The following text is reprinted
from the Air Improvement Centre antique care leaflet. Copies are available,
free of charge.
Much of the damage to furniture has been caused by central heating dryness,
and it makes sense to suggest that the client installs a humidifier, preferably
before the restored piece is returned home. Occasionally, there is the opposite
problem of excessive dampness, especially in unheated premises, or storage areas.
HOW TO PROTECT IT FROM THE RAVAGES
OF CENTRAL HEATING
SITING
Furniture should never be placed directly in front of a radiator. It should ideally
be at least two feet from any heat source. If a piece of furniture really has
to be placed near a radiator, a possible compromise would be to devise an insulating
protective ‘barrier’. This could take the form of a decorative fire screen with
an insulated/reflective backing.
A humidifier can be sited anywhere in the room near an electric socket, but not
under a piece of furniture or in front of a fireplace or open chimney. A good
position would be behind a sofa, and in front of a radiator, so it is hidden from
view but the rising heat helps circulate moisture in the convection currents.
Most house plants relish additional humidity, and can be used to hide the humidifier.
Some interior designers have come up with ingenious ways of concealing a very
functional humidifier within an aesthetically-pleasing cabinet.
ENVIRONMENTAL CONTROL
Antique furniture needs protection from low levels of relative humidity caused
by central heating. Without humidification the relative humidity may well fall
to dangerously low levels of 25-30% rH which is close to that in the Sahara Desert.
USE A HUMIDIFIER IF YOU HAVE CENTRAL HEATING
Prevention is always better than cure. It is possible to safeguard antique furniture
from dry air damage by investing in a good humidifier which will help maintain
a constant level of relative humidity in the air during winter heating. Simply
placing a bowl of water or a pot plant near a piece of antique furniture is of
little value in protecting it from the effects of central heating. For a normal
comfortable indoor temperature of 70ºF, aim to maintain 50-55% relative humidity.
Electric Humidifiers
The choice of humidifier depends on room size and purpose. It is important to
get specialist advice on the most suitable model.
Humidifiers incorporate a safety
cut-out to switch off automatically should you forget to refill. They are also
silent, completely hygienic, and simple to use. They are suitable for use with
hard water, and need only to be descaled periodically as for a kettle.
Different Features and Types of Humidifiers
Electric humidifiers operate by various different principles,
each with different features:-
Steam evaporation - Produces gentle, warm, visible steam. Silent (no moving
parts). Hygienic (sterile in operation), good moisture distribution. Easy to
clean. No filters to change. Suitable for hard or soft water.
Fan-assisted evaporation - Produces cool, invisible moisture. Motor noise. Regular
cleaning essential to avoid stagnation. Need filters changed regularly.
Ultrasonic/atomisation - Produces jet of visible cold mist. Humming noise. White
chalk dust deposits on surrounding surfaces. Localised effect. Needs water softening
cartridges changed regularly. Use distilled or very soft water.
N.B. For Health/Medical Use:
Steam evaporation humidifiers (such as Turmix) are the only ones which are completely
silent and suitable for use in nurseries, bedrooms and sitting rooms (no moving
parts, no ultrasonic humming). The Turmix also holds enough water to last right
through the night (safety cut-out).
They are also suitable for use in hard water areas. Any minerals in the water
are left behind in the water tank, which needs to be descaled periodically (as
with a kettle). Only pure water vapour is produced into the room (unlike with
ultrasonic and atomisation humidifiers which spray a fine film of white chalk
dust onto surrounding surfaces).
Similarly, because the steam has been heated, it is completely hygienic - the
gentle warm steam from the Turmix 200 is frequently used for inhalation to ease
congestion (with eucalyptus or tea tree) or aromatherapy (with lavender or camomile
etc. which are calming and soothing).
Non-Electric Humidifiers
If you prefer non-electric humidifiers, use a large capacity hang-on radiator
humidifier. These should be used on all radiators in the rooms concerned.
Such humidifiers can be hidden within radiator housings. The front of the housing
needs to be hinged to allow easy access for daily filling.
You cannot over-humidify with these non-electric humidifiers. To get the best
output, use the largest size that your radiator can accommodate and remember
to fill daily. Essential oils can be added if desired.
Hygrometers
Be sure to use a hygrometer to check that the relative humidity stays in the region
of 50-55%.
© 1999 Valerie Taplin Air Improvement Centre