What are the symptoms of low humidity?
Air that is too dry brings as many problems as air that is too wet. Often people accept these problems without understanding that they are avoidable. The effect of dry air is to initiate a flow of volatile substances including water from solids into air. In other words, things are more prone to drying than is desirable. Not only is this effect easily seen as cracks in woods used in furnishings and antiques but also consider the following symptoms;
Damage to paper and books
Damage to furniture, particularly old pieces and those with veneer, resulting from moisture being lost from wood and adhesive bonds.
Polished surfaces can become dull as microscopic cracks proliferate in the polish surface.
Damage to musical instruments, not only visual damage, but wooden instruments can stray out tune as wood looses it moisture content.
Paintings can flake as surface layers become drier than base layers.
The damage that can be caused by dry air to fabrics, furnishings, antiques and musical instruments, is increased by numerous rapid swings in the humidity level. (A similar effect to frost damage where several temperature changes across the freezing point can do damage to building materials like bricks cement and stone)
Health symptoms;
Dry skin is often just assumed to be a medical condition, however, dry air is a known contributory factor, with the effect that it can be come itchy, rough, flaky and inflamed.
Respiratory ailments. Increased levels of asthma, colds and coughs. Dry air tends to be more dust laden air and can provide an easy trigger for respiratory conditions.
Tiredness. Symptoms of fatigue are sometimes associated with dry air. The reason is because an oxygen deficiency in the body and blood can develop because although the oxygen is present in air, its' transfer to the blood stream in lungs is lower in dry air.
Dry hair. A contributing factor to dull lifeless hair with split ends is dry air.
As well as the obvious effects on building contents being too dry, there are other less obvious symptoms;
Static shocks. In dry environments static shock increase when touching metal objects.
Listless pets. Often forgotten, but pets can have as much discomfort as humans from dry air.
What can humidifiers do in the office environment?
Where people are uncomfortable in their homes it is largely their own concern, however, in an office environment it is the concern of the employer, because there are specific guidelines on air quality (including humidity) to be followed and because uncomfortable employees generally perform at lowered efficiency. In offices that are prone to have low relative humidity, the addition of a suitable humidifier will ensure that the humidity falls between 40 and 60% RH, which will have the following effects:
Optimal % RH for concentration
Lowered electrostatic shocks
Less absenteeism due to colds coughs, skin dryness etc.
Less eye irritation, particularly for those with contact lenses and those who work for prolonged periods at a computer terminal
Compliance with guidelines produced by CIBSE, BSRIA, and HEVAC
Compliance with Health and Safety Executives regulations
What can humidifiers do in the home environment?
Where homes are prone to having dry air, particularly modern, well insulated homes with central heating, the addition of a suitable humidifier can prevent the damage and symptoms that are associated with dry air.
Minimise split ends and dry hair
Reduce static electricity
Stable humidity with the 40-60% RH range is best for prolonging the life of antiques and furniture
Musical instruments more likely to stay in tune
Lowered incidence of tiredness and lethargy
Less airborne dust levels as humidity tends to capture dust and make it settle
Reduced dry skin issues and discomfort
Happier pets
It can be confusing when there are so many symptoms of dry air and many, some similar symptoms in air that is too humid. The the incidence of allergies, asthma, viruses and bacteria for instance, increase at both ends of the humidity scale, although the allergies and asthma may have different causes and the viruses and bacteria will be different strains, there is, nevertheless, a happy humidity medium that we should aim for to achieve the best environment for ourselves, our homes and our possessions.
The various professional guidelines on building and ventilation tend to agree that the ideal humidity level should be between 40 and 60% RH, and as close to 50% as can be economically achieved. Many offices and modern homes can have humidity levels in the region of 25-30%, and all of the symptoms that associate with dry air. With a suitable humidifier used in a home or office, the humidity level is very easily and cheaply increased to the desired level.
Mobile humidifiers have a water tank and some means of dissipating water. The dissipating system varies from one model to the next, but generally they are either a wick from which the water is evaporates or a misting mechanism.
Relative humidity, often referred to as RH, is the measure by which moisture in air is measured. It is represented by a percentage value between 0 and 100%, where the meaning of 100% RH is that the air cannot hold any more water at that temperature. A value of 25%RH would be typical of that found in a desert. Generally the 'ideal' value for enclosed living spaces is accepted to be 50% although in reality humidity variance between 40 and 60%RH is perfectly acceptable.
Is a humidifier any use to a gardener?
Yes. Gardeners should not overlook the benefit of humid air for propagating plants in their greenhouses. Most plants do better in humid conditions and by keeping the air humid the soil dries more slowly and seedlings particularly will be less likely to dry out.
Is a humidifier any use for aromatherapy?
Yes. Humidifiers are ideal mechanisms by which to release pleasant aromas though you home. By adding some aromatherapy fluid to the water in the tank, the aroma is released as the unit is used.