sensor that detects exported energy and would then command the immersion element to turn on... As for the original post, the one (potentially) significant advantage of the Tsmart device is that you could turn off your HW when you go away on hols via the app, but more importantly, turn it on again when you are a couple of hours away from home so you have a tank full of HW without having left it on all the time you were away... It would also allow those of us keen to minimise our energy use to understand better where the energy is going and when so it could be better managed... but that's about it!

Hi, I'm wondering if the OP has used his system for heating in winter as there is a good chance it would compare favourably cost-wise with either oil or gas these days...? My interest in this thread is purely from a heat POV as no requirement for cooling out here in the Hebrides! This would also mean that no condensate pipe would be needed meaning the hole between the indoor and outdoor units could be considerably smaller. I put in a single indoor/outdoor unit by Midea for my study (where I spend most of my time when indoors during the day) about a year back (as I say, for heating only) and it works out at about 1/3 the cost of the resistive heater that I used before - it comes on for about 12 hours from 0700 every day, maintaining 20C and has been using an average of about 2kWh per day these last 4 weeks (since I installed an Emporia energy monitoring system). For reference, the study is ~4m x 4m, has one poorly double-glazed (old-style alu frames) window ~1.2mWx1mH and 600mm stone walls on 4 sides, party wall one one side and internal wall on the other, uninsulated suspended timber floor with laminate on top and uninsulated ceiling void. Ie, it has poor overall thermal performance! Quite impressed - £600 to buy the kit and very easy (for a competent DIYer) similar-sounding to install as the OP but my outdoor unit is ground-mounted and thus is much easier. One point for others interested in heating systems (rather than cooling) is to get floor-standing or low-wall-mounted indoor units rather than the usual high-wall mounted ones as there is zero point in blowing warm air at 2m above (cold) floor level! These are often referred to as 'consoles' and are slimmer than the high-wall units. Also, I would really love to have installed a multi-way system having had a successful 'proof of concept' experience but would probably go with a more main-stream make than Midea. My cottage has only 4 rooms (+ kitchen and 2 baths, one small) and one indoor unit in the study, another in the lounge and a 3rd on the upstairs landing (and leaving the bedroom doors open during the day) would make a huge dent in my otherwise all-electric (everything - rented so not my choice!) energy bills - £2k5pa before the recent hikes...

Water requires about 1.2Wh of energy input to raise one litre by 1(degree)C. Assuming 'cold' means 20C (room temp) and 'hot' = 60C, a 100 lire hot water cylinder (HWC) would use about 100 x 1.2Wh x (60C-20C=40C) = 4800Wh or 4.8kWh. If you mean your immersion element is a 2kW one then it would take ~4.8kWh / 2kW = 2.4 hours to heat from 20C to 60C. In reality, the water in the cylinder will rarely be at room temperature (unless you have just used it all, of course) and so the re-heat times will generally be less. As ReedRichards says, there is little difference in the heating process efficiency between water in a cylinder and Sunamp's 'phase-change material', Sodium Acetate (a materiel used in the manufacture of potato crisps amongst many other things and therefore relatively cheap and non-toxic). So, the amount of energy you put in will produce the same amount of hot water. However, the insulation of a typical HWC is pretty woeful (like everything else in our hopeless country - why are we all banging on about different and horribly expensive ways to replace natural gas for our hot water and space heating - which, together, amount for 2/3 of the UK's *total* energy use (?!) when we *should* be installing *way* better insulation?) and that of a Sunamp storage device way better. As for the purchase cost comparison, if you carefully analyse the constituent components of the HWC Vs Sunamp store you will see that they are relatively comparable, likewise the construction process and so, like any new technology, in time the price will fall significantly with mass adoption. It's a complete no-brainer (in the medium).

Wow. My input having done a 5 bed MVHR DIY a few years back... Firstly, I can't help but think most people *grossly* over-engineer the design of these things. You *can* spend hours and hours designing the b-jesus out of a MVHR system - 'meeting the regs', sound-proofing etc, etc... but, in reality, ultimately you will not be changing the air at anywhere near what the regs say you 'should' and duct noise really is not going to be an issue at the air speeds involved (assuming you avoid rigid ducts - see late and even balancing is more art than science). For an average 3/4 bed house, just stick to 4" ducting between the heat-exchanger box and vents (and use insulated flexible ducting as it is very cheap and easy to use and you won't get condensation issues that you may with rigid, uninsulated ducting). Use round, plastic ceiling vents/diffusers with adjustable flow rates which are dead simple to install, clean and balance (if you feel the need). NOTE: Get a ventilation unit with summer by-pass facility - I can't believe these things are sold without this facility as otherwise, in summer, you either have to have all the windows open all the time or the house becomes unbearably hot due to the heat recovery thing still going on. You also would have to deal with bathroom/kitchen extracting being operational without any way to stop the house warming up, again, without opening the windows. Bear in mind I was doing a new-build with a central services area and so all my ducting runs were kept to a minimum length and were easy to integrate. If you are retrofitting then rigid ducts may make much more sense.