Search the Community

Showing results for tags 'mvhr'.

More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


  • BuildHub Guide: Information about the site : Introduce Yourself
    • About
    • Introduce Yourself
  • Build Design, Planning, Finance and Legal
    • Building Plots, Land & Renovation Properties
    • Design & Architecture
    • Funding, Finance & Tax
    • Insurance, Legal and Warranties
  • House Construction & Structural Issues
    • House Construction
    • Conversions & Extensions
    • Roofing & Lofts
    • Structural Works, Foundations & Demolition
    • Insulation & Ventilation
    • Landscaping & Outdoor Buildings
    • Damp & Infestation
  • Building Trades
    • Plumbing & Heating
    • Bricklaying, Plastering, Concrete, Blocks & Rendering
    • Joinery, Windows & Doors
    • Floors & Flooring
    • Electrics, Lighting & Home Security
    • Decorating & Tiling
    • Kitchens & Bathrooms
    • Building Materials
  • Environmental, Alternative & Green Building Methods
  • Self Build & DIY: General
  • Self Build Regional Groups


  • Salamander Cottage
  • The House At Mill Orchard
  • An Orkney Build (in ICF)
  • The House at the Bottom of the Garden
  • Hawthorn House
  • Rose Lane re-build
  • East Kent Self Build
  • Wee Hoose on the Croft
  • God is in the Details
  • Tennentslager
  • Kentish RenoExtension
  • Scooby Cottage renovation.
  • The Seasalter Sharp House
  • sussexlogs
  • Sips and stones may break my bones...
  • Our Journey North of the Border
  • Construction in Cornwall
  • The Fun Irish (House)
  • A house! A house! My kingdom for a house!
  • South Devon Self Build
  • Lucy Murray
  • Coffee Towers
  • caliwag
  • caliwag
  • Blackmore House
  • A woodland house
  • Self build on Skye
  • Escarpment to the countryside
  • Christine Walker
  • Netherwood lakes
  • Kingseat
  • Mr and Mrs Triassics New Home
  • Yaffles
  • Wedding Cake Re-build
  • Clancutt Lodge
  • Self-Build in Shropshire
  • South coast ICF build
  • 5 (2 adults, 3 dogs) go building in Dorset
  • Hillcroft
  • Self Build NE Scotland
  • Timber Portal Frame - but stick built
  • Self Building two in North Wiltshire
  • 1970s Chalet-style house renovation
  • Under the Chestnut Tree
  • The Larch House
  • Building in a woodland on the Isle of Wight
  • Back on the self-build waggon...
  • Gardening in the Lockdown
  • The BuildHub Gardening Blog
  • West Sussex Forever Home
  • Testing
  • Canalside Bungalow Renovation
  • Holywood Passive ICF Build
  • Finchampstead Passivhaus

Find results in...

Find results that contain...

Date Created

  • Start


Last Updated

  • Start


Filter by number of...


  • Start



About Me


Found 73 results

  1. We are trying to do our best to create a pretty airtight house.... Our Architect has suggested a joiner made front door. Will this be a huge source of air leakage? We are installing MVHR and ASHP and it will kill performance if the door lets wind through. Our current double glazed french patio doors let a gale blow through on windy days....
  2. Hi everyone! We are at the foundation stages of a newbuild. It's a replacement dwelling for a chalet bungalow in the centre of Marlow, Buckinghamshire. Very keen to read about other projects and get some advice on ours. Cheers, Steve 3_Westwood_Road_Design_&_Access.pdf
  3. Left this a bit late and BPC shut for the day. I need to build my external block wall tomorrow on the exterior of the timber frame. I will have to put 3 pipes in the wall to take the flow/return and power for the ASHP so I can seal them from the outside to the frame. I am proposing to use 50mm pipe for the wet pipes to leave enough room to insulate round the pipes afterwards (Passive) and 20mm duct for the power, does this sound ok or would people use smaller pipes? Do not know make of ASHP yet so do not know if I will need 28mm or 22mm pipes. How close can the ASHP be sited next to MVHR vents? I have a low level vent, approx 500mm off the floor and one at 2.2m and they are 1.5m apart and cannot anywhere else. TIA
  4. Hi everyone, I'd like your help pls. We're self building a new home and are installing an MVHR system. It's on a hill and therefore an upside down house; so bedrooms on the ground floor with bathrooms/plant room while the living room/office/kitchen are upstairs on the first floor. We have web joists and I was wondering about putting the outlet vents to the living room and office coming out of the floor of these rooms since this is much simpler. The duct to these would therefore be on the same level/branching as the ceiling ones that feed the bedrooms on the ground floor. So they would all run through the space between the two floors rather than having to run the ducts up the first floor walls and across their ceilings as well. Hope that makes sense? I've tried searching the forum and can only find a few references to a German floor vent brand. Is it better to do this? or are there any major downsides pls? Many thanks Iain
  5. I’ve just spent most of last week installing the distribution boxes, ducting and plenums on my BPC/Vent Axia system. I thought it would be worthwhile sharing some pictures, It went well and was relatively easy to do. I tried to keep ducting passing over each other in the joists to a minimum but it was unavoidable in some places. Having two ducts on top of each other in a web joist was a bit tight and didn’t leave a lot of room for insulation. I had already installed the 150mm PVC pipe through the roof and drilled a 150mm hole for the second PVC pipe through the wall. I then mounted the Vent Axia unit on the wall and figured out where to mount the distribution boxes in the metal web joists between the ground and first floors. We have vaulted ceilings upstairs so it seemed easiest to mount the boxes here rather than up high in the first floor. Here’s my rough in of the MVHR unit. Ignore the angles of the pipes. These will be straightened up on the final fix. Here are the distribution boxes. Required careful planning and it didn’t seem to matter where they were because of the metal web joists there was always at least one duct which was a tight squeeze through the joists. I have a change in levels between the main part of the house and the lower level which causes a bit of head scratching as to how the get the ducts from one section to another. This was exacerbated by the fact that there was a steel running across the lower level which I had to navigate around. I built a dummy stud wall in the lower level and ran the ducts behind this. I need to get 3 extract and 2 supply ducts into the lower level. Here’s a photo after the first 4 ducts were run. A bit of boxing in required to hide them, but relatively easy solution. and here’s what it looks like in the lower level. And finally, a ceiling mounted and wall mounted plenum. I quite enjoyed doing it and it was satisfying to see it all done.
  6. Has anybody had any experience of this product from BPC ? TIA
  7. How do I find out if I need fire rated terminals for my MVHR ducts. Is there some guidance written in stone or is it down to the whims of Building Control (who aren't answering my questions at the moment). Do you have to have them in the kitchen for example but not bathrooms? Any guidance would be much appreciated.
  8. Hi I'm looking for advice from anyone that has a Itho (Heatrae Sadia) Hru Eco 4 fitted in their home? We moved into a property in 2018 with 2 units (dating from 2010), both were serviced last year but we recently noticed that the discharge fan in one of them is no longer running smoothly and as a result, creating more noise and subsequent lack of air flow through the ducts. We ordered a new fan but we have exactly the same issue - the fan sounds like it struggling to maintain a constant speed. Any thoughts? We're trying to find an engineer who can come and look at it at the moment but no luck so far! TIA
  9. So finally everything is in place: * mvhr unit up and running * terminals and valves installed * house pretty much as air tight as it will ever be * Anemometer Tesla 405 borrowed with extra large valve covers - big thanks @JSHarris So to work on balancing. Any tips on how best to approach this? * Screw everything shut and open on longest extract one first get its flow rate right and then open another set it and go back to first readjust? * Set all valves at middleish point and randomly run around house? * Concentrate on extract first? Concentrate on fresh air first? pick and mix? Any other tips? * Place chairs under every valve before starting? * Get 5 tall mates from the pub? * wack the unit up to max and slowly decrease? * count the number of turns needed to add/remove 1litre/sec? Bit concerned this could take all day and night if I just run around the house randomly with the meter! Thanks in advance, Paul
  10. Is it me, or does the requirement to fit fire rated doors upstairs (in our case FD30) mean we can't have MVHR? (Because of the gap under the door for the MVHR). Please tell me I'm wrong. Please tell me I'm overthinking! Reviewing current threads on and around the subject of fire doors, nobody seems to have pointed out that MVHR and FD30 doors are incompatible. Yet common sense says they ought to have door auto closers on them (but that requirement has been removed @PeterW here ) , but it seems obvious to me that a fire door with a gap under it is about as useful, well, as a chocolate fire door. I've reviewed Approved Document B, and the table on page 64 seems to suggest we could use an FD20. Both our bedrooms have a suicide door in them, (with a Juliet) so I suppose it might not be too bad.
  11. We have a Vent Axia MVHR and are currently fitting the unit and associated metal ducts. The drawing from BPC specifies the silencer to be mounted vertically. No space for that in current position. Can this silencer be mounted horizontally please?
  12. Hello all. My six year old house was fitted with MEV by the developer but I’m planning to ‘upgrade’ to full MVHR. Although much MHVR goes on new build, plus some retrofit during refurbishment of older properties, I haven’t seen anything online about anyone upgrading existing MEV in this way. As background, my parents longed to do a self build, with MVHR oddly enough being one of the things mentioned a lot beforehand. It was installed in 2010/11, so I am familiar with such a system in practice. On buying my house new, the showhouses did have MVHR, but unfortunately all the others only have MEV. My original thinking was that I already have one half the of system in place, though perhaps I already get half the benefits. So while we get fresh air, humidity at reasonable levels and minimal condensation in the bathrooms, it galls me that trickle vents were cut into the frames of the triple glazed windows for supply and while I have two fans spinning 24/7, the heated warm air is just being pumped out. The extraction is not optimal – kitchen cooking smells permeate the whole house with the door closed, whether on boost or not. For some reason, only now are we getting some black mould in the en-suite bathroom. I have read up plenty since and so – as things stand – currently plan to go ahead. I’m also going ahead with an extension – highly glazed – and will need the SAP calc, so this is one of the few possible improvements I can make to the existing house if needed. (Loft insulation, firstly to building regs, though even better to the design spec, would be cheaper and easier so happening as well). The airtightness test result when new was 4.4 m3 /m2 hr @ 50Pa. Fairly average for recent new builds but certainly not spectacular. It’s below the figure where it should give some benefit, but above a level I expect some might think it’s not worth it. The extension will be built to a better standard, while there are some gaping holes in the existing house I am aware of and have filled or will do. Plus sealing up the trickle vents. Though at this sort of airtightness, I can’t justify a top end system professionally installed, it just will not pay back. Though I have acquired a good value unit and plan to do much work myself to limit expense. I don’t think I’ll necessarily use all that is currently in place. Rigid ducting was used for the extract and is not especially well sealed at joins where visible. The ceiling extract ducts were generally placed near the doorway, not at the opposite corner. The two existing roof extract terminals (there are two separate MEV units) are on the southern elevation but have insufficient free area to repurpose one as a supply and leave the other as extract. The manual boost switches might be the few parts I reuse. There is power to one of the MEVs that would also be the loft location – admittedly unheated – for the MVHR unit. I do have useful behind-shower voids at the front and back to enable semi rigid supply to all the ground floor rooms that need it, and back from the extract rooms. The doors already have sufficient gaps underneath. The reason for posting here is to ask a few queries on what I’m still unsure of. And if it does go ahead, perhaps be one of the few resources to document an MEV to MVHR upgrade. Savings are difficult to quantify at present. I would appreciate some hints on the following: Which of these positions, or something else entirely, would you put the external supply and extract terminals? A (Red): North roof through roof terminals, B (Gold): North roof soffits (might be easiest to install but need to watch the free area), C (blue): East gable end above the slightly lower roof. Overall I am trying to avoid the SW prevailing wind, be on the same elevation, far enough apart and be shaded in summer. I have seen a number of posts of DIY commissioning and producing the certificate for building control. As an alternative, there are a number of firms that can do testing, but is there a competent persons scheme for any of these testers? Reason I ask is that on speaking to building control they said it would be usual for installers to self certify as would be done for gas / electricity, in which case there is no BC fee. Though I have not found a similar scheme. If I have to pay the building control fee anyway, then I would probably test myself. Is this really worth going ahead with, or pulling the plug now? I am hopeful of getting this completed for under £2k all in for the parts, my labour counted as zero. One possible supplier for the large glazed doors for the extension wanted over £900 to add trickle ventilation. I’m not going with that firm, but whoever I use I avoid the need for those vents. Overall, I would hope to minimise the ventilation losses but have difficulty quantifying the payback. Non-financially, I would see benefits from input filtration (due to hay fever) and soundproofing from sealing the old vents. Sorry for the long post, and thanks in advance for any suggestions.
  13. Hello all. I am currently awaiting planning permission on a new build in Derbyshire, trying to make some decisions on my heating source and emitters, and how it works with MVHR. I'm looking for a sensible, economical solution but will pay a bit more for a clear benefit. I intend to move out of the house in 5-10 years so can't entertain anything with long payback periods. Plans are attached to hopefully give context. Intended build method is ICF, so the walls will have a u-value of 0.19. Likely to have either block and beam (maybe Tetris), or a concrete slab ground floor. Upstairs will be a suspended timber floor. Heating source - I'm guessing with gas (in the road but would need to make a connection) I'd be silly not to get a gas boiler? Or would an ASHP still be a sensible option to investigate? Heating emitters - With a solid floor, would UFH be an obvious choice for downstairs? For upstairs I've looked at Omnie TorFloor and Pug Screed, otherwise just radiators? Is forced air another option worth investigating? MVHR - it would seem this is an obvious thing to have on a new build? Should I look at an inline heat pump with this to provide some additional heating and cooling, or is this not really worth it? Be glad of any advice. Thanks! 19-003-20-E Proposed Floor Plans-[A1].pdf 19-003-21-B_Proposed_Elevations-[A1].pdf 19-003-22-B Proposed Section A-A-[A1].pdf
  14. We're planning on using our attic space as a playroom and I can't work out whether the temperature will be balanced or if it's going to be too hot up there in the summer and too cold in the winter. The house is an MBC build (0.11 walls, insulated roof and slab) which is currently in build, with triple glazed alu-clad windows (which are fixed apex windows in the attic). We're putting UFH on the ground and first floor but nothing in the attic. The MVHR unit is going up here so we can add vents into this space and there will be a number of rooflights, probably double glazed. Will this be enough to create a usable temperature up here? If the whole house is 3G, are we made to put double glazed up here (to cut costs)?
  15. I am planning the design for our new build and have created a nicely sized plant room on the ground floor. In our last build, our MVHR was put up in the loft and this appears to be a very standard place. However, it was horrible to get to to change the filters and more importantly, in this build we are having a flat roof so no lofts in sight! Is there any possible reason why the MVHR cannot go downstairs? If the intake and exhause vents need to be at first floor level, is there normally any resitriction on the length of pipework? We haven't even looked at MVHR units yet so checking the spec of "our" unit isn't possible. If there is no reason not to put it downstairs, am I missing something in wanting it accesible? I know you only change the filters once or twice a year ( not sure because I am not the one who would venture into the loft to do the deed), but it just seems to make better sense to me. It also caused us lots of issues when it came to doing the air-tightness tests at the end. We have learnt a lot from that build which was lovely to live in but cost a fortune to heat.
  16. My distribution box for the MVHR ( sometimes called spigot box or manifold) will sit beneath a flat roof , but above a ceiling. The roof build up from top down is; Alvitra Avalon over 270mm of insulation on some super expensive vapour stuff - forgotten the name - the price was so traumatic 22mm OSB3 POSIs above the ceiling build up which is Vapour control layer 25mm insulation 12 mm plasterboard 2mm plaster skim. There's enough space for spigot boxes to sit comfortably under the POSIs. That means they are outside the heated envelope. (just) The supplier says not to worry : but they would wouldn't they? Everyone has that problem, said the rep, What do you think?
  17. Hi. Firstly, not sure this is the correct place to post... never seen so many sub-forums in my life.... We're building a 245m2 passive(ish) house this year. South facing, plenty of solar gain when need (bris soleil and external blinds to minimise when not wanted). We're in a town and on mains gas, so it seems by far the most logical source of energy for heating and hot water. As much as I want to de-carbonise, a heat pump doesn't make sense in our case. So, that part is sorted. As we'll have triple glazing, ICF walls, large thermal mass, high air tightness, our energy demand will be low. I don't see the point in spending thousands installing a central heating system. Plus we'll have a wood burner - will be rarely used, so not fussed if there's a back boiler on it. Our initial PHPP assessment attached. I'm thinking plumbed towel rads in wet rooms and maybe 2kw post heaters (3x 150mm - one for each level - each with own control e.g. central warm water heater) Any issues with the above? Would also consider electric under tile heating mats for the master en-suite for my other half's chronically cold feet... My main query is hot water.... there's just the two of us and we both travel a lot for work so we've no regular routine. We have a combi boiler in our house which is great.... but hate the long delay for hot water to come out of the tap and the massive pressure and flow drops when somebody else flushes a toilet or turns on a tap. So I'm ruling that out. I'm also planning on a 3-4KW PV system with solar diverter to provide hot water in the summer... so that means some sort of storage. What are my options? In summary, we need instant DHW on demand, high flow rates, low running cost, heatable by gas and PV. Thernal store, unvented HW cylinder or sunamp type storage? Really unsure!!! Thanks
  18. I am a new member at the planning stage of a new build house for our retirement and looking to make it as comfortable, efficient and maintenance free as possible. I am trying to get my head round the many and various heating options – things have changed beyond recognition since we built our current house 35 years ago. The plan is that we will have one large room incorporating living/kitchen/dining. This will be on the first floor with ceiling at roof height and extensive glass to S & W to maximise the views. I know this isn't ideal, but we love the outdoors and the views are spectacular. Bedrooms all ground floor. My current thinking is to have wet UFH in concrete screed floors on both levels; either GSHP or ASHP (current preference). Can the ASHP be located in an outbuilding to avoid noise issues? My main concern is solar gain:- Can I utilise this free energy to heat the lower floors/DHW in winter (MVHR)?? How do I keep it cool as we experience the ever warm summers we are promised? (MVHR/AC/??) Thanks in advance
  19. Reaching the final straight, need to purchase the main MVHR unit. Was originally going to get an Adroit DV110 but the prices have rocketed, the Kinetic Advance SX looks a strong contender, however the limited reviews of the App on the Apple App Store do not seem very favourable... A key feature for me is being able monitor and interact with the MVHR when away from the property, (new build is over 100 miles away from main house) I've seen the Adroit in the flesh and used the 'cloud' function and whilst clunky it does what I need. Anyone actually got a Kinetic Advance SX, how are you getting on with it and the app?
  20. I found some mention of this in other posts but not my specific question. Now that the hot weather is back I have noticed that on occasion the master bedroom in our current house is a little uncomfortable at around 25C although opening the windows soon fixes this. In the new place the master bedroom has a lot more glass, basically a west facing glazed gable and insulation levels are higher. This got me thinking should I consider "comfort cooling" which I often see advertised on flats in London. I believe that @JSHarris has this on his MVHR, I think via running his heating in reverse? In my case I would have to change the MVHR unit to one that allows cooling. It is partly an attractive option because we will have 3 MVHR units (Dantherm) but one supplies the most used rooms in the house with the most glass so I would only have the extra cost of changing that one unit. I spoke briefly to the heating engineer and he felt it wasn't worth it as there would be an considerable increase in costs because we would have to also up spec the pipework to allow for the possibility of water condensing in it. It would effectively have the same costs as putting in an AC system. He felt that summer bypass is enough, certainly in Scotland it would be rare for the actual outside air temperature to be well above 20C, especially in the evenings. Also we can always open the windows. If this isn't enough he recommended looking at solar reduction film for the windows or a through the wall AC unit. Does anyone have any thoughts or experience of using comfort cooling and how well summer bypass works in practice?
  21. Hard hat on. It is possible to run MVHR ducting through a passive slab? I am starting to think about ducting runs from my bungalow with vaulted ceilings. As a bungalow, there are no joists to take the runs. Passive slab not poured for another few months at least.
  22. Fitting my vent terminals for my Mvhr supply and extract valves and I know a few on here have used BPC for the ducting etc. When cutting the plenums down to size, the bit that sticks through the plasterboard that the ceiling valve pushes into, have people left them to protrude a little bit lower than the plasterboard? It is just when I looked at how the valve attaches to the plastic tube it needs to compress a foam gasket and I assume for this to work properly it would need the tube to be left longer than the flat surface of the p/board to make a snug fit? TIA
  23. Hi guys, Just joined this group. Just finished building a Passivhaus in Penzance, Cornwall. My friend and I built 2 houses together, one for each family on a challenging plot chasing the passivhaus dream... We've been in the house since end July and just seeing how it copes with our first winter! So it's a timber. Frame design, sitting on a concrete raft (on 30cm insulation!) planned using the PHPP software to conform to PH standards. So it's super insulated, airtight (0.3ac/hr) no cold bridges, triple and quadruple (skylights) glazed with Brink MVHR system (ubbink plastic duct and plenum). My friend developed the wall buildup himself to achieve the PH standards without us having to buy premade PH timber frame sections, saved us a lot of money... Biggest struggle so far, trying to get the. Brink post heater to operate... It's wired up correctly but won't operate, even at high fan speeds...? Which is really why I joined this forum, to hopefully glean some info as our supplier hasn't solved it (or Brink at this stage!) Cheers.. Murray
  24. I need to improve the ventilation of my own house (2009 chalet bingalow conversion, done to roughly 2010 regs), as it now needs to run slightly warmer for parent comfort reasons and is starting to feel a little stuffy (need to check humidity). In theory I could fit an MVHR, but it is a warm roof chalet bungalow conversion so that would be more than a little complicated, and also of course it would be a big disturbance. The plan is to try: 1 - a PIV unit upstairs - which will be on a wall on the landing not a ceiling with the unit in a space behind a stud wall in the roof angle, as nearly all the ceilings are sloping and if I get into the tiny roof voids it will be very tricky outside. 2 - Replace both upstairs and downstairs bathroom fans with (100mm) dMEV fans. 3 - If necessary trim a few mm off bathroom doors. I would welcome any comments. I am not expecting a transformation, just an improvement. I routinely fit PIVs in rented properties, and a HR fan somewhere downstairs, and all of the installations have worked well. Any comments would be most welcome. Cheers Ferdinand
  25. In the most recent Passivhaus Trust newsletter (link below) is a link to this document, "Good Practice Guide, MVHR for single dwellings". Its a detailed description of how to design an MVHR system for a Passive House. The guide: Papers/2018 MVHR Good Practice Guide rev 1.2(1).pdf The newsletter: