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HRV and Cooker Hood

  • 29-07-2008 8:22pm
    #1
    Registered Users Posts: 103 ✭✭ Sparky78


    I intend to install a HRV in my new build but I dont know what the best approach for the cooker hood is.
    I've priced the hood that connects direct to the HRV but thats not a runner at 2500Euro+.
    Whats the best way of maintaining the air tightness of the house and installing a cooker hood?
    Thanks


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Comments

  • Closed Accounts Posts: 5,433 ✭✭✭ sinnerboy


    Shop around . Some systems can include them - others can't .


  • Closed Accounts Posts: 11 ✭✭✭ RJ75


    Use an extract charcoal filter cooker hood. if your installing whole house mechanical ventilation get a air tightness test done. on your build too! as obviously if your house is not air tight it will affect the efficiency of the HRV.

    main thing with HRV is there is a lot of cowboys about there and just love! Using waste pipe for ducting.

    Hmmm... maybe the forgot about flow rates in the ducting! and make sure they install silencers above the bedrooms and of course! Don’t place the unit over the bedroom of the person who signs the cheque ha..

    at the moment there is no guidelines on what type of ducting should be used in domestic but commercial there is. Try lindab ducting and make sure to insulate ducting too!

    Best of luck

    any other question just reply


  • Moderators, Home & Garden Moderators, Social & Fun Moderators Posts: 31,253 Mod ✭✭✭✭ dolanbaker


    I looked into running the extract hood into the HRV but the company didn't recommend it as it would clog up the heat exchanger.

    I tried the hood in recurculating mode last winter but it just fogged up the kitchen (the missuses idea of leaving lids off of the pans didn't help either :mad: ), so was forced into ducting to the outside wall.

    I intend to look for an automatic "duct valve" to close the duct when the extracter is not in use.


  • Closed Accounts Posts: 11 ✭✭✭ RJ75


    sorry new to the board and not used to some of the abbreviations.
    HHV means what??
    for starters if you are putting in whole house mechanical ventilation you want it designed right and a proper unit used. make sure it is on appendix Q
    otherwise the BER assessor with have to use the default valve of 66% for the HRV(heat recovery ventilation) in DEAP, hence will bring down your BER rating.
    make sure your house is air tight, draft lobby is recommended too. really u want the unit running max at 75% as if the unit is running at the max to get .5 air changes per hr it is using a lot of electricity. i know roughly its like having 2 light blubs on 24hrs a day. i would not have an air vent over the cooking air as all it will just get clogged up with grease etc. rule of thumb is put exhaust air vent over the sink in the kitchen. i have come across a new HRV unit, where when i quizzed them about having an injection supply feed by the open fire they said to use natural vent(hole in the wall) by the fire place! yes.. and open it when fire on and close it when fire is off! hmmm...i wont say any more!
    if your getting HRV installed in your house also asked about what is the ducting material, some guys love waste pipe, so how can u control proper flow rates? when you having a standard size duct run through out the build??? hmmm....
    HRV really is new to this country and there is a lot of companies just lacking experience at the moment with it. but if your handing over 5-6k for this you want it done right and no in bed at night and listening to a humming noise from the unit if not installed right or located in proper area of the attic as a lot of this units, not all though are located in the attic plus air flow noise from the air vent! thats why silencers are recommended in the bedrooms.


  • Closed Accounts Posts: 162 ✭✭ badolepuddytat


    RJ75 wrote: »
    i would not have an air vent over the cooking air as all it will just get clogged up with grease etc. rule of thumb is put exhaust air vent over the sink in the kitchen.

    i have come across a new HRV unit, where when i quizzed them about having an injection supply feed by the open fire they said to use natural vent(hole in the wall) by the fire place! yes.. and open it when fire on and close it when fire is off! hmmm...i wont say any more!

    A prev. poster reccomended putting a charcoal filter and then into HRV. That is the way to do it. If you dump it out you will dump the guts of a kwh out for every meal.... 2 or three on a sunday!

    Open fires/ stoves: We had an external air supply for ours (built in the early 70's) under the grate, there was very little draught and decreased the dreaded increased air changes. you'll change from a chimney to a flue in deap if you do this. If you had an internal boiler without a balanced flue , you'd think that strange! why not with an open fire!

    If i was Building.... I'd have the air Ducted in, flued out, through a high efficiency enclosed stove....


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  • Registered Users Posts: 13,313 ✭✭✭✭ AckwelFoley


    Sparky78 wrote: »
    I intend to install a HRV in my new build but I dont know what the best approach for the cooker hood is.
    I've priced the hood that connects direct to the HRV but thats not a runner at 2500Euro+.
    Whats the best way of maintaining the air tightness of the house and installing a cooker hood?
    Thanks

    As far as i know there is only one company that offers a purpose built cooker hood that connects directly into the HRV. Its an ITHO unit and its number 1 on the DEAP list and apendix q approved.

    You can buy a hood for probably 450 euros upwards.


  • Closed Accounts Posts: 11 ✭✭✭ RJ75


    HRU ECO 4
    yes.. its on appendix Q
    but remember as for DEAP you will not get an A rated house with HRV you will with solar. HRV is for comfort in your home. since
    HRU ECO 4 is on appedix Q you dont have to use the default valves in DEAP for mechanical ventialtion.only bad thing about Itho is it is for smaller houses as for bigger houses you will need 2 of them. i think its suits a house of air volume of 325m3 (cant remember off the top of my head)


  • Registered Users Posts: 13,313 ✭✭✭✭ AckwelFoley


    RJ75 wrote: »
    HRU ECO 4
    yes.. its on appendix Q
    but remember as for DEAP you will not get an A rated house with HRV you will with solar. HRV is for comfort in your home. since
    HRU ECO 4 is on appedix Q you dont have to use the default valves in DEAP for mechanical ventialtion.only bad thing about Itho is it is for smaller houses as for bigger houses you will need 2 of them. i think its suits a house of air volume of 325m3 (cant remember off the top of my head)

    Yes, that is correct, however considering that the largest cost for hrv in a house is with the ducting, design and installation - the extra unit will cost u about 1500 + vat


  • Closed Accounts Posts: 11 ✭✭✭ RJ75


    true...
    itho use/recommend plastic rectangular ducting for they units(which is how they got on appedix Q tests using plastic ducting!!!! a lot of folks have they opinons on that)
    rectangular ducting is great for uk but as forn ireland when rooms are put everywhere spiral round duct i think i easier to use! there a lot of suppliers of there lindab been number 1 but expensive! then u have the duct wrap (insulation) for the ducting recommended 50mm in attic and 25 inside the build there about 60euro a roll. it does all add up!
    the unit is the cheaper part! installation is easy! the ducting is like lego set!
    do a deal with the supplier and get one of there guys for a day then do the rest yourself!
    as for design! make sure it is design right! make sure the unit is sized right! for the build you want the unit only running at about 75% and then ducting sized to flowrates etc. you want silencers put in too in the sleeping areas and unit located away from the sleeping area.you want proper ducting drawings layout etc.
    i could go on.. but any good supplier should know of these!
    HRV is new to the market here and there are alot of cowboys out there!
    as well if your going with HRV make sure your house is air tight!
    get a air tight test done...
    HRV should be incoprated in the build form design stage, not when the house is nearly finished! false ceilings are ideal for duct runs otherwise bulk heads.


  • Registered Users Posts: 13,313 ✭✭✭✭ AckwelFoley


    U know ur duct and i agree. Lindab is better it has a double seal joint.. But what i say is to people.. If u are not prepared to get hrv done rite, dont waste ur money, buy a nice sofa!
    Im some salesman!


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  • Closed Accounts Posts: 16 ✭✭✭ daveoc16


    Hi Guys,

    About to start new build (bungalow 2500sqft with stairs - option to convert attic later).
    I've got a couple of quotes for: Air to Water Heat Pump/UFH and HRV.
    I'm fairly sure i'll go with the ASHP and UFH but not so sure about the HRV.
    My builder says he does the tape seal around the windows and doors for airtightness. Also i'm putting in a 150mm pumped cavity wall with 50mm insulated slab on inner leaf plus 50mm slab on ceiling with attic insulated as well.
    Question is: is this good enough for airtightness with regard getting a HRV unit or am i better off just getting vented windows?
    Any other suggestions gratefully recieved.....!!


  • Registered Users Posts: 5,294 ✭✭✭ Pete_Cavan


    daveoc16 wrote: »
    Hi Guys,

    About to start new build (bungalow 2500sqft with stairs - option to convert attic later).
    I've got a couple of quotes for: Air to Water Heat Pump/UFH and HRV.
    I'm fairly sure i'll go with the ASHP and UFH but not so sure about the HRV.
    My builder says he does the tape seal around the windows and doors for airtightness. Also i'm putting in a 150mm pumped cavity wall with 50mm insulated slab on inner leaf plus 50mm slab on ceiling with attic insulated as well.
    Question is: is this good enough for airtightness with regard getting a HRV unit or am i better off just getting vented windows?
    Any other suggestions gratefully recieved.....!!

    Im no expert and cant tell you if thats good enough for airtightness but my own opinion is why bother going for 100% airtightness and HRV? You spend a fourtune on the system and sealing the house just for you to open a window when it gets too warm. My own opinion (and thats all it is, my opinion) is that HRV is not worth it, spending so much time, effort and money sealing up the entire house for it all to be undone everytime you walk out of the house! I think the best thing you can do is to go to reasonable lengths to seal the house and you seem to be doing that anyway.

    As for the air to water heat pump, we have one in our house and I gave my opinons on it on another thread heres the link http://www.boards.ie/vbulletin/showthread.php?p=66942061#post66942061 (post #6). Hope that helps you.


  • Closed Accounts Posts: 16 ✭✭✭ daveoc16


    Hi Pete,
    Thanks for the reply. I see your point believe me, I'm struggling with both sides of the argument regarding HRV. The main advantage i see is that it provides (or is supposed to provide) cleaner healthier air for the people to breath inside the house, especially at night. Also i've been told helps prevent mildue and dust mites.
    I have also been to well insulated new homes with vented windows and they are happy out with their lot!
    The company i'm looking at to install the heat pump are willing to give a good discount if i also go with HRV as a complete package.

    As for the heat pump, I've looked at your other post. Very interesting. I'll send you reply/PM on this......
    Thanks again.


  • Registered Users Posts: 379 ✭✭ JuniorB


    The advantages of HRV are wide and varied and well documented on this forum. You spend a lot of time, effort and expense sealing your house so when you heat it the heat actually stays in the house. The heat lose from opening a door is minimal in comparison to an unsealed house that has air leaks all over the place and loses heat 24/7. To mimimise this issue you can have a draft lobby. Overall the cost of heating you house 'should' be reduced.
    And of course the main reason for HRV is that you 'should' get decent quality fresh air in the house, no dust mits, flys, etc etc

    All personal opinion of course!


  • Closed Accounts Posts: 16 ✭✭✭ daveoc16


    JuniorB wrote: »
    The advantages of HRV are wide and varied and well documented on this forum. You spend a lot of time, effort and expense sealing your house so when you heat it the heat actually stays in the house. The heat lose from opening a door is minimal in comparison to an unsealed house that has air leaks all over the place and loses heat 24/7. To mimimise this issue you can have a draft lobby. Overall the cost of heating you house 'should' be reduced.
    And of course the main reason for HRV is that you 'should' get decent quality fresh air in the house, no dust mits, flys, etc etc

    All personal opinion of course!
    I like the way you say 'should'. I suppose it all depends on the quality of the build/builder at the end of the day. I would imagine that any newly built house now-a-days should be of fairly good airtightness......unless the builder is a real cowboy.
    Also, on this forum regarding HRV opinion seems to be split IMO. I see here, and have spoken to many, who think HRV is a waste of money for use in an Irish climate which is relatively consistent and mild compared to very harsh Scandanavian winters where outside temp would be extremely low. On the other hand the others seem to think its worth it for the better air quality alone. I guess the debate will roll on until time passes and a true assesment can be made......
    If i have the cash I probably will go with it. Thanks for the replies.

    Air to Water Heat pump - now there's another debate.:):):)


  • Registered Users Posts: 551 Viking House


    Hi I'm back!

    Regarding HRV and the Cooker Hood; I would use a charcoal filter to remove the grease and then send the heat back into the kitchen. The air should be dry enough in winter in a house with HRV to take the extra moisture and you can leave a window open while you are cooking in summer.

    I live in a 1850's house with no extractor in the smallish kitchen, we don't have greasy walls and sometimes the windows fog up. Its not a big deal!

    I was lately working on an Electrostatic Precipitator to remove grease from cooking air before it went through a HRV unit but scrapped the project for the simple solution above.


  • Moderators, Regional North West Moderators Posts: 43,401 Mod ✭✭✭✭ muffler


    Hi I'm back!
    God help us :D


  • Registered Users Posts: 544 ✭✭✭ soldsold


    muffler wrote: »
    God help us :D

    For some reason a picture of Jack Nicholson with an axe and a crazy hairstyle just flashed in front of me...:D


  • Registered Users Posts: 558 ✭✭✭ beyondpassive


    soldsold wrote: »
    For some reason a picture of Jack Nicholson with an axe and a crazy hairstyle just flashed in front of me...:D

    Thats not an axe, its an 'Electrostatic Precipitator'.


  • Registered Users Posts: 30 ✭✭✭ newbie4


    Can any one tell me if ther is a manufacturer of the PVC heat recovery ducting in Ireland. Plenty of suppliers but are there any manufacturers ??


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  • Registered Users Posts: 111 ✭✭ Quack13


    Regarding HRV and cooker extraction - we toyed around with the idea of a charcoal filter for a while. In terms of maintaining airtightness etc this is definitely the best option.

    However after speaking with a couple of people who have used these type of extractors, they said they were not much use at all, and only really had negative things to say about them.

    After much deliberation we opted for the external dampener in the wall that would open when the cooker extractor is switched on and close when it is off. Similar system to what has been mentioned on here previously.

    I was not happy with comprising the airtightness like this, but after balancing out the pro's and con's of each option we decided to go down this route as the overall effect is minimal.

    BTW: we got a Steel dampener from a company in dublin. They do the plastic ones for €6 and steel ones for €47. I know it's a big difference price wise, but the steel one just seemed more robust and far better quality. They do them in various sizes.

    I'm not sure if I can mention the company on here? Can I?

    If not let me know and I can IM it to you...


  • Closed Accounts Posts: 2,948 gizmo555


    Quack13 wrote: »
    Regarding HRV and cooker extraction - we toyed around with the idea of a charcoal filter for a while. In terms of maintaining airtightness etc this is definitely the best option.

    However after speaking with a couple of people who have used these type of extractors, they said they were not much use at all, and only really had negative things to say about them.

    I've been using a recirculating cooker hood with charcoal filters in combination with HRV for almost two years now and I'm entirely satisfied with the results. What negative things had your acquaintances to say?

    In my experience, between the hood and the HRV itself, cooking smells are quickly dissipated. Even if you do fit a damper for when you're not cooking, it doesn't make sense to me to be taking the warm air generated when you are cooking and venting it straight out instead of passing it through the HRV.


  • Registered Users Posts: 111 ✭✭ Quack13


    I totally see what you're saying about removing the warm air alright, it seems a little nonsensical given we are building airtight houses that need to maximise the use of warm air.

    You are saying in your case that it does the job and that's great.
    If I was given a guarantee that it would have done a sufficient job then I would definitely have installed that system - 100%.

    A couple of people had told me that the charcoal filters were absolutely terrible at removing the smells, and as an extractor they were not much use. I didn't hear a whole lot of good things about them to be honest.

    In my own case after doing the research and weighing up the pros/cons of each we decided to go down the route I mentioned. It's working fine for us so far.


  • Registered Users Posts: 765 ✭✭✭ cuculainn


    gizmo555 wrote: »
    I've been using a recirculating cooker hood with charcoal filters in combination with HRV for almost two years now and I'm entirely satisfied with the results. What negative things had your acquaintances to say?

    In my experience, between the hood and the HRV itself, cooking smells are quickly dissipated. Even if you do fit a damper for when you're not cooking, it doesn't make sense to me to be taking the warm air generated when you are cooking and venting it straight out instead of passing it through the HRV.

    Hi Gizmo Can you PM me on the make and model of the hood you installed, we are getting close to this stage and I Have decided to go with the recirculating hood also.


    Thanks


  • Registered Users Posts: 3,911 ✭✭✭ creedp


    cuculainn wrote: »
    Hi Gizmo Can you PM me on the make and model of the hood you installed, we are getting close to this stage and I Have decided to go with the recirculating hood also.


    Thanks


    Gizmo I like a PM on your cooker hood's details also if you don't mind. Going down the same approach as you as given that I have a few insurmountable airtight problems such as unwrapped hollowcore I'd like to minimise all other sources of air leakage.

    Thanks


  • Closed Accounts Posts: 2,948 gizmo555


    Cuculainn, creedp, PMs sent, sorry about the delay in responding . . .


  • Registered Users Posts: 42 ✭✭✭ KG_SouthTipp


    Hi Gizmo, I would like a PM on your cooker hood's details also if you don't mind.

    I am building an airtight house and I have a fine big hole in for the extractor so I need to make a decision on where to block it or use it.

    Thanks alot,

    KG


  • Closed Accounts Posts: 2,948 gizmo555


    Hi Gizmo, I like a PM on your cooker hood's details also if you don't mind.

    PM sent . . .


  • Registered Users Posts: 254 ✭✭ Dozz


    Hi Gizmo.
    Sorry for hasseling you but i wonder if you could PM me the make and model of your cooker hood also?
    I am starting to do the airtightness end of my house and need to make a decision on this a.s.a.p.
    Cheers
    Dozz


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  • Closed Accounts Posts: 2,948 gizmo555


    Dozz wrote: »
    Sorry for hasseling you but i wonder if you could PM me the make and model of your cooker hood also?

    No hassle - PM sent


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