Lens Storage

You can always put a timeswitch on the humidifier...
say 3 hrs on 2 off to start. It's surprising how
heat will reduce the moisture content as well.

A dehumidifier costs about the same as a fridge to run - 'coz that's basically what it is. It should have a built-in humidistat that switches it off once the Relative Humidity (RH) has fallen to the humidistat set-point. If you want to keep the running costs down, put it in the smallest room you have and keep the room as reasonably sealed as you can. Using a timer might not have any effect on running costs, as the dehumidifier will still need to extract the same amount of water to keep RH at the same level.

Heating a room will reduce RH but increases the capacity of the air to hold water vapour. This can result in an increase in condensation if you use a fan heater intermittently. An open fire should help, because it massively increases the air change rate in a room, so takes all the warm damp air up the chimney.


Andrew

I would think in a damp environment the normal domestic
dehumidifier just keeps taking moisture out of the air all
the time. It probably never reaches a level low enough to
cut off and more damp is moving in all the time. By using
a timer it at least controls the running cost a bit and keeps
the moisture below a point where it will cause damage such
as rust metal objects.

Where do you get 60w bulbs these days.
Cheers
Dave

Amazon. Packs of 20 seem a good buy at under £10.00

Sorry, Algi, but your arguement makes no sense.

If the humidifier never switches off then either the humidistat is set at too low a RH level or alternatively the humidifier isn't man enough for the job. Using a timer only reduces running costs in the same sense as switching it off does. Practically, it is of no help in keeping RH at the desired level.

Andrew

Just looked on Ebac's site. It seems most of these can extract
up to 21 L a day but only have a 3.5 L tank, so it's going
to stop after 6 hours anyway

All the energy used is given off as heat plus heat is given
off by the water condensing on the coil. So you probably get
back twice as much heat for the enrgy put in. Would it not
be better therefore to run it mostly during the day when the
heat is usefull.

Just noticed that Soran has now said the RH has dropped to
60 this week so it looks like everything id OK now and the
de-humidifier won't be needed for more than a few hours a
day. I wouldn't even bother with it at 60.

Water extraction falls with room temperature. If the room is unheated, the extraction rate is much lower than the headline rate in the advertising. We had an Ebac 2000 series & used it in an unheated drying room (apart from the gas boiler that heats the house) - it took a couple of days to fill the tank.

I think that the COP (Coefficient of performance) for a dehumidifier is between 1.5 and 2 - maybe half that of an air source heat pump, so yes it will give out more heat than the electrical energy it consumes. For this application, the best way to use it would be to put it in the smallest room, keep all the doors and windows closed, leave it on permanently and adjust the humidistat to keep the RH below 60%. In that way, you can ensure that the RH never strays above 60% and minimise electricity usage.

If the humidistat is correctly set, and the RH is naturally below 60%, it will not switch on, so there is no need to switch it off manually or use a timer.

Andrew

My dehumidifier (can't remember the make) has an accessory in the form of a shallow funnel and plastic tube.

The funnel can be inserted at the back of the machine where it sits underneath the condenser to catch the distilled water and run it off to a sink or other receptacle like a 5 gallon container or similar.

Running the water off to a drain means the machine can be left on to maintain the relative humidity of the room 24x7.

Ebac list a drainage kit for the bigger models, but drainage
that's not up to building reg. standards can cause a lot more
trouble than just moisture in the air. 21 L/day onto the floor
can do a lot of damage. A floor gully would be the ideal
solution and might not be such a bad idea in the dining
room

This discussion is getting seriously out of hand (and off-topic?).

21 litres/day? AFAIK, the OP doesn't live in the Royal Albert Hall (nor even in "Albert's Royal Hall" as Albert Collins called it when he played there some years back)!!

Andrew

I've not been there recently, but the tunnels in a glass
museum in St. Helens would fill up to about 6 ft deep in
water if the de-watering was switched off. It used to be
programmed to run on cheap electric during the night....
fingers crossed I suppose during the day

Can we get back on topic please and try to avoid descending into the ludicrous?