Condensation Control in Homes - Important Notes for Householders
A post written & contributed by Mark Williams, J&M Remedial Services
A THERMOSTAT CONTROLS A REFRIGERATOR
A ROOM THERMOSTAT CONTROLS CENTRAL HEATING
A THERMOSTAT CONTROLS AN OVEN
ROUTE 1 - HUMIDITY CONTROL EQUIPMENT
1. In your kitchen and bathroom you may have a humidity controlled fan system. This is an extract fan controlled by an electric humidistat.
2. Air contains unseen water and the humidistat constantly checks how much. At a pre-set level the humidistat will automatically switch on the fan to extract the unwanted airborne water. It will automatically switch off when it has vented the moisture.
3. Most water is produced in the kitchen and bathroom and your humidity controlled fan systems will be installed there.
4. You will see the fan come on when you wash up, cook, bathe, wash clothes etc. Neither the humidistat nor the fan require you to operate them to work – they control themselves automatically, 24 hours a day, all year round.
5. Your humidity controlled extract fans have been installed to alleviate condensation, excess moisture on walls, windows etc. To vent the moisture the fans must operate. The fan will operate when moisture is detected which if not vented could result in unpleasant condensation.
6. Typically your fan will operate for no more than 3 hours a day. However, if your home (or a new house) has not dried out the fan can run continuously for up to two weeks after installation until the Relative Humidity is reduced. Also at certain times of the year (hot sticky wet days) the Relative Humidity of the air outdoors can rise above 65%. This may cause the fan to run for an extended period of time. Whilst this extended running may be a nuisance, it is vital so that it can maintain the minimum possible level of humidity in the home.
7. Your humidity controlled fan may be connected to an over-ride switch. Operate the switch only if you want the fan on continuously for a period of time. For example you may want to vent cooking smells or to lose indoor hot air on a summer's day. Remember to operate the switch again when you want the system to control itself.
8. Occasional cleaning of the fan is required – to be carried out by a service engineer.
9. Finally, the important matter of running cost and the effect on your electricity bills. Your humidity controlled fan system will run at 20 watts, compared with an economy light bulb at 25 watts.
ROUTE 2 - CONTINUOUS TRICKLE FANS
1. In your kitchen or bathroom you may have a constant trickle fan. These fans usually have a pull cord boost (override) – always switch this back to trickle after excess smells/moisture have been removed.
2. Air contains unseen moisture and if the trickle fan is fitted with a humidistat and there is excess moisture, ie
60-65% Relative Humidity, it will automatically boost the fan to a higher speed and reduce speed to trickle
when humidity is reduced.
3. Most water is produced in the kitchen and bathroom and your trickle fans should be located there 150mm
below ceiling to centre of fan on an outside wall.
4. You will see the fan come on when you wash up, cook, bathe, wash clothes etc. Neither the humidistat nor the fan require you to operate them to work – they control themselves automatically, 24 hours a day, all year round.
5. The trickle fans are installed to alleviate condensation, excess moisture on walls, windows etc. To vent the moisture the fans must remain ON.
6. Your trickle fan runs quietly 24 hours a day, 365 days a year and if a humidity model, will automatically speed
up or go back to trickle if the humidity level increases above 60% Relative Humidity.
7. There may be an override switch (with a cord) – only pull this to quickly remove smells.
8. Fans need occasional servicing and cleansing by a professional Service Engineer.
9. Finally, the important matter of running cost and the effect on your electricity bills. Trickle fans are very low drain and have 20watt electric motors, less than an economy light bulb at 25 watts.
Please visit www.jandmremedialservices.co.uk
for more information.









