Office Air-Con – What do "Heat" & "Cool" do….?

Cue sarcastic comments, no doubt but let me explain.

Our office air con has auto, heat & cool modes. In auto it seems to run fine. If it’s cool you just up the temperature and it gets warmer, decrease the temperature and it gets cooler. Simple.

But, some idiot in our office who I am yet to identify keeps sticking the temperature up to 24 deg. C and the mode to “heat”. This appears to do nothing, the units don’t operate and the room gradually gets cooler.

I want to put it back to auto (and a sensible temperature), but would also like to explain to the girls near the control thingy who will undoubtedly moan about it (and I suspect are meddling with the controls) what “heat” actually does as it doesn’t seem to, erm, heat.

When you work it out, can you explain it to our office too please?

There’s a storm front brewing where the air from our two ceiling mounted units meet. One on cool, 20, one on heat 26!

gravity-slave – Member
When you work it out, can you explain it to our office too please?

There’s a storm front brewing where the air from our two ceiling mounted units meet. One on cool, 20, one on heat 26!

HA HA!! We’ve only got one controller for all our units, but we used to have that problem at the last place I worked.

I’ve looked for a manual online, but couldn’t find anything of any use. Quite tempted to set the controls & superglue the little door shut.

http://www.comfort.uk.com/faq.htm#running

Dunno why “heat” doesn’t work, perhaps it’s broken. However. +1 to being sick to death of people who don’t understand how thermostats work. I sit right next to an aircon unit, and if I leave the controller unguarded for more then 30 seconds some mouth-breather will think it’s slightly too warm / cold and set it to 16′ or 24′. Rather than, y’know, altering it by the one degree it needs. Then the damn thing ices up and packs in, cos it’s been running full tilt all damn weekend trying to bring an open-plan office down to sixteen degrees.

Get the man in too many things that can go wrong with them, I hate working on A/ C units they are a pain in the arse.

We also have an occluded front in our office.

Iim going to buy a desk doppler as it could start to rotate 😯

We’ve just had a big brand new air con installed in the ceiling, I can confirm that sticking it on heat and banging the temp and fans up to max. does not blast out hot air on our brand new 7 day old system either. Been scratching our heads and considered calling the installer back, we’ve even seriously considered reading the instruction manual. I’ll try it on auto this pm and report back.

I had to try and explain to the boss the other day that turning it all the way down to 16 doesn’t make it cool quicker, it just measn it will keep going longer. As above, set it and forget it.

B.A.Nana – Member
We’ve just had a big brand new air con installed in the ceiling, I can confirm that sticking it on heat and banging the temp and fans up to max. does not blast out hot air on our brand new 7 day old system either. Been scratching our heads and considered calling the installer back, we’ve even seriously considered reading the instruction manual. I’ll try it on auto this pm and report back.

Let me know if you can glean anything from the manual!!

I don’t see the point of ‘heat’ & ‘cool’.
If it’s in auto and the set-point is higher than the actual it should heat, if the set-point is lower than the actual it should cool. ‘Heat’ and ‘Cool’ as separate functions seem redundant given that auto should do whatever it needs to do for you!

Ours have symbols, a Snowflake, a Sun & Auto. I thought these were symbols for the correspnding action, cooling or heating, but apparently not.
Engineer said in the Winter we need the Snowflake, in Summer the Sun. And Presumably Auto is for when its Auto’ing outside.
Ours freeze up if set higher than 23c. The engineer said if you set it higher it will freeze up & stop.
They’ve even put little moulded perspex boxes over our controllers, accesible with a key.

Ours freeze up if set higher than 23c. The engineer said if you set it higher it will freeze up & stop.

I think that’s why we had to buy a new one, broke down 3 weeks ago, engineer said a large block of ice had formed on the gubbins outside and compressor had gone, it couldn’t be repaired (gases were CFC and illegal now). The new system auto defrosts itself.
Being logical and reading the instructions is a bit alien to me, but I’ll give it a go.

Being an HVAC design engineer this cheers me up no end as I have a dislike of VRV air con.

Fundamentally heating an office block by electrickery is just wrong imnsho.

Yes people need to stop fanning about with the controls. If you want it at 22 then that’s shat you need to set it at and leave it. Most system have a couple of degrees dead band on the control side. Surprisingly it goes above for a bit switches off and then drops below for a bit before coming back on. There are reasons for this.

But mainly people need to realise that it’s not necessary to wander around in practically no clothing in the dead of winter and complain that they are cold. I mean what did you expect.

I’d love to be able to help but there are heaps of different makes and types of AC and surprise they are all different.

But asking facilities for some easy instructions would be the first step (there should be O&M manuals/instructions on site it’s part of the building regs now)

East Devon none-of-your-beeswax centre have a policy that all water must be SCALDING hot
(something to do with weils desiese or some crap)

ive just burnt my hand turning down the radiator.
some wet blanket keeps turning them back up again.
and im sitting here with the window wide open so i can breathe.

and having lava for water in the toilets isnt more hygenic, as its so bloody hot no one can wash thier hands properly.

they also have to have ALL lights on at ALL times to prevent someone walking into an unlit room and injuring themselves.

this INCLUDES locked cupboards.

morons.

metalheart – Member
But mainly people need to realise that it’s not necessary to wander around in practically no clothing in the dead of winter and complain that they are cold.

Oh so true!
In our workshop we tend to wear a layer or two more in the winter, but in the offices oh no “thin shirt/blouse is all the top clothing I need as I can just whack the heating up to just under HELL setting” its so warm up there that one lad from the packing area nearly passed out after 10 minutes due to the stifling heat!
Strange thing is if during the summer the office reaches the temp they have it at in the winter then they all want fans and its too hot?

Being an HVAC design engineer this cheers me up no end as I have a dislike of VRV air con.

Being a HVAC design engineer, you’ll know that VRF/VRV can (if designed correctly) be a very efficient and effective method of heating and cooling a building, more so that the use of a chiller. The problems are mostly down to design and specification of system and controls. The controls are often the most important part, if a central controller is installed then the local controls can be limited in operation. Personally, I’d have all local control removed and leave a central controller in a plant room or such, set on auto and left well alone. If people want manuals, drop me a mail and I’ll see what I have on my laptop. takisawa2 you need to get new maintenance engineers ASAP!

Being a HVAC design engineer,

Ooh, that’s good to know next time I have to spec out a comms room.

comms room? close control stand alone with 100% redundancy. Denco is the best bet.

Stumpy01, the instructions for our new unit (mitsubishi) are a bit rubbish, didn’t give any indication what each setting is for or under what circumstances to best use each setting. The only info re their use for heating was that ours operates down an outside temp of approx -10C. However, their ability to heat inside gets less as the temp outside lowers. The manual suggests other forms of heating in really low temps, which probably answers why ours has been a bit rubbish the last week. I tried it on other settings (auto, cool) with the temp set at 25C and it was no better.

East Devon none-of-your-beeswax centre have a policy that all water must be SCALDING hot
(something to do with weils desiese or some crap)

control of legionnaires disease actually in accordance with HSE guidance document L8 requires storage water heaters to be able to maintain 60degrees C and running water from hot tap should reach 50 within a minute, but carry on 🙄

on the AHU front CIBSE comfort criteria for an office is 21-23 c for winter most of the problems with temp/comfort is down to poor design of the office, increased thermal loading due to too many people in the office with all the associated IT etc.. and rubbish air flow with lots of little pockets of stagnant air.

One of the best I’ve seen was putting the controls for the air con next to the person sitting by a chuffing big window (nice cooling potential) so they were cold and kept turning the aircon up so everyone else was sweating to death.

Our “industry partner” designed and built our system which was always rubbish. After a few years they eventually twigged that perhaps siting the sensor where it caught all the warm air from the printers below was not the ideal setup. It was better but still not as good as the original electric wall heaters (which have now been reinstated for economy reasons – we’ve been fine this winter).

lipseal – Member

I hate working on A/ C units they are a pain in the arse

Seconded. Give me a multi compressor pack any day, but I bloody hate doing air-con calls.

adam, this one’s for you mate;