MVHR and open fireplace

[Ronan 1]

Appreciate all the input gents ?

[Iceverge]

I grew up with open fires as a kid. In the country. It was great. Or so I remembered.......

 

Then we moved into a rented stone house with open fires. IT. WAS. FREEZING. The memories of being a child in smoky drafty house with a permanent cough and cold returned.  

 

We moved again into a small cottage. Open fire. Right bollocks to that I said, went on Donedeal.ie and €200 later and a bit of mucking about had myself a stove. It was a revelation. 4 times less firewood and 4 times as much heat. Happy days. 

 

Then we had a baby and all my time disappeared. The novelty of lighting up a roaring fire gradually waned as every day I had to drag out ashes and drag in firewood and wait for a good hour to have any meaningful heat. It became more and more of a chore. I began to feel like this woman. 

 

 

Then I started to read up about indoor air quality. It wasn't too pleasant and now every time I refuel or clean out our stove I get a pang of guilt as a plume of particles drifts off towards our toddler.  I'm giving her a better chance of chronic lung problems every time I do this. You say your missus has notions but please make sure she's informed. Here's a good article. 

 

https://passivehouseplus.ie/magazine/insight/home-heating-choices-and-air-quality

 

 

 

On a less depressing note avoiding a fire in your house will save you money. Even with free timber the payback for our passive house to install a stove was 22 years compared to direct electric. 

 

Today my task is to install our entire heating system for our new build. 

 

Here's a snap!

 

[Onoff]

Unless you absolutely must toast marshmallows why not an electric, log effect stove for the traditionalists or an LCD flame effect heater?

 

Different I suppose if your wood is free. 

[Ronan 1]

17 minutes ago, Onoff said:

Unless you absolutely must toast marshmallows why not an electric, log effect stove for the traditionalists or an LCD flame effect heater?

 

Different I suppose if your wood is free. 

Woods free which helps but the main thing is we both really want the open fireplace, I suppose it like a new Porsche or the Rally car in the garage or anything else we throw into houses or our lives because we like them. 

I'm prepared to put up with all the downside to have them so if as stated elsewhere I have to "buy" SAP points or whatever to satisfy this I'm ok with that.

Horses for courses i guess I'll 

?

 

[joe90]

I was told my woodburner was no good for my new build but it’s great, don’t light it much but yes it’s my “Porsche “ (don’t need but want). Have the option of leaving the door open to toast marshmallows or shut to see lovely flames but keep the nasties out, best of both worlds IMO.

[Thedreamer]

40 minutes ago, Iceverge said:

 

Today my task is to install our entire heating system for our new build. 

 

Here's a snap!

 

 

I would not even bother attaching it to the wall, why not just get the below and keep in a cupboard and wheel out when necessary. Rather than having an eyesore on the wall?

 

We have this and have used it once when it was frosty, -5 and overcast, back in the cupboard afterwards.

 

https://www.amazon.co.uk/Dimplex-Cadiz-Electric-Free-Radiator/dp/B002G09OXQ

 

[jack]

Open fires are categorically one of the worst things you can do for the environment. They produce more of the worst kinds of particulates than just anything else you can do, as well as being a ridiculously inefficient use of fuel.

 

MVHR isn't the issue. You're planning to poison yourself, your family and your neighbours based on some romantic notion that could be 95% satisfied by a decent woodburning stove (ideally you wouldn't have one of those either, but I appreciate people want to burn stuff).

 

I just can't fathom the logic.

[Bitpipe]

1 minute ago, jack said:

Open fires are categorically one of the worst things you can do for the environment. They produce more of the worst kinds of particulates than just anything else you can do, as well as being a ridiculously inefficient use of fuel.

 

MVHR isn't the issue. You're planning to poison yourself, your family and your neighbours based on some romantic notion that could be 95% satisfied by a decent woodburning stove (ideally you wouldn't have one of those either, but I appreciate people want to burn stuff).

 

I just can't fathom the logic.

 

You've not spent much time in NI @jack.

 

[Thedreamer]

5 minutes ago, Ronan 1 said:

Woods free which helps but the main thing is we both really want the open fireplace, I suppose it like a new Porsche or the Rally car in the garage or anything else we throw into houses or our lives because we like them. 

I'm prepared to put up with all the downside to have them so if as stated elsewhere I have to "buy" SAP points or whatever to satisfy this I'm ok with that.

Horses for courses i guess I'll 

?

 

 

Give up on the idea of the Openfire. When we started I wanted one and was annoyed that the Scottish Building regulation prevented it. But using a stove is vastly superior, if we had put in a open fireplace I would 100% have regretted that. 

 

Openfire are less efficient, more harmful, blow downs , messy, costly,  the list could go on. 

 

We have a lot of trees and managed an area of woodlands. The more efficient our set-up better for us. Using our stove I can heat the entire house, with two wheel barrows of poor quality home grown spruce logs for the week.

[Ronan 1]

4 minutes ago, jack said:

Open fires are categorically one of the worst things you can do for the environment. They produce more of the worst kinds of particulates than just anything else you can do, as well as being a ridiculously inefficient use of fuel.

I spent years designing and building pipelines to Carry oil and gas, I drive a 6.3 litre petrol car, have a diesel for work and do over 60000 miles a year so I guess I'm not that bothered by my carbon footprint, also my nearest neighbour is along way away and they like 95% or higher of my the houses in the county never mind local also burn fires and have oil central heating. It may not be right, it may not be best and I may be wrong as I am ALOT BUT I can live with that and I will have my open fireplace. 

 

[jack]

14 minutes ago, Ronan 1 said:

I drive a 6.3 litre petrol car

 

I now know all I need to know about you, thanks.

 

[Ronan 1]

Just now, jack said:

 

I now know all I need to know about you, thanks.

 

? yupp I love cars ?? 

[jack]

Just now, Ronan 1 said:

? yupp I love cars ?? 

 

So do I.

[ProDave]

If this open fire proposal is for a new build, do come back and tell us what building control say and if they pass it please.

[A_L]

33 minutes ago, Ronan 1 said:

It may not be right, it may not be best and I may be wrong as I am ALOT BUT I can live with that and I will have my open fireplace. 

 

And the world suffers................

[Thedreamer]

35 minutes ago, Ronan 1 said:

I spent years designing and building pipelines to Carry oil and gas, I drive a 6.3 litre petrol car, have a diesel for work and do over 60000 miles a year so I guess I'm not that bothered by my carbon footprint, also my nearest neighbour is along way away and they like 95% or higher of my the houses in the county never mind local also burn fires and have oil central heating. It may not be right, it may not be best and I may be wrong as I am ALOT BUT I can live with that and I will have my open fireplace. 

 

 

I take it you are not going to be fitting PV and charging one of these.

 

 

I live in a rural area where people rely on oil, peats etc, but that doesn't mean you need to follow the same approach for a new build. As mentioned above I think you will struggle to get pass building control with what you want.

 

Presumably when you were designing and building pipes etc you would do this in the most efficient way to transport oil and gas, why would you not adopt the same approach with your build?

Edited January 20, 2021 by Thedreamer

[Ronan 1]

38 minutes ago, ProDave said:

If this open fire proposal is for a new build, do come back and tell us what building control say and if they pass it please.

Hi Dave yes it's a new build. It is for an ammended planning application and as the approved application has 2 fireplaces I don't see it as being a problem BUT I could be very wrong. It has been known ?

 

Whenever my architect finally comes back with the changes and let's me know if I need to do anything else I'll let us know.

 

This Covid aparently stops everyone from working quickly but hopefully I'll know in the not to distant future

37 minutes ago, Thedreamer said:

I take it you are not going to be fitting PV and charging one of these.

 

Probably would get 60000 miles a year outta one of them ? or not at least in the timeframe required.

[Mr Punter]

So the short answer is you will not benefit much with MVHR as it will not be able to compensate for the uncontrolled air losses through the open chimneys but feel free to have it anyway.

 

Agreed that you will struggle to get Building Regs to pass an open fire.  Not sure if the convector box ones would let you scrape through?  I think they are a bit more efficient than a straight open fire.

 

If you have a fair bit of land you may want to consider mounting the PV panels on an outbuilding or at ground level as you may need quite a few.

 

 

 

 

[Ronan 1]

8 minutes ago, Mr Punter said:

So the short answer is you will not benefit much with MVHR as it will not be able to compensate for the uncontrolled air losses through the open chimneys but feel free to have it anyway.

 

Agreed that you will struggle to get Building Regs to pass an open fire.  Not sure if the convector box ones would let you scrape through?  I think they are a bit more efficient than a straight open fire.

 

If you have a fair bit of land you may want to consider mounting the PV panels on an outbuilding or at ground level as you may need quite a few.

 

 

 

 

Thank MrPunter, yes I might look about another type of ventillaion only system that might negate the need for trickle vents and cold bathroom extractors fans.

 

I have just over an acre and a half and a 6m x 12m garage so it would be very suitable for pv if needed. I just need to see what my architect has done or has planned ....

 

I know I'm getting a bit of flack and have different priorities than some on here BUT I appreciate hearing all the different views / arguments on it regardless.

 

Keep up the good work BH ?

[Iceverge]

23 minutes ago, Ronan 1 said:

Thank MrPunter, yes I might look about another type of ventillaion only system that might negate the need for trickle vents and cold bathroom extractors fans.

 

I have just over an acre and a half and a 6m x 12m garage so it would be very suitable for pv if needed. I just need to see what my architect has done or has planned ....

 

I know I'm getting a bit of flack and have different priorities than some on here BUT I appreciate hearing all the different views / arguments on it regardless.

 

Keep up the good work BH ?

Whilst you're building at any rate I'd put MVHR anyway. 

 

It'll help with your SAP. Does away with trickle vents and room extractors and will ensure if you end up with some airtight rooms they won't be stuffy. Given your project is pretty large it won't be significant in the budget. 

[Adsibob]

It's been interesting following this thread. I'm in a similar, but different, position to @Ronan 1 in that I too want to avoid trickle vents on the windows, hate bathroom fans and thought that MVHR would solve that problem, but I also am a bit of a pyromaniac. I prefer wood burning stoves and was going to fit a Nestor Martin TQ33 which I am relieved to discover is "Closed Combustion Capable - This stove is capable of burning with external air via a connection pipe." Presumably that would satisfy the direct air requirement for it to be compatible with MVHR?

 

The other fireplace we have is a gas fire (one of those with fake coal, made from volcanic lava rocks I believe); it doesn't get much warmer than a radiator, but it is nice to look at. We really don't use it that much but it would be a shame to get rid of it because it does make a nice decorative feature. Presumably there is some sort of removable lid/cover that I can buy so that the chimney flue is blocked off when this isn't in use?

 

Ordering my windows soon, so need to come to a landing whether I can really go without trickle vents on the basis of having MVHR. 

 

Having now been persuaded by members of this forum that the noise of a well installed MVHR system itself isn't really an issue, I do remain concerned about the requirement to have an air gap beneath each door and the noise leakage issues that could create. @Bitpipe mentioned this was 7600mm2. So that's 10mm on a 760mm door and slightly less at almost 9mm on a much larger 860mm door. This seems quite substantial. Doesn't this result in sound getting through doors more easily? In particular, I have two concerns:

1. The design of our utility room includes soundproofing because it is off our kitchen and our kitchen is open plan into the the living room/dining room/ Tv area. Almost the entire ground floor is open plan except for the utility room, guest wc and a small playroom. Due to the amount of laundry we do, the utility room could pollute the whole ground floor with sound. Part of the soundproofing design therefore incorporates a clever door seal to properly seal the door when it's closed. Obviously that wouldn't work with MVHR. So do I have to lose the door seal, if I want MVHR or is there a way around this. 
2. The bedrooms upstairs are off a central open string staircase which would be quite porous to sound. If the bedroom doors have a 9mm or 10mm gap beneath them, wouldn't sound from downstairs travel into them? E.g. loud TV downstairs being heard by kids/wife trying to sleep. I know a simple answer is to get headphones, but I rather not have to rely on that.

Perhaps I'm reading too much into the gap - what's the standard gap at the bottom of a door when one doesn't have MVHR? 

[joe90]

4 minutes ago, Adsibob said:

The other fireplace we have is a gas fire

But that has an open flue so one big draught!

4 minutes ago, Adsibob said:

Presumably there is some sort of removable lid/cover that I can buy so that the chimney flue is blocked off when this isn't in use?

I think that is illegal (forget to open it and your all dead).

i have 10mm gaps under all my doors and can’t say I notice a noise issue (but I don’t have young kids!!,) you could always get a sausage draught excluder thingy,!!!

 

re the laundry room just try it, one small room excluded from the MVHR might not be a problem (But I would put the pipes in anyway in case it’s needed, you can always blank them off.  Quite a few here use the laundry room with MVHR to dry their clothes with a lot of success.

 

 

[Adsibob]

6 minutes ago, joe90 said:

one small room excluded from the MVHR might not be a problem

Just trying to understand how this would work with Building Control. Presumably, if my way of avoiding the requirement to have trickle vents on all new windows (distinct from replacement windows) is to say: well i don't need trickle vents because I've got MVHR, then the Building Regs inspector will want to see that the MVHR complies with Regs. In that case, wouldn't he fail me if it the door to the utility doesn't have the necessary gap and, worse still, has the additional door sealer? I guess I could postpone the installation of the door sealer until after the inspection, but he might still spot there isn't a 10mm gap beneath the 760mm door.

 

Another question I had is whether having MVHR means one can have less rooflight openings. E.g. in our master bedroom we are having quite a large rooflight installed, it's about 1800mm by 900mm. This is a lot more expensive if I want it to be openable as opposed to fixed. Would having MVHR mean I wouldn't rely on that opening, hence saving money by just getting a fixed roof light? I read on another thread (it might have even been you @joe90 who said this), that in summer one is better off not relying on MVHR to keep the house cool and instead rely on opening the windows.

[Bitpipe]

16 minutes ago, Adsibob said:

Just trying to understand how this would work with Building Control. Presumably, if my way of avoiding the requirement to have trickle vents on all new windows (distinct from replacement windows) is to say: well i don't need trickle vents because I've got MVHR, then the Building Regs inspector will want to see that the MVHR complies with Regs. In that case, wouldn't he fail me if it the door to the utility doesn't have the necessary gap and, worse still, has the additional door sealer? I guess I could postpone the installation of the door sealer until after the inspection, but he might still spot there isn't a 10mm gap beneath the 760mm door.

 

Another question I had is whether having MVHR means one can have less rooflight openings. E.g. in our master bedroom we are having quite a large rooflight installed, it's about 1800mm by 900mm. This is a lot more expensive if I want it to be openable as opposed to fixed. Would having MVHR mean I wouldn't rely on that opening, hence saving money by just getting a fixed roof light? I read on another thread (it might have even been you @joe90 who said this), that in summer one is better off not relying on MVHR to keep the house cool and instead rely on opening the windows.

 

Of interest to BC is meeting the regulation extract requirement  for WCs, kitchens and bathrooms and minimum whole house ventilation rates. Your MVHR needs to be balanced to work efficiently so you normally double duct extracts and single duct supplies.

 

You should have a supply in every habitable room and ensure cross flow of air through the house (hence the gaps under doors).

 

BC may ask to see a commissioning report but you can DIY this. They may or may not notice/measure the door gaps - but without them your MVHR will not really work.

 

Utility would not need supply or extract under the regs but we use ours for drying clothes (condensing tumble and rack) so have an extract.

 

43 minutes ago, Adsibob said:

I do remain concerned about the requirement to have an air gap beneath each door and the noise leakage issues that could create. @Bitpipe mentioned this was 7600mm2. So that's 10mm on a 760mm door and slightly less at almost 9mm on a much larger 860mm door. This seems quite substantial. Doesn't this result in sound getting through doors more easily? In particular, I have two concerns:

1. The design of our utility room includes soundproofing because it is off our kitchen and our kitchen is open plan into the the living room/dining room/ Tv area. Almost the entire ground floor is open plan except for the utility room, guest wc and a small playroom. Due to the amount of laundry we do, the utility room could pollute the whole ground floor with sound. Part of the soundproofing design therefore incorporates a clever door seal to properly seal the door when it's closed. Obviously that wouldn't work with MVHR. So do I have to lose the door seal, if I want MVHR or is there a way around this. 
2. The bedrooms upstairs are off a central open string staircase which would be quite porous to sound. If the bedroom doors have a 9mm or 10mm gap beneath them, wouldn't sound from downstairs travel into them? E.g. loud TV downstairs being heard by kids/wife trying to sleep. I know a simple answer is to get headphones, but I rather not have to rely on that.

Perhaps I'm reading too much into the gap - what's the standard gap at the bottom of a door when one doesn't have MVHR? 

 

We also have a utility off the open plan living / dining area. When the door is closed, we don't hear the washing machine. We have a dishwasher in the kitchen (same open plan area) and never hear that either. Investing in decent appliances will make a big difference (we have Miele/Siemens).

 

It is really difficult to soundproof rooms. You can go to expensive extremes, spent lots (rubber matting, resilient bars etc) and not got a lot of success. I used blue plasterboard on basement and GF ceilings and I suppose it makes some difference but noise still transfers.

 

I don't think the air gap will make much difference if the TV is up loud.

[Adsibob]

5 minutes ago, Bitpipe said:

Investing in decent appliances will make a big difference (we have Miele/Siemens).

Thanks @Bitpipe. Would you mind me asking which Miele / Siemens appliances you have? Architect suggested the same, but at least in the Bosch range there wasn't more than two or three decibels between the noisiest and the loudest.