jack

That was the primary driver for us.

This is all very familiar. I did this last year to my 5 year old, heavily scabbed garage floor (we had unexpected rains and frost the night after our slab floor, and we ended up with bad spalling). I ground back all the weak concrete over a weekend and laid an epoxy top. It's held up pretty well, although it will scratch if you drag something sharp and/or heavy along it. Very easy to keep clean though. You're right about the epoxy repair stuff being too granular. I had a couple of deep holes to fill, and it was fine for that, but no way would you get it into those smaller stone-holes. I got everything I used from Promain. They have a wide variety of products from lots of different manufacturers, and their technical department was very helpful and responsive by email and phone.

Not a roller door, but we have an insulated Hormann sectional door, which has worked well for nearly 6 years. It's a bit annoying having it above your head if you want to do things with the garage door open (e.g., ours is used as a gym and a workshop, both of which need overhead clearance from time to time). I can't gauge how good the insulation is - the door isn't airtight, and I think that has a big effect especially in winter - but it doesn't get that hot in the garage even when we get the mid-summer sun beating down on the garage door for a couple of hours in the afternoon during summer.

I'd be careful assuming that you'll get much, if any, heat moving upstairs as a result of maybe a square metre of warmer floor at the foot of the stairs. It depends on the floor temperature of course, but UFH isn't like radiators. In particular, the temperature difference with UFH isn't enough to generate convection currents.

Thermal mass? (I'm actually perfectly fine with the term "thermal mass", despite some of the hate it gets on BuildHub. I think the real problem is not the term itself, but the fact that self-builders, designers and architects don't really understand the mechanisms at work, and so the concept is misinterpreted.)

What're your heat input requirements? A number of us here with passive slabs have gone with 200mm spacing (the pipes are tied to the slab reinforcement mesh) and have no issues getting enough heat into our houses at low flow temperatures. At all but the very coldest outside temperatures I run mine at 25°C, which is the lowest temperature setting available with my ASHP. It may also depend a bit on your floor covering. We have ~70mm of polished concrete on top of our 100mm slab, so there's a lot of concrete for the heat to diffuse across before it reaches the surface. I don't notice any "banding" of heat, although there are a couple of warmer patches where pipes are closer together due to routing. Perhaps it's different if the pipes are closer to the surface?

Why not try posting something different for a change?

Nothing's been deleted from this thread as far as I can see. You sure you hit submit? Try posting it again now we're all alert for something that probably needs deleting.

Compared with ASHP, GSHP kit is more expensive to buy, much more expensive to install, is potentially more disruptive in terms of earthworks (less of an issue with vertical boreholes), and costs more in ongoing maintenance due to the need to replace a lot of glycol every few years. Some have mentioned that the pump itself is quite noisy, although I can't see why that can't be located outside in an enclose to keep the noise down. There have also been some horror stories on performance. Things like ground icing up and killing lawns/plants due to the loops not being buried deep enough, and soils with low thermal conductivity with not enough loop area causing the ground to freeze over the heating season to the point where little or no heat can be extracted any more. Most of these are installation issues that shouldn't happen in a properly designed system, but how do you as a lay-person know if a system's been designed and installed properly? For all this, you get a nominal bump in efficiency that will take decades or more to pay back in reduced energy consumption.

*it's self-evident ? What is "low heat transfer" in numerical terms, compared to turbulent flow? 2%? 20%? I mean, if it's just a few percent, can't you just make the larger diameter pipework a little longer to take that into account? The other thing is that surely the pump manufacturer and/or installer should be the ones doing the calculations on this? I appreciate it's a little complex, but if you're in the industry, coarsely modelling a system presumably wouldn't take more than a spreadsheet with a small number of inputs? One other thing: is the larger diameter pipework array typically the same length as the smaller diameter stuff? I ask because I understand that one of the major cost disadvantages with GSHPs is that the glycol needs replacing every few years, and if you have more volume in the pipes, it'll cost more.

Any help? https://forum.buildhub.org.uk/search/?q=viridian

We did this on our build. A few comments: By bringing the cladding in, you lose some of the view, and potentially a bit of the light (the impact is greater for smaller windows). You certainly see more of the cladding than would otherwise be the case. You need to be sure that you can consistently terminate the cladding so that it's flush with the frame. At best, this will be a lot more effort to do well than just cladding around the frames in the more usual way. In our case, a lack of attention to detail by the cladding installers means we have several windows where the cladding (a mix of brick slips and larch) randomly leaves 5-15mm of frame visible. Not the end of the world, but it's certainly more effort to do this correctly than to just clad with the frame visible. When I now look at other houses that have similar windows, I think I often prefer the frames being visible. Especially if they're dark, they provide a clean line that perhaps makes the whole thing look a little sharper. Up to you what look you prefer though. Agree with this.

I'm sure there's another option that relies on a free API at some weather site. I think the only limitation is the number of calls you make to it, and it's at least tens a day for free. Can't remember what it is though - might be mentioned on the Loxone Google group. We have some similarities. Floor to ceiling windows to the east and south corner of the kitchen at the east end of the house, and little to no solar gain anywhere else on the ground floor.

Isn't it though! It's been nearly 6 years since we installed our system (electrician did the wiring, I did the programming), and I still enjoy tinkering with it. I have quite a few ideas at the back of my head that I'll one day get around to implementing.

Presumably you have other windows open in the house to get the stack ventilation working? I've considered this (we have an electric roof window, although it isn't presently wired in), but we get insects in if we leave windows open, and I assume the stack ventilation won't work as well if the roof window is the only thing open. I've considered getting insect screens to windows can be left open all night in summer.

Yes, I'd initially planned to use that temperature, but the module needed to allow me to get that value from the MVHR unit into Loxone was quite expensive, so I haven't bothered. I did consider adding a one-wire sensor into the outgoing airflow duct and using that - I might still try it at some point when I get some time (maybe in about a decade at the current rate of progress through my to-do list!) I also considered adding a temperature sensor on the UFH return rail on the basis that it probably gives an earlier indication of where the floor temp is headed than waiting for the air temperature to change. All that said, everything works perfectly fine as it is, so I'm not greatly motivated to add more complication or expense.

Mine is extremely simple. We have 8 loops downstairs, all run as a single zone. No UFH upstairs. Temperatures from a handful of cheap 1-wire temperature sensors upstairs and downstairs are averaged within Loxone and used to call for heat from the ASHP via a relay. I decide when it's heating season and switch the ASHP mode accordingly. I could automate this, but I only have to do it a couple of times a year, so it's no real effort. I've read some reports about the Loxone control valves being unreliable. I think there was a tendency for something to break off internally. Worth a look at the Google Groups Loxone group for discussions about this if you're considering using them. I believe people may have used other types of port valve and controlled them with, eg, a PWM or 0-10V output. As for passive controls, we have external blinds. Again, I've kept it as simple as possible. They all come down automatically at dusk. Certain ones come up at 7 in the morning every morning, others only on weekdays, and yet others only at certain times of the year. For example, our east-facing kitchen blinds stay down in the morning during summer when we're concerned about solar gain. The blinds on the front of the house stay down but tilted slightly open all day in winter and summer. I'll occasionally manually open them fully if it's a sunny afternoon and I think the solar gain is worth it. I haven't actually programmed the system to automatically change behaviour over the seasons. I generally just nip into the Loxone config program at the change of seasons and manually change the programming. Takes about 3-5 mins twice a year. One day I'll get around to programming the relevant changes as a button on the interface (or, perish the thought, automate it completely), but I have other things ahead of this on my to-do list. Edited to add: MVHR is not currently controlled by Loxone. It's generally just left to its own devices. The only time I hit boost is if we're cooking something smokey like steaks.

I know it's an aggressive plant, but rhizome fragments don't extend themselves 5m underground without coming up to grow some leaves to power further expansion. If it's on her side of the boundary and not yours, she'll have difficulty pinning the blame on you imo. That said, it's very close to your property, so it's in your interest to make sure it's sorted properly. I don't envy you!

We have exactly this issue with a balcony in our house (except our beams are more like 3 and 9 in your drawing). Thermal breaks as mentioned by @saveasteading are one option. You mention insulating the beam inside. You can also insulate the outer end of the beam as well. Anything that slows heat entering (within the house) or leaving (in the balcony) the beam will help.

Probably true, although electricity is undoubtedly cheaper during off peak hours, so it may just be that the rate increases a bit. E7 and E10 tariffs are still going despite rises in the cost of electricity over the years.

There are gyms and there are gyms. If you plan to be doing olympic lifting and dropping weights to the floor, you'll need something a lot more robust than screed. Even just doing deadlifts in our concrete garage on very thick rubber gym mats, dropping from even an inch or so reverberates through the house. In the end I bought some lifting pads so I can drop weights, and they mostly work (I'm old enough that I no longer want/need to do heavy - for me! - lifts from full depth). If you're not expecting to drop weights, then you mainly need to account for point loads. Whether a screed will work depends on what type and thickness of screed you go for.

Thanks for the kind words @Gus Potter, they mean a lot to us. Thanks also for your own contributions, which are exactly the sort of helpful, unbiased information for which people come to BuildHub. Yes, there was a lot of work early on, and certainly there's ongoing effort to keep things running, but it's largely settled down so that it doesn't take up huge amounts of anyone's time. We've put reasonably robust systems in place to keep out spammers, and the odd one that squeaks through gets the immediate ban hammer. Admin is taken care of by a small group who have occasional online meetings. Because no-one is paid, we have modest financial needs: software licensing, site hosting, the costs of running the BuildHub company - that sort of thing. Probably the main thing we could do with is help on is the technical side. We have some great people helping us out with our IT needs, but having another experienced person or two to fall back on would be helpful, particularly if they have experience with the forum software we use. I'm not too concerned about the long-term viability of the forum. The admin and mod team has been pretty consistent for a long time. If/when we get to the point where people started drifting away, we'll try and recruit from existing members.

Are you going for an air source heat pump and underfloor heating? Many here have had success with underfloor heating using an air source heat pump in cooling mode?

This is almost certainly based on (and possibly just a rebadged) Brink Excellent 400. If you can confirm that, then anything you can find out about the Brink likely applies. The Brink unit is Passivhaus certified, is pretty quiet, and has good heat recovery numbers. I have 6 year old Brink Excellent 400 and other than an odd leak that took a bit of diagnosing, it's been faultless.

My grandfather had several bits of his fingers cut off through various accidents using a spindle moulder over a 60 year career working in lumber yards in Dublin. Deadly things apparently - I've now met two chippies who say they've seen them in use and would never touch one. The last one to go was one of his thumbs. Apparently, that one "really hurt". Silver lining though: every accident would have a payout, and he'd lend money to his kids for a house deposit, or use the cash to visit them overseas.