Is there a inexpensive MvHR diy option

[Wadrian]

Hi everyone

 

looking for an inexpensive MvHR option. We are soon to be starting 1st fix in next few months and would not want to be spending £10k on an a full

MvHR company system.

 

if anyone has experience of doing the own set up/what units they used/was it off the shelf etc? Finally am I right in saying once installed, get an independent company to certify it? 
 

many thanks 

[Conor]

It's easy. You can certify it yourself with an anerometer and a spreadsheet. 

 

I think there is an MVHR design sheet floating around the forum somewhere. Tl;Dr, make sure your duct runs are as short as possible and your diameters are as big as possible.

[Indy]

It depends on if its a retrofit or something that needs to be passed by BC. 

 

If its the former, there are obv ways to self install, balance and no need for certification. Cost will be the parts and your labour (unpaid) if you're skilled that way.

 

Ours was the latter as giving up trickle vents and exhaust fans in the bathrooms meant that we had to get it professionally certified. That means generally finding people who will want to do the whole shebang - design, supply, install and certify. You *may* have luck in finding someone to certify a self install but those people are few and far between. 

[MikeGrahamT21]

Work out the airflow capacity you need for your volume, and then double it so you run your unit only ever at 50% (less the better for noise), and then keep an eye out on eBay, loads of units come up, many are brand new and much less than buying from a store, they’re often mis-specified units which get sold on to recoup losses

[Post and beam]

No need to spend £10k.

I am guessing that you are talking about new build.

The ducting can be physically challenging to manipulate. I used 90mm ubbink and installed it all myself. 3 x rolls of 50 metre ducting for a 200 square metre 4 bed house. That should give an idea of cost for that bit.

The MVHR unit i bought is a Brink 400 at about £1900. Located in the loft. Make sure it fits through the loft hatch. Ask me how i know.

[Post and beam]

No need to spend £10k.

I am guessing that you are talking about new build.

The ducting can be physically challenging to manipulate. I used 90mm ubbink and installed it all myself. 3 x rolls of 50 metre ducting for a 200 square metre 4 bed house. That should give an idea of cost for that bit.

The MVHR unit i bought is a Brink 400 at about £1900.                Air-Haus.co.uk  as recommended by @NickfromwalesApart from a great price on the unit, they offered to commission and certify for me once i was ready.

 

[SteamyTea]

What figures has your air leakage test given.  That is your starting point.

[JohnMo]

2 hours ago, Wadrian said:

looking for an inexpensive MvHR option

Once you get your head around it it's a pretty simple system. Pretty easy to install if you plan ahead and know your duct routes. Our whole system was around £2k installed and commissioned DIY basis except commissioning sign off.

 

To certify yourself you need a certified 

2 hours ago, Conor said:

anerometer

Then you can self certify. I paid £200 for someone else to do it.

 

[Adrian Walker]

3 hours ago, Wadrian said:

Hi everyone

 

looking for an inexpensive MvHR option. We are soon to be starting 1st fix in next few months and would not want to be spending £10k on an a full

MvHR company system.

 

if anyone has experience of doing the own set up/what units they used/was it off the shelf etc? Finally am I right in saying once installed, get an independent company to certify it? 
 

many thanks 

Who said £10K?

[Wadrian]

Think I had read £10k on earlier post on Buildhub. Would be good to know if this is wrong 

[Onoff]

This is inexpensive:

 

http://www.builditsolar.com/Experimental/DIYHRV/DIYHRV.htm

[SteamyTea]

33 minutes ago, Onoff said:

This is inexpensive

I made one a few years back. Just used it on the bathroom, it worked.

The efficiency was not to good, about 70% if I remember right. Most of that was down to using a couple of Manrose bathroom fans.  They are terrible.

Big fans are needed, area is everything when it comes to shifting air.

[JohnMo]

Our first quote was £10k - it was dismissed very quickly