New bathroom
 

Greetings to all,
have recently joined the list and located in the Dunakanyar area. Living in a village style 'cob' house and considering some upgrades starting with a new bathroom. I'm a keen diy'er and like to keep things simple and functional and working on a limited budget so would be interested in any tips....The plan is to divide a room down the middle with a stud partition wall, one side to be the new bathroom containing hot water cylinder (heated from woodburner),bath, shower etc . The other side of the new partition wall (north side of house) will be kitchen pantry/storage so will need a good insulated wall. Moisture resistant gipszkarton on the bathroom side with regular on the other. The question is what would be the minimum thickness for the partion wall and which insulating material to use? After some research it seems a choice between expanded polystyrene (Hungarocel?) or rockwool wadding. We do live very close to nature (one of the pleasure of living in Hungary) and share our house with several species of small furry animals that my wife is convinced will be keenly interested in our choices of materials (this applies to the plumbing pipe material too but that for a later question....)
farka

Re: New bathroom
 

Hi and welcome
By cob I presume that you mean adobe bricks or in Hungarian vályogtégla. Great care must be taken with using the right type of materials with this type of construction. Do you have experience of working with this type of construction.

Anyway for a stud wall it will depend upon the size of the wall as to what size of timber framing is needed. Typical for a room divide that is 2.5m high would be 100mm x 50mm so the wall finishes up 100mm + 2 x 12.5mm (plaster board) so 125mm thick. If thinner studding is used then movement may happen with door opening etc. If the partition is not full height or only about 1m or 1.5m long then 75mm x 50mm can be used. On a small partition I have used 50mm x 50mm studs. 100mm x 50mm is standard building size timber. (use a builders merchant rather than the DIY sheds (OBI, Pratiker etc.) as a builders merchant is usually cheaper) The infill in stud walls is usually there for sound insulation and resonance deadening not thermal insulation as stud walls are internal walls, having said that use rockwool because for either sound or thermal insulation it is important to have no gaps at the edges and it is easier to get a good fit with rockwool (or fibre glass wool = üveggyapot).

The small furry animals need to be excluded because they can / will do a lot of damage. In order of size the options are - mice, rats, dormice or martens and from experience marten are the hardest to deal with, although we have never had rats. you won't have a problem with a stud wall because the all-round timber frame and plaster board will keep them out.

Do you have experience of wood burners? In Hungary unless you have your own supply of fire wood or buy it in bulk and can saw and chop it yourself then gas heating is about the same price as using wood and environmentally a lot cleaner. Wood needs to be seasoned for 2 years before use otherwise poor efficiency and pollution results so a good amount of storage is needed.

Re: New bathroom
 

Hi Peter and thanks for the help.
Yes, I have a little experience with repairing some of the exterior render on the house and understand the need to be careful about not using modern materials like cement that will inhibit the movement of moisture. For my experimental render mix I re-used some of the broken adobe bricks that the electrician brutally hacked out of one wall to install a new meter and fuse box. Mixed with some sand and lime it seems to be holding up well.

Before installing the new partition wall I will need to make a doorway through the adjacent internal adobe wall to give access from the kitchen to the pantry/storage. I haven't checked but I think this wall is not as thick as the house external walls and isn't a structual supporting wall so should be straightforward...
One thing I really like about thick clay walls is that they really do insulate you from the extremes of temps like we've been having in the last weeks.
The stud partition will be about 3m x 3m so I'll go with the 100x50 timber and hence 100mm thick glasswool as you suggest. I was only thinking that the hungarocel type stuff would be easier to cut and cleaner to handle. Is it necessary to fix the wadding in some way to stop it slumping down or will the horizontal noggins be enough to keep it in place?

Yes, we have the odd mouse depending on the season and the edible doormice (pele) that are the best climbers and acrobats and our cat does his best to keep the numbers down. No rats but when we kept chickens the martens were a big problem - partly solved by secure mesh fencing all around, but then the hawks attacked from above!

We have been using a woodburner (brought from the UK) for our main source of heating and fortunately we have our own source of wood to feed it. It puts out just about enough heat for two rooms in the winter and through experience (!) have learnt the advantages of having a stock of well seasoned wood. The stove came with a removable middle section with a copper water heating loop which I have never used. When installed this will also increase the volume of the stove and I am interested to see how efficient this will be in heating up a 150 litre copper cyclinder. Maybe also running a small radiator in parallel to heat the new bathroom.
The maximum horizontal run length of plumbing work will be about 5 metres. I have worked a bit with copper and as I understand it the primary cct will need to be of this and vented. The secondary will be fed from a rainwater cistern via a pump but maybe different (cheaper?) piping can be used? Also trying to make the secondary unvented (with expansion tank) so as to avoid raised up feed tank that will be problematic in the winter cold...
Anyway, I have some of the materials I need but will have shop around locally or online. Do you know the correct term in Hungarian for pressure relief valve or temp/pressure relief valve? Not sure which one I need...
Any thoughts, comments will be much appreciated,
farka

Re: New bathroom
 

What is the output of the stove to the room and output to water when the coil is installed?

It is always a bit difficult combining hot water (DHW) and heating on the same stove because conflicts will arise. E.g. when you have been running the stove most of the day (in the winter) and the DHW is up to 90 deg or more and you want to continue the space heating but can't because you risk boiling the DHW circuit so space heating has to stop or you have to dump (= waste) the DHW to lower the temperature. It is generally recommended as a best installation to separate DHW and space heating.

Design can over come the conflicts between DHW and space heating but this will involve 3 way valves and thermostats. Care has to be taken when using a pumped circuit on a wood burner because it is easy to over cool the stove which will reduce the efficiency, create more pollution and will quickly tar up the chimney which then becomes a fire hazard and the tar can leach through the brickwork to permanently stain the rendering or plaster (and can continue to stain through new rendering / plaster as well). The best solution to avoid over cooling the stove is to have a 3 way loading valve (Laddomat is one name that comes to mind) and these are put on the stove to maintain the stove water temperature at a minimum of 70 deg. These are about 130,000 forints. it is possible to maintain the stove temp. by use of a thermostat on the out put pipe preventing the pump switching on unless the temp is above 70 deg. but if the stove water volume is low then the pump will be short cycling and this doesn't provide a very good solution.

Running the water circuit on gravity flow solves the problem of over cooling as the flow reduces and then stops when the temp. of the water drops so is self regulating. But a gravity circuit needs to be installed correctly otherwise it won't work. Also you can't combine gravity and a pump on the same circuit.

You should (must) have a heat dump radiator on a solid fuel water heater that will work without a pump and is without thermostats that turn off the the radiator (i.e. runs on gravity and is permanently on). This is a safety requirement so that in the event of a power cut (or pump failure) with the stove running the system will not over heat to a dangerous level. A hot water tank just about covers this requirement but is only just because it is an insulated tank and when up to temperature can on longer act as a safety heat dump and will allow the system to boil up.

Given that you mention a 150ltr copper cylinder I presume this came from the UK. To be put on the stove it needs to be an indirect tank and with an immersion heater fitted (otherwise you will need to run the wood stove in the summer. If by primary and secondary circuit do you mean that the secondary circuit is the DHW and this water comes from a rainwater cistern? If this is the case then you will need proper filters before the pump and the water will not be regarded as potable so in theory should not be used for things like washing up. For this circuit you can use cheaper pipe, I would suggest the 5 layer Al PEX pipe as used for central heating. The expansion tank should be about 80lts and be placed between the pump and the DHW cylinder. you need a tank of this size otherwise the pump will be short cycling which will significantly shorten its life and give unacceptable quick pressure fluctuations at the tap. Check the pressure rating of your copper cylinder as lots of them won't take the pressure of an unvented system.

Are you on mains water?

Re: New bathroom
 

I don't have any manufacturers specifications for the stove but from browsing stove company websites I estimate from it's size to be between 4 to 5 Kw. With the extra midsection containing the heating loop I guess it will add another 1 to 2 Kw. As for the output to the water I haven't found how to calculate that figure. The actual coil is thick 28mm copper pipe and just less than 1 metre in length.
This is the plan - the one and only pump will be delivering the water from the rainwater cistern to the cold water taps and the copper cylinder and the primary cct. feed and expansion tank. This cylinder is uninsulated and made from heavy duty thick copper and contains in the lower half a separate 28mm copper coil to take the feed from the stove. It also has an electric immersion heater port in the top. I hope to site the cylinder on the otherside of the clay wall and about just over a metre horizontally away from the stove. Of course it will have to be raised up several feet above the stove output level so as to enable the thermosyphoning to take place. Also the the primary cct. will have to have a small feed and expansion tank set up above the cylinder with a suitable vent pipe coming up and over from the primary in the event of overheating.
I also have a small central heating radiator to act as a heat dump but not sure where is the best place to put this in the primary cct. (on the wall adjacent to but lower than the primary coil in the cylinder?)

The pump I have for the secondary cct. is a grundfos model scala sold as a booster pump for situations with low or fluctuating mains pressure but also suitable for rainwater cisterns. I intend to use it at it's lowest pressure output setting and yes I will have to do some pressure tests on the cyclinder. I was hoping to use a smaller expansion tank than 80 litre.

We are making progress - SWMBO has given a big thumbs up to the WHITE pex piping(!) and in the last days we have been sourcing batten wood and gipskarton from the scorching builders yards hereabouts...

No. When we moved here there was one of those blue streetside standpipes across the road from us but after some time the local council did some cost cutting and decided to get rid of it - without telling us...
Inspired one day during a thunderstorm whilst watching the water streaming off the roof we decided to dig a cistern as a temporary solution until we could raise the funds to have a pipe bored under the road to connect up to the main. We have also have a shallow groundwater well in the yard but the rain water proved so free and pleasant to drink and wash in whilst the mains water smelled heavily of chlorine (on some days stronger than others, which was worrying) that we never looked back...
Tnx again for the input.

Re: New bathroom
 

Because of the inevitable conflict between space heating and hot water it is generally accepted to keep the 2 separate. You will probably be heating the hot water with the immersion heater for 6 months of the year anyway so perhaps a standard 120ltr Hungarian pre-insulated electric hot water tank might be a better way to go. The normal UK type copper indirect hot water cylinder won't take much pressure. I tested one once and at about 2 bar pressure the bottom concave base belled out to become convex and whilst it did not burst this was clearly above its working spec. so it would be worth carefully checking the cylinder you have.

Do you have night rate meter on which to heat the hot water?

If you go down the route of combined hot water and heating then the indirect cylinder as you say should be on the wall above the stove level and the heat sink radiator should be below the tank and tee off the the pipe going to the tank. the return for tank and rad. tee back together to return to the stove as one pipe. Run the pipe to the tank in 28mm and tee off to the rad in 22mm. You will probably have to reduce the 22mm pipe to 15mm at the rad and increase to 22mm on the out flow in order to make the connections. If you can arrange the flow to the rad. then a cross flow will be better than in and out on the same side. If money is tight then you might get away with using 22mm to the tank and 15mm to the rad. if the horizontal distance is not too great. The trick with gravity pipework is to have an up gradient until you go down then down back to the stove (where you can go up to the stove) What you can't do is to go up - down - up - down because you will never get rid of any air locks.

You can use a tank smaller than 80ltrs but the pump will be short cycling more. Use a tank with a rubber diaphragm so that you can pre-load to about 1/2bar less than your designed operating pressure. You should try to get a tank designed for drinking water rather than central heating because the drinking water type use a different rubber and the central heating type can sometimes impart a taste to the water.

Care must be taken using rain water from the cistern for drinking water because small animals can sometimes get into the cistern and drown and even if this can't happen you get bird poo and other dirt on the roof which will wash into the cistern and contaminate the water. First level wells can also be contaminated by things falling in and also there are not many 1st level wells that are good enough for drinking water due to other contamination e.g. agricultural run off or leaking cess pits in the locality. The best advice would be to get mains water as soon as you can. Chlorine in mains water will evaporate in a day or two or you can buy filters to remove it prior to drinking. By the way we don't have mains water but we have a bore hole which is on the 3rd level water and is 120m deep

Re: New bathroom
 

We don't have the night rate meter, perhaps we should look into this being installed for top up situations when the wood is not being burned so much. During the fine weather we make good use of solar heated water for washing etc. (- another great plus to living in Hungary is the reliable summer temps!)

Will heed your advice about testing the cyclinder and arranging the pipework for the heat dump rad in relation to the cylinder. I already have enough 28mm copper pipe for the primary cct so will look for the reducer tees to connect the rad in parallel. Thanks for the tip about avoiding air locks - that's the sort of thing you realize after you've put it all together! Would you advise putting a pressure (+temp?) relief valve in the secondary indirect hot water cct and if so where to position it?

Always try to let the roof and gutters flush clean for the first 20 mins or so - again the reliable torrents of hungarian rain help with this. And of course ensure nothing can fall in to contaminate. Saw some research online from an Australian university (rainwater cisterns quite common there) that pointed towards the water reaching a state of equilibrium with colonies of beneficial bacteria living on the floor and walls. It advised against any kind of flushing and cleaning that would disturb the fine sediment. With this in mind I'll have to figure out a way to make the pump inlet foot valve float just below the surface.

In previous winters, did have some problems with the surface few cm freezing solid in January when we usually get temps under -10 C. But have since have enclosed the area within a terrace/conservatory which seemed to have solved the problem. Also looking into heating cable to tape along pipes to protect from frost for these short periods.