A dehumidifier is used to lower the relative humidity (RH) in a property. This article will tell you how long you should run a dehumidifier for to reach proper RH levels.
The ideal RH for a domestic house is around 40%-55% however the low annual average humidity levels for cities like Birmingham and London runs at 70% so it could be quite a battle to get healthy RH levels in your property.
Given that mould starts to grow at around 65% RH it is a must that your properties RH levels stay well below mould producing levels!
To get an accurate picture of RH levels in your property you should ideally buy a damp meter (also known as a hygrometer). A hygrometer will show you RH levels for each room in your house. Each room will, of course, show a different reading.
The kitchen, for example, could be a very wet place due to containing the stove, kettle, sink and dishwasher etc. Even your living room could be relatively wet due to water in flower vases, cups of tea and even breathing!
As you use your dehumidifier you can then monitor the RH levels with your hygrometer.
Note that only several of the more expensive dehumidifier brands feature a LED monitor on their control panel to show both the current temperature and relative humidity.
A control panel based LED monitor is something that we at ByeMould would love to see more of.
How Long Should I Run a Dehumidifier For?
As all properties vary in regards to size and dampness there is no set limit about how long to run a dehmuidifier for however here are some general guidelines.
Initially your property will, in all likelihood, be very wet therefore you should run your dehumidifier continuously in it’s highest setting.
Once the dehumidifier stops collecting water the set humidity level has been reached. If you are using Laundry Mode then you need to keep an eye on the humidity yourself as in Laundry Mode the dehumidifier will owrk continuously until the air contains a very dry 35% humidity level.
Generally speaking when first using your dehumidifier your 2 litre water tank will probably fill up after just 6-7 hours or even less!
Typically dehumidifiers have different settings for different RH levels. Therefore it is good practise to run your dehumidifier continuously until the RH falls below the 60% mark.
Once RH is below 60% you can then experiment with using the dehumidifier during day light hours and leaving the dehumidifier off during the night.
The Best Automated Dehumidifiers
The best dehumidifiers can sense RH levels themselves and have the ability to toggle between settings.
These type of dehumidifier are called automated dehumidifiers. The other type of dehumidifier are manual dehumidifiers on which the operator must change the operational settings.
Instead of running in a pre-set setting all the time these dehumidifiers go into fan only mode once the required RH level has been reached.
It is easy to see that these units are cheaper to run rather than having a unit that runs in a pre-set setting all the time.
In the case of the Meaco DD8L the unit goes to sleep mode when the set RH has been reached. It then switches into the pre-set setting after half an hour where it scans the RH for 5 minutes to ascertain that the RH is still at the required level.
If the RH has risen the unit keeps working to bring the RH down.
If the RH is still within set limits then the units reverts back to sleep mode.
Here is a review of the Meaco DD8L that describes how the unit was used;
I am so impressed with this little machine, I must admit when I first plugged it in it was on almost constantly for around 36 hours, the amount of water it collected during that time was simply amazing, the humidity in our bungalow was always around 57% and no matter how many times windows were opened or left open during the day, we would always wake up to dripping windows, this was despite having a refridgerate dehumidifier running during the day trying to combat the humidity (it was too noisy to be left on at night). The DD8L has brought the humidity down to around 42% and it hardly comes on during the day at all now. It is left on 24hrs a day, its fairly quiet but not super quiet, we have managed to place it in the hall away from the bedroom doors. The only down side to this machine is that because it is so efficient and the water tank being fairly small, it needs emptying regularly, if you forget to empty it before going to bed and the water tank fills, you will probably be woken by its ‘tank full alarm’ (three or four beeps).
I am pleased to say that our condensation problems have been solved.
It is important to realise that the Meaco DD8L goes into sleep mode while other dehumidifiers with energy-saving technology keep their fan running once the set humidity level has been reached.
Therefore while other dehumidifiers would run in fan-only mode for an hour the Meaco DD8L would only run in fan-only mode for 10 minutes every hour provides that the humidity levels stay sufficiently low.
The cost-savings of this feature are immense with Meaco claiming that up to 80% of power consumption can be saved through utilisation of Meaco’s Control Logic technology.
Check The Latest Meaco DD8L Price on Amazon Here
Handy Dehumidifier Features
Apart from energy-saving features such as Meaco’s Control Logic and EcoAir’s E7 technologies another useful feature to look out for is a timer. Both of the dehumidifier models listed above feature a timer.
Obviously a timer is useful if you are running out the door in the morning to go to work, if you are drying a painted wall or if you are drying laundry indoors etc.
We hope that the above article has answered your question however if you have any further questions feel free to ask in the comment section below.