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Mvhr self build

  • 05-07-2019 7:35am
    #1
    Registered Users Posts: 95 ✭✭✭ Jcanty85


    Hi all,

    Just started building (3000sq ft 2 storey) and am looking into mvhr units. I'm just wondering what people's opinions are on the rigid branhed ductwork vs the semi rigid radial system. Also what experiences people have with various units and what to look out for. Hoping to install myself and get contractor to balance/certify as house layout is straight forward so in one hand the semi rigid system looks easier as long as I avoid sharp bends however I have read some previous posts about smaller diameter ducts being potentially noisy so that has me worried. Apologies if this is in the wrong section


Comments

  • Closed Accounts Posts: 3,364 ✭✭✭ rolion


    Hello,

    You are not in the wrong section but just using wrong title... is MHRV not MVHR ... ;)

    I did a project few years ago. More H E R E
    Nice ,challenging and best investment in the house (after water softner,accordign to my wife).

    What budget you have in mind, where you based ?

    Few learned points:

    Oversize the unit, if you need a 250 get a 350
    Get best unit out there,mine was the best 3 years ago,not sure these days.
    Use round plastic pipes,75mm or 90mm
    Use two manifolds for sound and distribution
    Use static fixed outlets ,dont go for variable.

    Read my posts and ask any questions,please.
    Ive upgraded the unit since then with sensors that shows me in realtime the status of the system,as below:

    484468.jpg

    484469.jpg

    484470.jpg

    484471.jpg


    484472.jpg

    Have fun...


  • Moderators, Home & Garden Moderators Posts: 10,101 Mod ✭✭✭✭ BryanF


    Jcanty85 wrote: »
    Hi all,

    Just started building (3000sq ft 2 storey) and am looking into mvhr units. I'm just wondering what people's opinions are on the rigid branhed ductwork vs the semi rigid radial system. Also what experiences people have with various units and what to look out for. Hoping to install myself and get contractor to balance/certify as house layout is straight forward so in one hand the semi rigid system looks easier as long as I avoid sharp bends however I have read some previous posts about smaller diameter ducts being potentially noisy so that has me worried. Apologies if this is in the wrong section

    Rigid ducting is the right thing to do.
    I’ve just finished install of 125mm, taped &/or sealed.


  • Registered Users Posts: 95 ✭✭✭ Jcanty85


    Thanks for the replies guys. The readout a look great rolion, was hoping for a similar setup myself budget depending. Do you get any noise with the smaller, semi flexible pipes?

    Bryan was it just to reduce the risk of noise that made you decide on the larger pipe? Do you get any cross talk?


  • Moderators, Home & Garden Moderators Posts: 10,101 Mod ✭✭✭✭ BryanF


    Jcanty85 wrote: »
    Thanks for the replies guys. The readout a look great rolion, was hoping for a similar setup myself budget depending. Do you get any noise with the smaller, semi flexible pipes?

    Bryan was it just to reduce the risk of noise that made you decide on the larger pipe? Do you get any cross talk?

    Not for mvhr, for MEV (existing house)


  • Closed Accounts Posts: 3,364 ✭✭✭ rolion


    I found that the square format is better for retrifitting due to small space available and the round one for empty shell installs where you can do it proper design.

    I dont have exposure to square, i found them too industrial type to me.
    The round one are antistatic and antibacteria treated from factory.I remember the smell when opened the roll.

    Re noise,my unit have very fine tweking of the speeds and comprehensive timers.
    Speeds, for both engines,individual per DC motor and for each sense / flow,ie highe rspeed to extract air from inside and slower to bring it from outisde (more warm air winter) or reverse for summer,to cooler faster.
    Timer,gives you 3 (three) levels set up at small digit,per minute and for every day of the week and up to 8 different time slots.

    Level 1 - no sound at all;
    Level 2 - sound-ish but acceptable,less than airplanes,motorway and the fcuking dogs barking 25 hours here from iresponsible neighbours;
    Level 3 - well,thats a sound that you can hear it across the house AND feel the air flow hit you in the face.

    I have two manifolds,one for each sense that kills the sound travelling across rooms and it has noise attenuation.
    Oversizing my unit from a 250 to 350 made it running efficient most of the time at level 2.

    Good luck...


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    484980.jpg


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  • Registered Users Posts: 95 ✭✭✭ Jcanty85


    Sorry if I missed it but I couldn see what diameter piping you ended up going with? Been doing as much reading up on it as possible as nervous about noise. Going to try to position everything to keep runs as straight as possible, noise reducers where needed etc but due to the length of the house I still will have approximately 8m of pipe either side of a central manifold.


  • Closed Accounts Posts: 3,364 ✭✭✭ rolion


    Jcanty85 wrote: »
    Sorry if I missed it but I couldn see what diameter piping you ended up going with? Been doing as much reading up on it as possible as nervous about noise. Going to try to position everything to keep runs as straight as possible, noise reducers where needed etc but due to the length of the house I still will have approximately 8m of pipe either side of a central manifold.

    There is no noise !!!
    And believe me...i am very sensitive to it...

    My unit on my setup:
    - at level 1 i cannot hear it;
    -at level 2 is there, i can hear it confirming is working but i really have to focus so that i can select individual frequencies and noise chanel bandwidth to confirm it. Most of the time, i hear it, i am happy is running and move on with my things. Night time,very very soft lullaby ! ;)
    -at level 3 i select to completely refresh the air inside the house,sometime in the morning or evey evening, just before going to bed after cooking, running and sweating/farting all of us around the rooms.

    Overlal,is an extra background noise but is acceptable up to level 2 inclusive.
    No one complain(s) in the house apout the noise. Not a chance...
    Only one i have is from a child that lives in a small bedroom and the flow oulet is above her bed,air "dropping" on her head.i had to adjust the flow vents direction.Now,she grew bigger and i can tell to shout her mouth ! :)


  • Registered Users Posts: 95 ✭✭✭ Jcanty85


    That's great as you hear some horror stories due to (I think) poor installation. Did you go for a 90mm radial pipe? did you get someone to design the system I.e position of vents etc? We have a lot of open space so might need an indication on best location


  • Registered Users Posts: 95 ✭✭✭ Jcanty85


    Also I meant to ask did you put in any additional controls other than the timers etc I.e. is there any switches to boost extraction when taking a shower for example??


  • Closed Accounts Posts: 3,364 ✭✭✭ rolion


    I did it fully DIY after reading tons of material online.
    Bought the equipment from a company based in Dungarvan (Stephen) and i appreciated the fact that they strictly were after quality and not quantity,even if i bought all materials and they got no margins on installation.
    Also,i was forced to do it after also i DIY external insulation my home and .. as a result of that, condensation & dirty air killed us for couple of weeks until got the HRV system.

    No controls yet part of the touch screen for the central unit and third party wireless sensors with dashboard.Now,keep in mind my unit is already 4 years old,guess what controls you cna have today,wireless and mobile phones and reporting, alerts and so on... leave that you to find and share here,back .

    Depending on the unit,you can get:
    -automatically shutdown in event of a fire (hmm,nice feature...)
    -increase 100% speed on the unit for manually triggered ,with a switch located beside the bath/ensuite, in case of humitiy in bathrooms / showers ( i chose just to open the window as we take tooooo many baths and showers )
    -option to do something with the kitchen hood,for smells but worried about contaminating the unit,manifolds and pipes (not sure here,i think is to do with balancing and ...dunno ... )
    -some sort of "sixth sense" where the central unit senses if any people in the room and adjust or off the vent in e ceiliing (my house is too small for it )

    Re location,VERY peculliar,some companies advised for two vents in each room,one in and one out,same room space..
    Chosen to go with only one vent, fixed not adjustable in every room.
    I located them above the window and above the radiator but i blocked 80 degrees of the vent (one slot of the four ) so that hot air comes up from the radiator but the vent take it and pushes up the ceilling,across the whole room ? Not sure you can visualise that...

    Not sure re diameter,i think mine was 75mm at the branches level ?
    There were red pipes and blue pipes.

    For cross_rooms noises , you will need very good manifolds !!!

    Good luck...


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  • Registered Users Posts: 229 ✭✭ P2C


    Installed 9 yrs ago. No real issues since it was installed. Round ducts in the attic and rectangular ducts in the void on the downstairs . Self installed took a bit of time but no issues. No noice from the ducts or machine but some noise from the vents. I am a light sleeper and the noice is background and soothing. Build airtight and ventilate right. Airtightness was as important.


  • Registered Users Posts: 95 ✭✭✭ Jcanty85


    Thanks, could you pm me the name of the company in dungarvan please??


  • Registered Users Posts: 95 ✭✭✭ Jcanty85


    P2C wrote: »
    Installed 9 yrs ago. No real issues since it was installed. Round ducts in the attic and rectangular ducts in the void on the downstairs . Self installed took a bit of time but no issues. No noice from the ducts or machine but some noise from the vents. I am a light sleeper and the noice is background and soothing. Build airtight and ventilate right. Airtightness was as important.

    Was this a branched system so? I.e all rooms fed off a central line as opposed to individual pipes?


  • Closed Accounts Posts: 3,364 ✭✭✭ rolion


    @OP
    one more thing... make sure the unit it has "summer by-pass" functionality !

    485368.jpg


  • Registered Users Posts: 204 ✭✭ spose


    In the process of retrofitting during extension. DIY fitted 75mm radial ducting. Rigid ducting woundnt have been an option for where I needed the pipes to run. Cost was biggest driver for DIY. Quotes I received were crazy so saving 3.5-4K by diy. Haven’t switched on the unit yet so can’t comment on any noise


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