MHRV and indoor air quality (particularly pollen)

the_amazing_raisin

So I'm currently sitting at home, loaded up on antihistamines and feeling like Mother Nature is trying to kill me...

I've been thinking about getting an MHRV system for a while, partly due to the energy efficiency but mostly due to the improvement in air quality.

Currently the house has the standard Irish air ventilation, drill a big hole in the wall and pop a vent cover over it. These make a great home for the spiders as well as letting in a nice cold draught in winter. And in a calm, humid summers day they create some excellent stagnant air in the house

So I'm wondering how people find the air quality after changing to an MHRV? Do they make a big difference or is a lot of it just marketing spiel?

Has anyone tried getting filters fitted to the intake to reduce the amount of dust and pollen coming in? And did they work?

I know realistically I'll have to open the windows at some point or go outside. But some relief from the dreaded pollen would be nice

Borzoi

most MHRV come with filters capable of capturing any pollen. G3/G4 rated.

can recommend them for the improvement in air quality

silver_sky

Similar situation here. I looked into getting the ecovolt zero1 ductless mvhr last year. What with restrictions and all I never got round to doing it.

It slots into the hole in the wall and pulls air in and out. Washable filter I believe? There are other similar units from other companies but this looked pretty neat. I saw some comments on here about it but never saw any mention of anyone that actually got it. Interested if there is anyone to add.

Mr Q

I have no issues with pollen but do have MHRV. When I replaced the filters the last time one of the options was for F7 rated filters which apparently remove a lot of the pollen.

Some I have seen claim they will reduce up to 98% of allergens and microscopic particles. Others may even be better.

I always find the air quality good in the house.

KCross

https://www.boards.ie/discussion/2058251616/mhrv-and-indoor-air-quality-particularly-pollen

I find it great. Clean air 24/7. Moisture from cooking and showers is quickly removed.

And constant fresh air in a toilet is always a good thing! 😉

The efficiency is, of course, an important benefit too.

A retrofit of a ducted system would be tough going though, depending on your house/attic layout.

mike_2009

I installed one just upstairs a year ago. Bedroom air quality at night was always marginal and some nights very poor. No problems since, bathroom clears up nicely after shower and just changed the filters for the second time, nasty to look at the old ones! I live beside a busy road so using 2 x F7 ones for good measure. Was worth it but have it above the stairwell and ducts are all in attic. Bringing it downstairs is a bigger job and would require taking up the floor in a few places, didn't get around to it yet.

graememk

https://www.boards.ie/discussion/comment/119273244#Comment_119273244

What did you install?

I'm in a bungalow, so retrofitting is a good bit easier

mike_2009

Zenhder Comfoair 350. It's an old model now but Passive House certified so it's QUIET! The new models are a bit of a jump up in price. Got the semi rigid ducts, manifolds and other air valves from the same supplier, it all locks together nicely! Didn't fancy the intake/exhaust ducts in the gable wall so put them up through the roof, had a roofer fit the two glidevale vents over 2.5 meters apart, have stayed on since! No leaks. Lots of crawling around though!

cubix

Hoping to do something similar before the summer is out on a self install basis . Looking for a domestic unit for a standard 3bed house/ 2 bathroom. Any particular brands I should be look at. What is the average manufacter warranty on the main unit. Thanks

the_amazing_raisin

https://www.boards.ie/discussion/comment/119377354#Comment_119377354

Haven't dealt with these guys but they seem to have a decent selection and have DIY kits available

https://www.bpcventilation.ie/

Mr Q

https://www.boards.ie/discussion/comment/119381502#Comment_119381502

I have dealt with them for a continuous extract unit and the ducting. They were very good on price.

They are based in the North I think but there was no issue with the order.

L1011

Got single room MHRVs in all bedrooms and the bathroom. Filters are doing wonders for internal air quality. Only had it a few months so not had to clean or change them yet, though, so that could be quite nasty.

Don't have hay fever so can't really say what its doing for pollen.

silver_sky

https://www.boards.ie/discussion/comment/119382451#Comment_119382451

Which ones did you get?

L1011

https://www.boards.ie/discussion/comment/119394824#Comment_119394824

Sudwind Ambentika. The installers were awful (well - more misguided by the company that sold them to think they were doing a very basic job) - I'd seriously suggest just doing it yourself if you're willing to use a hole saw.

the_amazing_raisin

https://www.boards.ie/discussion/comment/119394853#Comment_119394853

I wonder could you use existing vents? My house has the top spec Irish standard of using a hole saw to drill a hole through one wall in each room then putting a plastic vent cover over it 🙄

L1011

https://www.boards.ie/discussion/comment/119395603#Comment_119395603

In the 1970s, the vents were made by omitting half a cavity block! If you have proper shaped/sized vents you should be able to re-use.

THE ALM

Been something we have been considering as well as we currently only have trickle vents in the windows as is.

Windows and doors due to be replaced which will make us considerably more airtight so this looks like our next logical step. Existing windows and doors are poor enough so has been on the todo list for some time.

Have emailed BPC our floorplan for a quote with a view to a diy install, in a bungalow so access is good.