low room temp HP

[multisync]

We have got to install a unit in a room where the minimum is 6 deg'c. There is no max.

However we all know most stats will only go down to 16 when on heat. With energy efficiency in mind -and the fact of heating a room 10 deg's above it's minimum is wasteful.

So we thought we could put a simple Ranco type stat set at cut in 8/out at 10. We thought the easiest way would be to break the signal no/3 (Daikin spec'ed) Sure it would comms error but it's only a 3.5kw unit so a flashing light wouldn't bother them too much..

What is the chance of the unit getting damaged longterm given the low operating indoor temp and the constant make/break of the comms (it's a 24/7 operation)

Plus and are we right in thinking Daikin small wall mounts will auto restart?

[brunstar]

well the unit will not like the low air temps over the indoor coil but instead of breaking the comms, why not use a krp board to turn the system on and off? Most air con units like to have a min of 15 to 18 degree air on temp, it should be ok though.
I would not break the comms but at least the crank case heater should be energized at the time at which the system is in thermostat off position.

[chemi-cool]

At 15 to 18 you have a high risk of a frozen evaporator. .
Is it 24 fins per inch?
Low air velocity?

Cant you just leave the windows open?

[multisync]

At 15 to 18 you have a high risk of a frozen evaporator. .
Is it 24 fins per inch?
Low air velocity?

Cant you just leave the windows open?

Chemi

I am talking about keeping it warm. It will never go on cooling as there isn't an upper limit to the product just that it must not go below 6 deg'c

[chemi-cool]

Set it on 22°C, heating mode and it should be ok.

To be on the safe side, you can simply add an electric heater, thermostat operated[just in case something goes wrong with the air conditioner]

[Clk320_Greg]

Useing a KRP board allows you to control the unit with a make or brake that could be offered from a stat.

However if you do use a KRP board on some of the IR controled units it does over ride the controer and even in some cases means that you will be un able to turn the unit off with anything other then the KRP control!

Was told by a Daikin rep that just cutting the power or the signal would void the warrentee!

[VRVIII]

We have got to install a unit in a room where the minimum is 6 deg'c. There is no max.

However we all know most stats will only go down to 16 when on heat. With energy efficiency in mind -and the fact of heating a room 10 deg's above it's minimum is wasteful.

So we thought we could put a simple Ranco type stat set at cut in 8/out at 10. We thought the easiest way would be to break the signal no/3 (Daikin spec'ed) Sure it would comms error but it's only a 3.5kw unit so a flashing light wouldn't bother them too much..

What is the chance of the unit getting damaged longterm given the low operating indoor temp and the constant make/break of the comms (it's a 24/7 operation)

Plus and are we right in thinking Daikin small wall mounts will auto restart?

Hi Multi,

This application is outside the operating range of an RXS35G unit (see attached). The unit will over condense big time
RXS35G op range heating.pdf

[al]

Multi

Why bother with a heat pump, why not use some wall mounted heaters(door curtain type), i know a heat pump is more green but running it to this extreme would be wasteful?

al

[multisync]

Set it on 22°C, heating mode and it should be ok.

To be on the safe side, you can simply add an electric heater, thermostat operated[just in case something goes wrong with the air conditioner]

Why heat a room to 22 when all you need to do is keep it above 6?
Seems terribly wasteful of energy..

[multisync]

Multi

Why bother with a heat pump, why not use some wall mounted heaters(door curtain type), i know a heat pump is more green but running it to this extreme would be wasteful?

al

I know but that is what the customer wants and that is what he gets. It's far more energy efficient to use a HP *supposedly* than electric heat so gotta be seen to be green

[multisync]

Hi Multi,

This application is outside the operating range of an RXS35G unit (see attached). The unit will over condense big time
RXS35G op range heating.pdf

I can set it at 10 and it will be within the envelope..Esp as the slant only coincides with a rise in outdoor temp,,With natural heat gains it won't actually run that often

[multisync]

Useing a KRP board allows you to control the unit with a make or brake that could be offered from a stat.

However if you do use a KRP board on some of the IR controled units it does over ride the controer and even in some cases means that you will be un able to turn the unit off with anything other then the KRP control!

Was told by a Daikin rep that just cutting the power or the signal would void the warrentee!

I did look at a KRP but it seems unnecessary. A simple eliwell stat to break the control will be sufficient. I am not too worried about the warranty and don't expect too much trouble.
We have one in our office which is turned off over the weekend and regulary gets below 10c . Monday morning do we run around getting the room warm first or do we just turn the heat pump on...

[VRVIII]

I can set it at 10 and it will be within the envelope..Esp as the slant only coincides with a rise in outdoor temp,,With natural heat gains it won't actually run that often

Multi,

Yes but keep in mind the min indoor operating range is 10 C WB (about 15 C DB @ 50% RH)

[Clk320_Greg]

I did look at a KRP but it seems unnecessary. A simple eliwell stat to break the control will be sufficient. I am not too worried about the warranty and don't expect too much trouble.
We have one in our office which is turned off over the weekend and regulary gets below 10c . Monday morning do we run around getting the room warm first or do we just turn the heat pump on...

Ah, I wondered why I could hear the "Ministry of Sound Pump It Up Work Out DVD" on in the background last time I spoke to you on a Monday! Must have had everyone cutting some moves to get the room warmed up

[multisync]

Multi,

Yes but keep in mind the min indoor operating range is 10 C WB (about 15 C DB @ 50% RH)

Ah my bad I didn't se it was WB

Still, I won't tell if you don't

[Billy Ray]

Multi,

how about wire a resistor across the fan coil return air sensor (offset the reading)?

Billy Ray

[El Padre]

Hi Multi,

I dont work that much with splits but if they come with T1/T2 terminals (forced on/off) you could use these terminals to cycle the unit on/off with a stat.

Cheers

[multisync]

We finally settled on a Fujitsu wall mount. Set the unit running and blow me down..The remote has a set back function with a 10C setting!

Excellent: problem solved and warranty retained..

[nike123]

We finally settled on a Fujitsu wall mount. Set the unit running and blow me down..The remote has a set back function with a 10C setting!

Excellent: problem solved and warranty retained..

That function is only available for floor models 9,12,14 x1000 btu.

I would use duct type air conditioner and I would use (and regulate it with termostatic controled flap) some portion of supply air passed back to return to increase indoor air in temperature to at least 15°C

[multisync]

That function is only available for floor models 9,12,14 x1000 btu.

I would use duct type air conditioner and I would use (and regulate it with termostatic controled flap) some portion of supply air passed back to return to increase indoor air in temperature to at least 15°C

Err read my email, again. I said "we set the unit running" so lets be clear that we have already installed it and set it running and set in on the 10c setback mode..I know because I visited site today and saw it in operation with a big fat 10 in the middle of the display...

So yes some do, possibly not in your country but in the UK the ASYA12LGC does have this facility

Hope that helps

[nike123]

Err read my email, again. I said "we set the unit running" so lets be clear that we have already installed it and set it running and set in on the 10c setback mode..I know because I visited site today and saw it in operation with a big fat 10 in the middle of the display...

So yes some do, possibly not in your country but in the UK the ASYA12LGC does have this facility

Hope that helps

Yep, you are right, I checked in manual. Models ASYA07LGC
ASYA09LGC
ASYA14LGC
also have that facility.
I did not found that first as option in catalog for 2009. Now I checked and it is there but only for models with wired remote control. Good for you!
Note that AC returns automatically to normal setting after it has been 48 hours in 10°C mode.

[multisync]

Yep, you are right, I checked in manual. Models ASYA07LGC
ASYA09LGC
ASYA14LGC
also have that facility.
I did not found that first as option in catalog for 2009. Now I checked and it is there but only for models with wired remote control. Good for you!
Note that AC returns automatically to normal setting after it has been 48 hours in 10°C mode.

It has an infrared wireless remote

[nike123]

It has an infrared wireless remote

Some problem with my eyes today!
Probably lack of carbohydrates.

[VRVIII]

Err read my email, again. I said "we set the unit running" so lets be clear that we have already installed it and set it running and set in on the 10c setback mode..I know because I visited site today and saw it in operation with a big fat 10 in the middle of the display...

So yes some do, possibly not in your country but in the UK the ASYA12LGC does have this facility

Hope that helps

Multi,
I was disappointed with the photo you attached, I was expecting to see you holding an infra red controller showing 10 C while grinning form ear to ear

[R1976]

Interesting thread but what about after the 48 hours?

It will revert to set temp ie.16 degrees.

Someone is going to have to go into the room every 48 hours and press a button.