MVHR, the Black box

Tifosi

Talked to a few companies on MVHR in Ireland and the UK and I am not feeling warm and fuzzy about the proposals and advice I am receiving locally.

While I appreciate they will not or reluctant to produce drawings, while these systems are not cheap I do expect slightly more than a few lines and a quote.

Sure how else do you known if they have everything included, the constraints of the build. What I have found is different companies are proposing different size units from the same Manufacturer.

While I am thrown an old quote when prying deeper they do not appear to be able to answer a few what I would deem simple queries.


What are the proposed duct runs.
What is the expected flow rates in each room.
What will be the flow rate in the ducts.
At what capacity will the MVHR run at.
Noise rating expected at the supply/extract terminals.

It appears they will put in an flexible duct for supply, 2no for extract(to be sure) and hope for the best.

Am I expecting too much, do I just hand over the money, say a prayer to St Anthony, light candles, I think not.

Any recommendation on vendors please PM me, or what level of detail you have received.

Calahonda52

You are being disingenuous in the extreme here with this sort of language:

"It appears they will put in an flexible duct for supply, 2no for extract(to be sure) and hope for the best."

and

"Am I expecting too much, do I just hand over the money, say a prayer to St Anthony, light candles.."

What you are expecting is a full design for free.

I do this work for a living: you expect folk to do up a detailed design, based on construction drawings, for free.

I wish you well.

Tifosi

Thanks

But if they cant answer simple question's then how do i know if the unit is sized correctly.

That the designed flow rates will be achieved at commissioning, that the unit is sized to run at 60-70% capacity. Velocity in the ducts will be kept to a minimum to reduce noise.

DBA levels will be kept to an acceptable level, no issue with crossflow at the supply, extracts from the MVHR.

I am relaying my current experience, happy to pay for a design but before I part with money, I am paying for a service I expect professionalism

Now if you wish to take this off line happy to discuss further

Gumbo

Tifosi wrote: »

Thanks

But if they cant answer simple question's then how do i know if the unit is sized correctly.

That the designed flow rates will be achieved at commissioning, that the unit is sized to run at 60-70% capacity. Velocity in the ducts will be kept to a minimum to reduce noise.

DBA levels will be kept to an acceptable level, no issue with crossflow at the supply, extracts from the MVHR.

I am relaying my current experience, happy to pay for a design but before I part with money, I am paying for a service I expect professionalism

Now if you wish to take this off line happy to discuss further

What has your Assigned Certifier got to say about it?

homewardbound11

6 years ago now but I asked the same from my installer . No drawings appeared even though they were asked for .
On installation the installers compromised the air tightness layer . Clearly not understanding the purpose . The company was made pay to make this right .
So I guess what I'm saying is that professional services may not be up to scratch back then and now .

B-D-P--

Sorry to steal thread, But can people PM me MHR suppliers they reccomend??

brendane

Why don't you employ a services consultant to produce a design and drawings for you. This way you can dictate what you require for every query you have above.

At least this way each contractor will be pricing based on the same specification

CaraK

B-D-P-- wrote: »

Sorry to steal thread, But can people PM me MHR suppliers they reccomend??

Can you send PMs to me also

Thanks OP for posting I am feeling exact same and my certified is most reluctant to go beyond the sales pitch of his preferred supplier

Fayre

Tifosi, my house is 3200 sq ft and to err on the side of caution I put in 2 HRVs.
One sits in the utility and serves the GF.
The other sits in the attic and serves the FF.
At least I won't have to worry about not being able to meet capacity and being too noisy because they are being run at too high a speed.

Water John

Well, if budget wasn't an issue, you do have a good solution.
So many see one, as an optional extra.

death1234567

I'm just doing up plans now and I am just wondering if someone could post up here best pratices in this area. i.e. do you get a specific consultant to do the drawings/design for you and then go to a company to install or does one contractor do all the work or should your architect be involved at the plans stage? Is there a way to hire a 3rd party expert to oversee the installation, air tightness and build quality and if so how much would this cost (roughly)?

Also what are the options, 1. go full MVHR and then use this to heat the house reducing Central Heating to core areas, 2. install "normal" central heating system and then use MVHR to "assist" with heating and control air quality in the house?

Sorry for the basic questions but just starting to research this now.

Tifosi

kceire wrote: »

What has your Assigned Certifier got to say about it?

Opting out as per the other 100% of private customers building houses.

Tifosi

B-D-P-- wrote: »

Sorry to steal thread, But can people PM me MHR suppliers they reccomend??

CaraK wrote: »

Can you send PMs to me also

PM's sent

Tifosi

death1234567 wrote: »

I'm just doing up plans now and I am just wondering if someone could post up here best pratices in this area. i.e. do you get a specific consultant to do the drawings/design for you and then go to a company to install or does one contractor do all the work or should your architect be involved at the plans stage? Is there a way to hire a 3rd party expert to oversee the installation, air tightness and build quality and if so how much would this cost (roughly)?

Also what are the options, 1. go full MVHR and then use this to heat the house reducing Central Heating to core areas, 2. install "normal" central heating system and then use MVHR to "assist" with heating and control air quality in the house?

Sorry for the basic questions but just starting to research this now.

So many queries

MVHR, depends on your level of airtightness as to your requirements, Assuming your not building a leaky old tin shed, then yes you will require one.

Can you use it solely for heating, potentially(But I personally would not), will require a heating coil, good airtightness, above building regs insulation.

Maybe consider UFH with Air to Water, GSHP, Oil, gas, Elec depends on all build other renewables

Airtightness, your architect, engineer and/or builders preferred specialist.

No expert so read around, ask queries on here but do your research as well.

corcadorcha

Tifosi wrote: »

CaraK wrote: »

Can you send PMs to me also

PM's sent

Please pm me info also.
Thanks