Green Building Forum - Cost effective whole house ventilation Tue, 19 Dec 2023 08:25:37 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273665#Comment_273665 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273665#Comment_273665 Wed, 08 May 2019 18:07:50 +0100 gravelld
Before I go into the details, some constraints:

- This is a refurb and people are living in the house
- I can't afford HRV
- I don't want the disruption of ducting
- I don't like the concept of PIV - pushing out moisture laden air through holes in the fabric does not sound like a good idea

Our current air permeability (before new windows) is 5.8 m3/hr/m2 @ 50Pa.

Our floor area is 285m2, five bedrooms.

We have seven wet rooms (1 x kitchen, 1 x utility room, 2 x toilet, 3 x bathrooms).

My reading of the guidelines in the AD is that we need to provide a minimum l/s of 85 l/s on a m2 basis. If the units provide 12l/s that almost covers it. Is the calculation that simple?

I've been looking at units like these:

https://www.vent-axia.com/range/lo-carbon-solo-plus-selv (the HT version to ensure ventilation goes up when humidity does)

I also believe Nuaire have similar units.

Are these units suitable for continual extraction and will seven of them (for each wet room) be "good enough" to meet the demands of BC?

Vent Axia weren't particularly helpful. BC are unresponsive. The window order is going in soon so I need to work this out!]]> Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273669#Comment_273669 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273669#Comment_273669 Wed, 08 May 2019 18:18:56 +0100 djh Posted By: gravelldIf the units provide 12l/s that almost covers it.
Sorry, what units? You mean the ones you talk about subsequently?

What are they, just continuous extract units? The web page doesn't seem to say!

I was going to suggest the alternative to PIV, namely MEV, which is what this is I think. So yes, go for it.

How can a product described as
"Continuous running products, such as the Lo-Carbon Solo Plus,
installed in all wet areas of a dwelling are classed as a wholehouse ventilation
system and therefore only need to move the amount of air as outlined
in table 5.1a and 5.1b of Building Regulations Approved Document F."
not be continuous running?]]> Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273671#Comment_273671 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273671#Comment_273671 Wed, 08 May 2019 18:42:50 +0100 gravelld
Yeah, the 12l/s mention refers to the VA units.

I guess I just haven't seen anyone else do this. From what I've read, they are mostly just used as intermittent extracts, so I'm interested if people have got these passed as continually running units.

I was just looking for some re-assurance really. Every time I try to contact BC I get very little help - I don't even understand what the process is - whether I might end up with some windows that make my house non-compliant.

Yeah, they could be described as MEV, but not ducted.]]> Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273674#Comment_273674 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273674#Comment_273674 Wed, 08 May 2019 20:23:15 +0100 djh Posted By: gravelldYeah, they could be described as MEV, but not ducted.
I expect the jargon is dMEV (decentralised MEV).

whether I might end up with some windows that make my house non-compliant.

Worst case, you would have to cut some trickle vents into the window frames? But I can't see that being needed.

Every time I try to contact BC I get very little help - I don't even understand what the process is

"You can apply to your local building control authority in one of two ways:

"a) Full Plans application: For the majority of these applications the building control team will check and ‘approve’ the plans before work starts. You’ll need to submit all drawings, specifications and, where necessary, calculations for structure, thermal, water consumption and so on. Submitting this type of application reduces the risk of contravening the regulations and helps avoid costly delays.

"b) Building Notice: The application is ‘accepted’ when the building regulations have been met on site. However there is a risk with this option as no plans are required and work carried out may need altering or upgrading to meet requirements.

"So if you are unsure, the Full Plans route with an approved plan will give you the assurance that you won’t be taking a risk on site.

"You then deposit your plans and calculations which are fully checked and approved prior to commencement so you have the confidence to obtain quotes, appoint contractors and order materials based on an agreed scheme with no nasty surprises."

from https://www.labc.co.uk/homeowners/5-steps-building-regulations-approval]]> Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273679#Comment_273679 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273679#Comment_273679 Thu, 09 May 2019 07:19:09 +0100 gravelld
Whenever I look at planning applications online the application forms always seem incredibly tersely written and with no detail at all about things like ventilation, window performance etc. You do normally get location diagrams and sections, but neither of these are relevant to this project.

I guess it's a case of submitting stuff until they accept it - I hope they tell me _why_ they don't accept it so I know what to change.]]> Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273681#Comment_273681 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273681#Comment_273681 Thu, 09 May 2019 09:46:57 +0100 Nick Parsons
https://www.dacorum.gov.uk/docs/default-source/planning-development/1---householder-leaflet-2--building-regs-mar2011.pdf?Status=Master&sfvrsn=0

Nick P]]> Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273683#Comment_273683 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273683#Comment_273683 Thu, 09 May 2019 10:21:49 +0100 djh Posted By: gravelldWhenever I look at planning applications online the application forms always seem incredibly tersely written and with no detail at all about things like ventilation, window performance etc.
Those issues are building regs, not planning.]]> Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273684#Comment_273684 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273684#Comment_273684 Thu, 09 May 2019 10:35:15 +0100 djh
https://www.planningportal.co.uk/info/200130/common_projects/14/doors_and_windows/2]]> Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273698#Comment_273698 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273698#Comment_273698 Thu, 09 May 2019 19:21:35 +0100 gravelld
The window installers will install the windows. It's difficult enough to convince them to even remove the existing windows (is it me or are window installers a bit... 'precious'?).

I'm meeting him tomorrow so I'll ask about this - my understanding was that under FENSA if it's a standard replacement following the standard rules (replacing windows with TVs with new windows with TVs) it's a straightforward building notice, but variations are a bit of a deviation. That said, they have to confirm all the other requirements are met (safety etc), so they must have to provide something...]]> Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273699#Comment_273699 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273699#Comment_273699 Thu, 09 May 2019 19:22:42 +0100 gravelld Posted By: Nick Parsonsgravelld, does this help?

https://www.dacorum.gov.uk/docs/default-source/planning-development/1---householder-leaflet-2--building-regs-mar2011.pdf?Status=Master&sfvrsn=0" rel="nofollow" >https://www.dacorum.gov.uk/docs/default-source/planning-development/1---householder-leaflet-2--building-regs-mar2011.pdf?Status=Master&sfvrsn=0
Thanks, some good advice there, but I think this is written for new construction... I'm guessing we don't have to provide a site location plan for example, we aren't moving the house ;-)]]> Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273700#Comment_273700 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273700#Comment_273700 Thu, 09 May 2019 20:34:32 +0100 djh Posted By: gravelldI'm guessing we don't have to provide a site location plan for example
It doesn't say it's just for new construction; it says: 'A full plans application can be used for all types of building work'. I'm guessing you DO have to provide a site location plan because it says you have to. I expect it serves two purposes, at least:
(1) it identifies the site, so they know which property is under consideration (as a double-check)
(2) it identifies where the building(s) is/are on the site and therefore which clauses of various regulations will be in force.

But there's no need to guess. Just start an online application and see what it says.

I would also think that if you have two different contractors, it is important to get the ventilation installed and commissioned (with a commissioning certificate duly notified to BC) before you install windows without trickle vents.]]> Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273701#Comment_273701 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273701#Comment_273701 Fri, 10 May 2019 10:42:43 +0100 gravelld Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273705#Comment_273705 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273705#Comment_273705 Fri, 10 May 2019 15:42:16 +0100 gravelld
Bit embarrassing, but I had not actually asked the window installers if they were FENSA registered. Turns out they aren't, so I have to do a building notice application anyway and sort BC out to come and look.

We have only eleven of twenty-nine apertures that currently have TVs. BC repeated the usual advice of replacing like with like and advised because our building is quite airtight (I didn't want to get into an argument about definitions, so left him thinking 5.8 m3/hr/m2 @ 50Pa was airtight) they would want TVs anyway to act as inlets for any dMEV system.

To make the application process quicker and get the windows ordered (the factory shuts in July/Aug and we need them for the school holidays) I have decided to retain these with the new order, and gradually introduce the ventilation system separately. The window supplier reckons they are easy to block up when additional ventilation is provided subsequently.

So I think that's what I'll do.

This does also leave the opportunity to investigate a more radical opportunity; if we do go for EWI in a few years and we do the Larssen Truss approach I favour we could run ducting in the truss cavities (like Beattie Passive do) and actually go for MVHR.]]> Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273710#Comment_273710 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273710#Comment_273710 Fri, 10 May 2019 17:32:19 +0100 Nick Parsons Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273712#Comment_273712 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273712#Comment_273712 Fri, 10 May 2019 20:28:05 +0100 gravelld Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273713#Comment_273713 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273713#Comment_273713 Fri, 10 May 2019 20:56:18 +0100 WillInAberdeen
If the ducts are a problem, others have used single room MHRV units in place of extractor fans, I have no experience with these myself.]]> Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273715#Comment_273715 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273715#Comment_273715 Fri, 10 May 2019 21:16:03 +0100 DamonHD
http://www.earth.org.uk/MHRV-Vent-Axia-Lo-Carbon-Tempra-P-REVIEW.html

Rgds

Damon]]> Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273736#Comment_273736 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273736#Comment_273736 Mon, 13 May 2019 14:48:20 +0100 gravelld Posted By: WillInAberdeen85l/s is a lot of ventilation, have you worked out how much energy it will use each year to heat that much air? Might be worthwhile to go straight to MHRVI know it's a lot, but AIUI the regs are very safety-first. My plan is to simply turn it down (many of these units can have different rates) and use humidity and CO2 monitors to make sure I'm not doing anything silly.

SRHRV wouldn't be so great in bathrooms imo because of the lower temperature of the air input but that probably depends on where it is sited and where the draught runs.

I actually just brought one of these to test in one of our en suites: https://www.greenwood.co.uk/product/153/unity-cv2gip . They make a newer one with NFC and app based wizardry but it appears to be a similar product and I don't really need the app stuff.]]> Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273990#Comment_273990 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=273990#Comment_273990 Fri, 31 May 2019 21:07:44 +0100 kmach https://www.aereco.co.uk/
It doesn't require for the building to be airtight especially if you're not doing a deep retrofit although the system would need trickle vents in the windows and background ventilation. The company was responsive and helpful as I asked a lot of questions. In the end though, we decided to go for the MVHR since we're doing a complete renovation.]]> Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=275390#Comment_275390 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=275390#Comment_275390 Thu, 05 Sep 2019 14:53:51 +0100 HoveTom
I can confirm Aereco are very helpful on the phone. They have air inlets which come through the walls or they sell a separate inlet which you can fit into the same slot a standard trickle vent comes in when you get your new windows. You just pull them out and screw their inlet in. They have extracts in all the wet rooms. The air isn’t filtered and no heat is recovered but the system is designed for a house which isn’t particularly air tight.

Does anyone have any practical experience of this system?]]> Cost effective whole house ventilation http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=275458#Comment_275458 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16116&Focus=275458#Comment_275458 Tue, 10 Sep 2019 07:43:54 +0100 gravelld