HRV Unit. Looking for info

selfbuildache

Hi,
So, we're about to start researching a HRV unit for a timber frame house/high spec/airtightness etc and I'm wondering if any of you would share tips on what to look out for, what's a good unit, what's not, as I'm pretty ignorant about these machines....(for now!)
Any good info websites out there?

sydthebeat

selfbuildache wrote: »

Hi,
So, we're about to start researching a HRV unit for a timber frame house/high spec/airtightness etc and I'm wondering if any of you would share tips on what to look out for, what's a good unit, what's not, as I'm pretty ignorant about these machines....(for now!)
Any good info websites out there?

a good unit:
any system accepted by the passive institute, namely 'PAUL' and 'Drexel und Weiss'

not a good unit: relative.....

use the SAP Appendix Q listing as your source of info....
http://www.sap-appendixq.org.uk/page.jsp?id=1

its the bible for selecting HRV systems

tomred1N

i'm thinking of going with the Vort Prometeo HR400 an Italian made unit from Vortice.

It seems to rate as one of the highest on effieiency and fan power on the sap index. I'm being quoted it with fexible ducting but can pay more for rigid if i want. the advantage of rigid is air move through ducts with less resistance but has been know carry more higher noise levels. Realistically it hard to see some flexible ducting not being used with rigid anyway so if performance isn't reduced too much i'm prob go with flex ducting and this unit. I'd be interested to hear from anyone who has one installed. the other unit i am considering is the Orcon hrv unit which runs off ec fans instaed of dc fans for the vort hr 400. However it does not score as high in the sap index

sinnerboy

1. That your ceiling inlet/outlets are fire rated
2. That the motor is linked to power down when your fire alarm activates
3. That you keep firmly in mind that filters will have to replaced - often ( at least bi monthly ) - so site the motor accordingly . In the attic behind the the Christmas tree and your 30 year old collection of Spiderman comics is not apt.

gman2k

Other helpful tips;
1. Rigid ducting is the way to go, but use flexi for the last metre or so and penetration down through your ceiling. Insist on your fitters letting the flexi hang 150mm below finished ceiling level. so as you have enough to cut back when fitting t-pieces etc.
2. Place the main unit over a hallway/ bathroom in your attic space, to minimize sound transfer to bedrooms etc.
3. Create a 150mm plinth for your unit to sit on - from rigid insulation - dampens vibrations
4. Make sure you have an attic hatch large enough to get the unit in through.
5. Keep the unit near your attic hatch, so regular maintenance is easier - not disturbing other insulation etc. (position a light in your attic near by.
6. Visit a house that has it installed, and view what the pipework does to your attic!
7. Position the inlet and outlet pipes on opposite sides of the building.
8. Keep the inlet pipe away from chimneys and SVPs.
9. Plan riser shafts and positions before going too far - boxing out for risers in rooms is no fun!
10. fix timber grounds above plasterboard within ceiling space so as screwing in t-pieces is easy.
11. If you are planning stoves anywhere, or open fires, plan for more ventilation in these rooms.

selfbuildache

Big thanks to you all. There's loads to go on here and I'm sure as usual from this board, once I start, there'll be a thousand more links and articles to follow up! Cheers

gizmo555

sinnerboy wrote: »

1. That your ceiling inlet/outlets are fire rated

Finally got my retro-fit HRV system installed last week and got these. Added about 12% to the total cost, but I suppose it beats being burned alive . . .

It was apparently the first time my supplier had been asked to fit this - their standard spec is an intumescent collar on the duct behind the vent.

sinnerboy wrote: »

2. That the motor is linked to power down when your fire alarm activates

I asked their electrical guy about this but he said he couldn't do it. Now, I have the connection for a mains-powered smoke alarm adjacent to the HRV power supply (a standard 3 pin socket) in the attic. It has a single wire interlinking it with another alarm downstairs. Can you suggest a straightforward way to tap into this to also control the socket?

sinnerboy

Sorry - I'm no sparks . Google HRV + Galway for a company that do this as standard - they may help

cut and paste from their site

Can the system be connected to my fire alarm system?

Yes, as a safety feature we can connect your fire alarm system to the HRV unit. We will require a two core cable from the fire alarm panel to our unit. Our unit will cut out in the event of the alarm going off.

selfbuildache

use the SAP Appendix Q listing as your source of info....
http://www.sap-appendixq.org.uk/page.jsp?id=1

So, having priced a number of units from companies, I'm now trying to figure out the differences between products. (Apart from price!)
I've gone into the SAP appendix but I'm not sure I'm understanding how to use it correctly - do I take it that if a product is not named in the SAP appendix, I don't go near it?

It seems to rate as one of the highest on effieiency and fan power on the sap index.

How do you work that out? I inputted details from one well known product and all it came back with was that it was there in the first place.
Is there some simpler way of comparing products and their performance etc? What am I not seeing here??
(Glad it's anon here - am feeling a bit stupid!)

sinnerboy

http://www.sap-appendixq.org.uk/searchresults.jsp?parentID=1&categoryID=3&bestPracticeCompliantID=&companyID=&brandID=&productSearch=&performance1ID=&performance2ID=&performance3ID=&Submit=Search

note

specific fan powers ( lower is better ) and
Heat exchange efficiency: ( higher is better )