Introducing myself

[Rob Johnson]

2 storey house now completed

240 sq meter floor space, vaulted ceiling  

Insulated raft foundation (homemade)  

Nudura ICF 0.11 u-value

Airtightness 0.3 cube per hour

Windows and doors Internorm 0.6 u-value

MVHR  Genvex premium

No gas, no underfloor

Total energy required measured for the last two years 30kwh per sq m/year

Minimum 21 degrees C

Cost 210K 

Took 8 years

 

Required advice on airfilters for Genvex Prem which I gratefully found on site. But wondered if Mr Harris would be kind enough to advise on the service requirements of the Genvex.

[ProDave]

Hi and welcome.

 

With a CV like that you should be answering all the questions.

 

I am sure @JSHarris will be along shortly.

[Russell griffiths]

Morning @Rob Johnson what Nudura blocks did you use, standard or ones with extra insulation 

im currently doing a nudura build. 

[Jeremy Harris]

Welcome @Rob Johnson.

 

I  find the intake filter (F7) tends to get very grubby after 6 months.  Sometimes I can vacuum it out and re-use it, sometimes it's too grubby to clean that way so gets replaced.  The room extract side filter (G4) barely gets dusty, and can easily be vacuum cleaned a couple of times or more before replacement. 

 

Filters are an odd size and spec, and very expensive from the UK Genvex agent (as are the Genvex units themselves - their markup is massive).  I had a batch of filters made up by Jasun Envirocare a couple of years ago, and am just about to have another batch made, as I'm down to the last spare intake filter.  In my next order I'm going to get twice as many intake filters as exhaust filters made up, as I still have four exhaust filters left over from the last batch I had made.

 

The last batch cost £12.19 + VAT each for the F7 intake filter and £5.50 + VAT for the extract side filter.  The filters that were supplied looked absolutely identical to the Genvex ones, apart from the label.  Quite how the UK Genvex agent can charge £41.87 + VAT for the intake filter and £12.15 + VAT for the extract filter I don't know.  It seems that rip-off Britain is alive and well!

 

 

[Rob Johnson]

Are your filter size 530mm long x 217mm high and 47 / 24mm wide ... just checking. Measure twice buy once!

Thanks for your information very useful.

[Rob Johnson]

I used the largest filler type that gave me the 0.11 but did I really need that ??? Putting the fillers in was a bit of a chore but easily done. I had to use foam for the corners and to fill up any gaps. Had to be careful at the corners because with that size of filler it seemed to bow the corners out a little but otherwise very pleased with the Nudura product. My wife and I with help from Jim at Nudura put the externals up ourselves. Glad I put in two load bearing walls inside (Newton 7 and rendered them with sand / cement mix) to act as thermal mass ... the house is constant 21 until it sunshines.  All the best. 

[Jeremy Harris]

15 minutes ago, Rob Johnson said:

Are your filter size 530mm long x 217mm high and 47 / 24mm wide ... just checking. Measure twice buy once!

Thanks for your information very useful.

 

 

The custom sizes I used last time were 417mm x 220mm x 50mm for the F7 intake filter and 417mm x 220mm x 25mm for the G4 extract filter and these fit the Premium 1L unit we have OK. 

 

However, I have found that the filters tend to get slightly squashed, lengthwise, by the neoprene seals, so I'm going to get the next batch made up 2mm shorter, 415mm long rather than 417mm long.  I've measured the filters after they've been in the unit and they seem to compress to a bit under 415mm long.