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February 22, 2006 08:06 PM

Broken: Roca temperature dial

From Kanngard: How do I get the room colder?, a poorly designed Roca temperature control in a hotel room.


Why are hotels prime spots for things that are broken?

Posted by: Andy Hoffman at February 22, 2006 09:34 PM

What's broken is temperature controls that make you choose between heat and A/C. In the spring here it can get to be 80 in the day, but 40 at night. I have to manually switch between heat or A/C (or be too warm or too cold).

Posted by: matt at February 22, 2006 10:03 PM

O.K. So the icon made out of circles and looks like a childs drawing of a flower means the sun, which is hot, so if it's hot outside, that's the icon I want.. O.K. I guess bigger fan moves more air than little fan.. O.K. 8 ball or cue stick, I think cue stick means ON .... "Is there cold air yet?"

Posted by: Timm at February 23, 2006 03:02 AM

"Why are hotels prime spots for things that are broken?"

Vicious cycle. When you go to a hotel, you are faced with unfamiliar equipment, so they try to make it simple, which just makes it more unfamiliar.

"What's broken is temperature controls that make you choose between heat and A/C. In the spring here it can get to be 80 in the day, but 40 at night. I have to manually switch between heat or A/C (or be too warm or too cold)."

Agreed. However, I strongly believe that everyhing automatic needs a manual override. As such, I like the thermostats which have the four-position switch: off, heat, auto, cool. 99% of the time, you will want it on auto, but it should be the end-user's choice.

Thermostats that switch between heat and cool make even more sense if the HVAC system is based on a geothermal heat pump, because these systems, when cooling, are essentially taking the heat from the controlled space and putting it away for later. When heating, they are essentially taking that stored heat and bringing it back out.

Posted by: Glenn Lasher at February 23, 2006 06:46 AM

Aside from the reported behavioural anomaly, the design of the control is actually rather good. The top switch is clearly for on/off using common symbols for the state. The middle switch is clearly the fan control and the size of the fan clearly indicates slower to faster. And the bottom switch ought to clearly distinguish between heat an A/C. The rotary temperature knob is also easily understood.

This is only speculation, but the control may actually be installed incorrectly. Might the A/C and furnace wiring be hooked up in reverse?

Posted by: Carlos Gomez at February 23, 2006 09:58 AM

Carlos, I suppose the wiring is bad. I've never seen a thermostat with the sun and snowflake behave wrong before.

Posted by: Johan Känngård at February 23, 2006 10:24 AM

I agree with Carlos and Johan, it must have been wired wrong. And also, for a thermostat, this is a pretty straightforward design. The only thing it's missing is a display of the current temperature, so you can tell whether you want to set it hotter or colder.

Posted by: E.T. at February 23, 2006 10:36 AM

Obviously, whoever thinks this is broken does not have a car made after 1990. Each of the symbols for the switches on the left can be seen in cars, especially ones with a/c. Even if you do not understand the symbols, one could spend a couple of minutes to figure out each one does.

And for the last switch: generally, the sun means heat (because it tends to be warmer when the sun shines), and the snowflake means cold (a/c) (because it tends to be cold when it is snowing).

The only broken piece is that us Americans are ignorant on international symbols.

Posted by: Tim at February 23, 2006 12:15 PM

Completely broken. Why not just have one dial to control the temperature. The other dials are unnecessary.

Posted by: david at February 23, 2006 12:19 PM

Tim: you are correct, they *are* seen in cars, and sun=heat / snowflake=cold *is* quite logical. However, the problem was that it was set up the other way round, so that snowflake was heating and the sun was cooling. That is what was broken. As you'd know if you'd read the text below the picture. Or the other comments. Which would seem to be a sensible thing to do before commenting.

Posted by: Simon at February 23, 2006 02:01 PM

didn't anyone read this?

"This was located in our room. It was 24 degrees Celsius when got there, and it's a bit too much. We decided to turn on the AC, but it only came hot air!!! The bottom lever had to be on the SUN (left) position (hot!) for the AC to produce cold air! Isn't that opposite to what it should be everywhere else in the world? Maybe they mean that "if the sun is up and it's hot, move the lever to the sun" and vice versa... "

Posted by: im_an_alien at February 23, 2006 03:11 PM

Yeah... well, thing is, this could have just been wired incorrectly. It really wouldn't be all that difficult to switch the wires that control the AC and the heater, thus confusing anybody who tries to use it.

Posted by: Rob at February 24, 2006 01:56 PM

This is an honest question:

WHY have four different switches controlling eight settings (which is what, 49 different switch position combinations + variable temperature) instead of a simple "set it and forget it" temperature dial?

WHY aren't thermostats smart enough to figure out that if it's below the set temperature then it needs to turn on the "heat" and the lower the temperature is the higher the fan needs to blow, and if it's above the set temperature then it needs to turn on the A/C and the higher the temperature is the higher the fan needs to blow?

WHY should I have to tell the fan to blow higher or lower? WHY should I have to tell the thermostat if it should blow hot or cold? WHY should I have to do anything but set what temperature I want it to be and let it figure out the rest?

Is that so hard?

Posted by: Erich at February 24, 2006 02:17 PM

As a matter of fact Erich it is difficult.

The on off switch is for when the room is unoccupied.(to save power)

Some people prefer more air circulation at a higher temperature and some prefer less air circulation at a lower temperature. Or vice a versa. Therefore the fan control is so that you can set your preference.(thus it is a feature)

As for switching between heating and air-conditioning there are three ways (that I know of) to automate it and there are problems with each:

1. Settable point that when the temperature is above a certain point the AC comes on and below that point the heat comes on. (Cheapest to install)

Problem: tends to alternate between AC and heat. Uses ALOT of energy.

2.leave a space between heat and AC (20°=heat 22°=AC)

Problem: Some alternating may still occur and it is impossible to set a precise temperature.

3.Mesure the temperature outside as well and use the difference to decide on heat or AC. (often used in office buildings)

Problem: expensive to install.

Posted by: Sean P at February 24, 2006 05:11 PM

By the way as for the original topic of discussion Carlos is almost certainly right, this installation definitely goes against the convention.

However "Timm" may have a point, maybe it is the convention that is broken. :p

Posted by: Sean P at February 24, 2006 05:26 PM

I think the sun means "summer" and runs the A/C. The snowflake denotes "winter" and therefore runs the heat. Or asked another way, "Is it hot (sun)?" "Is it cold (snowflake)"?

Posted by: Barbara at February 24, 2006 10:06 PM

I stayed at a Vegas hotel once that did use SeanP's #2 method described above, which is basically the central heat and A/C thermostat that most people are used to at home. They recouped the added cost by charging me $400+/night, which is obviously not something the LaQuintas of the world can do. Back on topic though, it would definitely be broken here in the US, not only for the backwardness of the icons but also because it uses Celsius instead of Fahrenheit. In Spain, though, perhaps they have different conventions regarding icons such as these? Probably a wiring error, though, so I can't call the design broken.

Posted by: Ron Mexico at February 25, 2006 02:18 PM

I've lived in Spain for five years now, and I still can't get used to two thing about the light switches. It's normally placed OUTSIDE the room that needs to be illuminated (...Where'd they put it this time???)- and to turn it on, typically it's flipped down for ON and up for OFF... contrary to the way I am used to.

Minor things sometimes matter

Posted by: Thom at March 7, 2006 02:34 PM

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