Multiple split units versus ducted air-con

It looks like they've decided to put air-conditioning in at work. It's a fairly small office building. 10 rooms in total, 2 of which currently have a split system installed.

A ducted system makes some sense to me but the manager seems to favour 10 separate split system units. My concern is that, in practice, employees will set these to different temperatures and we'll end up with some blowing hot air, others blowing cold air at the same time. A sure way to run up massive power bills for no benefit.

I can see it would be fine if they were all at the same temperature though. But the odds of that are unlikely - one employee considers 18 degrees rather hot whilst the other thinks high 20's is about right.

In practice, does anyone know how significant an issue the units "fighting" each other would be? I figure that if my heater in the lounge at home keeps the bedrooms at the other end of the house reasonaly warm then heat / cold is going to move between offices at work pretty easily if they're at different temps.

One company that came to quote on the job couldn't see how the units would "fight" each other in this way. But then they quoted a ridiculously high price for the ducted system (3 times that of another quote) so seem to be biased.

I managed an office years ago that had about 10 window airconditioners. There were about 4 in small offices and a lunch room and the rest in the main area where the general staff toiled away.

There was always ongoing debates about whether it was too hot or too cold. Women generally have different requirements to men and that can cause friction.

The noise was the main issue from the window bangers and I replaced the lot with a single ducted system which still had its hot and cold spots. Whilst I thought it was generally pretty good it never stopped debate in the office about whether it was too hot or too cold. Personally I favour the multiple splits option as it should be an energy saver and gives more people the feeling they have control of their environment. It is unlikely some extremist winding their unit down to 18 in summer or up to 30 in winter will have a major impact on the whole office area(just those in close proximity).

In terms of running cost I think it should prove cheaper as if u have a small office or other room that can be serviced on a separate unit when that area is all that is occupied it will cut down energy usage.

Office spaces cause no end of grief. especially when women are concerned.

To be brutally honest in a space of 23 Degrees C, there will be two girls next to each other. One will be fat one will be skinny. Ultimately one will be always cold, the other always hot. The skinny girl is just reliant on ambient temperature for a comfortable environment, the big girl needs a bit of extra airflow to maintain her comfortable conditions. Throw in a few hormone cycles and it's a nightmare.

what works best is to have one or two ducted systems with zone dampers for each space and thermostat in each as well. This way will still allow independent temp control but from a centralised unit. Also, there is no chance of one room being heated and the next cooled.

Depending on the size of the area being cooled, it will most likely be cheaper with ducted air.

I'm going to go with seperates - i have never worked in an air conditiond office that can gets its temps right - it seems impossible to fix the buggars - you always seem to end up with one room that runs at 25o with the air off, or 18o with the air on, and calling out engineers never solves the issue (this is in BIG installs).

I'd install the splits, set em all the same, and keep the remotes in one place, with a tough titties reply to anyone who wants to change them. ;D

I would say ducted with singles zone VAV's in each office. Basically this would allow each person to control the tempreture in thier office using a touchpad located there, it does have limitaions tho, as they are not connected to the unit and the unit will sence the tempreture from the point where the unit controler is. This is a simple system but it does need to be properly thought out and designed.

Ducted will be more cost than 10 small splits, all depending on size and brand. also it is easier to introduce fresh air into a ducted than it is to 10 seperate splits. A certain amount of fresh air is required in office spaces, using recirculated air all day in a office is a recipie for low productivity and more sick days.

If you need more info let me know