Hello everyone,
I've just joined this brilliant forum,and firstly I'm seeking help with a dilemma in my recently completed barn conversion.

I did all the work myself,and we love the results,but I was probably given some not so good advice along the way.we have a 390 l thermal store located on the small,first floor (rooms I'm the roof,so low volume as well as floor area),which is served by a 14kw wood boiler stove in the sitting room near the stairs. (Solar thermal yet to be fitted; coil waiting at the bottom of the store). The system seems to work really well; with plate heat exchanger for dhw,ground floor ufh,and a small radiator circuit on first floor which we will probably never use : (

Our problem is that it gets too hot upstairs for our two daughters bedrooms, sometimes even when the stove is not lit,but the store is hot.(me and partner,have gf bedroom which is cool if we want). As a result,the girls insist on opening the roof windows to cool their rooms,thus letting a lot of precious heat out and noticeably cooling down the ground floor. It really frustrates me; i meticulously fitted a lot of insulation in the roof, and even used a perlite/lime backing plaster on the thick cob walls for that extra bit of warmth (perhaps?!?).

My thoughts on how i can improve the situation are....

1. Add loads more insulation around the thermal store itself - which I'm in the process of doing,

2. Insulate the ts cupboard doors- done that, with 25mm celotex,

3. Add more insulation to the ts cupboard itself,

4. Tell the girls to shut their bedroom doors if their windows are open - they don't always, so I'm often trotting up the stairs to check.. A real hassle!

5. Fit door closers on their bedroom doors - "dad, you're getting a bit anal about all this heat loss stuff !" ,

6. Somehow fitting a fan somewhere clever to either send heat from the ts cupboard,or ff in general,downstairs to equalise the temperature of the barn.

I can't isolate the two floors,the landing is tiny so a door at the top of the stairs wouldn't work,or comply with regs, and the bottom of the(kinda) spiral stairs are open to the sitting room and a very beautiful feature,and i aint moving the store downstairs...there's nowhere it can sensibly go (and the thought of re-routing all the plumbing..!)

Soo, I'd love to know your thoughts; if any or which of my ideas,would help remedy the situation. Of course,it's not all the thermal store's fault,bless it...the woody puts out 5 kw max to space (officially),and,as i said, it's located near the stairs. Oh,and by the way,all first floor voids are well insulated,with super good underlay n carrpet above!

Many thanks, (as i have gone on a bit)

Jules

Turn the store temperature down, insulate all the pipes, is the store 4x spray insulated?

Insulation would be better than thermal mass.

Fan system or HVHR to circulate the unwanted heat.

Thanks for the responces..

Gyro,i simply don't have the space to add thrmal mass such as conc blocks,and would be concerned about the added weight on my joists. Tony,the store seldom gets above 65-70°c in normal use (remember we only have the wood stove at the mo; solar to come later. If we push the temp up beyond that with the stove, it tends to get a bit too warm downstairs (at this time of year) I've insulated all the pipes. What do you mean by 4x,spray foamed? The tank as standard only has 40mm insulation,so I'm in the process off adding as much as i can; basically a celotex 'box' around the store with the space between box and store filled with mineral wool.Not sure how to tackle the busy side of the store ,with all the bosses,pipes etc. I like the idea of a fan system though. Should i take heat from the girl's rooms,or from the ts cupboard? Djh, I'm sorry,I'm not able to provide a floor plan or temperature readings right now; though it would be useful to have an ir thermometer. Suffice to say,the store cupboard is right against one bedroom,and the store is a very tight fit in there.

Iwas half expecting to be told it was simply heat from the woody going upstairs! But given all your responses,i think it best for me to carry on adding as much insulation as i can around the store,and also the cupboard, and see how that helps. If the girls are still too hot and opening windows, i may fit a fan to take heat directly from the ts cupboard to downstairs,perhaps to our cooler gf bedroom if possible.

Tbh,,i have been suprised at how quickly the store cools down when theres no heating on or showers etc used. I guess 40mm insulation isn't much.

Thanks to everyone for your help and ideas. I'll let you know how i get on.

Cheers

Jules

40 mm of insulation is not a lot but something else to consider is the insulation on the pipes to or from the store which needs to be good for a surprisingly long way from the store to stop losing heat along them.

Julesbarn - something like this might work:

http://www.treehugger.com/gadgets/totally-tubular-innovative-fans-redistribute-hot-ceiling-air-floor-warmer-rooms-lower-heating-costs.html

I don't know the layout of your house but would it be possible to have the top of the tube close to the ceiling inside the TS cupboard and the bottom end near the floor of the room below?

Too late now obviously but I wonder why you put the thermal store on the first floor? The water plus the store itself is almost half a ton in weight - that's a heck of a load on the floor joists! That's why mine is on the ground floor (concrete). It is difficult to retrospectively insulate the store as I have found to my cost. I should have gone for a much thicker foam layer to start with as I cannot insulate the store as I would like because of all the pipe connections, immersion heaters etc. Our TS is in a cloakroom so it comes in handy for drying out wet coats etc! I did think about putting a fan in the door so as to extract the warm air from the cloakroom and blow it into the hallway but have never got around to it.

Posted By: djhYou really should get an IR thermometer. They're available at screwfix or maplin or lots of other places. That will help decide exactly what the problem is and so where to direct your efforts (and money).

Of course you already come equipped with a fairly good temperature sensor - the Mk 1 hand. Unfortunately, it's quite difficult to calibrate, but it's pretty good for deciding whether pipes are cold, warm or hot. Go and feel all the pipes connected to the store - any that are hot are definitely losing heat, any that are warm need more investigation.

One more question - what ventilation do you have? Especially in the bedrooms and the thermal store cupboard?

When I insulated my DHW cylinder and cupboard, I reduced losses by about 2 kWh/day (cylinder is 200lt and I run it at 50°C).
So that is power reduction of about 90W. So could be well worth doing as you are running hotter and have a larger surface area on your cylinder.

The quick and easy way to stop overheating may be to put a fan in and just pump that hot air out to somewhere else. Somewhere else may well be outside, or to a colder part of the building. Just depends how easy the route is i.e can you put in some boxing and pump it downstairs.

Photos of the store would be good. I have just bought a load of K-Flex insulation from http://www.insulationandlagging.co.uk/Pipe-Insulation-Lagging/K-Flex-Class-0-Rubber-Pipe-Insulation and put it on my TS and it has made a huge difference.

I worked out sizes so I doubled up the insulation to a minimum of 22mm wall thickness on a 22mm pipe, and more for some of the hotter pipes. I also bought the glue so the joints are all properly sealed and also some tape for pipe joints that would be difficult to insulate otherwise.

My TS is in the integral garage (to prevent such overheating) but the garage was always a bit warm. Having eventually insulated the pipes properly it has made a huge difference.

Broken out the IR thermometer (measurements taken at same level on tank):
Ambient fabric 16
Internal Tank 65
Surface of tank 18
External pipe on entry to tank 22 (2x13mm wall thickness 28mm pipe)
External pipe 50mm from tank 20 (no flow)

Actually on entry to the tank insulation is thinner as there are some big fittings.

I do feel that glueing the insulation makes a big difference to the efficiency of the insulation.

Posted By: JulesbarnDjh..no ventilation in the ts cupboard. Why on earth should there be? The bedrooms have big velux type roof windows with high spec dg,and little closeable vents at top.

Well, we're discussing adding ventilation to the cupboard is why; I asked more for completeness. So the house is passively ventilated, with trickle vents and extraction fans in bathrooms?

My guess is that extracting air from around the thermal store will help - do make sure it isn't drawing air through the insulation. If the 'hot' bedroom is still too hot, I would make small air channels alongside the wall of that bedroom, perhaps using corrogated cardboard or twinwall polycarbonate to form air tubes, and make sure the fan is drawing air through those tubes.

But a few measurements with your IR thermometer when it arrives will confirm exactly where the problem is coming from.

I used glass wool to insulate my TS and cut the wool for best fit around the pipes and then stuffed bits of glass wool into any holes left to complete the jacket. When it was done I covered the whole lot in a plastic sheet taped and tied together with special attention around the pipes. Not the most pleasant job I have ever done!!! Luckily there are no pumps etc within the insulation jacket volume. If you have such then you will have to contrive some shielding to keep the insulation off the pumps and alike. (or move them)

By the way my TS is 2000lts and came without any factory insulation, so took a fair amount of glass wool.

Posted By: SteamyTea

The quick and easy way to stop overheating may be to put a fan in and just pump that hot air out to somewhere else. Somewhere else may well be outside, or to a colder part of the building. Just depends how easy the route is i.e can you put in some boxing and pump it downstairs.

I think maybe Julesbarn has missed my post above where I suggest the same idea. It's what I would do but I don't know the layout of the house so it may not be possible to find a suitable place to discretely place the necessary duct?

Posted By: JulesbarnNo,sorry i was aware of the suggestions to add a fan. A senior moment on my part perhaps.
IF the insulation doesn't do the trick, there is a very discreet route ducting could take,not to the coolest gf room,but much better than venting it outside and wasted.

Many thanks

Jules

Oh good - worth considering I think, especially if you can get a low energy fan.

..and I've never typed the word 'insulation' so many flippin times in me life!!

Yep steamy,just said that above. Will the pumps be happy only just outside the ins.?