Underfloor air conditioning
as part of a refurbishment

FS for Refurb as well as New-build

AET refurbishment project at Millbank where the high ornate ceilings were preserved as a valuable feature.

The growing attraction of underfloor systems as part of major refurbishment work, however, owes much to the fact that an entire generation of buildings in the UK are due for refurbishment and renovation.

According to Glan Blake Thomas, Managing Director of Advanced Ergonomic Technologies (AET), this kind of retro-fitting is increasingly desirable – both for developers and tenants – with the use of AET’s Flexible Space concept. The right approach is very often dependent on the extent of the refurbishment and the vintage of the building.

Architectures have changed over the years

AET project at 103 Wardour Street where a new building was created behind a famous existing facade using Hiross underfloor air conditioning to cater for low floor-to-floor heights.

From 1950 onwards buildings started to accommodate heating and ventilation instead of fireplaces. At that time glazing had a high heat loss so windows were minimal and generally higher up the walls so that radiators fitted conveniently under the windows against the brickwork.

Now, in the case of modern buildings with low-emission glass and the desire for more ambient light, windows are becoming larger and wall space is generally decreasing. In the newer buildings it is possible to take advantage of FlexibleSpace and design the structure with the right relationship between slab and building envelope so that the relative position of floors optimises safety and vision.

60's and 70's Buildings

These structures were designed for ceiling-based ventilation and therefore needed to have an integral ceiling void. When it comes to refurbishing such buildings, since they already have a ceiling void it would appear that they are not suited to benefit from the height saving offered by FlexibleSpace. However, this begs the question, how can underfloor air-conditioning be the best solution ?

The answer is quite simply that the cost of putting in the underfloor system at the time of refurbishment will often be less than for a conventional ceiling-based system refit. Furthermore, the ongoing cost in accommodating future changes will also be less.

The cost of change

Nesite raised access floor finished in high quality parquet.

As so often , it comes down to who’s paying the bill. If the developer is not only constructing the building but also looking to sell it, he will want maximum economy. Tenants are wiser now, though, and seem more confident in questioning services. Developers are having to deal with a much more discerning and more highly educated potential customer base, who may already have experienced first hand the costs of relocating fan-coil units to accommodate office churn. They are becoming increasingly interested in alternative air-conditioning.

Those involved in refurbishment need to examine the cost of structural change and change prompted by aesthetic considerations. One major aspect of such refurbishments, for example, might be the raising of windows to ensure that sills comply with statutory height requirements.

FlexibleSpace comes into its own

Wellesley Road in Croydon is typical of an area which blossomed in the 1960s; buildings were created out of cheap, flat slab concrete. They are still there but tenants now need to upgrade the accommodation to meet modern requirements, and the answer lies beneath the floor.

The alternative is to put ducting in the ceiling but there is an immediate problem with windows that extend to the overhead slab. Refurbishment performed in this manner requires the inclusion of a 500mm or 600mm overhead beam in order to put in the services, which in turn impinges on the window space from above. It becomes demonstrable that even with the raised floor requirements for underfloor air conditioning and cabling systems, the projected floor-to-ceiling height is still greater.

AET supplied Nesite raised access flooring system at the Willis Corroon building in Ipswich which contained a swimming pool which needed to be converted into office space.

In the Croydon type buildings the floor is likely to have a screed in which electrical trunking will be embedded. Within this format cables have no more suitable route to work stations than to run over the floor. The height in these buildings is such that to install a ceiling void would take away half the window. The underfloor approach removes the screed and puts in a raised floor to say 200mm. A direct comparison of how the options effect the window shows that the underfloor approach makes the floor just 7 inches higher, whereas the ceiling-based option makes the ceiling 24 inches lower.

Alternatives have problems

An alternative, traditionalists might argue, would be to consider perimeter fan coils around the walls. This means, however, that one has to run pipes around the walls to feed each unit. The architect or interior designer will probably insist that the pipes should be boxed in and the result is that thousands of square feet of lettable space are lost in prime positions.

Additionally, tenants would be limited as to where they could position office equipment. If they ever wanted to site machines against the wall they would not be able to. Moving perimeter fan coils to facilitate such changes or to bring the sources of conditioned air closer to trafficked areas produces considerable relocation costs, often running into thousands of pounds. With a floor-based fantile system the cost is minimal and the operation can be performed in minutes.

FlexibleSpace is Good!

	Flexiblespace may be the only satisfactory answer in a heritage building with important lofty or decorative ceilings.
	Where ceiling height is critical FlexibleSpace will give you more headroom.
	And most important, FlexibleSpace could well be the least expensive and most efficient solution.