MVHR is Largely Bogus

[GT1]

Firstly, as this is my first post since joining the forum a few years ago, a big thank you for all the invaluable info your debates have provided. I ended up here again while doing research to confirm my MVHR design. Most of what I want to say has been said in this thread already - I just want to say it my way!

 

After years of struggling with planning authorities I am finally half way through an extensive bungalow extension/refurb for my parents, not the original plan for my whole family but that's life, compromise had to be made, we keep their draughty old house! The plan is also to divide off a previously built side extension to provide a separate rentable property to help pay back the mortgage quickly.

 

As for the current topic; a term I have not seen mentioned so far, and one which provides the best argument against the thread title, is cost/benefit ratio. Many purchases are unjustified on pure cost alone (House/Car/TV/Weddings/Holidays/Eating out/Drinking/Pets/Kids! etc) but the ultimate goal in life surely must be to live happy and content. In a world that increasingly seems to be run by accountantcy principles, I think the value of the latter is often sadly overlooked.

 

As these will be kept as my own properties but not occupied by me, I will concentrate on the cost/benefit to me regarding my investment.

 

On one hand, I can justify an MVHR system in the house my parents will occupy as it will contribute to keeping the house fresh (I can relate to all of joe90's comments about his parents - and to add: my mother's cooking odours make the whole house unbearable and she often forgets to turn the hood on!). Without this, chances are I will be spending more on a refresh when I eventually get my house back. Also, there is a small possibility I may want to move here after my parents so the personal comfort benefit is coming into play to justify this investment. 

 

In the second rentable property, I have opted to splash out on UFH as I believe the general public is now beginning to recognise this as a 'love to have' comfort feature and the benefit to me is a more desirable property. The MVHR would be wasted on this property as I can see no benefit to outweigh the installation/maintenance cost. I don't think the general public are aware of the comfort benefits yet so I don't believe it will affect the value of the property.

 

To sum up, MVHR certainly has undeniable benefits but the ROI is debatable, so if on a tight budget and you worry about your life's pot of cash running out before your end then there are cheaper options to keep you happy. On pure cost/ROI, the OP has made a very good argument, but the title of the thread is very misleading and aggravating to those who are realising it's benefits, it is not a bogus technology which should be dismissed. It's like saying buying Mercedes cars for lifetime cost is bogus because several budget cars will do the same job cheaper, I'm sure there are strong arguments both ways for efficient ROI, but bottom line is: if you can afford it then the feelgood factor from the extra comfort is undeniable.

 

I know a few individuals who, despite having a generous income, constantly debate ROI without giving equal importance to quality of life/environment, all come across as boring miserable people.

 

Whoops! I have a habit of writing too much then editing bits out to make it less of a novel to read. Just realised I need to get ready for work very quickly so posting as is before I lose it all. Sorry 

 

[Onoff]

3 hours ago, GT1 said:

On one hand, I can justify an MVHR system in the house my parents will occupy as it will contribute to keeping the house fresh

 

My late Mum, on top of/because of her mixed dementia, became doubly incontinent. To the point my kids wouldn't go up there. The smell had to be experienced to be believed. It was a care issue with my father insisting he could cope when he couldn't. Once we got (forced) carers in, the situation improved but at times it still wasn't good.

 

An odd aside in her behaviour was that she took to barricading doors and windows on top of locking them. Add to that drawing all curtains tight shut.

 

Then there's that as they get older they tend to clean less generally.

 

I'm pretty sure that MVHR would have massively helped with both the smell and to keep down the mould that ensued from the general lack of ventilation/cleaning.

 

"Mould" incidentally has also been indicated in some studies on the causes of dementia.

 

A pretty sad way to go considering how houseproud she once was! 

[AliG]

My dad likes to say that my mum never found a switch she didn't want to turn off.

 

They don't have MVHR currently, but they have trickle vents and a central air  extraction unit for the kitchen and bathrooms.

 

She keeps turning it off because she says the noise keeps her up. I don't believe her, it is because she thinks it costs money to run. I can tell as soon as I go into the place that she has turned toff as the air is stale. She also likes to close the trickle vents.

 

The other day she was complaining that a neighbour in the block of flats was running his Karcher off the communal electricity supply. The fact I pointed out that this was unlikely to even cost her 1p didn't seem to matter. He was being cheeky and she would never use everyone's electricity like that.

 

Their new place will have an ASHP and MVHR. I am trying to think of a way to stop her turning them off!

Edited April 10, 2021 by AliG

[Mr Punter]

Bloody hell @AliG we try not to stereotype Scots for being tight but your mum is not helping!

[joe90]

25 minutes ago, AliG said:

Their new place will have an ASHP and MVHR. I am trying to think of a way to stop her turning them off!

False switches (real ones hidden) ?

[AliG]

19 minutes ago, Mr Punter said:

Bloody hell @AliG we try not to stereotype Scots for being tight but your mum is not helping!

Oh I know. Other times she will be wildly generous. She doesn't seem to have any perspective on the amounts involved.

 

I still remember dragging our suitcases home from the station after our holiday one year ,when I was around 10, as it was only about a 12 minute walk and taking a taxi was considered  beyond the pale.

 

In fairness my parents have ended up very comfortably off relative to what they earned and my dad was able to retire when he was 58 so it has its benefits.

 

 

Edited April 10, 2021 by AliG

[curlewhouse]

Restarting work I'm seriously reconsidering my plans for MVHR.  We have a SIPS build and I fanatically filled and sealed every joint or gap real and imagined (mostly imagined) during the build.  For various reasons (without too much detail, a divorce in middle of it all and a serious back injury) everything came to a halt and I ended up been living in basically an unfinished house and have restarted work only really last week after 2 years. Less than 1/4 of the house is plasterboarded and is all green recycled polythene vapour barrier inside. So all during that time there have been daily showers, cooking etc etc ... for 2 people now,  and yet I have zero condensation.  I keep wondering where the heck it goes, but its nowhere to be found. Now the house volume is I suppose big for just two people, and the main living areas are a constant 21c except for when it gets a little warmer in sunny weather ( I am really pleased with how the SIPs and my underfloor insulation panned out) from solar gain. So whether the moisture in the air just gets so spread out (not very scientific an explanation, I know, but it doesn't even really condense on the loo cistern which must be the coldest surface in the house when full of fresh freezing cold country water).  Air filtration is a bit of a non issue pollutants wise - we have rare lichens growing here which experts tell us are extremely sensitive to any pollution, and its never ever stuffy (I have no way of scientifically measuring Co2 levels like some of the posters on here I'm afraid) even when there have been 4 people staying pre covid.  So now although it was considered an absolute in my plans, I'm really wondering if MVHR is necessary for me after all. I was relying on it moving heat around a bit as we don't have upstairs heating so in winter the rooms can be a little cool (though if you leave the doors open during the day, the heat does rise up and they are warm, but if the doors are shut this doesn't happen, so I'm toying with small panel heaters on stats for the very odd winter night they might be needed as a cheaper option if we have anyone staying who feels cold in bed at around 17c).  It means I'll need to add bathroom extractors, for regs reasons, but with the money I'd save I'll look at heat recovery ones - not brilliant but better than just pumping heat out.      I'm really surprised, as with having to move in whilst working I expected vapour to be an issue with showers etc. yet not a sign. I understand that once plasterboarded theres even more "natural" absorbtion and gradual release of water vapour in a building - and I don't even have that advantage yet. 

[Onoff]

2 hours ago, AliG said:

My dad likes to say that my mum never found a switch she didn't want to turn off.

 

It got pretty bad with my Mum. Anything with a neon or even a socket where when on it showed red was a magnet for her. She'd:

 

- turn the thermostat in the hall in passing, fully up, fully down, whatever

 

- press buttons at random on the CH/HW programmer

 

- turn off my Dad's induction loop hearing aid system ( that annoying green led ?)

 

- frequently turn off the emergency lifeline system leading to a call to us as the designated contact

 

 

[Iceverge]

On 10/04/2021 at 17:56, AliG said:

My dad likes to say that my mum never found a switch she didn't want to turn off.

 

They don't have MVHR currently, but they have trickle vents and a central air  extraction unit for the kitchen and bathrooms.

 

She keeps turning it off because she says the noise keeps her up. I don't believe her, it is because she thinks it costs money to run. I can tell as soon as I go into the place that she has turned toff as the air is stale. She also likes to close the trickle vents.

 

The other day she was complaining that a neighbour in the block of flats was running his Karcher off the communal electricity supply. The fact I pointed out that this was unlikely to even cost her 1p didn't seem to matter. He was being cheeky and she would never use everyone's electricity like that.

 

Their new place will have an ASHP and MVHR. I am trying to think of a way to stop her turning them off!

Does she run indoctrination courses ?

 

might send the mrs...........

[jack]

1 hour ago, Iceverge said:

Does she run indoctrination courses ?

 

might send the mrs...........

 

I came home on Christmas Eve a few years ago to find that every single light in the house was on. I mean that literally - every bathroom, toilet, hallway, bedroom etc light was blazing, with just my wife and two children at home (all of them downstairs in the kitchen).

 

A recent tweak to my home automation programming lets me open my phone, click a single button on the app, and turn off every single light in the house except the living room where we watch TV. It gives me great pleasure.

[AliG]

I have set the automation to switch off all of the lights at 8.10am and then again at 10pm so that it switches off all the lights (or at least the ones that are automated) during the school run in the morning and after everyone has gone to bed.

 

My daughter absolutely insists that she needs all the lights on in the kitchen whenever she is in there, no matter how bright it is outside. I also find TVs on in empty rooms all the time.

 

Clearly things have changed since my mum was younger.

 

[joe90]

5 minutes ago, AliG said:

My daughter absolutely insists that she needs all the lights on in the kitchen whenever she is in there, no matter how bright it is outside. I also find TVs on in empty rooms all the time.

Perhaps give them a good allowance but make them pay the electricity bill from it (and give them a copy of the usage and amount it costs).

Edited April 12, 2021 by joe90

[joe90]

6 minutes ago, AliG said:

she needs all the lights on in the kitchen whenever she is in there,

my other half is the same, but is always wearing her sunglasses ?‍♂️.

[jack]

15 minutes ago, AliG said:

I have set the automation to switch off all of the lights at 8.10am and then again at 10pm so that it switches off all the lights (or at least the ones that are automated) during the school run in the morning and after everyone has gone to bed.

 

Double-clicking my bedside light switch turns off all lights in the house and garage. I'd put this feature in the top three must-haves if I were to build again.

 

I also have a dedicated switch at the base of the stairs that turns off all the upstairs lights. It's nice to be able to click it as I walk past on the way to the kitchen from my office!

 

I've also put many of the lights on a timer, so they turn off automatically after a certain period. I think it's a couple of hours for the kids' rooms (I started with an hour, but there were complaints about the lights turning off too soon). It's half an hour for the pantry and the laundry, both of which my wife would leave on all day after using them for 30 seconds in the morning. 

 

None of this would be necessary if anyone but me knew how to switch off a light as they left the room. Still, I distinctly remember how bad I was at this even when I was in my 20s, so maybe there's hope for the kids yet, even if the wife is a lost cause.

[AliG]

2 minutes ago, jack said:

 It's half an hour for the pantry and the laundry, both of which my wife would leave on all day after using them for 30 seconds in the morning. 

 

I have all these rooms on sensors. I noticed in our last house that whenever we had visitors they never turned off the en suite lights. These were also connected to an extractor fan so that would be left running for hours as well.

 

I don't know why it is not standard to have bathroom, utility room lights etc on a sensor. Not only does it save electricity but you don't need to install switches and root around for lights in the dark.

[ToughButterCup]

4 minutes ago, jack said:

...None of this would be necessary if anyone but me knew how to switch off a light as they left the room....

 

Oh bleedin' 'ell...  I thought it was just me... it makes me so cross.

My folks would not (affect not to)  notice if all the lights - inside, outside in my lady's chamber, garage, hen house, piggery all came on at dawn and weren't switched off  at about midnight

[jack]

22 minutes ago, AliG said:

I have all these rooms on sensors. I noticed in our last house that whenever we had visitors they never turned off the en suite lights. These were also connected to an extractor fan so that would be left running for hours as well.

 

I don't know why it is not standard to have bathroom, utility room lights etc on a sensor. Not only does it save electricity but you don't need to install switches and root around for lights in the dark.

 

I have wiring for sensors in a lot of places but didn't get around to installing them during the build. Rough calculations suggest it would take a long time to pay back the cost of the sensor in most positions, so I haven't (yet) bothered.

[jack]

19 minutes ago, ToughButterCup said:

Oh bleedin' 'ell...  I thought it was just me... it makes me so cross.

My folks would not (affect not to)  notice if all the lights - inside, outside in my lady's chamber, garage, hen house, piggery all came on at dawn and weren't switched off  at about midnight

 

My parents in law are like this. They like the house to feel bright, and they can afford the electricity, so they just leave the lights on without any consideration of wasting energy. 

[AliG]

3 minutes ago, jack said:

I have wiring for sensors in a lot of places but didn't get around to installing them during the build. Rough calculations suggest it would take a long time to pay back the cost of the sensor in most positions, so I haven't (yet) bothered.

You are right, It wouldn't pay for itself, it only really works if you replace a light switch with a sensor. When my electrician priced it up it was £60 installed for either.

 

This should be standard practice in all new builds, I am surprised it hasn't been put in the building regs.

[jack]

Just now, AliG said:

You are right, It wouldn't pay for itself, it only really works if you replace a light switch with a sensor. When my electrician priced it up it was £60 installed for either.

 

For me, the best option is a combination of switch to turn on (and off, if you wish) and a presence sensor to keep the light on for as long as someone is in the room. I'm not a fan of lights coming on automatically - I don't want a light to come on if I go to the bathroom at night, for example.

[AliG]

The automation guy wanted me to put in extra sensors that could be programmed to put the lights on at a lower brightness level at night, but as I already had sensors going in it was too late and a lot of hassle to change.

[Mike]

On 10/04/2021 at 14:06, GT1 said:

In the second rentable property, I have opted to splash out on UFH as I believe the general public is now beginning to recognise this as a 'love to have' comfort feature and the benefit to me is a more desirable property. The MVHR would be wasted on this property as I can see no benefit to outweigh the installation/maintenance cost. I don't think the general public are aware of the comfort benefits yet so I don't believe it will affect the value of the property.

I'm adding both to mine - though it's true I'll be living in it initially myself. I agree that MVHR is less well appreciated at the moment, but it's growing - and also difficult to retrofit.

 

MVHR reminds me of debates I regularly in the 80's had back in to 80's with clients who didn't think it was worth fitting double glazing. By the 90s everyone wanted it.

[SteamyTea]

On 12/04/2021 at 09:23, AliG said:

Clearly things have changed since my mum was younger.

Yes, lights are now 5W instead of 60W.

I have leaving a light on, but as all mine are 3W LEDs, it takes 20 minutes for the meter to register.

 

What is the difference between light and hard?

You can sleep with a light on.

[ProDave]

1 hour ago, SteamyTea said:

Yes, lights are now 5W instead of 60W.

I have leaving a light on, but as all mine are 3W LEDs, it takes 20 minutes for the meter to register.

 

 

II added up all the lights in the house, and if every single one is on, it's about 130W

[SteamyTea]

7 minutes ago, ProDave said:

II added up all the lights in the house, and if every single one is on, it's about 130W

36W here.

I should buy a 50W LED security light and leave it on 24/7, just to compete with my neighbours old incandescent one.