Stove & Lime

[Flyfisher]

That makes sense --- horses for courses, as you say. What model was yours, and what (roughly) does it cost per year to run?

According to my records, DeLonghi DES12, £134.99, John Lewis, 3rd March 2012 (how sad is that?! :lol: )

I don't know the running cost but it's a good question. I didn't notice a significant increase in our electricity bills so I guess it's not too much. Basically, it's just a very small refridgerator. But I recently bought one of these plug-in power monitoring gizmos https://www.amazon.co.uk/Energenie-429-856UK-Power-Meter/dp/B003ELLGDC so perhaps I should check.

I also came across this video, and in the comments below it, the conservation specialist who posted the video effectively stated that dehumidifiers are not a solution. That said, his solution sounded very expensive, and so I thought it might be worth spending a couple of hundred quid on a dehumidifier and giving it a try (I can always sell it afterwards), before spending thousands on something more permanent.

Hmm. So moisture-laden warm air (relative to the outside) from the cellar is ventilated outside on a frosty day and onto a, presumably, freezing paving slab. I'm not at all surprised by the condensation on the paving slab. Is anyone?

Now imagine a summer situation. Warm summer air laden with moisture is pushed through the cellar to ventilate it. The cellar is cooler than the outside temperature so what will happen to the moisture in the air drawn into the cellar? Yes, you've guessed it already. :wink:

As for dehumidifiers being useless, perhaps I should post a video showing the outflow of my dehumidifier filling up a 20 litre water container over a week or two (depending on weather conditions)? That's water being removed from our cellar whichever way you look at it - maybe not by that video poster's preferred method of forced ventilation, but being removed all the same.

I'm not suggesting ventilation is a bad thing, on the contrary, it's generally a very good thing, but there will undoubtedly be times when the outside air is more humid than the inside air, which could cause[/] moisture to condense inside a building, whereas a dehumidifier can never cause moisture to condense inside a building, it can only remove it in a controlled manner.

 

[worms]

Now imagine a summer situation. Warm summer air laden with moisture is pushed through the cellar to ventilate it. The cellar is cooler than the outside temperature so what will happen to the moisture in the air drawn into the cellar? Yes, you've guessed it already. :wink:

FF, I’m In complete agreement! So often you read the advice that interior RH levels should be kept below 60 and the answer is more ventilation, so open the windows. That works fine for a heated building in winter but not so great for an unheated building in a wet Scottish summer!

 

[88v8]

Our heating is pretty well Off now, and the RH has crept up over 60%. In summer, it hits the 70s.
The two (ebac) dehumidifiers are each sucking their customary gallon of water every couple of days.
Without them, the RH would be about ten points higher.
Running cost? No idea. Trivial.

They're on Auto. I can make them work harder, but as a rule, I don't.

In summer, when the doors are usually open - we lit a stove on Wednesday night, never in 45 years recall a fire in June - I should put them on time switches for overnight only.

Year-end when I was lime plastering and the RH in the sitting room hit 95%, I did eventually put a dehumidifier in there. Temperature was, ummm, cold, and eventually it iced up.
But if one is going to make the cellar habitable, it's not going to be below 50F anyway? The dehumidifier itself generates a bit of heat of course, and ye olde storage heater down there would keep the chill off when the stove is not in use.

Ivor

 

[Flyfisher]

Now imagine a summer situation. Warm summer air laden with moisture is pushed through the cellar to ventilate it. The cellar is cooler than the outside temperature so what will happen to the moisture in the air drawn into the cellar? Yes, you've guessed it already. :wink:

FF, I’m In complete agreement! So often you read the advice that interior RH levels should be kept below 60 and the answer is more ventilation, so open the windows. That works fine for a heated building in winter but not so great for an unheated building in a wet Scottish summer!

Yes, windows can do more than just let light in! I don't know if it's just me but in many/most of the old pictures I see of houses one or more of the windows are open. I suspect the general trend was to open up the house on warm days and keep it closed up on cold days. Basic commonsense really, but something that worked well for keeping RH under control, at least on average over a year. Modern living, with daily hot showers, indoor clothes washing and drying, even dishwashers etc, tends to generate far more moisture inside plus, of course, levels of insulation and draft-proofing are far higher. Not so much rights or wrongs, more of a mismatch perhaps?

Anyway, our doors and windows are generally open throughout the warmer months; it's lovely having fresh air breezing through the house!

 

[Flyfisher]

But if one is going to make the cellar habitable, it's not going to be below 50F anyway?

Good point - and obvious now you've mentioned it (so why didn't I? :roll: ).

 

[Househunter]

Thanks, folks, for the replies.

I can’t remember it being expensive to run (I’m a cheapskate, so I would have noticed!). I avoided using the more expensive settings.

...As would I, being a man after your own heart!

If I was buying another one, I think i’d still go for the desiccant type, although I suspect that a refrigerant one would be just as good and perhaps longer-lasting.

Righto --- thanks.

As FF says the summer months are often the worst - the heating is off, the wood-burner is off and the outside RH can be really high, especially if the weather is unremitting ****** rain!

Yes, I'm noticing this! Still, did get the washing (semi-)dried out on the line today, though it had to get drizzled on a few times first.

According to my records, DeLonghi DES12, £134.99, John Lewis, 3rd March 2012 (how sad is that?! :lol: )

That's not sad, that's splendid! Information at your fingertips! (I always had a soft spot for Martin from Ever Decreasing Circles.)

£135 is pretty reasonable, too, especially if it's still going strong after seven years.

I don't know the running cost but it's a good question. I didn't notice a significant increase in our electricity bills so I guess it's not too much. Basically, it's just a very small refridgerator. But I recently bought one of these plug-in power monitoring gizmos https://www.amazon.co.uk/Energenie-429-856UK-Power-Meter/dp/B003ELLGDC so perhaps I should check.

I'd be very interested to hear your findings!

I should mention that I've actually got a dehumidifier --- in fact, I have three! However, they are only small and extract water very slowly (probably less than a litre a week!). That said, they are quiet and cost next to nothing to run, and are very handy to dot about the house. ...And even half a litre every few days is better than nothing! (Particularly if it costs only pennies.)

However, for the cellar I think I'd need something with a bit more oomph to keep it comfortably dry.

I also came across this video, and in the comments below it, the conservation specialist who posted the video effectively stated that dehumidifiers are not a solution.

Hmm. So moisture-laden warm air (relative to the outside) from the cellar is ventilated outside on a frosty day and onto a, presumably, freezing paving slab. I'm not at all surprised by the condensation on the paving slab. Is anyone?

No, not really! I imagine it might be a bit dangerous in the winter, too, as the condensate would freeze over: it should be drained away.

Now imagine a summer situation. Warm summer air laden with moisture is pushed through the cellar to ventilate it. The cellar is cooler than the outside temperature so what will happen to the moisture in the air drawn into the cellar? Yes, you've guessed it already. :wink:

That's an excellent point: the air would need to be conditioned/dehumidified on entering the building first for it to work at all. I don't know whether it would even be possible to dehumidify that sort of throughput of air as it passes into the building. I went and looked up the website of the conservation professional who posted the video, and found this article, where it says his company has "joined forces" with the firm which installed that ventilation system in the video. Hmmm.

...And I'd like to see how he would answer your point above!

As for dehumidifiers being useless, perhaps I should post a video showing the outflow of my dehumidifier filling up a 20 litre water container over a week or two (depending on weather conditions)? That's water being removed from our cellar whichever way you look at it - maybe not by that video poster's preferred method of forced ventilation, but being removed all the same.

Absolutely: it's doing its job (and very well, by the sound of it) --- it'd be interesting to find out how the cost of your system compares with the cost of the one recommended in the video. Maybe your new energy-gizmo will provide a rough idea...

I'm not suggesting ventilation is a bad thing, on the contrary, it's generally a very good thing, but there will undoubtedly be times when the outside air is more humid than the inside air, which could cause moisture to condense inside a building, whereas a dehumidifier can never cause moisture to condense inside a building, it can only remove it in a controlled manner.

Again, this is an excellent point, and one which I have yet to hear made by any conservation professional whose work I've read so far --- they seem consistently to favour ventilation over the use of dehumidifiers. But you're right: today I tried reducing the RH in my bedroom by opening the windows, and realised that all I was doing was exchanging the humid air in the room for the similarly humid air outside. Even when it was nearly blowing a gale through the house, the RH didn't once drop below 60%. In the end, I just shut the window and stuck one of my little dehumidifiers in there.

But if one is going to make the cellar habitable, it's not going to be below 50F anyway? The dehumidifier itself generates a bit of heat of course, and ye olde storage heater down there would keep the chill off when the stove is not in use.

The dehumidifier idea is an alternative to the stove idea: i.e. no stove in the cellar; just a dehumidifier and an electric heater of some sort. Were I to go down the dehumidifier route, then the cellar would be heated only when in use. That is, the dehumidifier would (presumably) be running constantly to keep the RH down (even when it was chilly) and I'd just flick on the heater whenever I went down in the cellar. It's the simplest option, but whether it would be able to keep the cellar dry and comfortable enough to use, when not heated continuously, I'm not sure. ...Still, as I say, I think --- despite the opinion of the conservation expert in the video I linked --- it's probably worth blowing a couple of hundred quid on a dehumidifier and giving that a go first, before trying either of the other more permanent routes (installing a ventilation system or putting stove in the cellar). People here do seem to have good experiences with dehumidifiers, and don't report that they cost a fortune to run.

Anyway, thank you, Ivor, FlyFisher & Worms: your input is much appreciated!

 

[Flyfisher]

I don't know the running cost but it's a good question. I didn't notice a significant increase in our electricity bills so I guess it's not too much. Basically, it's just a very small refridgerator. But I recently bought one of these plug-in power monitoring gizmos https://www.amazon.co.uk/Energenie-429-856UK-Power-Meter/dp/B003ELLGDC so perhaps I should check.

I'd be very interested to hear your findings!

Me too!

So today I have plugged the power meter in line with the dehumidifier and emptied my 20 litre water container and will report back some figures in due course. Power consumption of the dehumidifier when running seems to be 181 watts.

 

[Househunter]

So today I have plugged the power meter in line with the dehumidifier and emptied my 20 litre water container and will report back some figures in due course.

Thanks, FF: I'll get my pencils sharpened and my calculator ready...

Power consumption of the dehumidifier when running seems to be 181 watts.

That's pretty economical --- some of the dessicant-type dehumidifiers I was looking at went up to something like 600W at full power, which would be most depressing to a frugal fellow like me!

Also, did you make a note of the temperature and relative humidity? One of my bugbears with the performance data that manufacturers give is that they are typically for ideal conditions --- so for example, the extraction rate given in the manual for my little dehumidifiers is based on conditions of 80% relative humidity at 30°C, which even the bathroom wouldn't reach, let alone the cellar!

I do hope I'm able to sort out the cellar: I was down there today, doing a spot of carpentry (making a backplate for my letterbox), and it was a delight to use the place as a workshop, even now before I've put it all right. I've been keeping all my tools down there, and the high humidity had had its way with them a bit --- the cardboard sheath on the saw felt like I'd just fished it out of a puddle. Anyway, here's hoping the investigations into the various dehumidification options will bear fruit...

 

[Flyfisher]

OK, here are some figures to mull over.

I started monitoring my cellar dehumidifier performance on Mon 17th early evening and have just taken a new set of readings, so that's a total of 6 days +/- a few hours.

Total power consumption was 20.3 kWh @14.5p/unit = £2.94 or 45p/day

Cellar temperature was 15.6C

Relative humidity was 78% - a little high perhaps but we had torrential rain earlier in the week and today has been very warm and humid.

Water extracted was about 18 litres - an estimate based on the 20 litre container used to collect (see photo below) - or about 3 litres per day.

 

[Househunter]

Thanks for the reply, Flyfisher, and apologies for the delay in getting back to you --- been a bit of a strange week...

OK, here are some figures to mull over.

I started monitoring my cellar dehumidifier performance on Mon 17th early evening and have just taken a new set of readings, so that's a total of 6 days +/- a few hours.

Total power consumption was 20.3 kWh @14.5p/unit = £2.94 or 45p/day

That's pretty good --- £165 a year, if that sort of consumption is representative.

Cellar temperature was 15.6C

Relative humidity was 78% - a little high perhaps but we had torrential rain earlier in the week and today has been very warm and humid.

Mine's a couple of degrees cooler, and has an R.H. of about 90%, but I'd guess extraction rates would be similar.

Water extracted was about 18 litres - an estimate based on the 20 litre container used to collect (see photo below) - or about 3 litres per day.

That's pretty amazing! ...So roughly 15p per litre!

That is about the cheapest dehumidification cost I've seen --- certainly cheaper than my mini-dehumidifiers. Even if it only lasted a year, and I had to buy a new one every twelve months, it'd cost only £300 a year --- I imagine that were I to have a through-ventilation system installed, it'd be between nearly ten years before it worked out any more economical than the dehumidifier.

...So I'm rethinking my plans for the cellar: maybe I'll just get a machine like yours and put the stove up in the living-room instead. Maybe I wouldn't even need LBC for that --- I'm not sure whether having the flue lined and installing a stove in a ground-floor fireplace would need LBC. It wouldn't require removing anything original or harming or altering the character of the property, so maybe I could just go ahead and do it.

Anyway, thanks for performing the experiment and reporting back: very useful, and much appreciated!

Have a good weekend,

HH.

 

[Flyfisher]

I can’t be sure, because I don’t run the dehumidifier in the winter months, but I suspect the £165/year extrapolation would be a bit on the high side because the colder months should be less humid.

The through-ventilation thing is interesting. Our cellar only has a single ventilation grille (the one in the photo) so there’s little draft through the cellar. It would be interesting to compare my results with a similar cellar with through-ventilation because there would be times when the ventilated air was warm and very humid. Perhaps it would average out over a year and make little difference?

Yes, the amount of water extracted each day is quite impressive and a constant reminder that I should really finish the job so that the sump pump empties into a proper surface drain rather than a container that needs emptying each week. Still, it’s a good source of deionised water for car batteries and steam irons :wink:

As for LBC, I doubt it’s necessary for a chimney liner and a wood stove. We have four wood stoves in total and although I included two of them on LBC applications it was only because I was making a submission for other things anyway. The other two were added later without LBC and the heritage police haven’t arrested me yet (now I’ve done it! :wink: ).

 

[88v8]

Agree with FF regarding LBC for the stove.
Providing it's just having a flexy liner installed, and not lining the flue with concrete or altering the fireplace nor the external stack, no LBC needed.

We added a chimney pot to one of our stacks, to raise the height above the ridge - we're thatched - and that was regarded as de mininimis.

I just put one of our dehumidifiers on a time switch so it will only run overnight. With doors and windows now open, it's trying to dehumidify the whole of Gloucestershire. Dehumidifiers work best in a closed system.
I had intended switching it to a more aggressive mode so it would work harder during its abbreviated operational hours, but when switched off it reverts to Auto. Heyho.

Ivor

 

[Tom-H]

An alternative idea may be to use an external air fed stove with the duct running below into the cellar if that route is possible? So air is then pulled from the cellar but with the stove being much easier to keep going in the main the living area of the house.

The cellar of my parents house would have originally had a range cooker constantly running so I agree that was one of the main reasons a cellar would have been drier. We used the cellar mainly as a storage/workshop room so I’ve never taken any measurements of temp/rh but just gone of how it feels/smells damp. In the end the best solution was increasing the air flow from the front of the house to the back and the installation of a ch radiator (Set to low). With this the cellar always feels dry and requires zero effort to maintain.

 

[Flyfisher]

Dehumidifiers work best in a closed system.

Good point. Perhaps I should block up our single cellar air vent during the summer months when I’m running the dehumidifier, then open it up again in the winter months for natural ventilation when the dehumidifier is off.

What with you dehumidifying Gloucestershire and me dehumidifying Norfolk we’ll climate between us :wink:

 

[Househunter]

Thanks for the further comments.

I can’t be sure, because I don’t run the dehumidifier in the winter months, but I suspect the £165/year extrapolation would be a bit on the high side because the colder months should be less humid.

A good point: the dehumidifier option certainly looks like it's going to be the least costly...

The through-ventilation thing is interesting. Our cellar only has a single ventilation grille (the one in the photo) so there’s little draft through the cellar. It would be interesting to compare my results with a similar cellar with through-ventilation because there would be times when the ventilated air was warm and very humid. Perhaps it would average out over a year and make little difference?

That's quite possible: it would be an open system and, as Ivor points out, one would essentially be dehumidifying the county!

Seems it's an either-or: either forget dehumidification and go the through-ventilation route or close the vents and use a dehumidifier.

Still, it’s a good source of deionised water for car batteries and steam irons :wink:

Snap! I too fill the iron with the water that comes out of my little dehumidifiers.

As for LBC, I doubt it’s necessary for a chimney liner and a wood stove. We have four wood stoves in total and although I included two of them on LBC applications it was only because I was making a submission for other things anyway. The other two were added later without LBC and the heritage police haven’t arrested me yet (now I’ve done it! :wink: ).

That's what I thought, too: putting a liner in not only has no impact on the character of the place, but acts to protect the chimney --- and is completely reversible. If they complained about something like that, I think I'd complain about them! ...Though I don't know to whom one would complain about a CO: COs don't appear to have much accountability or oversight as far as I can tell.

Agree with FF regarding LBC for the stove.
Providing it's just having a flexy liner installed, and not lining the flue with concrete or altering the fireplace nor the external stack, no LBC needed.

I'm wondering whether a stove would indeed fit in the living-room fireplace: it is a poky, modern affair with a brick/cement surround, and appears to have been used for open fires, so it may need to be modified to accommodate a stove, which no doubt means LBC. And I suppose if I must apply for LBC, then I could apply to remove it altogether and have a look what's underneath...

We added a chimney pot to one of our stacks, to raise the height above the ridge - we're thatched - and that was regarded as de mininimis.

They said LBC was unnecessary for that? You have a very reasonable CO, by the sound of it!

I'm not entirely sure what the CO here is like: a neighbour had her round for a pre-planning consultation (for which they charge £250). Despite the consultation, the neighbour still had to jump through a couple of hoops and make amendments to the plans, so I doubt that the CO here is the laid-back sort. I was reading this article the other day, and I've a feeling that she might prove to be one of the "zealous newcomers" he describes.

An alternative idea may be to use an external air fed stove with the duct running below into the cellar if that route is possible? So air is then pulled from the cellar but with the stove being much easier to keep going in the main the living area of the house.

I did actually consider that, but wasn't sure whether one could get a stove to draw its air from a pipe running up from the room below. Were it possible, then yes, it'd certainly be another option.

The cellar of my parents house would have originally had a range cooker constantly running so I agree that was one of the main reasons a cellar would have been drier. We used the cellar mainly as a storage/workshop room so I’ve never taken any measurements of temp/rh but just gone of how it feels/smells damp. In the end the best solution was increasing the air flow from the front of the house to the back and the installation of a ch radiator (Set to low). With this the cellar always feels dry and requires zero effort to maintain.

Interesting. That corroborates the view of the conservation guy in that video I linked, that through-ventilation is the optimal solution. ...Though no doubt also the most expensive! I'll have to do my sums and weigh up the various options.

Anyway, thanks to you all, FF, Ivor & Tom --- more food for thought for me to chew over!

 

[Tom-H]

I remember reading (on here I think) about somebody venting there stove from there sub floor so it’s definitely an option. Peter Ward seems very knowledgeable so I would trust his opinion but by more ventilation I simply enlarged the external air bricks and added new air bricks in between the internal walls.

Also another thing to consider, in my experience using a flue liner (which I do recommend) will massively reduce how much the chimney breast above heats up.

 

[88v8]

I was reading this article the other day...

Good article. Albeit alarming. LBC for repairs? Haha.
The CO's job is or should be one of high status, requiring as it does a considerable scope of theoretical and practical knowledge. And command a commensurate salary. But most Councils regards Heritage as a PITA to which they have to pay lip service.
Better not get started......

....wasn't sure whether one could get a stove to draw its air from a pipe running up from the room below....

The stove will pull air through the line of least resistance. Below? Certainly.

Beware; paralysis by analysis creeps up on one.

Ivor

 

[Flyfisher]

Better not get started......

Indeed. And charging for CO visits must surely be detrimental in the long run. A free, expert CO service seems to me to be a small price to pay to help the custodians of our national heritage do the right things. After all, we pay through the nose for everything else associated with listed properties.

As you say, better not get started . . .

 

[Househunter]

Also another thing to consider, in my experience using a flue liner (which I do recommend) will massively reduce how much the chimney breast above heats up.

I would actually want it to be fairly warm! The rooms above can be rather chilly, and so having a nice warm chimney breast in them would be a bonus!

Beware; paralysis by analysis creeps up on one.

Yes, it does!

Anyway, thanks both for your replies.

 

[Househunter]

Indeed. And charging for CO visits must surely be detrimental in the long run. A free, expert CO service seems to me to be a small price to pay to help the custodians of our national heritage do the right things. After all, we pay through the nose for everything else associated with listed properties.

I completely agree.

An idea that occurred to me after reading the article I linked was that, given how COs seem to be both so variable and so overloaded, it'd be a good idea to have something like the government's Competent Person Schemes --- i.e. where professionals can self-certify that a job complies with Building Regulations --- so that conservation professionals and their clients don't have to spend the time, money & effort of getting LBC for things which are routinely approved. Filing paperwork and waiting months to get permission to point the front of your house in lime is surely a waste of everybody's time.

Conservation professionals who have been plying their trade for years have far more experience and nous than this cohort of punctilious "PYT" COs fresh out of college described in that article; owners who employ conservation professionals are clearly doing so because they actually value their property and its history and are anxious to preserve it, yet they're treated like potential criminals who have to be monitored by officialdom at every turn.

Here in Wales we have Cadw, and it's depressing to read their official publications about conservation and applying for LBC, since they effectively take the position that owners of Listed Buildings have to justify any changes they wish to make to their property: surely the assumption should be that a change to one's property does not have to be justified at all, unless it would actually be against the law. (That is, unless it would involve the damage or destruction of historic material or would spoil the historic character of the property.)

It is unfortunate that the owners of Listed properties don't have much of a voice. It'd be good were there some sort of pressure-group comprised of Listed Building owners and professional conservationists, to lobby for common sense to prevail in the conservation of old houses, as time and again government & officialdom demonstrate that they cannot be trusted to exercise common sense in anything.

Indeed, they need oversight more than we do...