It is currently 28 Mar 2024, 21:36

Domestic Heat recovery systems

Hang up your Chisels and Plane blades and take a load off with a recently turned goblet of your favourite poison, in the lounge of our Gentlemen's (and ladies) Club.

Re: Domestic Heat recovery systems

Postby 9fingers » 24 Jan 2015, 14:00

I expect you have lath and plaster ceilings? if so you can use a metal detector to search for the nails. lots of closely spaced nails along a joist and a wide space to the next joist and another run of closely spaced nails.

the metal detector trick should work through the carpet too but the nails will be spaced wider - every few inches along a joist. If you don't have a metal detector then buying one will be a useful workshop tool when processing reclaimed or green timber. Rutlands have one on offer at the moment well reputed maker (wizard) but I have not used that model.

Usually the upstairs ceiling joists (viewed in the loft) will be the same direction as the floor joists but no guarantees esp in an older place.

hth

Bob
Information on induction motors here
https://drive.google.com/file/d/1dBTVXx ... sp=sharing
Email:motors@minchin.org.uk
User avatar
9fingers
Petrified Pine
 
Posts: 10038
Joined: 21 Jul 2014, 20:22
Location: Romsey Hampshire between Southampton and the New Forest
Name: Bob

Re: Domestic Heat recovery systems

Postby Charlie » 24 Jan 2015, 21:20

The house is a barn conversion done in the 1990's I understand so no lath & plaster. However I can check the loft joists so will do that tomorrow, thanks.

I have a small metal detector, never thought of using it due to the carpets!
Charlie
Now that I've made this mess, how do I fix it?
Charlie
Seedling
 
Posts: 30
Joined: 08 Aug 2014, 18:22
Location: West Devon
Name:

Re: Domestic Heat recovery systems

Postby Charlie » 29 Jan 2015, 19:24

Well the joists in the loft span the shortest distance so if the floor joists are the same then not sure how the pipes could be run.

I emailed Vent Axia who replied that the only way to retrofit this system would be to remove the ceilings! That would be extremely messy never mind costly.

Has anybody retrofitted one of these systems and how was it done please?
Charlie
Now that I've made this mess, how do I fix it?
Charlie
Seedling
 
Posts: 30
Joined: 08 Aug 2014, 18:22
Location: West Devon
Name:

Re: Domestic Heat recovery systems

Postby bluebirdnick » 04 Sep 2019, 15:52

Apologies for dragging up an old thread but I stumbled across MVHR systems in Mike’s posts on the renovation of his house, and I am wondering if it is the perfect cure for the troubles we have with our house.

Background: I have a 1930s detached house. We built a rear single storey extension in 2016 and are getting ready to build a two-storey side extension. I attach a floor plan. It is not finalised yet, but let’s assume this is what I will end up with. There are some irritations I have with the house, many of them of our own making. In order of importance, they are:
- The kitchen gets very hot very easily – it is often 30 degrees in the summer when we come downstairs. Separately, the extractor above the hob is laughably ineffective
- The living room also gets stuffy in summer, as it is long and narrow.
- We will have a downstairs WC and a downstairs laundry room with no windows so concerned about smells and moisture
- The bathroom fan does nothing – it’s like a sauna after the shower has been on for 5 mins
- The bedrooms at the front of the house get very hot in summer and very cold in winter

Unless I have misunderstood horribly, an MVHR system would help alleviate problems (except maybe the bedrooms being cold in winter). And as we are building a two storey side extension, now is surely the time to install an MVHR system. Ideally I would have done it when we renovated the original house but I didn’t know about MVHR then and the architect never mentioned it. So my questions are:

1) How do I test airtightness? It’s a 1930s house, so despite new windows and bifolds it’s still going to be, I assume, a lot worse than a new home. Surely the chimneys alone are a significant issue?

2) My wife wants a wood burner in one of the reception rooms. I understand that for this to be compatible with an MVHR system we would need an external air supply for the fire so that it doesn’t draw in air from the room but what about the flue? How does this work if I am supposed to seal up the chimneys? Or do I just leave this for the wood burner installer to deal with?

3) On the subject of chimneys… I will need to somehow run the piping for the MVHR from the loft into the downstairs rooms on the side of the house where we are not extending. Can I run it down a chimney? (I anticipate it being much easier to get ducting into the rooms in the new extension and the rooms on the side of the house where we are extending. While we have insulated and boarded the loft now, I also expect that it will be relatively straightforward to get into the upstairs rooms assuming we fit the unit in the loft)

4) Do vents in the rooms have to go on the ceiling? I can imagine that it will be easier to install them high on the walls in the downstairs rooms

Any thoughts appreciated!

Nick
bluebirdnick
New Shoots
 
Posts: 112
Joined: 13 Jun 2017, 22:33
Location: Herts
Name:

Re: Domestic Heat recovery systems

Postby Mike G » 04 Sep 2019, 16:17

HI Nick.

1/ You don't need to test for air-tightness, and a MVHR system will work well regardless.

2/ The woodburner is an interesting one. I am going through this myself at the moment. You'll need a woodburner which draws all of it's air supply from the independent source, and not from the room. Here is a useful source:https://www.stovesonline.co.uk/direct-air-supply-stoves.html#acr So long as the chimney has a baffle plate with the flue penetrating it, then the fir is a sealed system, drawing air in directly from outside and pushing smoke out in a sealed circuit. You will need the Building Inspector to sign this off.

3/ & 4/ Pipes and vents can go anywhere convenient. I have a number in walls rather than ceilings. I don't think there would be a problem using a chimney as a route for the ducting, but I'd want to know that the void was capped, the ducts insulated, and the whole thing vented.

Just be a little thoughtful about where you site the main unit as the make a barely discernible (but annoying at night) noise. Try to put it over a bathroom, but allow lots of space around it as the ducts are bulky.
User avatar
Mike G
Sequoia
 
Posts: 9834
Joined: 30 Jul 2014, 22:36
Location: Suffolk
Name:

Re: Domestic Heat recovery systems

Postby 9fingers » 04 Sep 2019, 16:29

I've been wondering whether to reply or not :D As I have no experience with these systems but do take an interest in such matters.
So on the strict understanding that I could be wrong, here goes.

Whether or not you have a heat recovery system the woodburner should be considered as "room sealed" ie its combustion air should come from outside and all combustion product apart from most of the heat, should go up a sealed flue. Utterly pointless in burning your already heated room air.

Unused chimneys need blocking off subject to leaving a little ventilation or simply removing at roof level. They strike me as ideal routes for heat recovery ducts.

Condensation both water and cooking fats/oils concern me a bit as in the depths of winter sub zero air can come in from outside to be warmed by the liquid laden warm air and condensate is bound to be formed. I presume the heat exchangers are designed with this in mind and drain provided. Cleaning accumulate cooking gunge out of the heat exchanger does not sound like a nice job so i think a high spec filtration and grease trap system should be in the cooker hood so that it is only clean(ish) water laden air that hits the heat exchangers.

I presume the controls on these devices are such that they don't/can't extract the heat out of all rooms to the extent that they become too cold for comfort.

The bedrooms sound like the cause is lack of insulation, or it could simply be inadequate heating in the winter and huge solar load through windows in the summer.

We don't heat upstairs at all apart from the bathroom. bedroom doors are left open and the living room door is opened an hour or so before bedtime so the accumulated heat downstairs flows up stairs.
We try to manage the summer solar load of southfacing windows by drawing the curtains and resisting the temptation to throw open windows during the day and let the DG insulate us a bit.

just my 2p

I expect Mike will be along with some more factual info. Ah I see has has already!

Bob
Information on induction motors here
https://drive.google.com/file/d/1dBTVXx ... sp=sharing
Email:motors@minchin.org.uk
User avatar
9fingers
Petrified Pine
 
Posts: 10038
Joined: 21 Jul 2014, 20:22
Location: Romsey Hampshire between Southampton and the New Forest
Name: Bob

Re: Domestic Heat recovery systems

Postby RogerS » 04 Sep 2019, 16:39

MikeG is really your expert on this and so I'll comment from my own observations relative to our place.

The kitchen gets very hot very easily – it is often 30 degrees in the summer when we come downstairs.

You don't say what time of day. Where is the heat coming from ? Solar gain through the windows ? Cooking ?

We have a large West facing glass wall and whenever (rarely) we get any sun in the evening then the kitchen stokes up nicely. I'd dearly love to be able to store that heat for elsewhere but the kitchen is in an extension and there are 4ft thick stone walls between. I live with it..too many other higher priority things.

Where does the extractor 'extract' to ? We didn't bother in our kitchen to fit one.

The living room also gets stuffy in summer, as it is long and narrow. Orientation ? South facig ? Size of windows etc ? Our living rooms are South facing with tall sash windows. On a good sunny day the rooms get warm. Not stuffy per se. Our plan is to install internal shutters to trap some of that heat for the evening.

One of the rooms has an open fire. At the moment, the air supply comes through a doorway without a door ! When that gets filled in, I'll take a view to see what's needed. I do need to ensure a good supply as the builder cocked up the internal opening of the fireplace. :( One idea is to put low-level grilles on either side of the fireplace that will open up into the lovely void we have behind the insulated stud partition. Benefit of that is it will give me some air circulation there.

I don't think air-tightness has anything to do with MVHR in an OLD house.

We will have a downstairs WC and a downstairs laundry room with no windows so concerned about smells and moisture Ditto. At the moment we do use the utility rom but the WC is not yet fully operational. I do have extract points in the ceilings that go up into the roof space where my "unconnected' MVHR system is located. No condensation though with the utility/laundry area.

The bathroom fan does nothing – it’s like a sauna after the shower has been on for 5 mins Fit a larger fan. The ICON range are stylish and have a cover that opens and closes automatically. They can also be controlled by a built-in humidity sensor. They look good as well IMO

We do have an extract pipe in the bathroom..as yet unconnected but the bathroom isn't finished so not an issue. Ditto in en-suite No1 ...also unconnected.

En-suite No 2 is a problem because SWMBO didn't want any vents. She realises that that is wrong in hindsight and so now I need to grovel around up in the loft to put in a pipe to connect in to the system one day. VBoth it and the adjoining bedroom get steamed up.

Before I forget, don't forget to insulate the extract piping. I use plastic trunking for mine. Also in a new build they get very exercised about being able to adjust the extract flow from each room. I haven't bothered.

I'd also planned to have an extract vent up in the ceiling upstairs also to connect to the system but that's way down the TUIT list.

As is my MVHR system ! I can actually see me leaving the house with it till non-functional :lol:

Oh yes...you will need a condensate drain from the MVHR...that Gotcha nearly caught me out.

Hope the above helps.
If opportunity doesn't knock, build a door.
User avatar
RogerS
Petrified Pine
 
Posts: 13291
Joined: 21 Jul 2014, 21:07
Location: Nearly finished. OK OK...call me Pinocchio.
Name:

Re: Domestic Heat recovery systems

Postby Woodbloke » 04 Sep 2019, 21:25

9fingers wrote:
We don't heat upstairs at all apart from the bathroom. bedroom doors are left open and the living room door is opened an hour or so before bedtime so the accumulated heat downstairs flows up stairs.
We try to manage the summer solar load of southfacing windows by drawing the curtains and resisting the temptation to throw open windows during the day and let the DG insulate us a bit.

Bob

We do the same; no heat on upstairs regardless of the season and it's only the bathroom towel rad that's on. I also open the upstairs windows so that any heat that does build up in the summer might hopefully disappear.

Our south facing lounge used to get seriously hot so we fitted a thermal roller blind to the window which lets in a fair degree of light but no heat, so the lounge stays relatively cool and the curtains stay open. The kitchen/diner has a ceramic tiled floor which is very cool in the summer, but it can get a bit 'parky' in the winter; again there's a thermal blind fitted which can be rolled down during hot weather to cut off the rays - Rob
I no longer work for Axminster Tools & Machinery.
User avatar
Woodbloke
Sequoia
 
Posts: 5866
Joined: 22 Jul 2014, 10:06
Location: Salisbury, UK
Name:

Re: Domestic Heat recovery systems

Postby Andyp » 05 Sep 2019, 06:22

I aint no expert either but with 12 years of living with a south facing aspect, with windows also facing east and west, that gets the sun from dawn to late afternoon the undeniably best way of keeping the heat out are external shutters.
I do not think therefore I do not am.

cheers
Andy
User avatar
Andyp
Petrified Pine
 
Posts: 11718
Joined: 22 Jul 2014, 07:05
Location: 14860 Normandy, France
Name: Andy

Re: Domestic Heat recovery systems

Postby RogerS » 05 Sep 2019, 06:30

Andyp wrote:I aint no expert either but with 12 years of living with a south facing aspect, with windows also facing east and west, that gets the sun from dawn to late afternoon the undeniably best way of keeping the heat out are external shutters.


Out of curiosity, have you tried internal shutters ? I know that externals are La Mode Francaise a la Provence. ;)

Externals are easier over there as your windows IIRC open inwards .
If opportunity doesn't knock, build a door.
User avatar
RogerS
Petrified Pine
 
Posts: 13291
Joined: 21 Jul 2014, 21:07
Location: Nearly finished. OK OK...call me Pinocchio.
Name:

Re: Domestic Heat recovery systems

Postby Andyp » 05 Sep 2019, 07:06

I have not tried internal shutters here but have seen them in use. Old fashioned wooden ones that fold into the reveal.

Internal shutters do not stop the glazing from heating up, the shutters themselves can even get warm. External shutters prevent the glazing from heating up.

Yes all our windows open inwards. PITA for furniture placement but excellent for cleaning and decorating. All on lift off hinges too.
I do not think therefore I do not am.

cheers
Andy
User avatar
Andyp
Petrified Pine
 
Posts: 11718
Joined: 22 Jul 2014, 07:05
Location: 14860 Normandy, France
Name: Andy

Re: Domestic Heat recovery systems

Postby Rod » 05 Sep 2019, 13:00

Andy do your doors open outwards? I’ve noticed from some TV series (mainly Scandinavia ones) that theirs do.

Rod
User avatar
Rod
Old Oak
 
Posts: 4471
Joined: 21 Jul 2014, 21:34
Location: Winchester, Hampshire
Name:

Re: Domestic Heat recovery systems

Postby RogerS » 05 Sep 2019, 13:13

Andyp wrote:I have not tried internal shutters here but have seen them in use. Old fashioned wooden ones that fold into the reveal.

Internal shutters do not stop the glazing from heating up, the shutters themselves can even get warm. External shutters prevent the glazing from heating up.

Yes all our windows open inwards. PITA for furniture placement but excellent for cleaning and decorating. All on lift off hinges too.


Does glass radiate much ? I thought that it was the rays of the sun through the glass and warming the room air up rather than the glass warming up and radiating (a little).

From a practical perspective, I'd hate to have to get the ladder out twice each day to shut the external ones :lol:
If opportunity doesn't knock, build a door.
User avatar
RogerS
Petrified Pine
 
Posts: 13291
Joined: 21 Jul 2014, 21:07
Location: Nearly finished. OK OK...call me Pinocchio.
Name:

Re: Domestic Heat recovery systems

Postby Mike G » 05 Sep 2019, 13:59

RogerS wrote:.... I'd hate to have to get the ladder out twice each day to shut the external ones :lol:


:) Most people just open the window and pull the shutters closed.
User avatar
Mike G
Sequoia
 
Posts: 9834
Joined: 30 Jul 2014, 22:36
Location: Suffolk
Name:

Re: Domestic Heat recovery systems

Postby Andyp » 05 Sep 2019, 14:28

This is going a little off-topic. Sorry

Gary -AKA Taffy Turner did some heat loss calculations for me a few years back. More to do with heat loss than solar gain but interesting none the less.

https://www.ukworkshop.co.uk/forums/hea ... 32-15.html
I do not think therefore I do not am.

cheers
Andy
User avatar
Andyp
Petrified Pine
 
Posts: 11718
Joined: 22 Jul 2014, 07:05
Location: 14860 Normandy, France
Name: Andy

Re: Domestic Heat recovery systems

Postby bluebirdnick » 05 Sep 2019, 15:20

IMG_20190905_150630.jpg
(412.75 KiB)
bluebirdnick
New Shoots
 
Posts: 112
Joined: 13 Jun 2017, 22:33
Location: Herts
Name:

Re: Domestic Heat recovery systems

Postby bluebirdnick » 05 Sep 2019, 15:37

Thanks all. For some reason the image of teh ground floor layout didn't upload to my previous message so here it is. The new bit is bordered in red. It won't quite be like that as we won't be extending the kitchen quite so much and instead using that area as a utility/storage space and what is marked as the utility will be the laundry room. The hardest rooms to get to will be the living room and dining room which is why I was asking about using the chimney.

Point taken re the location of the unit itself. It will likely go in the loft, above the new bathroom we install as part of the extension. I actually want the upstairs extension to be wider than the downstairs by about a meter, and incorporate a pathway into the design to allow access to the garden and still look normal but that is another challenge! We had insulated the loft with 100mm insulation and boarded it out as that was easy, but I might actually run the ducts over the boards; insulate between/above them with a further 170mm; and board out again. we've got loads of height in the loft space so it could work. I suspect we will need to include some sort of vertical run on the "extended" side of the house to get the ducts down to the kitchen, and from there into the downstairs WC and utility/laundry room.
bluebirdnick
New Shoots
 
Posts: 112
Joined: 13 Jun 2017, 22:33
Location: Herts
Name:

Re: Domestic Heat recovery systems

Postby RogerS » 05 Sep 2019, 16:28

Where are you planning for your recovered heat to feed back into the house ?
If opportunity doesn't knock, build a door.
User avatar
RogerS
Petrified Pine
 
Posts: 13291
Joined: 21 Jul 2014, 21:07
Location: Nearly finished. OK OK...call me Pinocchio.
Name:

Re: Domestic Heat recovery systems

Postby Mike G » 05 Sep 2019, 21:11

The recovered heat normally goes into all the "dry" rooms (ie bedrooms, lounge, dining room) where air goes in rather than out. The principle is out from the wet rooms (kitchen, bathrooms, utility etc) and in to the dry rooms.
User avatar
Mike G
Sequoia
 
Posts: 9834
Joined: 30 Jul 2014, 22:36
Location: Suffolk
Name:

Re: Domestic Heat recovery systems

Postby bluebirdnick » 08 Sep 2019, 14:01

Thanks both. I'll take advice on it, but my basic expectation is that I would extract from the kitchen, bathroom and living room which are on the south-east side (and the utility and WC which will be internal), and pumping it back into the front bedrooms which face north-west. Ideally in the summer I would extract from the front bedrooms too as they can get seriously hot, but if not then I am hoping a summer bypass will have a similar effect as I will at least be sucking warm air out of the house and creating a gentle circulation of fresh air.

I may not bother having anything in the front reception room. It stays cool in summer and we plan to have a woodburner in there which we would use in winter.
bluebirdnick
New Shoots
 
Posts: 112
Joined: 13 Jun 2017, 22:33
Location: Herts
Name:

Re: Domestic Heat recovery systems

Postby SamQ aka Ah! Q! » 08 Sep 2019, 23:06

Woodbloke wrote:
9fingers wrote:
We don't heat upstairs at all apart from the bathroom. bedroom doors are left open and the living room door is opened an hour or so before bedtime so the accumulated heat downstairs flows up stairs.
We try to manage the summer solar load of southfacing windows by drawing the curtains and resisting the temptation to throw open windows during the day and let the DG insulate us a bit.

Bob

We do the same; no heat on upstairs regardless of the season and it's only the bathroom towel rad that's on. I also open the upstairs windows so that any heat that does build up in the summer might hopefully disappear.

Our south facing lounge used to get seriously hot so we fitted a thermal roller blind to the window which lets in a fair degree of light but no heat, so the lounge stays relatively cool and the curtains stay open. The kitchen/diner has a ceramic tiled floor which is very cool in the summer, but it can get a bit 'parky' in the winter; again there's a thermal blind fitted which can be rolled down during hot weather to cut off the rays - Rob


....Jeez...you south coast wombles do not know you are living...parky enough here tonight for heating to be on already. I was down in Somerset and Cornwall for the the last two weeks and it was like being in a different country...sub Saharan Africa maybe...just didn’t have the exotic wildlife (even in Glastonbury village!)...


Shivering Sam
A pragmatist inside a perpetual optimist, heavily influenced by an experienced cynic, wrapped around by an aging relic.
SamQ aka Ah! Q!
Old Oak
 
Posts: 1030
Joined: 21 Jul 2014, 23:06
Location: High above the Aln.
Name: Sam

Re: Domestic Heat recovery systems

Postby RogerS » 09 Sep 2019, 05:45

SamQ aka Ah! Q! wrote:....

....Jeez...you south coast wombles do not know you are living...parky enough here tonight for heating to be on already. I was down in Somerset and Cornwall for the the last two weeks and it was like being in a different country...sub Saharan Africa maybe...just didn’t have the exotic wildlife (even in Glastonbury village!)...


Shivering Sam


But they're still walking around Newcastle in shorts and skimpy tops !! You need to man up ;) :D
If opportunity doesn't knock, build a door.
User avatar
RogerS
Petrified Pine
 
Posts: 13291
Joined: 21 Jul 2014, 21:07
Location: Nearly finished. OK OK...call me Pinocchio.
Name:

Re: Domestic Heat recovery systems

Postby Rod » 09 Sep 2019, 10:56

The heating switched on the other night, so not always toasty down south.
Drizzling and max 13C today

Rod
User avatar
Rod
Old Oak
 
Posts: 4471
Joined: 21 Jul 2014, 21:34
Location: Winchester, Hampshire
Name:

Re: Domestic Heat recovery systems

Postby 9fingers » 09 Sep 2019, 11:11

I've not allowed the CH to come on yet on principle. :lol:

But I have flipped the air con into air source heat pump mode for the last couple of evenings to bring the lounge upto 20C.
OK it cools the outides air by a micro-degree or 3 but I don't think the neighbours notice.

Bob
Information on induction motors here
https://drive.google.com/file/d/1dBTVXx ... sp=sharing
Email:motors@minchin.org.uk
User avatar
9fingers
Petrified Pine
 
Posts: 10038
Joined: 21 Jul 2014, 20:22
Location: Romsey Hampshire between Southampton and the New Forest
Name: Bob

Re: Domestic Heat recovery systems

Postby RogerS » 09 Sep 2019, 11:18

9fingers wrote:....
OK it cools the outides air by a micro-degree or 3 but I don't think the neighbours notice.

Bob


Ah...so it's all your fault then why we're shivering up here, Bob :lol:
If opportunity doesn't knock, build a door.
User avatar
RogerS
Petrified Pine
 
Posts: 13291
Joined: 21 Jul 2014, 21:07
Location: Nearly finished. OK OK...call me Pinocchio.
Name:

PreviousNext

Return to The Woodmangler's Retreat

Who is online

Users browsing this forum: canoemoose, Harv-53 and 22 guests