Replacing MHRV unit

FarmingApps · 13-05-2021 5:58pm #1

Hi Everyone,

I’m currently shopping for a replacement MHRV unit for my ProAir 600 (2009 Model) which has failed.

My house is 220M3 with 2.65M ceilings, 4 Shower/Bathroom/WCs and kitchen.

The current unit has a press and release switch to trigger the boost at each wet room.

I would like a unit which has a full summer bypass which the ProAir unit does not have.

Looking for recommendations for units.

This will be a DIY replacement.

Cheers
FA

keno-daytrader · 14-05-2021 1:15pm

VENT AXIA SENTINEL KINETIC ADVANCE S

This is the unit we have, diy installation was very simple.

Extremely happy with the unit, especially the summer bypass!

Its bizarre that a company these days would sell a MVHR without summer bypass, the company that I originally wanted quoted me an extra 600 for summer bypass. (this was only last year)

Delighted we didnt go with them, we would have roasted in the summer.

FarmingApps · 14-05-2021 9:25pm

Current unit without bypass was installed in 2010

Thanks for the recommendation. I'll check it out.

Did you buy local or overseas?

spose · 15-05-2021 4:33pm

Did diy with vent axia as well and very easy. Can connect your boost switches but you won’t need them. The unit ramps up as it detects the increased humidity anyway. I like not needing to boost it, the summer bypass and it has a setting that reduces the fan speed during the night to reduce any noise from the unit

DM1983 · 15-05-2021 4:44pm

Hi folks, we're in the middle of a major renovation and have just upped the budget to replace all windows and doors and also internal insulation throughout. Are we mad to not include the MHRV system at the same time? Builder didn't seem too keen on it. 200m2 floor area - anyone hazard a guess on cost?

FarmingApps · 15-05-2021 8:55pm

It all depends on your level of airtightness.

If the house will have good airtightness after renovation then go for it.

Best things I ever spend money on where extra underfloor insulation and triple glazing.

It would be much cheaper and easier to run the ducts now while you're renovating than at some point down the road.

Don't mind the builder, it's your house and money. It's not like he'll be doing it for free

FarmingApps · 15-05-2021 9:04pm

I’m liking the look of these two units.

Vent Axia Kinetic High Flow 630m3/hr

and

Blauberg Komfort LB400 580m3/hr

I want to be able to run at 30-40% capacity to keep it quite.

The Blauberg suits my current pipe layout better and has wifi but not a lot of feedback and user info out there.

The Vent Axia has higher airflow is very popular and has cheaper and easier to obtain filters.

The Vent Axia is about 200 euro dearer.

Hmmm decisions.

spose · 16-05-2021 3:51pm

DM1983 wrote: »

Hi folks, we're in the middle of a major renovation and have just upped the budget to replace all windows and doors and also internal insulation throughout. Are we mad to not include the MHRV system at the same time? Builder didn't seem too keen on it. 200m2 floor area - anyone hazard a guess on cost?

I think it’s a must have. If you’re going to end up with a fairly well insulated house then what else are you going to use to meet your ventilation requirements

MicktheMan · 16-05-2021 7:17pm

spose wrote: »

I think it’s a must have. If you’re going to end up with a fairly well insulated house then what else are you going to use to meet your ventilation requirements

The OP doesn't mention airtightness and the builder isn't keen on a ventilation system.....

It really all depends on the airtightness target and what is achieved, imo. It would not be unusual to have a "very well insulated" house that is still losing a significant amount of heat through a lack of airtightness.

MicktheMan · 16-05-2021 7:18pm

DM1983 wrote: »

Hi folks, we're in the middle of a major renovation and have just upped the budget to replace all windows and doors and also internal insulation throughout. Are we mad to not include the MHRV system at the same time? Builder didn't seem too keen on it. 200m2 floor area - anyone hazard a guess on cost?

Airtightness target?

Water John · 16-05-2021 7:46pm

That might indicate why the builder isn't keen. An air tightness test might be carried out.

spose · 16-05-2021 11:19pm

I retrofitted to a house that wouldnt count as anything near airtight but would be reasonably well insulated and I would never go without it again. Huge improvement in the air quality in the house. Lower humidity in the house means no chance of mould in bathrooms, no more condensation on the inside of windows, better heat distribution around the house from the likes of the stove lighting or the sun heating up one side of the house. What’s the alternative...core a hole in the wall, window vents?

DM1983 · 17-05-2021 7:31am

The plan was old school passive ventilation! Wall vents everywhere and open a window in the bathroom for bath and shower. I'll now arrange an airtightness test or at least get professional advice on this. With all new windows and doors being installed, I think (wrongly?) that this should just leave upstairs ceiling/attic losses? Will investigate.

Is there any guidance on the level of airtightness below which MHRV is not advised?

keno-daytrader · 17-05-2021 2:12pm

FarmingApps wrote: »

I’m liking the look of these two units.

Vent Axia Kinetic High Flow 630m3/hr

and

Blauberg Komfort LB400 580m3/hr

I want to be able to run at 30-40% capacity to keep it quite.

The Blauberg suits my current pipe layout better and has wifi but not a lot of feedback and user info out there.

The Vent Axia has higher airflow is very popular and has cheaper and easier to obtain filters.

The Vent Axia is about 200 euro dearer.

Hmmm decisions.

Sent ya a pm about the vendor we used, extremely happy with them.

Our house is around 215m2 and we run our unit at 20/23% in normal mode and all vents are totally quite.

MicktheMan · 17-05-2021 10:47pm

DM1983 wrote: »

1. With all new windows and doors being installed, I think (wrongly?) that this should just leave upstairs ceiling/attic losses? Will investigate.

2. Is there any guidance on the level of airtightness below which MHRV is not advised?

1. Eh, a bit more to it than that. A proper survey / air tightness test will set you on your way.

2. Yes, IME, an air tightness result below 5 m3/hr/m2@50Pa would necessitate a MV solution such as MEV and below 3 would be needed for the HR piece of the MVHR to be efficient.

homewardbound11 · 17-05-2021 10:55pm

FarmingApps wrote: »

Hi Everyone,

I’m currently shopping for a replacement MHRV unit for my ProAir 600 (2009 Model) which has failed.

My house is 220M3 with 2.65M ceilings, 4 Shower/Bathroom/WCs and kitchen.

The current unit has a press and release switch to trigger the boost at each wet room.

I would like a unit which has a full summer bypass which the ProAir unit does not have.

Looking for recommendations for units.

This will be a DIY replacement.

Cheers
FA

Have you gone to proair . I know that they were looking to upgrade my unit 2 years ago . It was expensive so I didn’t need it at the time.
What has failed? Mine is in since 2011. Still going but wonder for how much longer ?

DM1983 · 18-05-2021 7:18am

MicktheMan wrote: »

1. Eh, a bit more to it than that. A proper survey / air tightness test will set you on your way.

2. Yes, IME, an air tightness result below 5 m3/hr/m2@50Pa would necessitate a MV solution such as MEV and below 3 would be needed for the HR piece of the MVHR to be efficient.

Apologies, for the thread derailing here but last question. The house looks like a building site at present so obviously can't do an airtightness test yet but surely now is the time to run all the ducting etc. while block work is exposed? What am I missing? Have a guy calling out on Thursday to go through everything with me anyway.

keno-daytrader · 18-05-2021 1:10pm

DM1983 wrote: »

Apologies, for the thread derailing here but last question. The house looks like a building site at present so obviously can't do an airtightness test yet but surely now is the time to run all the ducting etc. while block work is exposed? What am I missing? Have a guy calling out on Thursday to go through everything with me anyway.

Probably would be better to explain whats going on in the house. if its a major renovation, what are the provisions for making all the new windows airtight and is he knocking out walls also?

If your builder isnt making them airtight, then there are serious red flags in this day and age.

if your house is gutted then now is the time to put in ducting for mvhr and question the builder on aspects of how he intends to make things airtight.

Some builders are stuck in 2008 and dont want to hear anything about new regs or airtightness, or anything new for that matter.

DM1983 · 18-05-2021 1:26pm

keno-daytrader wrote: »

Probably would be better to explain whats going on in the house. if its a major renovation, what are the provisions for making all the new windows airtight and is he knocking out walls also?

If your builder isnt making them airtight, then there are serious red flags in this day and age.

if your house is gutted then now is the time to put in ducting for mvhr and question the builder on aspects of how he intends to make things airtight.

Some builders are stuck in 2008 and dont want to hear anything about new regs or airtightness, or anything new for that matter.

OK so I think he mentioned airtight tape around all the doors and windows. I haven't drilled into this at all. Will discuss details with the ventilation people on Thursday. I just found out that we are falling under those new Part L regs for major renovation so BER will have to come up to B2 anyway. I'm now thinking I won't have any choice on the MHRV and will just have to suck it up.

listermint · 18-05-2021 1:46pm

DM1983 wrote: »

OK so I think he mentioned airtight tape around all the doors and windows. I haven't drilled into this at all. Will discuss details with the ventilation people on Thursday. I just found out that we are falling under those new Part L regs for major renovation so BER will have to come up to B2 anyway. I'm now thinking I won't have any choice on the MHRV and will just have to suck it up.

Make sure then air tightness is coming into all conversations then now. It's actually small money when considered at this point..you don't have to go for passive. But common sense applications of tape correctly applied..paint in some cases and an eye on holes in walls properly filled in like chasing and through holes sealed up

keno-daytrader · 18-05-2021 2:33pm

DM1983 wrote: »

OK so I think he mentioned airtight tape around all the doors and windows. I haven't drilled into this at all. Will discuss details with the ventilation people on Thursday. I just found out that we are falling under those new Part L regs for major renovation so BER will have to come up to B2 anyway. I'm now thinking I won't have any choice on the MHRV and will just have to suck it up.

If you can get the house relatively airtight you will never regret putting in a MVHR unit.

Best of luck, let us know how ya get on.

MicktheMan · 18-05-2021 5:21pm

homewardbound11 wrote: »

What has failed? Mine is in since 2011. Still going but wonder for how much longer ?

I would like to know the same ... mine is a 2008 install. I always thought that when the fans eventually failed it would be a relatively straight forward job to replace them. Can't imagine any other component failing that would require a replacement unit!

MicktheMan · 18-05-2021 5:31pm

DM1983 wrote: »

Apologies, for the thread derailing here but last question. The house looks like a building site at present so obviously can't do an airtightness test yet but surely now is the time to run all the ducting etc. while block work is exposed? What am I missing? Have a guy calling out on Thursday to go through everything with me anyway.

Yes and also now is the time to get the major airtightness issues agreed to and done. Unfortunately, if the builder is not on board with a positive attitude towards achieving a decent airtight result, then you are really up against it. Getting an experienced & knowledgeable air tightness tester/surveyor/engineer to consult with you and your builder on site and point out the opportunities as well as the pitfalls is probably the best approach to take at this stage.

DM1983 · 23-05-2021 8:02pm

Pushed for a ballpark figure and it seems MHRV is going to cost roughly €5k and DCV roughly €3k. Worth the extra to go for MHRV? I have two friends who have DCV and are really happy with it. Thoughts on the pros and cons?

MicktheMan · 23-05-2021 10:34pm

DM1983 wrote: »

Pushed for a ballpark figure and it seems MHRV is going to cost roughly €5k and DCV roughly €3k. Worth the extra to go for MHRV? I have two friends who have DCV and are really happy with it. Thoughts on the pros and cons?

It depends really. One the one hand, the main energy efficiency difference between the 2 systems is the HR part while on the other, there are two fans running in the HR system versus 1 in the DCV. Is the nett saving in energy costs over the lifetime of the unit worth the 2k difference in upfront cost? Could the 2k be better spent on improved air tightness for example os some other valuable upgrade measure?
I have a MVHR system and wouldn't be without it but have no real life experience with DCV. Your friends have and they are happy too.

At the end of the day, both systems will ventilate you house sufficiently and provide a healthy & pleasant indoor environment and that is the primary function of each.

AGC22 · 02-02-2022 7:32pm

https://www.boards.ie/discussion/comment/117186147#Comment_117186147

Hi, would you mind sending me name of vendor? I'm looking at getting a system installed and don't know enough about it yet. Thanks 👍

McGrath5 · 06-03-2023 12:43pm

Thought I would resurrect this old thread instead of starting a new one - I have a MHRV unit in a new build that is permanently in "Boost mode" , it's a Vent Axia Sentinel Kinetic Plus B. I can't get the fan speed any lower than 50% and find it is a bit loud at night time. Is there a way to get it into "Normal mode" to decrease the fan speed especially at night?

spose · 06-03-2023 3:22pm

https://www.boards.ie/discussion/comment/120320171#Comment_120320171

The power cable has 4 wires. Normal live and a black switched live that’s supposed to be attached to a boost switch. Could be boost switch is permanently switched on/broken. Could be both lives were wired together

McGrath5 · 06-03-2023 9:59pm

https://www.boards.ie/discussion/comment/120320971#Comment_120320971

Thanks Spose, are they located on the main unit itself?

spose · 07-03-2023 1:52am

The boost switch should be in the house somewhere and usually has boost or something written on it. If you don’t have a boost switch then it might be connected wrong. The power cable from the main unit should be going in to a fused spur. If the black wire is connected in that then that’s probably your problem

keno-daytrader · 07-03-2023 1:54pm

On the unit go into commissioning.... password should be 0000 then into user mode. There you can check the fan speeds of the modes which should be low, normal, boost and purge.

This is the first thing I would check.

Replacing MHRV unit

Comments