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In the last few months work on the house was on hold because of the COVID 19 pandemic. With the rules starting to be relaxed we have now been able to make some progress. A few months ago I posted on BH about being a bit concerned about the bath being a tight fit as it’s 1800mm and the distance between the wall was 1802mm. Not sure how the plumber got it in but happy that it fills the space. The bath is made from Carronite so it should feel more rigid when showering. Our joiner fitted the hydro lock panels and the plumber came back to fit the shower fittings. The Joule Aero tank has now been connected up. The tank holds 260 litres and utilises a heat pump which draws air from the bathroom, utility and ensuite. We visited a couple of properties that utilised this set-up and although they were happy with the efficiency of the system the feedback we got was to consider potential vibration noise from the tank. We took some steps to do this, firstly sitting the tank in a cupboard in the utility room, using a thick anti vibration mat with 22mm plywood on top. The ducting throughout the house is metal but we switched to flexible ducting for the last bit to ensure any vibration would not travel through the ducting. We also fitted a silencer to reduce the noise travelling through the ducts particularly to the ensuite. These steps have had the desired effect. Because we have yet to move in, I was able to monitor the electricity consumption of the tank when it heated the first 260 litres. To get the water to 50 degrees it used 4 units of electricity which would be about 50p. The tank also has a dual immersion which could be used to heat the tank more quickly if desired. After the air has gone through the system it passes through an external vent through the utility wall. In the last entry I mentioned that we wanting to prepare the ground for grass seed. The first job was removing a lot of stones. I’ll probably use the smaller stones to extend the parking area slightly and it would be good to use the larger ones for a small wall or some other feature in the garden. After the stones were removed, we raked the ground and then sowed the seed. The grass is starting to come through which is promising but we will need to fill in any patchy gaps. I can see why people go for the more expensive option of turfing but a big bag of seed is very cheap and although it takes some time and effort it’s satisfying to see the grass come through. I guess this is a good analogy for our self build! We had a sunny weather spell which allowed me to finished off some painting and my wife put some oil on the cladding. This had been previously left to weather but as this is on the southern elevation this could now do with some oil. We chose one which had a slight pigmentation and after applying the finished result was that it looked very similar to the pre oiled look but helped to even out the upper areas that had yet to sliver as they are shaded by the soffit. We plan to work our way around the house with the oil. We have used various tins of Osmo throughout the house and although it is quite pricey it does the job well. This is the tin what we used on the cladding. What is next? We had hoped that we could order some furniture from Ikea to furnish the downstairs but I think the pandemic is affecting stock issues and delivery. We now need to decide whether we want to move with limited furniture or wait a few more weeks. The next jobs: - a little bit of electrical work, lighting fittings, connecting up cooker, towel rails etc - BT due to connect us up on Tuesday - need to get some tiling work done for splashbacks - order some chips to spread around the site. - need to decide what to put as a finishing layer on the access road. - need to order materials for ramp, decking and downpipes for guttering. I hope everyone is keeping well and thanks for reading.

...And I realise now that I basically re-iterated what @Ferdinand said in his earlier post

Yes but I expect the dT is something like 8c based on 45/37 which is the hot end and traditional flows. It is also designed to get the room temperatures up within 60 minutes from memory - there is a set of parameters hidden somewhere and you can alter these. If you’re using ASHP as a heat source then you really want to be using E7 and overnight - slab on at 3:30am to absorb low grade heat for 3 hours etc. That needs a lower flow temp and closer to the final room / slab temp you’re looking for so ideally it’s nearer the 35c flow (most ASHP have 35c as optimum for CoP) blended with the return water. Ignore that entirely !! That’s the flow the ASHP needs, not the floor. The floor flow is set by the manifold circulation pump, not the ASHP pump and it’s a bad idea to just connect the ASHP to the manifold and hope it runs ok as the zones closing will play havoc with the flow. I’d use a small buffer - 60-100litre - and let this do the balancing to the ASHP. The heat pump then uses the tank stat on the buffer to fire rather than the call for heat from the UFH controller as it is less likely to short cycle or find flow restricted.

Exactly right. And that's what hooked my interest. Because doing that isn't easy. Snatched moments reading here and there point to hints that may help answer your questions. My aim is to beat @Ferdinand to a well argued answer for you. You up for that F?

I know. It's crazy. The problem is putting all private planning matters under one umbrella labelled 'problem'. I am labouring, rightly or wrongly, under the belief that a house should not put the average person under a lifetime of debt.

I use recycled aggregate Medium density blocks

Probably teaching to suck eggs, however it is often necessary to do some manual untangling before cutting ivy stems as they become very well attached over time.

Someone needs a Dutchman ...

Thinking about the physics of this a bit more, it might be a good idea to contact your preferred lift vendor and get a base spec.from them as the required strength could vary a lot depending on the design of the posts: if they have biggish "spreaders" to distribute the force then the torque on the mounting from an unbalanced load will be a lot less than if say it's just a 500mm square plate, and the requirements for your base will follow. By friend Big Nick had one installed a few years back and the first thing the guy did was to drill some test holes in various places in his workshop floor. He wouldn't install it where Nick really wanted as there was only 5 or 6" thickness concrete there, and so it got put somewhere else where there was 10...11" IIRC. FYI, the 200mm figure Tony gave me was based on a 6m x 12m slab and being able to carry/work on a small van.

You are correct. As in Here be Dragons. What an interesting question. You have me hooked. To help unravel this type of complex problem I always resort to Martin Goodhalls blog. No guarantee of a definitive answer but always interesting, always evidence based. What more can a boy need? This link is a search to mentions of the term derelict in his blog Just found this .... in farminguk.com

One thing to watch is that driven rain runs down the door and easily gets underneath it, in our last house, they didn't put a run on the area under the door so water ran under the door and into the garage. I don't think the door closing into a slot is a good idea as it would fill up with water. Looking at your picture, why not run the flagstone just under the door above the Fibran, putting a slight run on it so the water runs away from the door. Then cut a 20mm wide channel in the screed behind the door (or put an edge there when you screed the floor) this way the flagstone will not touch the screed. As the channel is inside, it wouldn't need covered, you can just drive over it. You might want to cover it to avoid it filling up with dirt or rain when the door is open however. Garage_Threshold1.pdf

Stick to one manifold. As long as the runs are 100m or less you’ll be perfectly ok. As peter says, ask Wunda for the auto balancing actuators and you don’t need to do any commissioning whatsoever. Just plug and play, and go to the pub. Where the pipes are congested, just insulate the flows and leave the returns bare. If you’re on an ASHP then stick to 150mm centres to keep the water volume high.

What’s the Delta- T and output temperature they have designed it to ..?? Screed depth and material..?? 150mm is quite tight for some of those loops - I would look at 200mm centres and run it lower temperature for longer. Like others - need it in the En-suites and a lot to be gained from using the individual flow and return pipes in hallways etc. Loop lengths are irrelevant, they should be roughly equal where heating the same room, but use the auto balancing actuators and 99% of the problems go away.

Nice outcome. It is fairly common to see applications to have conditions varied or removed. Feel free not to reply but I would be interested to know how much were the fees for the planning consultants?

We all like different things, I have deliberately never put up my floor plans as I know some people wouldn’t like them, so what I’m building it for me not them. If you like your lindab gutters then that’s great. I personally don’t it’s not that you have crap taste, just different to me.

FWIW, I didn't risk having the manifold splattered with concrete (and didn't want it sat outside anyway), so we just left the pipes too long, capped them, and tied them to a timber frame poking up out of the slab.

The Salus actuators don't care about the direction, they just try to establish a temperature differential between the two (unmarked) sensors. The temperature differential they aim for depends on the flow temperature, so if this is less than 30°C the valve will aim to get a 4°C differential, if the flow temperature is over 30°C then the actuator will try to maintain a 7°C differential. So, when in cooling mode the actuator tries to maintain a 4°C temperature differential between flow and return, which seems to be OK (it's the same differential as it tries to maintain in heating mode for us). The manifold TMV just fully opens, as it tries to get the manifold temperature up to the set value and can't, so it stays wide open. The manifold temperature in cooling mode is then determined by the ASHP set temperature.

I run my supply temp at 15C. I get a breath of condensation on the manifold - never any droplets. I came in having been out for a bit this afternoon and it was like bloody heaven walking in the front door. Can't recommend it highly enough.

Thanks Conor. The first quote I've had works out at about £135/m2 but doesn't include hardcore, binding, DPM/tanking. The insualtion itself is being quoted at £65/m2 for 'passivehaus standard'. Give me a shout with any alternatives who travel, if you can!

I noticed that as well. There are lots of different perfectly valid installation approaches. Lots of debates about the advantages and disadvantages of S vs Y plan, though for an installation of this size, I would have expected S plan. SY plan if such a thing exists is just bizarre, and smacks as if the installer doesn't really know what he or she is doing, IMO. A Y plan value in this configuration is just plain wrong, IMO. Surely you don't want a preference setup on this system as the boiler could drive both; this needs replaced by standard S plan.

They do come in different shapes and sizes, but all do the same thing, they ensure that the UFH runs at the set temperature, irrespective of the heat source temperature. Yours may be a smaller three port blender valve, with a smaller control. I've not seen a UFH manifold without a form of temperature control valve, either a two port one like ours, or a three port one. The three port ones look very much like the ones used on thermal stores or other hot water storage systems to control the DHW temperature. The UFH flow temperature needs to be adjusted to give just enough heat to the floor to warm the house quickly enough, without too much overshoot, just for comfort. Having a high UFH flow temperature tends to result in greater swings between the maximum and minimum room temperature, as it takes time for the heat to get from the UFH pipes to the floor surface, so if the UFH pipes are running too hot, the heat will continue to soak out to the floor for a long time after the thermostat has turned the heating off, resulting in the rooms continuing to warm up for some time. We suffer from this if the flow temperature exceeds about 26 deg C; as long as I keep the thermostatic valve set down below that level things are fine. The ASHP flow temperature, just like any other heat source, needs to be set to give best performance at the load it is operating at. Running an ASHP at too cool a flow temp will tend to cause the unit to modulate down to a low level, all the time, and never operate at it's most efficient temperature. One key point is to get the difference between the flow and return temperature of the ASHP up to a reasonable level, as this sets the modulation level and also has a significant impact on the anti-short cycle timing. If the ASHP is running with the anti-short cycle system kicking in a lot, then it's efficiency will drop because of all the additional starts and stops, especially in milder weather, when the heating isn't being required to deliver much heat.

I'm a bit puzzled. We run our UFH with a flow temp of around 25 to 26 deg C, but run the ASHP flow at a fixed 40 deg C, as that seems to give the best COP in practice. So, why couldn't the Panasonic Air Rad have been plumbed directly across the ASHP flow and return?

In my garage, I want all the Pirelli calendars ever made.