rco

Apologies — Freeair is described on the web as a "decentralised MVHR", and Fresh-R was discussed here in a decentralised MVHR topic 🙂 I appreciate both of them can have extra extract ducting added — though IMO neither of them particularly well explain as to whether that's an "as-well" as the main extract or an "instead-of": the blueMartin video at least suggests "as-well". I like the idea of the BluMartin Transfer & Fresh-R-Forward cascade units for making these all-in-one units go further still. As I said initially, main issues for the condensation is in the upstairs of the existing house, so maybe it's a case of getting a small "full" MVHR unit in the attic and just ducting that together sensibly (through ceilings & under insulation); then having a blueMartin Freeair100 / Fresh-R in the extension space and calling it done.

Hi all, Thanks for the replies Yes, the "middle" of our house is a stairwell/landing & a chimney... but more nastily, the joists all run front-to-back, so to get to the middle is always across joists. Hence the idea of running it between joists to the eaves and up to the attic that way. _Potentially_ I'm estimating the longest run would be a supply: from the MVHR unit 8.5m horizontally, a 90° bend, down 1m, a 45° bend, down 1.5m, a 90° bend, and then 6.5m horizontally (total 18m). That excludes any distribution boxes in the middle. Is that getting ridiculously long & windy, or fairly normal for a multi-storey house? Who are you getting quotes from? That seems... cheap to me? We're soon to be a 4 bedroom, 2 bathroom house with 3x living spaces (1 is big). The indicative number was from Paul Heat Recovery, I guess it could be gold-plated, and I can certainly push back on it. Yes, the Fresh-R/Freeair/Prana stuff all seems Our house (upstairs, where the issues are) has very little wall space. If a unit could be connected out through a sloped tiled roof it'd be a possibility, otherwise we're limited in where we can locate it — but I haven't seen any dMVHR units with that option except maybe the Prana commercial ones? Thanks all! Any more suggestions welcome.

Hi folks, After some advice. We're building a ~50m²/125m³ open plan pitched-ceiling extension on the side of our 1950s two storey detached house in Scotland (downstairs 70m², upstairs 49m²). Ventilation in the existing house is rubbish, and condensation/damp is a regular occurrence: particularly upstairs. We've been gradually improving the insulation & airtightness on the existing house, and the extension is well-designed. We've had a pseudo-MVHR on another house on the other side of the world and it certainly kept the house dry, so I'm investigating options here. Drawings are attached, hopefully gives a reasonable idea. I'm getting a design done for a full MVHR — I think there's a sane way to get ducts from the ground floor ceilings to the attic through the existing accessible eaves, and then locate the unit in the (floored & cold) attic at the gable end. Without boring through joists. But the indicative quote was £8K+VAT with us self-installing. The other option I have thought of is two dMVHR, something like the Prana 210G ERP PRO-mini in the extension (we have enough wall thickness), and another dMVHR for the upstairs, maybe a small ducted unit serving the bedrooms and located in the attic. And forget about downstairs. Is something like the Prana commercial series what we should be looking at? What other options are worth considering? dMVHR will obviously work out a lot cheaper upfront and quicker, but will we be constantly disappointed? Thanks in advance, Rob buildhub-1.pdf

Try Central Rebar in Alloa — they wholesale to lots of other places and commercial sites, and are happy to do small orders too, cut to size, the works. VASTLY cheaper than Travis/etc. I feel like they'll have shipping/contacts for you as well. Worth a call.