MHVR for just a few rooms, worth it or not?

[Lurkalot]

I'm planning on installing some sort of ventilation to the upstairs of our house, not sure if MVHR is worth it. The reason for wanting it is just for ventilation, I seem to sleep better with the window open as long as there’s a bit of a breeze to move the air around, but the bedroom window is at the front of the house so there’s a lot of road noise in the mornings. The bedroom humidity gets high overnight, and we get condensation on the window most mornings if it’s closed. We also have an en suite with no extractor fan and the main bathroom extractor fan has stopped working too.

 

The house was built around 2008 and not air tight etc, but as I’m planning on doing something to the ventilation anyway it feels like saving some heat is better than nothing, and I just like the idea of MVHR. It would probably be cheaper to just get two new humidity controlled extractor fans for the en suite and bathroom, and some sort of ducted ventilation for the bedroom.

I really don’t know how efficient an MVHR system would be in this situation as I have no idea what the air tightness level of the house is, although given there is an open fireplace downstairs it probably is quite low.

 

Any advice on how useful it would be? And if so what system to go for, I can find a Vent Axia HR100R for just 280 euros, has anyone got any experience with these?

[Iceverge]

From my reading the only way to have a permanent good quality of internal air is some kind of continuously operating mechanical ventilation so it's worth pursuing. 

 

If it was me I'd look at the price of a whole house continuous extract system as you may get most of the benefits of MVHR as you may have poor airtightness. 

 

That vent axia unit looks fine but perhaps a little small. Rated only to 40m2. A larger unit running less hard will be quieter. 

[MJNewton]

If you're not quite sure - or just what to keep costs as low as possible - keep en eye on eBay as MVHR units often come up for sale at half retail price or less. Many are brand new or at least 'as new' but might be missing packaging etc and without warranty. There's definitely money to be saved. Mine had been fitted but never used, as part of a development of multiple houses but they hadn't met the spec so they were all ripped out and replaced with the next size up. The bloke doing the reinstall action stuck them all on eBay for just a few hundred each. I reckon I'd still get the manufacturers warranty as the serial plate is date stamped so I could easily claim it was fitted prior to me moving in hence no receipt.