SimonD

Yes, it is isn't it. Reviewing the small print it says @ 50% RH. Will have to see how it goes with us and keep some records of temps.

So, I've been playing around with my new thermal imaging camera around my house, and randomly pointing it at parts of the house. I'll do it properly over the next few days when I have some more time. But there were some interesting findings. From the outside my thermal envelope looks good, no obvious thermal bridges but I can actually just see the ewi anchors even though they're thermally broken. However, when I pointed towards my yet to be insulated plinths, it was warmer than the ewi, not by much but it was noticable. I then went inside and noticed that the junction between the suspended timber floor and wall was colder on the brick side. Bear in mind I only have 3 small rads heating the downstairs, but the exterior walls measured above 18C as did the main floor. At the junction the temp drops to 14.2-14.5C at its coldest. This is retrofit so these wall and foundations all existed before and I do have insulation extending below the floor at the walls by 150-250mm below the joist where there is the room above the over-site. Looking up information on this, Passivehaus International mentions that the problem is where the temperature falls below 12.6C as this is when mould could form. I'm obviously above this and when I actually have full heating, there will be improvement. What's the view here? Should I hang my head in shame about this, or is this acceptable on a retrofit? And can anyone shed further light on what is typically deemed to be a problematic cold bridge?

It depends on the finish you want to achieve. Companies like envirograf have clear varnish and paints and uses a multi coat system. For a clear 'invisible' finish that requires no further coating, there's products like Flametect C-WD

If looking at wood wool, I'd recommend looking at Celenit as they've got coloured boards and three different textures. Useful if you're using them for decorative purposes too: https://www.celenit.com/en-UK/colors.php https://www.celenit.com/en-UK/en-uk-texture.php

Yes, look very cool, but as @jack said, the price is insane right now. Was expensive before even Brexit - here's my cost trajectory: I bought 3 pallets of interior birch ply (1525mm x 1525mm) @ 15mm thickness for flooring just before Brexit - cost was about £18/sheet. Just over a year ago in December I bought Birch plywood for making the kitchen, this time exterior grade (2440mm x 1220mm) @ 18mm thickness at £84/sheet. My wife and I then decided to build a new bit to the kitchen a few months later. Then, just before the Russian invasion of Ukraine, the price went to over £240/per sheet for the same stuff (so we left this plan). It's now gone back down to £170-180/sheet and that's for BB/BB. I dread to think what S+ is going to cost. If you're into plywood, then I'd recommend you look into softwood such as Pine as you'll get it in a B grade face at a fraction of the price. Also look at some of the construction grades as they can be more rustic with knots etc. but still be a good finish. Clear Poplar ply is over £100/sheet atm for 15mm and over £120 for 18m althought the red faced construction poplar ply can be had for about £40/sheet. The problem with any timber interior finish is fire protection and you'll most probably be required by BC to treat it all and it's not particularly cheap. I like the plywood look and have a lot of it going in but don't do it for budgetary reasons, it'll be far cheaper to plasterboard and skim. I actually think it might be cheaper to do internal wood cladding! With wood wool boards you'll need minimum thickness of 25mm, especially on the ceilings and you'll also need to check batten spacing on both walls and ceilings.

Another interesting analysis on the current UK infrastructure supporting RE, its problems and proposing some solutions. https://archy.deberker.com/the-uk-is-wasting-a-lot-of-wind-power/

God no. We've now gone so far above budget I stopped counting and had to go back to work to start earning money to pay for the rest. Still got some 1st fix to do let alone the 2nd fix. It really is worse than an episode of Grand Designs except however hard I've looked I can't find that extra 500k down the back of the sofa. Spec has taken a bit of a hiding. But I'm still smiling as at least it's nice and warm and not costing much to heat....and we're not living in a caravan any more.

Can't say I needed the encouragement, but it helped, thanks.! New toy is on its way. Then I'll be able to check out the quality of my own building work for heat loss and cold bridging and either hang my head in shame as a building standards hypocrite, or just come on here and be even more cocky than normal about fabric first coz I can now prove I've dunnit. 😁 Which one's it gonna be I wonder and will all the endless hours of detailing have paid off?

Yup, I have a couple of Huepar, but the 603CG with the receiver unit and an extendable pole, so works great for landscaping too. Couldn't be happier with it. It's robust, dropped off scaffolding and out of my hands at height a couple of times. The other day I accidently kicked it out of a loft hatch and it landed on one of the ladder rungs in an unfortunate way that broke the protection cage and glass over one of the lazers, but it's still working fine with no harm to the lazer itself. The first one I bought developed a fault with the horizontal lazer. One email and a video and I received a warranty replacement within 24 hours, so the customer support is there too.

Hmmm, how does it deal with internal measurements? My favourite is a bit more low tech but effective: Advent 2 in 1 Gap Tape https://www.amazon.co.uk/Advent-Professional-AGT-5025-16ft-Measure/dp/B0021FXI5Q My next toy is probably going to be a thermal imaging camera, was thinking about this little one. Might be worth a punt https://www.amazon.co.uk/Topdon-TC001-Consumption-Temperature-Sensitivity/dp/B0BBRBMZ58/ref=sr_1_1_sspa?keywords=topdon&qid=1674846376&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1

Details are all in this thread, but as per my earlier comments about the Vogue Max, you won't find this arrangement detailed within the Logic manual either, but the Logic has an SL2.

@Radian, I'm looking at this with interest. You're not the only one to find a glitch with Vaillant modulation and anti-cycling - a discussion you may have already come across http://vaillantcyclingproblem.blogspot.com/2012/01/anti-cycling-mode-and-d2-parameter.html. There is clearly a link between the flow & return delta, but I'm interested to understand the size of your buffer and volume of ufh system. It would also be interesting to know actual room temp, plus the time points of motorised valve on/off switching for ch. How have you set up the valves? E.g. when calling for heat does your system provide heat to both ufh/hw and ch, or do you swtich between the two?

This isn't really a research paper and in my view it's unfortunately flawed both in its assumptions and conclusions. I've critiqued this paper on one of the other forums and suggested how dissapointing it is to see such a poor quality publication from an organisation that really should know better. It clearly needs to do its research properly, particularly around natural ventilation strategies. It reads more like an industry sponsored paper trying to sell additional tech.... What it actually needs to do is differentiate between building fabric design as well as geographic local and local climate in order to come to more a more reliable conclusion. I do think MVHR has its place, but I think it's important to position ventilation in terms of whole house design and function, which it rarely is. If you've got a house/building that has been built for high levels of airtightness but uses non-moisture buffering materials as part of its fabric, then MVHR is most likely the only option due to the ventilation requirements such a design requires. This is because the greatest burden of mechanical ventilation is down to the removal of moisture as opposed to air quality. On the other hand, if the fabric of the building is designed to be fully moisture buffering, hygroscopic, and vapour permeable, this can reduce peak internal relative humidity by as much as 25% which massively reduces ventilation requirements and therefore properly designed natural ventilation strategies are both effective and energy efficient. As you said earlier though, the op has multiple issues fundamentally caused by the fabric and lack of ventilation all which lends itself to some kind of MVHR , although with the single room options, I'd be concerned that they don't provide sufficient flow and movement through the whole house. I'll await the incoming now....😁

Yes, Opentherm does work and I'm sure that the Drayton wiser system will work providing it's installed correctly

I think that, as @SteamyTea has pointed out, the radiators effectiveness at heating a room is more down to convective currents that radiation. A wooden shelf above a radiator may not hamper that at all. In Sweden, it's a very common design element in houses where the window sill is extended (or cantilevered) out over the top of the radiators installed under windows. Provides some useful space, usually for house plants. Some of these are slotted which can be a nice effect.

This is the kind of argument that comes from the nuclear gaslighting sector, with very little understanding of the reality of nuclear, especially both the current and future waste problem. Here's an amusing video looking at the US situation alone- Otherwise perhaps this, which interestingly deals with the similar false argument that solar is somehow worse from a recycling perspective than nuclear: https://www.scientistswarning.org/2020/06/04/nuclear-power-a-risk-analysis/

Still isn't. Nuclear costing only includes 60 years of dealing with the waste, so yet another energy technology that will leave a horrible and expensive mess for many, many future generations, all for the sake of us not facing up to the real problem of how much energy we consume compared to what is actually sustainable.

I'd argue that this doesn't demonstrate that it's what people want, merely that it's the only choice they've got. Price is a another question but looking at the profits of the large developers, the margins are good and people are only paying that price due to restricted supply. I don't think it's in developers' interests to look at future needs, rather to bank the money they can now and look forward to another sale tomorrow.

The Vogue MIs don't cover the ins and outs of using SL1 & SL2. All you need for SL2 is a switched live from your wiring centre & programmer to the boiler SL2 IN when the cylinder calls for heat so it can be as dumb as it needs to be. The bit that does the modulation is the room stat which is what gets connected to the opentherm on the boiler. SL1 is then just bridged between L & IN at the boiler so there's no switched live to SL IN on the boiler from the programmer/room stat as this is managed through opentherm. If you were to upgrade to the T6R you wouldn't get any particular benefit from this perspective because as soon as you wire it up to opentherm the heating switched live connections are automatically disabled on the receiver (this permits the installation of the receiver for dumb on/off ch control using switched live, or load compensation through opentherm - the disabling of the switched live when opentherm is connected ensures you can't double connect to the boiler and confuse things).

Interesting publication about the effects of retrofit insulation, which, as ever, points towards a mix of interventions as well as behaviour. https://www.cam.ac.uk/research/news/insulation-only-provides-short-term-reduction-in-household-gas-consumption-study-of-uk-housing

Yes I'm aware of tado and aware of the reversal in decision to bring it back, even if messily. Every other controller I install has a clear ERP label that tells me what I'm installing. The Honeywell T6 is ERP class V which is a modulating control using opentherm. Ideal Halo products are class VI, again modulating using opentherm. I'm interested to hear who else you're claiming has degraded opentherm to on/off?

This is simply not correct. In my experience, it's often not the controllers that are at fault, it's how they are installed. When choosing a controller it's important to check the ERP rating of the controller as the combined controller and boiler ratings give the overall ERP of the boiler installation according to Part L. Below is a good explanation of the ERP classes taken from https://phpionline.co.uk/feature-articles/erp-control-classes/. Class I On/off Room Thermostat: A room thermostat that controls the on/off operation of a heater. Performance parameters, including switching differential and room temperature control accuracy are determined by the thermostat’s mechanical construction. Package/system space heating uplift = 1% Class II Weather compensator control, for use with modulating heaters: A heater flow temperature control that varies the set point of the flow temperature of water leaving the heater dependent upon prevailing outside temperature and selected weather compensation curve. Control is achieved by modulating the output of the heater. Package/system space heating uplift = 2% Class III Weather compensator control, for use with on/off output heaters: A heater flow temperature control that varies the set point of the flow temperature of water leaving the heater dependent upon prevailing outside temperature and selected weather compensation curve. Heater flow temperature is varied by controlling the on/off operation of the heater. Package/system space heating uplift = 1.5% Class IV TPI room thermostat, for use with on/off output heaters: An electronic room thermostat that controls both thermostat cycle rate and in-cycle on/off ratio of the heater proportional to room temperature. TPI control strategy reduces mean water temperature, improves room temperature control accuracy and enhances system efficiency. Package/system space heating uplift = 2% Class V Modulating room thermostat, for use with modulating heaters: An electronic room thermostat that varies the flow temperature of the water leaving the heater dependent upon measured room temperature deviation from room thermostat set point. Control is achieved by modulating the output of the heater. Package/system space heating uplift = 3% Class VI Weather compensator and room sensor, for use with modulating heaters: A heater flow temperature control that varies the flow temperature of water leaving the heater dependent upon prevailing outside temperature and selected weather compensation curve. A room temperature sensor monitors room temperature and adjusts the compensation curve parallel displacement to improve room comfort. Control is achieved by modulating the output of the heater. Package/system space heating uplift = 4% Class VII Weather compensator and room sensor, for use with on/off output heaters: A heater flow temperature control that varies the flow temperature of water leaving the heater dependent upon prevailing outside temperature and adjusts the compensation curve parallel displacement to improve room comfort. Heater flow temperature is varied by controlling the on/off operation of the heater. Package/system space heating uplift = 3.5% Class VIII Multi-sensor room temperature control, for use with modulating heaters: An electronic control, equipped with three or more room sensors that varies the flow temperature of the water leaving the heater dependent upon the aggregated measured room temperature deviation from room sensor set points. Control is achieved by modulating the output of the heater. Package/system space heating uplift = 5%

I lean towards the Vogue Max as my preference but have done a few Logic Max installs now too. I've installed some T6Rs with heat & hot water so if these have the same wiring as the earlier T6, then is fairly straight forwards. In the receiver box, wire up your heating to opentherm on the boiler (bridging the SL1 connection) and then wire the hot water switched live to SL2 on the boiler via the junction box, cylinder stat and motorized valves. I prefer using 2-port diverter valves, so have a normally closed on the dhw side and normally open on the ch side that is wired to the normally closed valves switched live so that it closes when the dhw diverter opens. Intergas are good boilers but if you look at the minimum output on modulation the Ideal is slightly better, except for the 40kW intergas system boiler. By this I'm assuming you're intending to have everything on constantly and rely entirely on the flow temperature set point to manage room temperatures? The T6 controller will provide you with some additional control, especially if you don't want your heating on all the time. I also wonder whether this setup provides less overall control of the system than load compensation using programmers/room stat/ and opentherm. Ideal's own installation manual gives an ERP of 2% with weather comp on its own and 4% used in combination with a programmer.

I think Part L has been done really badly. There is a separate section with the AD that details what needs to be done for boiler only replacements. I've seen there's also confusion about what impact Part L has on boiler servicing requirements. I'm completing my Part L energy efficiency and low temperature system design soon for MCS registration so I wonder whether this training will help to decipher more of the code!

My experience is so far is mixed. With the new Part L we're technically only required to design to 55C flow temps where there is a new heating system installation. When it comes to replacing a boiler, it's about ensuring that the new one doesn't perform any worse than the one you're replacing and then that controls are installed that provide either weather/load compensation, or automisation/optomisation, or flue gas heat recovery. There is also a requirement that if you install a new boiler you should also install trvs if there aren't any. The part that does get a bit messy is where you rightly point out that in order to make the system efficient, you ideally need different dhw and ch flow temps. In my experience in many instances it's the boiler rather than the controller that causes the problem, simply because it cannot deal with this difference - it beggars belief the number of installers around me chucking in a certain model Worcester Bosch boiler despite this problem, for example. However, you can find the ones that do, even if the manufacturers might not explicitly tell you about this. I've personally gravitated towards Ideal boilers because they have a separate switched live for dhw that gives a flow temp of up to 80C and a normal switched live that can be set to 55C or lower for CH. Even better, I can install an opentherm controller to the boiler to modulate the ch but still use the 80C sl2 for hot water (it's also possible on some models to set a max boiler water temp to bring down the dhw to whatever you like, if you want). What I've been doing with system and heat only installations is reconfiguring to PDHW using a combination of normally open and normally closed diverter valves that make this system work properly, even in multi-zone installations - basically the normally open valve is used on the ch side and normally closed on dhw and when the cylinder stat calls for dhw heat, it opens the normally closed at the same to as closing the normally open. For controllers I've been using either the Ideal own systems (Ideal Heat & System Halo does support priority hot water, which is good) or Honeywell, but have done and will be doing installs using Nest/Hive/Tado, usually specifically down to customer specifically asking for them. With Tado, I'm still very unhappy with how they've dealt with Opentherm here in the Uk and when I explained what was needed now - a wired unit + wireless extension, a recent customer wasn't too happy either, asking me if I couldn't just get an EU version for them.... Problem is that most customers have no idea how each individual controller works and it's difficult even as an installer to know these things properly. More widely it's a total mess, a lot of installers are ignoring these new controller requirements so they're quite happy to bung in a new boiler and wire it up to existing controls and don't seem to know about modulation. I suspect it's the same for new whole system installations where it'll be rule of thumb. From a customer perspective, feedback has been quite interesting. Only very recently are they asking about flow temperatures and how to best set them up, so the message is starting to get out there. I've just read this. I understand the rationale behind the idea but I think they've missed a number of critical elements and is a bit misleading. For example, you won't get a replacement boiler in just 2-3 days as there's a serious shortage of installers across the whole country, and according to recent industry research only about 1/3 of existing gas engineers are planning to train to do heatpumps, leaving us in a very dire situation for resources. Yes, the boilers are most often distress decisions, but I don't think the library idea necessarily works. If a customer is going to be asked to pay £1500 for the installation of a new boiler that is expected to last for 10 years, it's a bit steep to ask them to front this cost for a leased boiler, for potentially a year or so, something that will impact poorer purchasers much more. I also think they've got to reconsider the reality of making the home heatpump ready. In many instances I think it'll take a good 10 years for this to happen and by then they're better off just purchasing a replacement boiler (from a convenience, cost and function perspective). The one thing that doesn't get much air time, but has been making the rounds much more in the industry press is the hybrid heatpump/boiler, contained within a casing about the same size as your typical boiler. As a transitional idea, this is making more and more sense to me, simply because of the problems we've got with our housing stock and existing boiler install base of combis. It would also help in respect of making the boiler much better at modulating output through the year.