Heat Recovery Worth it?

ninjaBob

After being told my Heat Recovery Supplier didn't know what they were talking about:

What is the air tightness you are building to? The reason for asking
this is if you are building an air tight property, i.e. less than
3m3/h/m2 then 2 units will be required. However if you are not building
to a high level of air tightness, then 1 unit will e able to service
your property.

So I wanted to know if people believe that HRV is worth it? Given the cost of relocating warm air from one room to the next, is it really worth the investment of 5000 - 8000 euro.

Considering that I would already have a well insulated house and GeoThermal with Underfloor would I really gain much from having HRV or should I just have my builder core out some vents and place restrictors on it.

I have been informed that these such vents would be considered a natural flow of air and more beneficial than HRV.

So is HRV actually worth it?

GoneShootin

It's difficult to get an honest answer. Home owners with HRV installed for a couple of years will seldom tell you that they wouldn't do it again, beacause:

a) They spent on avg 6k on it, and not wanting to sound stupid having wasted money they will convince themselves that it's a good investment

b) They are in a new build, and as such won't know any better having nothing to compare it to properly like with like.

So what you have to do is research it - learn the facts, and make a judgement on it for yourself. NEVER believe a salesman, because that's what they are supposed to do is sell. They have to believe in their product, and even if they don't they will make themselves believe in it.

Personally speaking I AGONIZED over the decision. In the end I didn't go with it. My main driver for it was that it's not proven, that each salesman had a different take on the technology, and some even didn't know the detail of what they were selling. For me I prefer to spend 6k on something like my kitchen, where I know the money will be used and the results can be proven

tipperary

Hi

we have recently finished a new build and with the HRV. We built using ICF and achieved a very good air tightness result thus making the HRV more effective. Nevertheless if looked at from a purely financial point of view I don't think the systems will be worth it (in general anyway). However it is when you consider the improved comfort and air quality that the decision becomes a bit more difficult.

Mazotasan

The other thing is not to forget that HRV is a piece of an overall jigsaw if your going down the road of investing in air tightness, insulation, low u value windows etc. If you invest in all of the above and then start coring the walls for vents the jigsaw falls apart...a bit like having air con switched on in the car with the windows down!

I wouldn't consider open vents a natural flow of air I would view them as a hole in me oil tank or heat pump.

I agree its a pain in the ass to find a good supplier who knows what they are talking about and know what they are selling! I am still researching this and hoping to strike gold soon.

gears

There are a lot of problems with HRV in this country and the basic one I think and I see others think the same is the lack of knowledge by those selling them.
But from reading posts here I think a few points can help sort out potential suppliers.

Are they using an SAP Appendix Q certified machine.
Have they made any provision for a fire out break in the home, fire rated valves, electrical cut out etc.
Ask what ducting they are using and why plus do they insulate it and with what.
Can they show a calculation of how they sized the units suitability for your home.
To answer this topic, can they give a reason for you to install one, that doesn't sound like them simply making a sale.
Have they had any independent (not a 30 min session from the manufacturer) training on how to design and install a HRV system.

There's probably lots more but my 2c worth on the topic is that they are worth it as part of an overall package and simply sticking one in with out looking at air-tightness, insulation etc doesn't make sense.

sinnerboy

+1 Gears

OP - you will one day have to produce a BER cert

So - find a good assessor now . One who is/was an architect or architectural technician

They are trained to use software name DEAP ( Dwelling energy Assessment Procedure ) . That software serves 2 purposes

1. BER cert production
2. Show compliance with B Regs

So with a suitably trained and experienced professional you can literately "play" with options and make an informed choice

What if I increase wall insulation + triple glazing - no HRV
What if I leave wall alone - double galzing - yes to HRV
UFH vs Rads
Heat pump va bolier
What will solar panels do for me
What if I go for reasonable ( only ) air tightness ( Q50/7) - not best practice* ( Q50/3 )

.... no guesswork any more

*BRSRIA - not PHI

sinnerboy

GoneShootin wrote: »

It's difficult to get an honest answer. Home owners with HRV installed for a couple of years will seldom tell you that they wouldn't do it again, beacause:

a) They spent on avg 6k on it, and not wanting to sound stupid having wasted money they will convince themselves that it's a good investment

b) They are in a new build, and as such won't know any better having nothing to compare it to properly like with like.

So what you have to do is research it - learn the facts, and make a judgement on it for yourself. NEVER believe a salesman, because that's what they are supposed to do is sell. They have to believe in their product, and even if they don't they will make themselves believe in it.

Personally speaking I AGONIZED over the decision. In the end I didn't go with it. My main driver for it was that it's not proven, that each salesman had a different take on the technology, and some even didn't know the detail of what they were selling. For me I prefer to spend 6k on something like my kitchen, where I know the money will be used and the results can be proven

How cynical GS

Nahh.. just chiding .

You sound like my last 5 clients . I do remind all my clients that the average lifespan of a kitchen or bathroom fit out is 15 years and that those bright shiny things will be skipped when the investment in the build spec continues to pay back .

But people want their MTV - on a plasma screen .
I am not judgemental at all - ( not my house /mortgage)
I just like clients to make decisions with open eyes .

gears

sinnerboy wrote: »

+1 Gears

OP - you will one day have to produce a BER cert

So - find a good assessor now . One who is/was an architect or architectural technician

They are trained to use software name DEAP ( Dwelling energy Assessment Procedure ) . That software serves 2 purposes

1. BER cert production
2. Show compliance with B Regs

So with a suitably trained and experienced professional you can literately "play" with options and make an informed choice


What if I increase wall insulation + triple glazing - no HRV
What if I leave wall alone - double galzing - yes to HRV
UFH vs Rads
Heat pump va bolier
What will solar panels do for me
What if I go for reasonable ( only ) air tightness ( Q50/7) - not best practice* ( Q50/3 )

.... no guesswork any more

*BRSRIA - not PHI

When I was posting last night I was tring to remember the independent training for HRV systems but it completely escaped me so thanks to sinnerboy for reminding me.

http://www.bsria.co.uk

Quote from their site "a consultancy, test, instrumentation and research organisation. We provide specialist services in construction, building services and facilities management" and in my research I have only found one company who has sent someone to them for training on HRV systems.

Carlow52

Mazotasan wrote: »

The other thing is not to forget that HRV is a piece of an overall jigsaw if your going down the road of investing in air tightness, insulation, low u value windows etc. If you invest in all of the above and then start coring the walls for vents the jigsaw falls apart...a bit like having air con switched on in the car with the windows down!

I wouldn't consider open vents a natural flow of air I would view them as a hole in me oil tank or heat pump.

I agree its a pain in the ass to find a good supplier who knows what they are talking about and know what they are selling! I am still researching this and hoping to strike gold soon.

'air con' : perhaps the more correct description given a lot of the sales talk around HRV.

It is one of the 'new' home owner technologies that in my view that if it not (designed/installed/maintained) correctly poses a greater risk to the occupants than say roof panels/ geo/ wind etc; at worst they don't work but dont pose a potential health/fire risk.