Air Conditioner - How To Limit The Min Temperature

[ClaudeFeller]

In my holiday home I never charge the guests for electricity - most of them are very nice peoples and they appreciate this.

Lately a couple kept the AC in the bedrooms running day and night, of course the doors open to get an icecold living room as well.

Enough, I want to avoid this.

Is it possible to limit the minimum temperature on the remote control?

P.S.:

No advices like:

- Charge for electricity

- Get a key with power switch

I like to keep it like that.

[Naam]

In my holiday home I never charge the guests for electricity - most of them are very nice peoples and they appreciate this.

Lately a couple kept the AC in the bedrooms running day and night, of course the doors open to get an icecold living room as well.

Enough, I want to avoid this.

Is it possible to limit the minimum temperature on the remote control?

i don't think it is possible. i was trying to rig two remotes the opposite way, meaning to have the compressor run even when the set minimum temperature has been reached. no success as all functions are embedded in a single chip (both transmitter and receiver).

[Crossy]

A Cunning Plan

Dismantle your remote, find the 'temperature down' key and stick one of those sticky paper circles over the contact, re-assemble the remote. Set the temperature by pushing the 'up' button, guests cannot reduce the temperature 'coz the 'down' button no longer works.

QED

There could be an issue with the set temp going to 18C (or whatever) when you remove the remote batteries (so smart guests will not be defeated), but I currently have no better ideas

EDIT Naam, can you not simply unplug / remove / short / replace with suitable resistor the air temperature sensor in the fan unit so the unit thinks it's always too warm?

Actually, our OP could possibly re-calibrate his temperature sensors so that '18C' is really 25C, could be worth a chat to the aircon man

Edited August 4, 2008 by Crossy

[ClaudeFeller]

Thanks Crossy,

but QED ("Quod erat demonstrandum", not sure) means that if the guest is pushing the temp. up buttom it will be a bigger problem for me.

I will talk with a good aircon man..

[Crossy]

but QED ("Quod erat demonstrandum", not sure) means that if the guest is pushing the temp. up buttom it will be a bigger problem for me.

I will talk with a good aircon man..

555, QED really isn't the correct phrase, 'sorted' would be better

Disable the button that DECREASES the temperature setting so the guest can only INCREASE the temperature (reduce the cooling) which should reduce your electricity usage.

Edited August 4, 2008 by Crossy

[AFKAFSinLOS]

Not a technical solution, but I always feel that if people are doing things you don't like, then ask them not to do it.

Applied in your case, it is probably better to ask them before they cause a problem not after. Most people are pretty good natured and fair, so appealing to their better nature will help. Hotels and guest houses can do this quite effectively with messages in various places, that make people think twice, along the following lines:

- Thailand is a beautiful place, please help us keep it that way by saving the environment, and switching off the aircon when you don't need it.

- We do not charge for electricity. We trust that our guests care and will switch off aircon when not in the property,

blah blah blah

Personally these messages do change my habbits, and I'd assume they do for others too. Won't work for everyone as you'd like, but if it cuts some out that would be better than zero...

BTW If someone gave me a remote that only allowed me to increase the temperature that would just p**s me off. Short term gain maybe, but I wouldn't come back...

[think_too_mut]

Is it possible to limit the minimum temperature on the remote control?

It is possible but requires low level programming (assembler) and burning the result into the chip of the remote control.

People who do that for a living charge 20US$ per unit.

Hotels do that - see if you can make the aircon in a hotel cool down under 18C or heat up over 28C.

Mostly, you can't.

[Khun Ngo]

It is very simple:

Go to where they sell electronic stuff, Ban Mor for example and

buy a thermostat that plugs into a standard 230AC power outlet.

Connect the Aricon through this thing and place it where the tenants

can't find it, maybe in the wall, ceiling etc...

Set the min. tem. and you are done.

Will cost you maybe 500- 2000 baht depending on the thermostat.

[ZZZ]

Many aircons work without the remote.

There is a switch on the aircon that you can use to start and stop it, no remote required. When switched on this way the aircon will run at preset settings, usually hi fan speed, 22C. (Check your manual for more info)

[think_too_mut]

Many aircons work without the remote.

There is a switch on the aircon that you can use to start and stop it, no remote required. When switched on this way the aircon will run at preset settings, usually hi fan speed, 22C. (Check your manual for more info)

True, but the poster has remote controls for his aircons.

[Naam]

Many aircons work without the remote. There is a switch on the aircon that you can use to start and stop it, no remote required. When switched on this way the aircon will run at preset settings, usually hi fan speed, 22C. (Check your manual for more info)

setting the unit at 22ºC is exactly what Claude wants to avoid (i assume)

[Naam]

A Cunning Plan

Dismantle your remote, find the 'temperature down' key and stick one of those sticky paper circles over the contact, re-assemble the remote. Set the temperature by pushing the 'up' button, guests cannot reduce the temperature 'coz the 'down' button no longer works.

QED

There could be an issue with the set temp going to 18C (or whatever) when you remove the remote batteries (so smart guests will not be defeated), but I currently have no better ideas

EDIT Naam, can you not simply unplug / remove / short / replace with suitable resistor the air temperature sensor in the fan unit so the unit thinks it's always too warm?

Actually, our OP could possibly re-calibrate his temperature sensors so that '18C' is really 25C, could be worth a chat to the aircon man

i tried to wrap the sensor that it is not exposed to the airflow Crossy but this does not solve my problem because sensitivity (up and down) is lost and i need sensitivity again at a later (several hours) stage. the easiest way (i think) would be drilling a hole in the wall and bridge the compressor relay with a simple on/off switch mounted on the inside wall. in other words, the switch overrides the thermostatic control of the inside unit. switch on = compressor on, switch off = inside unit takes control. unfortunately my limited detail electrical knowledge is nowadays buried under nearly two decades of retirement

[ClaudeFeller]

Nam, I want to avoid temp below 22°C. Personally I think that 24°C with a dry air is a nice temperature to relax in LOS.

AFKAFSinLOS, your goodwill in gods sake, some people like to get a maximum out of what they have paid for. But I will try it although...

Generally I believe it is nonsense to have a temperature below 22°C but at the BKK hotels I know even 23°C is very cold because the aircon is oversized.

[Naam]

Nam, I want to avoid temp below 22°C. Personally I think that 24°C with a dry air is a nice temperature to relax in LOS.

AFKAFSinLOS, your goodwill in gods sake, some people like to get a maximum out of what they have paid for. But I will try it although...

Generally I believe it is nonsense to have a temperature below 22°C but at the BKK hotels I know even 23°C is very cold because the aircon is oversized.

= much too cold for my liking and dangerous for the health. temperature differentials (inside/outside) should not exceed 8ºC to avoid colds, bronchitis and the like.

[ZZZ]

Nam, I want to avoid temp below 22°C. Personally I think that 24°C with a dry air is a nice temperature to relax in LOS.

AFKAFSinLOS, your goodwill in gods sake, some people like to get a maximum out of what they have paid for. But I will try it although...

Generally I believe it is nonsense to have a temperature below 22°C but at the BKK hotels I know even 23°C is very cold because the aircon is oversized.

= much too cold for my liking and dangerous for the health. temperature differentials (inside/outside) should not exceed 8ºC to avoid colds, bronchitis and the like.

I don't think 24°C is dangerous for your health and temp diff has nothing to do with it, if it's -20°C in winter Europe do you keep the temperature at -12°C ??

24°C is probably to hot for most tourists from europe, 22°C should be ok for most tourists.

Another option you have, if your aircon has this, is to use the Auto-Restart option. On some air cons you can switch this option on and it will then re-start, at the previous settings, after a power failure. This means that you could set the aircon to whatever temp you like and then remove the remote from the room, the aircon can then be switched on and of by the power switch, provided there is one, and the temperature will always remain to the preset temp.

Failing this it looks like your only option is the thermostat suggested by Khun Ngo

[Khun Ngo]

Yes, my suggestion is rock solid and you don't even need to open

up the AC and make any changes, no problems with warranty etc.

Edited August 5, 2008 by Khun Ngo

[think_too_mut]

I'm telling you guys, the only proper way to do it is via PLC. It can also detect fast rising temperature (i.e. when someone opens a door/window while aircon is running) and shut down the equipment or switch into "fan only" mode.

PLC Programming

PLC Services

[ClaudeFeller]

think_too_mut:

Thats interesting, but if I go to a AC technician ans ask him about this he will say "no hap".

Do you have any practical advice for Thailand?

[longball53098]

In my holiday home I never charge the guests for electricity - most of them are very nice peoples and they appreciate this.

Lately a couple kept the AC in the bedrooms running day and night, of course the doors open to get an icecold living room as well.

Enough, I want to avoid this.

Is it possible to limit the minimum temperature on the remote control?

P.S.:

No advices like:

- Charge for electricity

- Get a key with power switch

I like to keep it like that.

I think I have read most of this thread and how about a different approach?

You say that the customers you have issue with are leaving the bedroom door open to try to cool the living/sitting room also?

One possible solution is to connect a circuit with a switch to the bedroom door and if the door stands open for say more than 5 minutes it cuts the AC off. I would think some type of timer electronics could be found to do this. (Brainstorming here)

The other possible solution is to spend some bucks and install another AC in living room?

And one more is to make the rental agreement clearly state that any extra electrical usage will be billed to the customer at the usual rate of the electrics and make sure the customers understand this up front. Most people will understand this and not complain if they know going in that they will incur extra charges they are likely to be more cautious.

[Crossy]

And one more is to make the rental agreement clearly state that any extra electrical usage will be billed to the customer at the usual rate of the electrics and make sure the customers understand this up front. Most people will understand this and not complain if they know going in that they will incur extra charges they are likely to be more cautious.

Actually, I think this is going to be the best solution.

Get some cheap electic meters (if your bungalows don't already have them) and set a maximum usage that is free, charge for any units above that.

Do some tests to see how much is used in a unit set to your 'preferred' consumption and use that as your upper 'free' limit

[tjo o tjim]

The Mitsubishi Mr. Slim units we use for server closets have override controls terminals on them to allow you to shut the unit down with a remote contact (needed for smoke detector shutdown). You just need a thermostat somewhere in the room (fixed temperature or non-adjustable ideally). You might need an extra relay to make it work properly depending on if the remote contact is normally open or closed.

If you add in a PLC, you can do some "fun" things like monitor door switches, dewpoint sensors, and timers and vary the minimum setpoint based on that information.

Without a PLC, you might have problems when the unit is trying to de-humidify.

The problem with all of this is that the jumper information isn't really well documented.

[elkangorito]

Bear in mind that thermostats are placed very close to the "return air". If they are not, you will have all manner of temperature problems.