Central Heating Versus Pianos

by Bill Kibby MIMIT

From 1976 to 1990, I carried out a detailed survey involving thousands of wrestpin torque readings on hundreds of pianos, from brand new ones to 200-year-old, in an effort to arrive at some answers to the disastrous effects which the new popularity of central heating and cavity wall insulation had upon the majority of the pianos I tuned. That research could be documented in many pages of boring statistics, but the principal finding is a simple matter of measurement: In order to be worthwhile, room humidifiers need to consume up to a gallon of water a day to have any significant impact in a large room or small flat, and although low humidity is a factor, it is a relatively minor one, resulting in an increase of up to six times the natural rate of shrinkage. You think that's bad?...

Direct heat is the main problem:

KEEPING A PIANO WITHIN FIVE FEET OF A HEATER, OR IN DIRECT SUNLIGHT, WILL ALMOST CERTAINLY CAUSE SERIOUS, PERMANENT, IRREPARABLE DAMAGE.

In this danger zone, natural shrinkage is multiplied by up to THIRTY TIMES its normal rate. Strange as it may seem, even where there is a major obstruction such as a brick wall between a heater and the piano, the five-foot rule still holds good, with surprising accuracy, and the wrestpins within 60 inches are the ones which are most likely to suffer, not 59" or 61".

Since this is about the deterioration of wood, it probably applies equally to soundboards, keys, etc., as well as guitars, clarinets, and antique furniture. Thermostatic valves on radiators certainly can help a great deal, if used carefully, because they can stop the radiators reaching a high enough temperature to cause the problem.

The iron frame in a modern piano should remain quite cold, and dissipate heat, so it probably compensates for a lot of climatic change. However, my research makes it clear that if the iron frame does not feel cold, it is a reliable indication that the piano is receiving too much heat, and will suffer damage. Perhaps you should take your piano's temperature, and see if it is feeling under the weather!

WANTED: Any kind of paperwork or information about pianos or piano makers, such as adverts, articles, booklets, books, catalogues, diagrams, directory lists, guarantees, letterheads, pictures, postcards, posters, pricelists, receipts, record sleeves, trade cards, warranties, &c.