Managing Heat in a Large space

**mattcz** · 11th Jul 2010, 08:58 PM

[warning: the house is in Czech Republic (-25 in winter) so all normal assumptions need to be flipped on their head]

120 y.o. farm house, 65cm walls.

The house is 8m x 20m (plan). Upstairs, I am removing the ceiling into the loft and gyprocking between the loft beams. [I won't go into the reasons why but it is more than aesthetic.] This means the space will be akin to a small cathedral 8m x 20m x 5m (round abouts). This space was originally for storing and drying hops and grains. There are no internal walls and I don't plan any.

This is a mother of a space to heat but there will be a boiler in the cellar going to radiators AND a combustion fire within the room. The problem is fairly obvious: it will be 40 degrees at the ceiling before it is 10 degrees on the floor (I have no idea of the accuracy of this but you get the picture).

Grateful advice for circulating the warm air - possibly even back to the ground floor - in a way that is not expensive (there's the rub!).

(Right at the apex of the loft ceiling is a large,round, ventilation opening. It would be great if there was a venting mechanism that would allow me to blow heat out through this in the brief summer hot period but be switchable for the long winters to draw the heat back from the ceiling).

THANK YOU!!!!!

**jago** · 12th Jul 2010, 10:12 AM

I have 6 metre high ceilings in my bedrooms and whilst it doesn't get that cold, correctly placed ceiling fans to circulate the air makes a huge difference with winter heating...on the flipside I have windows at this heigh that can vent the summer heat.

So IMO Fans with a summer / winter mode

**mattcz** · 13th Jul 2010, 01:36 AM

hi jago and thanks for the response.

Can you please elaborate on "correctly positioned" and "fans with summer/winter mode"? It may sound as though I want you to install the f 'en things for me but I just have to be very clear in my head before i translate it here. Cheers

**mattcz** · 13th Jul 2010, 01:42 AM

jago - no worries, found the info quickly:

What direction should my Ceiling Fan go in the winter?

**mattcz** · 13th Jul 2010, 01:50 AM

wow...and this:

http://www.bloglighting.com/1/2007/1...eiling-Fan.cfm

answered more of my possible stupid questions about fans.

Thanks Jago, this looks like the low cost answer. I was looking at ducting made from old toilet rolls

**Black Cat** · 13th Jul 2010, 07:57 AM

If you haven't already done it, order your firewood now as there will be a long list of people waiting and it's tricky to deliver it in six foot snow drifts.

**GraemeCook** · 13th Jul 2010, 12:31 PM

Good Morning Matt

We used to live in Boston, USA where the winter temperatures hovered around -10*C and occasionally headed towards the Czech temperatures. Invigorating !!!

Radiators give off a mixture of radiant and convected heat. Radiant heat is much more pleasant and efficient. The larger the surface area of the radiators and the lower the temperature of the fluid then the higher the proportion of radiant heat. If you have a choice, go for the biggest radiators available.

Heat transfer fans are great but the have a downside. Moving air, even warm air, has a wind chill factor, so you have to warm the room a little higher (say 2*C) for the same level of comfort in still air.

Also worth looking at insulation in depth. Think about roof R=10, walls R=7 and Floor R=5, Hope I converted correctly from imperial american standards! Also think about at least double or triple glazing. We had double glazing plus secondary glazing. The payback period from double/triple glazing may seem long, but the real gain (besides reduced energy bills) is greatly increased comfort from elimination of drafts within the building.

Cheers

Graeme

**mattcz** · 15th Jul 2010, 04:32 PM

Thanks Graeme - I have only ever lived in very hot countries so all of this is a mystery to me. The very large upstairs area has 12 beautiful windows that sit only 320mm off the floor. My elementary understanding of radiator placement had me looking at low-profile radiators that would sit below each of the windows.There are two problems with this: I think that it will have a significant impact on the aesthetics of the windows and (importantly) such low-profile radiators exist but are crazy expensive.

If they don't have to go under the windows, everything changes and I can, as you suggest, buy the largest radiators that I can find.

On the fans: can anyone suggest the best distance from the ceiling for maximum effect? 2.5m from the floor are the original loft floor beams which are spaced 80cm to 1m apart.

hahaha - and here is a really stupid question: can you install fans upside down (or is there a type that you can install upside down)? It is easier for me to affix them to the top of the former loft floor beams than it is to affix them to the loft ceiling.

Thanks all.

**jago** · 16th Jul 2010, 09:37 AM

a pic of the space would help to visualise the problem....a helicopter room that could be different, have you posed the question to your sober Czech gutter man?

**mattcz** · 16th Jul 2010, 12:49 PM

lol...when is the gutter man sober?

As the floor is still in-situ, a photograph would not be as helpful as it sounds.

From an end view of the house, imagine a triangle on top of a rectangle - the triangle being the loft and the rectangle being the existing grain room. Where the two shapes meet is currently the grain room ceiling (and loft floor) on large wooden beams. These floor/ceiling boards will be removed, leaving only the 24 beams. From beams to grain room floor is 2.4m and from beams to loft apex is about 3m. Clear as mud?

Will post photos soon but they won't help with visualising this problem.

Cheers!

**jago** · 16th Jul 2010, 02:00 PM

Two things I remember about CZ was the beer and beer,I used to go Brno for the bike racing.

Ok so got the height approx 5.5 metres what are the other dimensions width and length of the room ... a friend back in London bought a converted victorian hospital ward apartment,i t sounds a very similar shape.

His was approx 25m long 7m wide by 5m high, bloody big lounge dinner with very large windows (about 600mm off floor, think bed height) can't remember how many but he put cast iron rads vertically on the walls in between the windows it looked fantastic. He had a series of stainless fans above the beams which were suspended from steel spacer bars, from memory I think 5 ..its a big space.

Not sure what your budgets are but have a look at this company Low Level radiators

Get the picture up I'm a visual person...lol

**mattcz** · 16th Jul 2010, 02:17 PM

yes...the beer is unspeakably excellent...

the grain room is roughly 20m x 8 m. Keep in mind that the 5.5m is at the apex of the loft ceiling.

I have some destroyed boards that I will remove early next week. That should enable me to take a photo that reflects the future space.

Thanks for the radiator link - there are some excellent (and FOR THE LOVE OF GOD expensive) radiators there. I am just on my way out the door for a weekend of beer up north but I will go through their clearance page early next week.

If anyone knows the answer to the radiators under windows/ largest radiators possible question (i.e. do I lose the value of having large wall radiators by not having any under the windows? Is it more efficient to place one underneath each of nine windows or have three or four very large wall radiators?)

Be back online Tuesday - have a great weekend.

M

**jago** · 16th Jul 2010, 02:27 PM

A man after my own heart drinking on a Friday morning..lol

Check out the FAQ on the link I sent you and it is probably worth a call to them or email a sketch and see if they can advise the heat BTU's. Again not knowing your budget I saw some 2100h stainless steel tubalar models at a couple hundred each ...a steal!

**GraemeCook** · 19th Jul 2010, 03:02 PM

Good Morning Matt

Our Boston radiators were, from my imperfect memory, approximately 500 x 2500 mm and maybe 20 mm thick placed mainly beneath windows. Exceptions were the hallway and the kitchen where they were against internal walls.

My understanding is that as the windows are usually the worst insulated part of a wall the heat escapes rapidly through them. The inside window surface gets very cold, and moving air in the room is chilled, falls down the window face to the floor and then circulates across the floor creating a draft and spreading cold. Hence heaters are placed under the window to attack this problem.

In our Boston kitchen - largish room about 5 x 4 metres with 3 m ceilings - the radiator was on an internal wall perpendicular to the external wall. The windows were above the sink/work bench. This still worked well; so while its best that the radiators be under the windows, it is certainly not mandatory.

Its probably even less important if you double or secondary glaze the windows.

Cheers

Graeme

**mattcz** · 20th Jul 2010, 03:19 AM

Thanks Graeme - understand now. Scared but understand

@ Jago - well it was indeed a boozy weekend on a Czech mountain for a commemorative weekend celebrating Czech, German and Polish friendship. The mountain has changed hands a few times through war and annexation. Inexplicably, the German group sang a song that basically said that the area is part of German Sudatenland.

I will check the FAQ on that site- cheers to both of you. You haven't heard the last from me.

**mattcz** · 22nd Jul 2010, 03:28 PM

some pics of the space with floorboards removed as promised.

The loft ceiling will be insulated and gyprocked around the beautiful hand-carved roof beams. The 20 horizontal beams (formally the loft floor/first floor ceiling) will remain floating between the two spaces. Ok...now I sound as though I am on drugs... see the pics and ask questions if it's not clear.

m

**andy the pm** · 22nd Jul 2010, 03:51 PM

Matt,

Its not critical that the radiators go under the windows. As others have suggested they put them there to provide a heat curtain in front of the window to stop cold air infiltration. Much like overhead heaters above shop doors. If you have double glazing and nice thick curtains with a pelmet then the radiators could go anywhere.

The important thing is to get the right number and size for the area you want to heat. My concern is that your area is quite large and I would be worried heat from the radiators would go straight up (as heat does) and the middle of the room would still feel cold. Ceiling fans could help (as most modern ones now have a summer/winter switch allowing the fan to be reversed) but I would be thinking ducted heating supplied through floor grills would be the way to go.

Another option would be perimeter heating which are basically just radiators made to fit in a trench. Here is a link for an example...
Sill-Line Perimeter Heating Limited

If you have the room under your floor you could have them fitted fairly easily I would think.

Andy

**andy the pm** · 22nd Jul 2010, 04:00 PM

I should also point out that perimeter heating is a commercial application and your boiler and circ pump may not be up to the job flow wise, I'm not sure if there are domestic applications, you would have to have a search around.

**jago** · 22nd Jul 2010, 04:10 PM

Great space... are you planning to convert this into your apartment and then rent out spaces below? Are you considering a mezzanine ?

What are the white stone piers are the chimneys or roof supports?

Where/what will be your heat source back burner boiler/ aga boiler/ gas boiler.

Are you considering putting some Velux windows in the roof openings to vent your summer heat ?

As I suggested earlier give the Rad company a quick email asking what size and spec for the volume you're trying to heat...they will work out the BTU and spec it for you.

Sounds like the weekend was a sledging weekend as much as a drinking one. So Pilsen is near the German border do you get across into Germany much, they have some fantastic heating products suited for your weather conditions and they should be slighly less drunk during the day, unless its late September in Munich.

**jago** · 22nd Jul 2010, 04:30 PM

Heat Recovery Ventilation System - Mechanical MVHR Heat Recovery Ventilation System Installer

not sure of the costs but similar to your original thougts about toilet rolls and recovering the heat I believe.

**GraemeCook** · 22nd Jul 2010, 05:33 PM

Originally Posted by jago

Heat Recovery Ventilation System - Mechanical MVHR Heat Recovery Ventilation System Installer

not sure of the costs but similar to your original thougts about toilet rolls and recovering the heat I believe.

Good Morning Matt

If you put in a quality European heat orientated heat pump such as Nibe, Heliotherm, Oschner, Neura, IVT, Sofath, etc, then a heat recovery system on the ventilation air is a very economical extra. Its almost mandatory on the near air-tight super-insulated modern buildings.

But a stand alone heat recovery unit can be quite expensive to install and to operate. You need to do the sums carefully here; perhaps getting professional advice including and energy audit.

The costs of a good heat pump system will terrify you, but the recurring costs are far lower than any other heating system in a very cold place.

Cheers

Graeme

**mattcz** · 22nd Jul 2010, 06:58 PM

some many questions, so little time. I will answer what I can quickly now and get back to the rest tonight (my time).

@andy - trench heating system out as it can't be fitted into the existing wooden floor without removing loads of floor and cutting the trench into the floor support beams. Same goes for floor grills although less destruction. If fans won't be enough, ducting in an exposed/industrial way is my low cost diy option.

@jago - the Dutch, in particular, pay good money for holiday accommodation. While my plan is to finish this area first and live in it, anyone will be able to rent it and I will go and stay in Prague or Berlin or anywhere.

The white things are chimneys. There are three: two normal size and one monster. here is a possibility of using one of these as ducting: sucking air in at the top and bringing it back to floor level (with a fan within the chimney to deaden the sound). One will be used for a combustion heater that will be used in the early and late parts of the long cold season as well as supplement the radiators in the very coldest couple of weeks.

The radiators will be heated from (probably) a combination coal/wood furnace which will either be in the cellar or in a service room on the ground floor. Not my first pick but the national gas grid ends 400 metres from my house (grrrrrrrrrrr) and coal and wood are plentiful, not controlled by Russia and fairly cheap. Before deciding to go into the loft space, they were recommending a 32kw. I am now thinking a 40kw ma be safer. But this is quite difficult to design a flexible system. There are times when I need to heat the entire house and other times when I only need to heat a small area.

Sadly, there will be 8 velux windows in the roof. But this is more because the house is catastrophically oriented so that it gets absolutely no sun in winter. Will stuff the look of the place from the outside but will be a much happier place inside.

I am heading to Germany next week to buy tun oil. It is priced like an elixir of eternal life here in cz. I often look on German sites for materials - many things are cheaper. Drives the Czechs crazy(er) as their wages are about 1/4 of the Germans'.

Will get to the heat pump link and your response, Graeme, later. Sorry - must get to the bar for lunch or the daily specials will be scoffed.

Cheers!

**Smurf** · 24th Jul 2010, 08:29 PM

Originally Posted by mattcz

The radiators will be heated from (probably) a combination coal/wood furnace which will either be in the cellar or in a service room on the ground floor. Not my first pick but the national gas grid ends 400 metres from my house (grrrrrrrrrrr) and coal and wood are plentiful, not controlled by Russia and fairly cheap.

Given the low temperatures outside, I would be comparing local fuel prices very carefully since you'll presumably be using quite a lot of heating. Choosing the wrong fuel could end up quite expensive.

I have no idea about fuel prices in your location, but I would certainly suggest you make sure that what you're going to use is in fact reasonably cheap.

**mattcz** · 24th Jul 2010, 08:44 PM

Hi Smurf,

Coal is pretty cheap here as it is mined here. Many Czech homes are heated by coal (including brown coal

) and the government is always wary of the backlash associated with coal price rises. A ton of excellent quality coal brickets is about $30 delivered.

I am also onto a great scheme: the local council has the contract to clear up and maintain the surrounding forestry plantations. This means cutting and taking away dead trees. Current cost for 4 cubic metres is $20 for tractor petrol and 80c per m3

.

Again, this is not my preferred option but I am thinking the same way that you are. There is no point in creating a beautiful; space if I can't afford to heat it.

Bottoms up!

m

**Smurf** · 24th Jul 2010, 09:04 PM

Originally Posted by mattcz

Hi Smurf,

Coal is pretty cheap here as it is mined here. Many Czech homes are heated by coal (including brown coal

) and the government is always wary of the backlash associated with coal price rises. A ton of excellent quality coal brickets is about $30 delivered.

Depending on how it's used, brown coal isn't as bad as many seem to think.

It's just that the high moisture content means that in a power station, more brown coal is used (in terms of energy content) than would be the case with other fuels since the moisture lowers efficiency. More coal used = more environmental effects.

But if you burnt the brown coal with equal efficiency to black coal then overall there's not a lot of difference. You could do this if the the coal is processed into briquettes, for example.

But anyway, $30 per tonne for coal and almost free wood seems like a much cheaper option than oil or gas (or electricity) are likely to be (without knowing the cost of these other fuels in your location, but I'm guessing they're more expensive).

I've used coal for heating briefly in the past. Only real problems (bearing in mind this was in a heater designed to burn wood, not coal) were a lot more ash and it was hard to get the fire lit. That was using brown coal briquettes that used to be made in Victoria (Australia).

**mattcz** · 24th Jul 2010, 09:12 PM

the rest are same price as in oz - sheesh

**woodbe** · 24th Jul 2010, 10:56 PM

Matt, what are you doing by way of insulation?

The building walls look to be solid masonry - is the exterior precious? I'm thinking of the thermal mass, and the possibility of insulating outside the walls, thereby bringing that thermal mass and associated benefits inside the house.

Michael

**mattcz** · 24th Jul 2010, 11:10 PM

Hi Michael,

The outside is decayed. I had considered doing it but I really dislike the uniform look that it gives to period houses. The ones around here look more like something from Disneyland than a well-maintained, hand made, piece of heritage. I KNOW that it would be REALLY sensible to do it but I just can't get over the look of it.

I suppose I could bash it around with a hammer and drag it behind a tractor to 'age' the polystyrene

m

**mattcz** · 24th Jul 2010, 11:12 PM

sorry - and to answer your substantive question: euro glass in traditional windows, best possible insulation in the roof, finding a warm woman

**woodbe** · 25th Jul 2010, 11:31 AM

Matt,

Originally Posted by mattcz

I KNOW that it would be REALLY sensible to do it but I just can't get over the look of it.

I can't disagree with that sentiment, we're in the same boat but ours is a house and just 60 years old. I'm considering putting 75mm of foam board with radiant barrier on battens on the inside of all external walls - we already have deep window reveals, another 100mm isn't going to look strange or take a lot of space out of the rooms. Internal dividing walls in our place are featureless (hard-plastered) masonry, so it might not be all bad on the thermal mass front for us...

When you say 'euro glass' you mean decent window frames and double/triple glazing?

Michael

**mattcz** · 25th Jul 2010, 02:39 PM

m,

yes, double glazed, gas-filled, windows. I would love triple but, with a total of 24 large windows, it would send me broke (quicker).

The facade will be the last thing that is done on the house. If all other measure have failed to provide a liveable winter space at reasonable cost, I may just have to do it.

This is the first time I have heard of doing it internally (also not an option aesthetically for my place) and sounds like a good option.

The sad thing about all this for me is that it is something that I can do myself without any great learning curve. A friend did his (admittedly, smaller house) including a pre-coloured stucco finish for about $1,200

m

**mattcz** · 25th Jul 2010, 02:42 PM

a clarification:

in an earlier post - which, for some reason, I can't now edit - I said that I was going to Germany for 'tun' oil. This was a typo. It is, of course, TUNG oil.

**jago** · 26th Jul 2010, 11:47 AM

Wood is the best sustainable product but Coal is okay... my parents still use it in their London house its a good source of heat, theres is a product called smokeless coal has a very high burn temp ! They've had back boilers on wood/coal fires and they'e very effective, although with 3 kids in the house they did have to put a gas combination boiler in for the mornings when all the bathrooms were going at once.

You can make you heating system flexible by having either flow control values to create zones or just enusre the rads you chose have there own manual thermostats.

Quick call the typo police TUN v Tung.

**mattcz** · 27th Jul 2010, 05:12 AM

jago, most of the coal that they use here seems to contain all the smoke that they have taken out of the smokeless ones. It is a sickly brown belching smoke.

One of the problems that I have read about these boilers is that they have a fairly small tolerance in terms of heating past their kw AND heating under their kw. I had already planned on a three zone system with thermostats but my research suggests that running a 40kw heater to heat a 15kw space (as I may want from time to time) is also asking for trouble. Because the usage of the house will vary enormously from time to time, I am half tempted to just throw bullerjan heaters in each major room and underfloor heating in the bathrooms - would save a lot of money and trouble.

Your beer is getting warm.

**jago** · 27th Jul 2010, 10:15 AM

Matt - Thats too easy I thought you wanted to make work for yourself.

I know what you mean about the old tar soaked coal...yellow smoke and a creseote smell.

Those Bullerjan heaters look the go ... Bullerjan-UK amazing the sizes (kw) they come in...and you already have the chimneys, who put you on to these? The only issue is heating your water.

Not sure what boiler set up my parents had in terms of size but the water was for the Rads as well as tap water so baths,showers etc. We never needed to have the fire going at full bore. I think alot of country dwellings still use the Aga - cooker, boiler and heater a 3 in1 effect. I will ask the folks what there systems was.

Beer - I actually got very drunk of steins of Budejovicky Budvar at the weekend it must be all the talk of Czech beer.

**mattcz** · 27th Jul 2010, 02:53 PM

morning jago,

the bullerjans (and czech copies) fairly common where I live. The originals are crazy expensive.

For water, I am actually considering instantaneous electric - something that I would never consider in Australia. Again, it is due to the great variation in usage that the place may get from time to time. If I buy a sleeve to run it through the heating system, I still need a separate system for summer.

It is frustrating that the gas finishes 400 metres away - it would solve so many problems. I gather that the village was asked how many people wanted it and they all did a quick calculation on how much alcohol they would be missing out on in making the conversion and knocked it back.

Can you get Gambrinus beer there? I can't remember seeing it.

**jago** · 27th Jul 2010, 03:44 PM

Originally Posted by mattcz

Can you get Gambrinus beer there? I can't remember seeing it.

Argh the King of Flanders; beer, wasn't he ordained as the "God of Beer"....yes it can be had in Australia but not on draft I believe a couple of places in Sydney (Resturant Bar Prague) sell it...its the Devils drink that I had when we used to go to Brno.

They probably thought we cant drink Gas ..oh well lets go to the bar ! Never to think about it again....

I dont have gas here either and its soooo short sighted... feckin town elders trying to keep the place in the 1950's but as I keep saying they're dying breed!

Have you asked the cost seeing as everything else is ...! You could get the pipe laid and terminated at yours and become the local Gas Tsar for those wanting it!

I off to do a couple of hours rubbish loading before it gets dark ....have a good one.

**mattcz** · 27th Jul 2010, 04:07 PM

yeah...I made enquiries about personally extending the pipe and the story changed to "it doesn't have enough pressure to service any more towns". Bollocks! But I think that the battle to get it might be a bit beyond me at the moment requiring, as it does, the goodwill of others.

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