Home Automation - Fan timer with "stay on" option

Author

Fan timer with "stay on" option

Lacustral

2007-07-31, 1:25 pm

Is there a fan timer that has an option to just leave it on? I'm planning
to get a bathroom fan, but I also want to be able to just leave it on, to
use it to clear air out of the house generally. The fan wouldn't be more
than about 2 amps.

I'm sure it's also possible to set up a circuit to bypass a timer that
doesn't have a "stay on" switch. How would one do that?

I want a quiet fan timer. Someone told me of a timer which goes up to
12 hours, but they said it makes noise. So something electronic, maybe.
Something quiet that goes up to 12 hours would be fine, as long as it
also lets you leave the fan on for only a few minutes.

Such a thing wouldn't have to be a *fan* timer specifically, any timer
that has a "stay on" option that is good up to 2 amps or so would work.

Thanks
Laura

Arfa Daily

2007-07-31, 5:25 pm

"Lacustral" <lark@adore.lightlink.com> wrote in message
news:46af4e5a$1@news2.lightlink.com...
> Is there a fan timer that has an option to just leave it on? I'm planning
> to get a bathroom fan, but I also want to be able to just leave it on, to
> use it to clear air out of the house generally. The fan wouldn't be more
> than about 2 amps.
>
> I'm sure it's also possible to set up a circuit to bypass a timer that
> doesn't have a "stay on" switch. How would one do that?
>
> I want a quiet fan timer. Someone told me of a timer which goes up to
> 12 hours, but they said it makes noise. So something electronic, maybe.
> Something quiet that goes up to 12 hours would be fine, as long as it
> also lets you leave the fan on for only a few minutes.
>
> Such a thing wouldn't have to be a *fan* timer specifically, any timer
> that has a "stay on" option that is good up to 2 amps or so would work.
>
> Thanks
> Laura
>

I don't know whereabouts you are, but here in the UK, such an item is
commonly available as a shower extractor fan with a built in light

http://www.screwfix.com/app/sfd/cat...-25652&ts=10039

It is hooked into the normal lighting circuit, and as long as the light is
on, the fan runs. When you switch off the light, the fan continues to run up
to an adjustable time of 20 minutes

Arfa

Lacustral

2007-07-31, 9:25 pm

Arfa Daily (arfa.daily@ntlworld.com) wrote:

>I don't know whereabouts you are, but here in the UK, such an item is
>commonly available as a shower extractor fan with a built in light

>http://www.screwfix.com/app/sfd/cat...-25652&ts=10039

>It is hooked into the normal lighting circuit, and as long as the light is
>on, the fan runs. When you switch off the light, the fan continues to run up
>to an adjustable time of 20 minutes
>Arfa

That's interesting. I don't want to leave a light on when the fan is
running, but I wasn't going to have a light hooked up to the fan anyway.
Sounds like I could use such a switch on a fan, without a light, and
leave the switch on if I want ventilation overnight, say. I wouldn't care
if, when I go turn the fan off, it keeps on running for a few minutes
after I switch it off.

Thanks. You may have come up with a creative solution that the fan
company tech support didn't.

I live in the USA.

Laura
[color=darkred]
>"Lacustral" <lark@adore.lightlink.com> wrote in message
>news:46af4e5a$1@news2.lightlink.com...

Arfa Daily

2007-08-01, 9:25 am

"Lacustral" <lark@adore.lightlink.com> wrote in message
news:46afe52b$1@news2.lightlink.com...
> Arfa Daily (arfa.daily@ntlworld.com) wrote:
>
>
>
>
>
> That's interesting. I don't want to leave a light on when the fan is
> running, but I wasn't going to have a light hooked up to the fan anyway.
> Sounds like I could use such a switch on a fan, without a light, and
> leave the switch on if I want ventilation overnight, say. I wouldn't care
> if, when I go turn the fan off, it keeps on running for a few minutes
> after I switch it off.
>
> Thanks. You may have come up with a creative solution that the fan
> company tech support didn't.
>
> I live in the USA.
>
> Laura

There's no reason that you could not run this particular fitting without the
lamp installed. It employs a switch mode power supply, which doesn't care
much whether it's got the combined load of both the fan and lamp, or just
the lamp on it. I'm sure a similar unit would be available through Home
Depot or wherever.

Arfa

Jasen Betts

2007-08-01, 9:25 am

On 2007-07-31, Lacustral <lark@adore.lightlink.com> wrote:
> Is there a fan timer that has an option to just leave it on? I'm planning
> to get a bathroom fan, but I also want to be able to just leave it on, to
> use it to clear air out of the house generally. The fan wouldn't be more
> than about 2 amps.
>
> I'm sure it's also possible to set up a circuit to bypass a timer that
> doesn't have a "stay on" switch. How would one do that?

wire an ordinary switch in parallel with the timers contacts

> I want a quiet fan timer. Someone told me of a timer which goes up to
> 12 hours, but they said it makes noise. So something electronic, maybe.
> Something quiet that goes up to 12 hours would be fine, as long as it
> also lets you leave the fan on for only a few minutes.

the cheapest timers are clockwork and do 'tick', but probably make less
noise than the fan - they're quiet enough to use in classrooms etc...

> Such a thing wouldn't have to be a *fan* timer specifically, any timer
> that has a "stay on" option that is good up to 2 amps or so would work.

I've also seen timers used to control lights and heating

Bye.
Jasen

Bill Jeffrey

2007-08-01, 9:25 am

Jasen Betts wrote:
> wire an ordinary switch in parallel with the timers contacts

Seems to me this is the easy, cheap, and obvious answer. The fan timer
would normally be mounted in a single-gang outlet box. However, you
would install a dual gang outlet box in your wall. Mount the fan timer
in one half, and a plain ol' ordinary light switch in the other half.
Wire the two devices in parallel. (That means that the incoming
black/hot power wire should be connected to one terminal on the fan
timer, AND one terminal on the switch. The outgoing black/hot wire is
connected to the other terminal on the fan timer, AND the other terminal
on the switch. If the timer is electronic, it may call for a connection
to the white/neutral wire. Both the timer and the switch may have
connections for the bare/ground wire.)

The above covers US installations. Just noticed you are in NZ. The
connection theory is the same, but I am not aware of NZ wire colors.

Bill

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