crispy_wafer

A question i've been too afraid to ask. How do you work out how much screed depth is required - so when speaking to suppliers you sound like you have a clue... At present I've been guessing, and now i'm getting closer to getting it done, I dont want to have too much poured in. Buildup is block and beam floor Dpm 150mm Insulation DPC located 1 block above floor Main entrance door has been installed at the dpc level but has a 15mm upstand. At this point I've no idea what the finished floor layer will be or thickness which doesnt help. Is there a rule of thumb.

Nice, You have one unit ducted into both rooms, or two separate controllable units? I'm personally yet to make my mind up, or more likely to have the courage to say yes. Money is getting tight as it is, a 6 unit system with 2 multi splits is a bit of an uplift on the ASHP after the BUS Grant. But the ability to cool and heat areas in the home is a winner and if it can be done with the least amount of equipment, all the better for me.

Just to add my tuppenny worth, I've had two MCS accredited installers quote, one estimated an 8kW unit, another 11.2kW. the smaller unit was a Midea, the larger was a Mitsi Ecodan. No real discernable difference in costs, but will run through the calcs and see what the spreadsheet suggests.

Ducting would be standalone as far as I know, it's a larger bore and needs to be insulated, aircon recirculates, mvhr brings in outside air. I used Our Guide to Air Conditioning | Air Conditioning World as a guide to work out unit capacity and rough requirements, but am consulting local installers too. I think a max of 5 indoor units from each outside unit, but depends on the duty requirements, I think if all units need to run at full tilt and the total of the indoor units are rated higher than the outside unit then indoor units are derated to cope with demand. But in my case I cannot forsee when all units will be going at the max and requiring more than the outdoor unit can provide. Centralised control is a nice to have as well, as is energy saving features. We've probably got more informed posters than me on this site somewhere though. So take what I say with a pinch.

Sounds like you are after multi split AC heatpumps or Air to Air heatpumps as they are known in some circles, reasonable pricing... Depends on how many rooms and the amount of area you are looking to cool/heat. They can emit via radiator looking things, ceiling ducts, wall mount units, built into bulkheads, ceiling cassettes etc. Usually the same mfr's as the regular ASHP's so likes of Daikin, LG, Panasonic, Hitachi, Midea, Haier etc. Panasonic openly market heating and cooling on some of their units and have fan coil units to spread the cool air. The only issue - i think may be around the number of units you are allowed to site before getting planning involved. Something I'm looking into at the moment, it'd be nice to have a solution I can integrate now for heating/cooling whilst I'm at first fix.

Well done @LA3222 - job well done, It seems though Installers arent keen on ASHP cooling, if done right - no problems, if wrong, then condensation risk, and mould. A lot that I've spoken to, just aren't keen to have their business names put to a risk that may or may not happen. For what it's worth to the OP, I'm putting aircon in and will put shading in place too. The Daikin (others are available too) Heatpump Split units are pretty nice looking if wall mounting, or slim ducted units hidden in voids with diffusers located in the ceilings, or in bulkheads above doors, all accessible for future maintenance of course. I'm planning on 2 multi split systems, one for upstairs and one for down. I will use them for space heating this winter to see how we get on with it. They don't need to be jet turbines blowing force 9 gales in your faces. If it works, then I'll not bother with the ASHP, or will wait for a few years till supply and install prices come down to the same as a gas boiler. The GF UFH gear will be going in regardless, as will plumbing for FF Rads. For the cost of the AIrcon stuff at first fix, I'm going it. It may be a folly, but sod it, I'm doing it anyway.

Got some quotes coming in for 2 multi splits systems, mixture of wall mount and slimline ducted units for our build. Bedrooms, lounge, living area and kitchen, cooling and taking the edge off later in the year with a touch of heating. I'm putting the Air to Water HP on pause for now, but will install the UFH kit just in case my plan backfires and is needed at a later date, I'll be in and out of the build over winter so will be able to see if this will work for us or not. Daikin as a manufacturer look good, as does Haier, Daikin almost twice the cost though.

I've just started internally taping up my Window and door openings with Isocell Airstop flex tape which is a bit cheaper...

Depends on the builder, if it is a small firm, then Stage payments and make sure money paid is for work done and not work to do. They'll usually buy materials on account, so no need for you to pay up front for this either. Hold a percentage back for when the job is finished too for snagging. Worked for us, infact that's what my builder at the time suggested to me. Its in their interest to get the job done in as few hits as possible as they'll no doubt have a diary full.

Drop a pump in and use it to water the garden.

Not sure the orange stuff is UV protected, so may degrade over time, but I guess your application will suggest whether that's a problem or not... Ventilation systems generally use 4,5,6 inch round ducting so you may need to transition.

Ran 45m of 25mm from new build to old bungalow, 80A switched fuse in the meter box. No complaints from the electrician. I did feed it through the ducting 60mm ish I think before burying it though. When Western power came in to move the supply the main supply went through 100mm ducting that I laid for them quite easy, I left a nice thick piece of rope in there though.

if the higher level is in a particular part of the property you could use a slightly thinner layer over this to mask the base difference, if its all over then beware as thicker PIR sheets are quite rigid and like to rock over undulations . I think others may get round this by using thinner PIR in multiple layers.

I used one of these to get me from 3/4" to 25mm Plasson 77017 universal coupling 20-27 x 25mm | Wolseley I was fretting about it for weeks as the 3/4" wasnt in the best state being buried under earth and rubble, bloomin amazing, they come with a range of input sizes so just pick t he one that suits the 1/2 inch pipe and make sure you clean and square up the 1/2" pipe before if not already done so.

It's fine Our builder did the same, but did spread them out a bit. Not too many pallets on the same span of beams, and closer to the edges rather than middle. He did come and set the blocks out quickly though as he was keen to get a crack on. Not too many images of this but found one. edit: Reading George's post, I guess it depends on the type of block too, some weigh a bit less than others, maybe you could ask when they are likely to set out the blocks, Not sure I'd want pallets sat on there for weeks on end...

I've to core 5" holes through brick&block for the supply and extract, access externally is a bit tricky as it's about 5m up in the air. I plan on doing this from the inside out. I'm a bit scared of making a mess of the external brickwork, any tips? Also with the mind of doing the job right, I dont want to just wang the pipe through the wall stick the cowl on and leave it, what's an appropriate way to seal up and make an airtight seal around the penetration. Any products I should use to make a proper job of this? Curious to know what others do?

and here she is, in all her glory 🤣, just enough room to get to get the flexi coupling bit of duct then a couple of 45 degree angles. It's a bare unit, so what sort of add ons are worth buying, I've got 3 bathrooms and a kitchen to extract from. They do a pcb with 2 extra switched lives on, and another pcb for volt free accessories, pirs/timers/humidistats etc. Thinking I need it to boost when any of the bathrooms are in use, as well as when cooking, and needing extract.

Looking to install the main unit in my loft, is there any issue with the MVHR unit being the highest point in the system. I'm building a small frame to attach to a gable wall rather than on the floor, to help absorb any vibration. The loft is insulated at rafter level, so all the gubbins is inside the thermal envelope.

Been following this very closely, taking notes along your journey, I dont see the point in isolating locally, think it's overkill, as long as the manifold is accessible easily. Changing Tap's or washers or flush components down the line it wont be too much of a hardship to pass by the manifold on the way to the job...

I'd heard that a slight thicker slab will act more like a slow release heatstore but never experienced in practice so could not comment further. Here's some prelim prices I had for screed if it helps for comparison, I think these are a bit on the high side though

When we finally get the last window in, and the UFH down, we'll be pumping in about 60-65mm - bit of a halfway house, as I'd read others doing 50mm and others going thicker, then I managed to get 150mm boards as good seconds so that made my mind up. Have you already laid the insulation? If so I'm not totally sure of the minimum thickness boards you can get hold of at reasonable money to build up the level, I've seen 20mm, not sure if you can get any thinner.

Emptied the brick unit and yes found an old outlet from the brick chamber, clambered in and had a good look and poke at it, it's been concreted up and the newer outlet cut a couple of bricks higher, can only guess that the persons who installed the fibreglass unit had an issue with depth or another reason. Feeling a little deflated by this, one of the reasons behind building my own, was to get away from the general lash up of other people and this sodding bungalow. I'll call out a drainage company to see what options I have. A little unexpected, no doubt be on beans on toast for a few extra months. Thankfully I guess we can install downstream of the brick chamber and day to day usage wont be disturbed.

Getting the brick chamber emptied today fingers crossed. I'm hoping to find evidence that suggests the out has been altered (moved) in the past to suit the inlet of the fiberglass onion, I wonder if one of the previous incumbents who installed the fiberglass tank had an issue with getting the depths. Either that or it was built back to front... I do have a land drain running through the field about 50m away I suspect a treatment plant and outlet to drain might be an option

Sorry, using the forum as a sort of blog of my exploits. Another little milestone crossed off today. So, struck a deal with Western Power to remove my old overhead power line to the bungalow and class it as 'a hazard, or dangerous' to replace with a new supply to the new build. Today, finally after managing to synchronise WPD and my electrician we have power moved to the new build and a 'Temp supply' to the old. Success! Only without power for 3 hours, and that was an hour too long as WPD naffed off with my 100A fuse from the PME. Total cost to me... 50 pound for the new 100A switched fuse. 250 for 45m of 25mm2 of SWA 350 for the sparky, 80'ish for the ducting - 2 years ago Digger was already on site... I guess it could have been a lot, lot more.

I think it does help, thanks, it's good to understand these things, those before us had good knowledge and experience of how things 'work' on a less 'technical' level, whereas these days there is so much book theory and reinventing of the wheel to sell us something new that we 'need', sometimes we need to understand the ways of our fathers.