The all electric office building.

[adam2]

Decades ago, offices and similar premises were normally heated by hot water radiators, the water being heated by a coal burning boiler that also heated domestic hot water for toilets etc.

Then to save labour the coal burning boilers were replaced with similar appliances that burnt oil or gas.

Then came the general use of air conditioning often from large central electric chillers that chilled water.
It was usual then to remove the radiators but retain the boilers. Each room or area would be equiped with fan coil units, either mounted above a false ceiling or on the walls.
Each fan coil unit would have a coil through which passed chilled water from the chillers, and another coil through which passed hot water from the boilers. A fan would take air from the room, pass it over the coils, and blow the air back into the room. Electricly operated valves would control the flow of chilled or heated water in order to heat or cool the room to the desired temperature.

In addition, it was usuall to provide an AHU (air handling unit) that would take fresh outside air, filter it, and warm or cool the air as needed and supply this air via ducts to most areas of the building.

A central extract fan was usually provided, to remove stale air and avoid excessive pressure within the building.

If well designed and properly maintained such systems work well, and are still the norm for existing offices.

There are however numerous ways in which energy can be wasted, including
Defective valves in the fan coil units or AHU resulting in heating and cooling being supplied at the same time.
Heat loss from the hot water pipes, especialy if passing through an area that needs cooling
Heat gain into the chilled water pipes, especialy if passing through a heated area, or near hot pipes.
Air that has been expensively heated or cooled being extracted.
The AHU heating the fresh air to say 20 degrees, and this air being supplied to a warm room in which the fan coil unit is cooling.

The most modern installations have no boilers, and are all electric.
Despite the higher price of electricity, they make economic sense due to greater efficiency.

The AHU and extract fan are placed near each other. One or more heat pumps warm or chill the fresh air supply.
When heating the fresh air, the heat pump(s) cool the extract air and work far more efficiently with extract air at say 24 degrees than with outside air at say 10 degrees.
In summer when the fresh air needs cooling, the heat pumps dump the resultant heat into the extract air.
Heat pumps used thus are very efficient.

The fresh air supply is of course at the same temperature to all areas of the building. To give local temperature control, each room or area also has a local heat pump air conditioner that heats or cools the room air as required.

A BMS (building management system) monitors the numerous local heat pumps and "counts" how many are heating, and how many are cooling.
If the majority are heating, then the BMS increases the temperature of the fresh air supply.

Each local heat pump is controlled by a presence detector and/or time control to avoid waste in heating or cooling empty spaces.

Despite the cost and complexity, such schemes are increasingly viable.
Apart from reduced running costs, other advantages exist including

1) no space taken up by boilers and flues. The space otherwise taken up by a boiler room can be let for thousands of pounds a year. Even the floor area taken up by a flue duct can be worth a thousand pounds a year or more.

2) the absence of a gas supply removes risk and complexity. No gas safety inspections, no gas bill to process.

3) the absence of heated or chilled water, means that it can not freeze or leak, either of which can result in great expense.

4) MAY be greener, depending on how the electricity is generated.

[PS_RalphW]

Our office uses an electric heat pump heater/cooler unit which has one large fan unit outside and two 4 way blowers in the false ceiling. Office is about 15 feet high...

Definitely better than the other half of the building - which has original even higher ceiling and has long, thin gas burners that provide some air heating and some radiant heating. These consume vast amounts of gas, and just about get the building habitable by lunchtime.

Neither system benefits from being in a warehouse with solid walls and large, north facing single glass metal framed windows with significant drafts.

[RenewableCandy]

Blowing hot air down from the ceiling is ridiculous. A/c (or indeed hot-air systems) in buildings in which lots of people (have to) congregate were in fact invented by the Comon Cold virus in order to help it propagate. As indeed was the popular concept of saving money by not having the filters and ducts regularly cleaned. And of course, the ethic of "soldiering on" at work when a cold's got you feeling rough as feck.

I often thought of these things while having to work in such a place during the Swine Flu Scare a few years back.

[adam2]

Update after 10+ years. Some years ago I was made redundant from the company that maintained the all electric office building referred to above.

I have however heard from several sources that the building has in many respects been a failure. specific issues included.

Inadequate electricity supply to offices. In particular, the supply to each tenancy was sized on the basis of a bit less than existing guidelines. 25 watts per square meter actually works fairly well for very large areas.100, 000 square meters if given a supply of 2,500 kw is often satisfactory.
But in this case, foolish persons applied the same rule of thumb to very small offices. A small office of 100 square meters was calculated at 2500 watts.
And then rounded down to 2.3/2.5 kw, I.E. a 10amp circuit. A 10 amp circuit already loaded to nearly 10 amps will trip almost instantly if a kettle, or a vacuum cleaner or a power tool is used.

My PERSONAL guideline or rule of thumb was 25 watts per Square meter and an additional 5 KW for use of kettles, power tools or cleaning equipment. Round up to the next standard circuit size. And never less than a single 10 amp lighting circuit and a 32 amp power circuit, no matter how small the area.

[BritDownUnder]

A lot of people swear by underfloor heating.

Heating air seems to be a bit if a waste of time all said as it does tend to want to rise to the top of rooms. Radiators are the best but I have not really seen any in Australia, at least where we are at 32 degrees South anyway.

Sorry to hear of your redundancy. Happened to me too mainly in roles where I had overreached my capabilities. I did hear from someone in Australia who said their brother, a process engineer, had been made redundant 20 times.

[adam2]

I have heard of additional problems in the above building, mainly due to over complexity.
1) Defective emergency lighting on internal fire escape stairs. This has so many controls and sensors that can turn it off, that in practice it is seldom on. I suspect the most of the self contained emergency lights will operate from the internal batteries in the event of a power failure. But what about an emergency evacuation with mains power present ? In my view, emergency lighting should be on at all times, either from the mains supply or from batteries if the mains fails.

2) Part of the fire safety strategy is that the escape stairs are pressurised with fresh air so as to exclude smoke, The fans to achieve this are duplicated, but with a manual changeover switch located on the roof (not automatic changeover as described). The electricity supply to these fans is described as duplicated. This consists of two cables, or the ordinary plastic insulated type (not fire resistant as described on the plans), taking the same route.(not diverse routes as detailed on plans) These cables are connected to adjacent switch fuses in the same switchboard. The plans refer to the availability of a "standby mains voltage supply" There is no generator, nor is there any secondary DNO supply from another substation, preferably one on a different 11KV circuit.

Both of the above were noticed by myself and reported YEARS ago, but the assumption was that the problems would go away once they had got rid of me. I understand that prosecutions have resulted or are pending.