Mr Blobby

I'm sure there are lots of shitty clients just as there are really good M and E consultants. I can assure you however that bad M and E does not mean bad client. Quite the opposite. To summarise... My passive house architect got the M and E team on board early to ensure proper service voids and plant room etc go into the design. M and E have the PHPP model hence the M and E team know this is a low energy build and what heating load to expect. The M and E team have been supplied with a full list of all plumbing requirements including all sanitaryware and taps, showers. Designs done at single local bathroom showroom etc and liasing with M and E. M and E team have met with KNX designer to finalise all the lighting and electrics. Full kitchen spec including appliances supplied. Solar PV specification including battery and locations for installs etc all done. Meters, connections, all agreed. Car chagers included in spec etc. Every single detailed requirement and design from my side has been supplied in full to my M and E team. No changes, no messing about. The problem is that, for example (and there are many), when my M and E team tell me that the heating company only do serpentine UFH layouts because they are better than counterflow layouts (despite my objections) then I am left to conclude that the M and E team are more interested in what their business partners want than listening to their clients. When they tell me they won't specify an IVAR manifold because the same heating installer doesn't like them, then again, this is the M and E team ignoring their client for no good reason other than to try and set me up with a pretty crappy heting installer they work with. The M and E team appear to be guided by their own commercial relationships, not by best practice design or serving their clients best interests. It happens. ... back to my original question, @PeterW, as an M and E guy, should I avoid using AAVs and vent outside on all three soil pipes?

Yes, I'm pretty certain my M and E consultants' specifications are unduly influenced by third party heating companies who want to maximise profit from a lazy installation. No cooling, no counterflow loops, no IVAR manifolds? I'll go elsewhere thank you. The M and E heating specification should be vendor (ie installer) independant. It isnt. I think anyone who engages M and E consultants should be wary of the independance of their adivice and conflicts of interest. Its a bit shit really.

So for an update, my M and E consultants have reacted with absolute horror to my suggestion that AAVs can be used on the internal soil pipes. They say AAVs are a really bad idea and I must not use them. Which is odd because that doesn't seem to be the experience of members on this forum. But then my M and E people are also pushing back on my request for cooling the slab. And they insist serpentine UFH layout is better than counterflow. And they don't want to specify IVAR manifolds because they say they're rubbish; They want to use mixing sets that go no lower than 25c. I welcome their advice but its not always great and I suspect they do things the way they have always done it and get very few clients who ever disagree with them. So, M and E are pushing back pretty hard on my AAV suggestion for the two internal soil pipes. The head stack furthest from the sewer connection will be venting (and outside) so no BCO issues. If I do decide to vent the internal soil pipes then that requires of course a hole in the (aluminium) roof for each of the two pipes. Surely a hole in the roof presents a greater risk from failure (and more initial construction cost) than the risk from a £25 AAV failing. Am I missing something here? Are my M and E guys right in in objecting to AAVs or are they being obstinate and ignoring the bigger picture? It seems like members here on this forum have no AAV issues, contrary to my M and E advice that they are rubbish and guaranteed to fail. What should I do? Should I stick to my guns and insist on two AAVs in the loft or accept my M and E advide to put two holes in the roof to vent the two internal soil pipes?

And the energy markets set up for market participants are fiendishly complex and costly. And less efficient.

So our M and E are suggesting 3 SVP all internal venting out through the roof. In a passive house I would have thought that one venting and the other two soil pipes capped with an AAV in the warm loft would reduce cold draughts. Which option is best? Does it really matter?

Thanks all for your replies here. I hadn't thought about the sun coming through the cord-run holes so I think the internal roller blinds will remain. I'm not too fussed about getting black-out levels of light blocking but I can imagine pinholes of light reflecting off the TV screen would drive me bonkers. That's interesting, so high winds are not as harmful as I had thought. Looks like they'll be down most of the time then... I actually like the aesthaetic of the venetian blinds on the windows.

Just to resurrect this old thread, do acoustic soil pipes like Marley Blue actually work? And by work, I mean can I get away with a smaller box around the pipe with similar noise suppresion as a big box and rockwool? Or maybe just put the pipe outside, it is on a hidden part of the house.

Yes, this is how we will integrate the blind box, into the outer block leaf with the render-able face. We are looking to increase the outer leaf to 140mm form 100mm to be same width as blind box. My architect has specced internal roller blinds on windows with external blinds. This seems a bit unecessary. Is there anyone on here with external blinds that has regretted having no internal window shade?

Or aluminium for standing seam? Something like prefa?

Thank you @craig. So is it possible to transpose the above diagram to a (200mm) block cavity? If so then the blind box would be inside the cavity supported by the window and the window inside and fastened to the inner leaf (140mm) blockwork?

... or the blind box sits in the cavity with the window within the inner leaf. Which I think makes more sense.

I think its probably easier to install the blind box in a timber frame as the blind box can be fastened to adjacent timber. With a block cavity then I guess the blind box would sit under a steel on the external leaf. The top of the window is of course lower than the top of the blind box so there would be a smaller opening on the inner leaf I think. I need to get my head round the construction detail for this and discuss with my architect 🤔 Anyone done this already ?

Very interesting. Do you have a block cavity build? If so then did the head unit (140mm > 100mm block) fit flush to the external leaf and the window move into the cavity?

Any update on the Warema blinds? Trying to source windows with external venetian blinds is not easy. Internorm are clueless. Has anyone used Gaulhofer/Roma? Any other suppliers?

In the Zhender perforance data the ouput air, after being cooled, is at 100% RH, which kind of makes sense I guess because the air has been cooled. The input air is, if I am reading this correctly, at 80% RH and water temp input is at 7C. That seems a little ambitious, I'm not sure the panasonic ASHP can cool below 10C An enthalpy exchanger is relied upon in the technical data to get the extra moisture in the air to transport the heat. I imagine that otherwise the comfopost heat exchanger wouldn't work so well with dry air. Basically I agree that the comfopost will take some heat out of the air, which will be nice upstairs, but it shouldn't be relied upon as the only means of cooling.

I think it does from what I have read in the manual I don't think Panasonic support this but I would hope that 18C flow to the UFH would be warm enough to avoid condensation on the manifold umnless RH levels were >95%. I looked at the conmfo post data, I don't get how the cooling output relies on 100% humidty ! Coolind demand is ony 500W, but your'e right, there will be parts of the house without blinds that will suffer local overheating. I think I need to speak to my M and E people about using the UFH for cooling.

Sorry to ask again about my heating system but my M and E consultants are not good listeners. They are proposing two MVHR post-heaters/coolers connected to a Panasonic ASHP. The UFH to be used for heating only. I'm OK with the Comfopost post-heater upstairs but they don't want to do UFH cooling downstairs, which seems like a no-brainer to me. The M and E propsal would have 3 zones, CP1, CP2, and UFH. This just seems over-complicated, more expensive, and less efficient. Before I go on, I am very grateful to @Dan F who over the weekend has patiently answered my questions and explained his similar setup (with comfopost but a different ASHP vendor) and how mixed circuits can control flow temps on the different "zones". Before I make an ass of myself by telling my M and E people how to do their job, I just want a sanity check here first because the solution below is so much simpler and more effective than my M and E proposal that I think I must be missing something. From the latest manual it looks like Panasonic support 2 mixed circuits out of the box, with each "zone" having a pump, mixing valve and temp sensor. A single buffer can be set up to be controlled by a temp offset from the heating/cooling circuits flow temps. UK_INSTALLATION_MANUAL_H 2020V11 (002).pdf Here's page 37 from the latest Panasonic manual: So if I were to replace the radiators above with the comfopost, then I can run UFH and comfopost at different flow temps, say 45,25 heating and 10,18 cooling. This is far too simple to set up. Is this the right way to set up my system for UFH and comfopost heating/cooling. Have I missed anything? Has anyone else set up a Panasonic heat pump in a similar way with mixed circuits for heating cooling, and if so, is it really this simple?

Its funny, I think MandE consultants don't get challenged very often. At least mine don't Thinking more about the buffer connection, I can see how a 2-pipe connection is better for heating but would it be better to have a 4 pipe buffer for cooling? My setup will have a large buffer for the UFH and a smaller buffer for the heat/cool through the post heat exchanger in the MVHR. In cooling mode the Zhender comfo-post buffer would be cooled to, say 10C, while the UFH buffer to, say, 18C. Would a 4-pipe connection to the UFH buffer be better for maintaining different cooling temps? My reasoning is that the 10C flow from the ASHP would mix in the buffer before going to the UFH manifold, whereas in a 2-pipe connection it may go to the UFH directly at too low a temperature. From reading other threads I know others like @Dan F have a similar setup with seperate buffers for cooling. I would be really grateful for any advice on setting this up.

.... also, my M&E people are pretty much refusing to design any cooling of the slab, quoting the dreaded condensation argument. Which is bullshit of course at 18C flow temps. (there will be cooling through the Zhender comfo-post add on the MVHR, which I'm ok with, but it does cost an arm and a leg) Should I put my foot down and insist on cooling the slab as well.

Ahhhh, now I get it. The flow remains the same but the pump brings warm water through in the same direction with the ASHP in cooling mode to heat up the frozen bits. In that case the check valve can remain.

Thank you everyone for your very helpful answers. I will go back to my M&E guys and ask them to change to a 2-pipe connection. I'm not sure they get questioned on stuff like this very often! I like the idea of 1 less pump. I think panasonic ASHPs have a pump inside, if so then does that mean no additional pump to the buffer? That's interesting. I thought the defrost cycle sucked warm water from the buffer back into the monoblock. Have I misunderstood how this works? I don't have a copy of the schematic but from memory it includes a second smaller buffer on the cooling circuit. Is there any reason why I can't use the same buffer to simplify things? I'll try and get a copy of the schematic to explain!!

Our M and E guys didn't seem to know much about a 2-pipe connection when I questioned their schematic (with a 4-pipe connection) last week. This is the 2-pipe connection...... From what I have read, a 2-pipe connection is more efficient than a traditional 4-pipe connection. Is that really the case and do members of this forum configure their system this way? Should I ask to change to a 2-pipe connection? Or does it really matter? For background we are aming for passive build with little heat demand. Buffer to sit between ASHP and UFH. Does the flow from ASHP to the buffer need a check valve and if so then are there any defrost cyle issues

Latest Power NI E7 rate is 11.91p My Tesla averages about 270 W/mile Rounding up that's 3 miles for 12p Or 300 miles for £12 Not sure an ICE can beat that yet.

Yes but with long start times the conventional fossil plants can't shutdown overnight and are left running at minimum generation. Their efficiency is terrible, with much higher pollution and cost per MWh. I'm all in favour on renewables but that's the cost of high wind penetration overnight. And that;s why E7 will, I think be around for some time. I hope so anyway because in the winter my EV will be charging. I just hope the price of PV doesn't go through the roof before I get to install it next year.

Here in Ireland windfarms are being curtailed overnight. Free energy is being thrown away. Even at E7 prices it is profitable to supply. The UK (that has a dfifferent energy market) also has several GW lower nightime demand and too much supply. I understand that, intuitively, E7 looks fragile in light of recent price increases but the system needs it. I just don't think it will dissapear anytime soon.