Minimum Temperature for pipe organ

[beagleboigb]

I play a Patrick Murphy Pipe organ at church. There is much debate over the lowest Temp that the church can be during the winter. According to members that were there when the organ was installed they were told that the temp cannot go lower than 55 degrees or the organ would be damaged. Yet I know when I was in Germany many of those churches had no heat in them. Would appreciate thoughts and opinions on this.

[Menschenstimme]

Your church's organ is probably rather different in design and physically than an organ in a old unheated German church. The organ in the German church, be it hundreds of years old or almost new, was probably designed with the unheated church in mind. I would suggest that 65 is much better than 55 and 70 is even better.

Has there been any discussion regarding the temperature in the church while the organ is being played with the tuning in mind? Was the organ originally tuned at a certain temperature? I would hope that a church that can afford a pipe organ can also afford some extra utility bills to both protect the organ and have it in tune while it is being played. I guess that it all comes down to priorities - which is something that church people rarely agree upon.

Perhaps you have an interested member who is willing to donate extra money for climate control bills?

Good luck and God bless!

[davidecasteel]

I know that all-tin pipes will chrystallize and crumble to dust if they get too cold. I thought the critical temperature was about 40°F, though.

David

[Pipeorganbuilder]

Most churches I service have a very small split unit central heat and air installed in the pipe chambers and have the shutters to default to closed when the blower is off to keep chamber climate controlled. This keeps organ in tune not to mention helps keep all close tolerance valves from distorting. Really does not cost that much when you are only cooling these rooms and not the whole church.

[beagleboigb]

The church is alawys brought up to 70 degrees for worship services and for tuning. The church was doing very well when the organ was purchased and installed. However, like many churches now the membership is dwindling and aging and looking to find ways to save funds.

[SBurton]

I know that all-tin pipes will chrystallize and crumble to dust if they get too cold. I thought the critical temperature was about 40°F, though.

David

Sounds like an old wife's (organist's) tale to me. :P

The metal is already crystallized unless it is molten.

Then again, Wikipedia has this to say:

β-tin (the metallic form, or white tin), which is stable at and above room temperature, is malleable. In contrast, α-tin (nonmetallic form, or gray tin), which is stable below 13.2 °C (56 °F), is brittle. α-tin has a diamond cubic crystal structure, similar to diamond, silicon or germanium. α-tin has no metallic properties at all because its atoms form a covalent structure where electrons cannot move freely. It is a dull-gray powdery material with no common uses, other than a few specialized semiconductor applications. These two allotropes, α-tin and β-tin, are more commonly known as gray tin and white tin, respectively. Two more allotropes, γ and σ, exist at temperatures above 161 °C (322 °F) and pressures above several GPa. In cold conditions, β-tin tends to transform spontaneously into α-tin, a phenomenon known as "tin pest". Although the α-β transformation temperature is nominally 13.2 °C, impurities (e.g. Al, Zn, etc.) lower the transition temperature well below 0 °C (32 °F), and upon addition of Sb or Bi the transformation may not occur at all, increasing the durability of the tin.

So, if you want your tin pipes to be cold-climate compatible, add a little Antimony or Bismuth!

[SBurton]

So, if the organ has 'pure' tin pipes, it might be advisable to keep the temperature above 13.2 °C.

But, (taking the focus away from the pipes and considering the wooden components), low relative humidity and cold temperatures could play havoc with the wind chests and cause cracks to develop and seams to open up.

[Terpodion]

I have serviced a 1904 Bates and Culley tracker for many years. It is in a "summer church" - there was no heat or AC until a few years ago and the newly installed HVAC system used very sparingly. The organ is unrestored. The only work that has been done on it since installation has been the addition of an electric blower, tuning and some work on the pedal action to replace worn bushings and bumper felt. Otherwise it is in excellent shape. The leather nuts are only now starting to go. I attribute this to it being "put in a refrigerator" all winter. IMHO, heating and AC systems do more damage by lowering the humidity than temperature extremes. Granted, the B&C tracker is located in the northeast US, close to the Atlantic so the humidity never gets too low. Were it in southern Arizona, this would be another story. The low to nonexistent humidity would have worked havoc on those old slider chests. The "zinnpest" that is a big concern for the historic European organs is most pronounced at extremely low temperatures - about 45 degrees below zero, C or F (the scales meet at this temperature). Few American organs have pure tin pipes and very few places in America get that cold. I find lead sugaring more of a problem but only with the lead tubes found in action parts and poorly made reed pipes. As far as I can tell this is due to poor quality lead alloys. I was told by a pipe maker that recycled battery plate was often used for lead tubing and reed blocks.

To answer the question directly; I tell my customers that it doesn't matter how they set the thermostat during unoccupied periods as long as the organ has enough time to get up to the temperature where I tuned it. This can vary quite a bit depending on the layout of the instrument. A small organ in a case will come warm up (or cool down) quickly where an organ that is spread out in chambers and / or "flower boxes" will take more time.

[davidecasteel]

Just where in "historic Europe" does the temperature ever get to -45°? (The crossover temperature where the C and F scales are the same is -40°, BTW.) I spent 3 years in Germany and seldom even experienced 0°F. However, I believe that long exposure to even that temperature would cause "tin pest" in pure tin pipes. Admittedly, alloying the tin with any of several metals reduces or eliminates the problem, but then it is not "pure tin" is it?

I believe the "tin" pipes in our Klais instrument are actually 85% tin (not sure what the alloying metal is--probably either lead or bismuth). Here in Dallas I don't think we need to worry about them (and they are beautiful).

David

[VaPipeorgantuner]

The issue in American churches is not so much the minimum temperature (which I advise my clients should not be allowed to go below 55 to 60 degrees F) but the damage caused by rapid, large swings in temperature and humidity produced by modern heating plants. Pipe organs, being made in large part of wood products, are able to absorb and dissipate moisture, even after being kiln dried. a cool room with 50% relative humidity, when heated rapidly, may see the relative humidity drop to 20%, and that low humidity will extract moisture from wooden objects in an effort to equalize...and THAT is what causes the damage to pipe organs, not so much the temperature itself, which will cause tuning issues (but that's a different topic).

Rick in VA