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Can you retrofit a Heat Recovery Ventilation (HRV) system

  • 06-03-2019 11:05pm
    #1
    PaidV
    Registered Users Posts: 71 ✭✭


    Hi all, would appreciate some advice. We extensively renovated a bungalow a few years ago and I really regret not getting a HRV system, is it possible to retrofit or would I be wasting money?


«1

Comments

  • #2
    xl500
    Registered Users Posts: 863 ✭✭✭xl500


    PaidV wrote: »
    Hi all, would appreciate some advice. We extensively renovated a bungalow a few years ago and I really regret not getting a HRV system, is it possible to retrofit or would I be wasting money?

    You will get answers that they are best installed during renovations due to airtightness tests etc

    I retrofitted a system in my Home when I was upgrading insulation It is a 1960s Semi very poor BER I installed External Insulation closed up old external Vents and installed HRV now of course its not up to passive house standards but the HRV is Great always Fresh air no condensation in Bathrooms or Bedrooms I think they are a great addition to any house

    BER is now B3 which is great for a 1960s Cavity Block Semi


  • #3
    PaidV
    Registered Users Posts: 71 ✭✭PaidV


    Thanks for the reply. Mine is an early 1990s bungalow but we extensively renovated and its circa B1 now if memory serves me.
    Any thoughts on n air source heat pump with the HRV. I currently have oil central heating...


  • #4
    xl500
    Registered Users Posts: 863 ✭✭✭xl500


    PaidV wrote: »
    Thanks for the reply. Mine is an early 1990s bungalow but we extensively renovated and its circa B1 now if memory serves me.
    Any thoughts on n air source heat pump with the HRV. I currently have oil central heating...

    Sorry have no experience of Heat Pumps but with a B1 Rating it could take a very long time to return your investment with fuel savings, I presume your Heating Costs are Low with a B1 rating

    I would definitely go for a HRV though it's not just about saving money the internal atmosphere and comfort is so much better with one


  • #5
    Muahahaha
    Registered Users Posts: 19,609 ✭✭✭✭Muahahaha


    PaidV wrote: »
    Hi all, would appreciate some advice. We extensively renovated a bungalow a few years ago and I really regret not getting a HRV system, is it possible to retrofit or would I be wasting money?

    Looking into this myself and the answer for retrofits seems to be ductless heat recovery systems. By going ductless it avoids the need for extensive remedial work connecting ducts from every room to a unit in the attic. A 50sqm space would need two ventilation units and when set automatically one sucks and the other blows for a minute then they swap over function and so on.

    If you google around there are now a few single room MHRV units on the market at about €300-€400 a piece, these have two ducts inside them so you only need a single unit for a large room. Some versions have add on extras like touch screen controls where you can monitor temps, humidity, and it can control up to 12 units at a time. They can be installed by any competent DIYer.

    Will likely go down this route myself when other works are done, just for the kitchen/living room at first and then extend it later to other rooms. Seems to be a no-brainer going ductless for an older building, likely works out cheaper too.


  • #6
    H.E. Pennypacker
    Closed Accounts Posts: 844 ✭✭✭H.E. Pennypacker


    Muahahaha wrote: »

    Will likely go down this route myself when other works are done, just for the kitchen/living room at first and then extend it later to other rooms. Seems to be a no-brainer going ductless for an older building, likely works out cheaper too.


    Are you thinking of Demand Controlled Ventilation? Will you not have to run wiring to each unit? I had considered this as an option but when I costed it for the entire house, MHRV was cheaper and less work overall (in a bungalow)


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  • #7
    Muahahaha
    Registered Users Posts: 19,609 ✭✭✭✭Muahahaha


    H.E. Pennypacker wrote: »
    Are you thinking of Demand Controlled Ventilation? Will you not have to run wiring to each unit? I had considered this as an option but when I costed it for the entire house, MHRV was cheaper and less work overall (in a bungalow)

    Yeah Id imagine installing MHRV in a bungalow with lots of attic space is a lot less hassle than a 2 or 3 storey.

    Wasnt thinking DCV but had looked at it last year, specifically ductless DCV as my house would need a lot of work to run ducts. But DCV only changes the air, it doesnt heat it so I ruled it out.

    But since then there are new units after coming onto the market that provide MHRV but through a single unit attached to the inner wall and ducted directly outside. The unit has two ducts inside it and some sort of device that takes the heat from the extracted air and puts it into the intake air. They say each unit covers about 50sqm so an average 3 bed semi could have one unit downstairs and one up. Units are approx €1000 a piece so not cheap but as they seem to be new I'm hoping prices come down and more competition to enter the market. I havent seen any reviews of them yet but one attraction seems to be very low running costs (about 5w per hour) and not having the need to clean out ducts.


  • #8
    derekbro
    Registered Users Posts: 152 ✭✭derekbro


    Muahahaha wrote: »
    Yeah Id imagine installing MHRV in a bungalow with lots of attic space is a lot less hassle than a 2 or 3 storey.

    Wasnt thinking DCV but had looked at it last year, specifically ductless DCV as my house would need a lot of work to run ducts. But DCV only changes the air, it doesnt heat it so I ruled it out.

    But since then there are new units after coming onto the market that provide MHRV but through a single unit attached to the inner wall and ducted directly outside. The unit has two ducts inside it and some sort of device that takes the heat from the extracted air and puts it into the intake air. They say each unit covers about 50sqm so an average 3 bed semi could have one unit downstairs and one up. Units are approx €1000 a piece so not cheap but as they seem to be new I'm hoping prices come down and more competition to enter the market. I havent seen any reviews of them yet but one attraction seems to be very low running costs (about 5w per hour) and not having the need to clean out ducts.

    Is it something like this https://www.amazon.co.uk/gp/product/B004VW3RGW
    Are they any good? Thinking about a couple of them for my place.


  • #9
    0lddog
    Registered Users Posts: 3,292 ✭✭✭0lddog


    derekbro wrote: »
    Is it something like this https://www.amazon.co.uk/gp/product/B004VW3RGW
    Are they any good? Thinking about a couple of them for my place.


    Any views on putting one of these in a blocked up fireplace and installing a flexible duct up the chimney for the fresh air ( or maybe stale air.....? ) ?


  • #10
    Muahahaha
    Registered Users Posts: 19,609 ✭✭✭✭Muahahaha


    derekbro wrote: »
    Is it something like this https://www.amazon.co.uk/gp/product/B004VW3RGW
    Are they any good? Thinking about a couple of them for my place.

    Cant comment if they are any good as I havent sorted ventilation yet. Mitsubishi do single unit MHRVs but the ones I'm hoping will drop in price somewhat is the Lunos e2. There are other options on the market but the Lunos seems to get decent reviews. However Im not seeing much that can be controlled via an app and synced with smart home devices like Google Home and Alexa. I would want features where you can set the target temperature/humidity of the unit and control it remotely. I think the market for these units is new enough so we are not yet seeing full features.

    I wont be purchasing for at least another 6-9 months anyway so would expect more options on the market then, especially as ducting a house is quite expensive in a retrofit situation so these single units seem to be a good way of getting MHRV without the need for it.


  • #11
    metricspaces
    Registered Users Posts: 793 ✭✭✭metricspaces


    Muahahaha wrote: »
    Yeah Id imagine installing MHRV in a bungalow with lots of attic space is a lot less hassle than a 2 or 3 storey.

    Wasnt thinking DCV but had looked at it last year, specifically ductless DCV as my house would need a lot of work to run ducts. But DCV only changes the air, it doesnt heat it so I ruled it out.

    But since then there are new units after coming onto the market that provide MHRV but through a single unit attached to the inner wall and ducted directly outside. The unit has two ducts inside it and some sort of device that takes the heat from the extracted air and puts it into the intake air. They say each unit covers about 50sqm so an average 3 bed semi could have one unit downstairs and one up. Units are approx €1000 a piece so not cheap but as they seem to be new I'm hoping prices come down and more competition to enter the market. I havent seen any reviews of them yet but one attraction seems to be very low running costs (about 5w per hour) and not having the need to clean out ducts.

    I think this is the product you are describing? http://www.lunos.ie/product-details.php?ID=252


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  • #12
    Muahahaha
    Registered Users Posts: 19,609 ✭✭✭✭Muahahaha


    metric that link isnt working for me. But yes you are right, the company is Lunos and the product Im thinking of going for is the Lunos eGo which only requires one unit at the fans work both intake and exhaust air. As said Im not undertaking it for a good few more months so hope to see some reviews in the mean time on this Amazon listing https://www.amazon.co.uk/Decentral-Ventilation-Recovery-Dezentrales-Lraumbel/dp/B01080T0HA/ref=sr_1_1?keywords=lunos+ego&qid=1562191205&s=gateway&sr=8-1


  • #13
    Blowheads
    Registered Users Posts: 429 ✭✭Blowheads


    Hi,
    Lot of installers fear the word retrofit. We did it in a 2 story house 3 years ago, great job. Bungalow should be easy to run the ducts to all the rooms. We ran ours downstairs through cloakroom. Obviously needs good other insulation, windows and doors etc. Mitsubishi system


  • #14
    randombar
    Registered Users Posts: 3,360 ✭✭✭randombar


    What kind of prices are people looking at for a retrofit to a two story. Reckon the ducting would be ok going through wardrobes and the likes.


  • #15
    Blowheads
    Registered Users Posts: 429 ✭✭Blowheads


    GaryCocs wrote: »
    What kind of prices are people looking at for a retrofit to a two story. Reckon the ducting would be ok going through wardrobes and the likes.

    Depends on how many rooms etc and what part of the country you're in. Think 3.5k as a ballpark


  • #16
    randombar
    Registered Users Posts: 3,360 ✭✭✭randombar


    Blowheads wrote: »
    Depends on how many rooms etc and what part of the country you're in. Think 3.5k as a ballpark

    Cork 4 beds, 3 baths upstairs, 5 rooms and a bath downstairs.

    3.5k isn’t bad.

    House is well insulated. It’s just windows open in winter to get fresh air in drives me mad.

    Would be hard to calculate Roi on it id say.


  • #17
    Blowheads
    Registered Users Posts: 429 ✭✭Blowheads


    GaryCocs wrote: »
    Cork 4 beds, 3 baths upstairs, 5 rooms and a bath downstairs.

    3.5k isn’t bad.

    House is well insulated. It’s just windows open in winter to get fresh air in drives me mad.

    Would be hard to calculate Roi on it id say.

    Something similar as ourselves so. Check your runs and how you can get to the rooms downstairs. Maybe not possible to get to them all like utility or conservatory but then again no need to get all just for the sake of it.

    We ducted the hot press as the warm room (typically the kitchen) as well as the bathrooms and the kitchen. We also did it in 2 stages, upstairs first and then downstairs.

    Sealed up all the vents in the rooms and windows. Get a few quotes as there can be big difference in prices and buy a system a little larger than you actually need so you can run it at half speed as opposed to a smaller system at full speed


  • #18
    randombar
    Registered Users Posts: 3,360 ✭✭✭randombar


    Blowheads wrote: »
    Something similar as ourselves so. Check your runs and how you can get to the rooms downstairs. Maybe not possible to get to them all like utility or conservatory but then again no need to get all just for the sake of it.

    We ducted the hot press as the warm room (typically the kitchen) as well as the bathrooms and the kitchen. We also did it in 2 stages, upstairs first and then downstairs.

    Sealed up all the vents in the rooms and windows. Get a few quotes as there can be big difference in prices and buy a system a little larger than you actually need so you can run it at half speed as opposed to a smaller system at full speed

    I reckon I'd be able to do a bit of it myself, once I got a couple of rooms done and the house was sorted out for air tightness.

    Thanks for the info.


  • #19
    Markcheese
    Registered Users Posts: 8,428 ✭✭✭Markcheese


    Do people keep their regular cooker hood extractor fan(or is it considered a no no, cos I've seen several recirculating/filtration ones and they're brutal...

    Slava ukraini 🇺🇦



  • #20
    FlipperThePriest
    Subscribers Posts: 684 ✭✭✭FlipperThePriest


    This is something I've been thinking about of late. Currently upgrading attic insulation. Next step will be upgrade the oil boiler and heating controls... then hopefully mhrv. Bungalow, fairly airtight for the age.

    https://www.bpcventilation.com/vent-axia-kinetic-bh-kit

    Has anyone ever used anything like the above? Is it doable diy? Or would you be better off going for a reputable supplier / installer? For example the above with ducting for 6 rooms would probably cost about €2k for my place.


  • #21
    randombar
    Registered Users Posts: 3,360 ✭✭✭randombar


    zippy84 wrote: »
    This is something I've been thinking about of late. Currently upgrading attic insulation. Next step will be upgrade the oil boiler and heating controls... then hopefully mhrv. Bungalow, fairly airtight for the age.

    https://www.bpcventilation.com/vent-axia-kinetic-bh-kit

    Has anyone ever used anything like the above? Is it doable diy? Or would you be better off going for a reputable supplier / installer? For example the above with ducting for 6 rooms would probably cost about €2k for my place.

    There's a thread on here about someone doing themselves. The actual work is ok I'd say it's more about testing for air tightness that I think you'd need someone for. i.e. Could install the system but it might run very poorly if the air tightness isn't done.

    Also might be better to do this before attic installation if you are getting it done. Access etc.


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  • #22
    Muahahaha
    Registered Users Posts: 19,609 ✭✭✭✭Muahahaha


    Markcheese wrote: »
    Do people keep their regular cooker hood extractor fan(or is it considered a no no, cos I've seen several recirculating/filtration ones and they're brutal...

    Not sure if it is a no no, I think some modern extraction units can have a baffle in them that only allows the air to go one way. Definitely try to avoid recirculating ones, they are next to useless if you do any cooking that involves high heat and lots of smoke. Did a renovation myself recently and after years of smokey kitchens in rentals I completely over specced the extraction unit to solve this problem, the thing sounds like a wind tunnel and is noisy when operating but no more smokey kitchens after cooking a steak or a stir fry in a wok.


  • #23
    randombar
    Registered Users Posts: 3,360 ✭✭✭randombar


    Any recommendations of people to talk to in Cork about this?


  • #24
    FlipperThePriest
    Subscribers Posts: 684 ✭✭✭FlipperThePriest


    GaryCocs wrote: »
    There's a thread on here about someone doing themselves. The actual work is ok I'd say it's more about testing for air tightness that I think you'd need someone for. i.e. Could install the system but it might run very poorly if the air tightness isn't done.

    Also might be better to do this before attic installation if you are getting it done. Access etc.

    I've spoken to guys who say if your house is tight enough that you need to open windows for condensation etc, then it's tight enough to benefit from mhrv. I spoke with a guy in BPC ventilation just a short while after my last post, he said they encourage DIY installs, 2 out of 3 of their sales are DIY, they will commission the install to make sure everything's as it should be.

    I agree re. attic insulation, but it's unfortunately not going to happen. I'm really only adding a layer to what's already there anyway, but yes, access won't be as good.
    Markcheese wrote: »
    Do people keep their regular cooker hood extractor fan(or is it considered a no no, cos I've seen several recirculating/filtration ones and they're brutal...

    I believe you'd replace your cooker hood with a recirculating hood... yes on its own it might not be great, but once you've the mhrv installed, all it's really doing is filtering out grease and oil over the cooker and recirculating to allow the mhrv do the venting.


  • #25
    randombar
    Registered Users Posts: 3,360 ✭✭✭randombar


    Found the old thread.

    https://www.boards.ie/vbulletin//showthread.php?t=2057496673

    Any recommendations for installers in Cork? If I'm doing this I would try and do the ducting myself and get an installer to commission.

    I might need them at the start to show me where to put things though.


  • #26
    Shefwedfan
    Closed Accounts Posts: 18,958 ✭✭✭✭Shefwedfan


    I have been thinking about this for a while....think it is best option. Live in bungalow so easy access to all rooms etc

    Anyone know companies that are doing this? self install I dont think will work.....


  • #27
    randombar
    Registered Users Posts: 3,360 ✭✭✭randombar


    Shefwedfan wrote: »
    I have been thinking about this for a while....think it is best option. Live in bungalow so easy access to all rooms etc

    Anyone know companies that are doing this? self install I dont think will work.....

    Go for it!!! We'll get a good deal :D


  • #28
    Shefwedfan
    Closed Accounts Posts: 18,958 ✭✭✭✭Shefwedfan


    GaryCocs wrote: »
    Go for it!!! We'll get a good deal :D


    Im already looking at quotes



    Also found a quote from UK company that ship direct.....:-) I forgot I asked for it


  • #29
    P2C
    Registered Users Posts: 251 ✭✭P2C


    I installed my own mhrv although not a retrofit. I can’t see any issue why not into a bungalow as long as you have attic space that can house the unit and insulated ducting. In a two story as long as you can hide or box in the ducts why not. The biggest hassle would be cutting the plasterboard but that’s not difficult. I would get a blower door test done first to asses if the house is airtight enough as manufacturers have specs


  • #30
    Shefwedfan
    Closed Accounts Posts: 18,958 ✭✭✭✭Shefwedfan


    P2C wrote: »
    I installed my own mhrv although not a retrofit. I can’t see any issue why not into a bungalow as long as you have attic space that can house the unit and insulated ducting. In a two story as long as you can hide or box in the ducts why not. The biggest hassle would be cutting the plasterboard but that’s not difficult. I would get a blower door test done first to asses if the house is airtight enough as manufacturers have specs




    Attic is huge.....just dont have the balls to take on installation solo :p


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  • #31
    randombar
    Registered Users Posts: 3,360 ✭✭✭randombar


    Shefwedfan wrote: »
    Im already looking at quotes



    Also found a quote from UK company that ship direct.....:-) I forgot I asked for it


    How much were they looking for.

    Anyone any recommendations for a blower test?

    Thinking a uv/escaping heat one would be good too.


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