Dan F

Yes, forgot that.. I think you'd calculated impact before right? 250mm might be bit better (or your 30mm PIR), but doubt you'll have a major issue with 200mm. Have you recalclulated without PIR?

Two layers of soundbloc achieves the necesary fire rating too. We've followed a robust ceiling detail that uses 2xsoundbloc on resilient bars below steels and joists and this is satisfactory. From what our building control guys said, it's the ceiling that needs the protection rather than the steels needing to be encased.

You're good then. I would just look at depth of EPS though as 200mm doesn't sound like that much. U-value of 0.17 roughly?

It's not a great if slab/walls aren't very well insulated: - If slab isn't well insulated below primarily (but also at edges), then you'll loose more heat than if you were using UFH in screed above some insulation. - Reaction time is slow (the thicker the slab the slower) so if the house isn't well insulated/airtight then this can be an issue, and supplementary heating that reacts quicker may be needed. If everything is well insulated though, (and you have a control system will work with the reaction times ideally) then the collective experience is that it works really well and helps keep house temperature very stable. You can actually use the slab as a storage heater and use low tarrifs at night to heat/cool slab at night. Disclaimner: We haven't turned ours on yet. Our slab is 150mm minumum, 250mm in some areas (45%)

You do need to be very careful with dB ratings because "sound power" on full power is very different to "sound pressure" at 1m or more, or running in a low-noise mode. Marketing materials , for obvious reasons, often use the later. For example, the ASHP we are using has 55dB sound power running at A7/W55. (This equates to 47 dB sound pressure at 1m and 37 dB sound pressure at 3m). They also specify 46dB sound power running A7/W35 is quiet mode. (This equates to 38 dB sound pressure at 1m and 29 dB sound pressure at 3m) IF you look at the Veissman Vitodens-200W technical data, the actual "sound power" values are 46dB for 26kW version and 48dB for thr 32kW model. At partial load it's 36dB though, so about the same as a fridge. Only you know how much noise is an issue, a lot of this depends on how far away from your garden and windows you may open you could put one. In our case it's 4m to nearest window and 10m from garden, so we won't hear a thing from the garden and at the window sound pressure will be 30dB max and so not noticeable above background noise.

http://www.windandsun.co.uk/products/PV-Mounting-Structures/Flat-Roof-Mounts#.YH9kaJNKjUY

R10 isn't enough around a swimming pool but should be fine in a wet room unless you deliberately want very extra good slip resistenence. R9 isn't a good idea for wetroom though. Couple of things: - If slip resistence is an issue, there are various products than can be applied to tiles after the fact to improve slip resistence. - The R rating for slip resistence is determined using "cleated safety boots". There are other standards that look at bare feet, that could be worth looking at for the product you like. Such a standard is DIN 51097, where you want "B" for a wetroom. - For what it's worth e are using R10 in all wetrooms. In one we are using R9, but will likely apply a product in the shower area only. e.g. https://www.safe-grip.co.uk/

Does look to be very quiet (AIR HAWK 208 at least), but: - Doesn't seem to be any more effieicnt than other newer heat pumps available. - I won't be putting compressor in the house, however quiet it is: i) wouldn't want to loose space ii) prefer any small amount of noise to be outside and not inside. - What is the dB rating of the gas system you are looking at? The boilers i've seen are 55/60dB (sound power). not much different to most ASHP's I don't think which seem to be around 55dB. (remember 55dB sound power at 5m, assuming one reflective surface and no barriers, is 34dB sound pressure which is what you perceive)

85? 8.5kW? We were offered 7kW or 10kW.] Out of interest: - Did you have hydraulic module installed or the decoupler (with built in buffer tank). - What approach are you using for controls? Vailant controller + "functional module"?

How does this work, the installer just declares a design flow temperatuere in the MCS submission?

ASHP is £3,500-4,000 max, any idea what the other £13k is for? Or is 17k based on Ochsner ASHP?

These are the links our MVHR guy sent us: https://www.holyoake.com/product-details/LDO-T_item.html https://www.koolair.com/en/catalogue/unidades-de-transferencia-de-aire-acustica-kat/#guia_seleccion https://www.specifiedby.com/waterloo-air-products-plc/dsr-acoustic-air-transfer-grilles

To be fair, I don't think heating systems are most architect's area of expertise! If you can, get some advice from an M&E consultant or from talking to various installers that have experience with renewable systems. - Already more electrcity comes from renewables than fossil fuels (2020 data) and this will likely improve futher over time (see quote below) - If you have fair amount of PV (or solar thermal) you can get free hot water in the summer with no need for a boiler or burning fossil fuels. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/972779/Energy_Trends_March_2021.pdf

What is a " 3-point signal"? Do you are also have a temperature sensor on output of this and are using something like https://www.loxone.com/enen/kb/mixing-valve-controller/ ? Was just talking about this with out installer this morning, he was suggesting a mixing value with 0-10v input for UFH/Comfopost, not sure which one though...

Few more leads: - https://www.baswaacoustic.co.uk/baswaphonclassicfine - https://www.acosorb.com/acoustic-plaster - https://www.oscar-acoustics.co.uk/acoustic-solutions/oscar-elite.asp Almost certainly all a lot more expensive that standard board and skim, but I'll try to call a few and get some ballpark prices..

Agree, most of the benefits are from the partial charging, which is why we are going to try to use the indirect coil even though we are using a ASHP. I gave up trying to work out how I could possibly use Sunamp with a ASHP when I discovered each ASHP model had to be i) tested ii) have it's own ASHP specific controller!! On the PHE, this is what they say: - Delivers 10-20% more usable hot water than a similar sized conventional cylinder - More efficient heat transfer with high surface area PHE minimising heat pump delivery and return temperatures - More even temperature in tank (due to pump I guess) - PHE is easier to service/replace than a coil. Of course, the down side is that there is a pump involved I guess.

I'm sure you'll pick all of these points apart, but in theory at least (and dependent on heat source and requirements): - If using ASHP, the use of the PHE gets you more effective capacity than a large heat-pump coil would. - If using top indirect coil and/or immersion, the ability to "partially charge" if you don't need full tank heated (e.g. low occcupancy) which in turn reduces both energy usage and heat loss. - Improved inlet difusor and circulation pump both of which improve stratification over a more standard UVC - Reaheat time much less of an issue because coil/immersion are at top of tank and due to effective stratification. The app can be seen as a toy yes, but if you don't have any home automation set up and it allow you to i) avoid fully heat the tank when not needed ii) heat tank at specific times based on dynamic tariffs, then IMO this does add significant value, at least for the average user, maybe less so for an advanced users who doesn't need a proprietary app to automate this. (I won't be using app, and will instead use Modbus interface). I'll be able to report back, hopefully with data, once everything is set up. The 300L is around £1200 and the PHE is an additional £160, not sure what the additional £300 for controls comes from? EDIT: Prices are from sometime last year, direct from Mixergy and exclude VAT. I see midsummer wholesale prices are quite a bit higher!

Did they actually check and measure it on-site? Did they know you were using MVHR and see the flow calcs...

We are 300m2 PH and have approx 3kW heating load. Going with: - Vailant Arotherm Plus 7kW (+ the Vaillant on-wall buffer tank) - 300L Mixergy Tank. - MBC installed in-slab UFH operated as 1-zone with Salus auto-balancing actuators for heating + cooling. - Comfopost on first-floor MVHR supply for supplementary first-floor heating/cooling. - WWHRS for showers (to save energy, but also to effectively increase the capacity of UVC and make the reheat time less critical) We are going to try to run the Mixergy using the indirect coil which allows for partial "charging", but may revert to using their ASHP approach which is to use an external PHE if needed. We are only just starting to install elements of this setup though, so won't be able to report back on it for a few of months.. ASHP/UVC is about sizing it for you requirements plus any preference in terms of brand and also supply availability, not sure that is a huge amount more to it. Use of Sunamp, Mixergy, ComfoPost, WWHRS etc. are all alternatives or optional extras that you need to consider if make sense or not for your setup and what you want to do.

I guess it depends if you want to prioritize sound insulation or sound absorption. I'm no expect, but I would probably think about doing the following if build-up depth was limited: Sound insulation with some absoprtion: 2 SB + surface mounted Akupanels (50mm total) Sound absorption with some insulation: 1 SB + 25mm battens (mineral woold in. between them) + surface mounted Akupanels (60mm total) We have one ceiling panel where we'll use 2SB + 38mm battens + Akupanel, but we also have a wall that is already boarded, so might just surface mount, even though this isn't ideal from a sound absorption perspective.

Our main contractor ordered some aCupanel samples. I've just ordered some Akupanel and Slatwall samples. Will report back. (One of them, can't remember which, sells inividual depper slats that allows you hide the backing from the side if you surface mount)

So are Acupanel and Akupanel two different products? It looks like Danish Akupanel (with a K) is the good one? There is also one called SlatWall. @Thorfun The effiveness looks pretty good from looking at datasheets, especially if you use mineral wool behind them rather than service mounting on PB.

Master bedroom will have drop seal, so will TV room. In master bedroom the MVHR extract in en-suite is the same as MVHR supply in bedroom so not needed here. In the TV room we will be fitting a "acoustic air transfer unit", still need to source one though...

Which install method are you using: - Surface-mount on plasterboard (class C absorption) - On 45mm battons with mineral wool between them (class A absorption) - Somewhere inbetween? We've already boared one of the walls where these are supposed to go, so unless we undo things looks like we're going to need to surface-mount which I'm only now realising isn't ideal.

I think they are all the same thing. Also https://lignosi.com/ (which have "woodup" branding on their web-site). Where were the underwhelming samples from? @joth Please comment on my other thread on "sound absorption" if you have any ideas on the school hall problem...