Astraeus—The Baltic Wind

Understand the wind and assist climatic regulation of buildings in the 21st century

Astraeus is the Greek name for the ancient God of the Four Winds. The gods of ancient Greece and Rome were notoriously fickle, which makes the name doubly appropriate, since the Baltic Wind, as most winds, comes as it pleases, from different directions, at different times, at different strengths.

The history of vernacular architecture is also a history of man’s fight to harness the forces of nature, and the fight for, or against, the wind, is an old architectural story.

But Engineers have largely ignored this history and knowledge, and they developed mechanical ventilation, man’s own wind. The logic of this is that nature’s own forces are too unruly, so that they should be shut out from a building, and engineers can create artificial replicas that are more reliable.

Of course this is, in a way, true. Wild horses can run like the wind, but if they are harnessed to a carriage and run in opposite directions there will, at best, be no transport.

However, it is a defeatist attitude of those who cannot train wild horses, and it is also a very unsustainable attitude, because “free as the wind” is not just a good phrase, it is true in the sense that mechanical ventilation costs money, whereas the wind is free.

But we must be careful not to polarize the discussion, because of course mechanical ventilation in industry, for example, to keep fumes from welding operations away from the lungs of the welders, is necessary and irreplaceable. No doubts.

Equally though, large mechanical ventilation systems for dwellings or other simple buildings are only necessary for the bank balance of those who sell such equipment.

So what is the appropriate balance for a building such as The Hermitage? The first thing to realize is that we are dealing with forces as unpredictable as wild horses. Therefore we need not one type of bridle and saddle, but several.

As described in other leaflets, such as the “Fortochka” section, the answer lies in design of components that can be regulated—flexibility is the key—and Rastrelli provided an excellent series of responses to the various climatic influences of The Baltic Wind.

“Astraeus” is a pleasant friend as a gentle cool breeze bringing the fragrance of the flowers in the heat of summer.

Unless of course this breeze is polluted with positive electrical ions, such as the infamous Mistral or Sirocco winds of Southern Europe, which affect the serotonin balance of the brain and bring depression and other ill-being to people.

However, there is no Sahara desert to cause this type of summer wind in St. Petersburg, so the summer breezes from the Baltic are invigorating, charged with the negative electrical ions that promote well-being. So this summer breeze should be used to the full in The Hermitage.

On the other hand, winter gales are a heavy load for the climatic system, especially since we are dealing with a museum which has an essential requirement for climatic stability—especially a stable relative humidity in the rooms. A winter gale can bring extreme low humidity to the museum rooms.

So the challenge is clear. How to deal with a force of nature that is sometimes a friend, sometimes a foe, and sometimes a fickle friend, absent when you need it, or a devious foe, comes when least expected? And from any direction!

How did Rastrelli, the architect of the Winter Palace, deal with these problems?

In the first place is the choice of site, and the influence of surrounding features; natural, such as the river Neva, or man-made, such as surrounding buildings.

In the design of the building itself, Rastrelli included many inner courtyards, with windows facing onto them, and these of course allow the building owner to at least open windows onto an area under control. A simple planning solution to the question of providing security, quiet, and fresh air.

Rastrelli did not of course foresee the problem with vehicle exhausts around the Winter Palace, but his design certainly did allow the possibility for avoiding these fumes by opening windows onto the courtyards. See also the “Dagmar” section regarding the possibility for providing cool, clean air to the Winter Palace from the trees in the courtyards.

Also, of course, is the consideration of the impact your own building will have on surrounding features, perhaps beneficial, sometimes a cause of new problems.

Many modern architects who have designed new, large, buildings, in existing cities have been surprised to receive complaints from the neighbours to their building. Sometimes such extremely strong funneling of wind has occurred that physical damage is added to the nuisance of struggling against a breeze amplified to a gale by a neighbour’s inappropriately sited building.

A basic problem of using the wind, whichever direction it should come from, was solved by others several thousands of years ago—the invention of the chimney.

A simple open shaft sticking up above the rooftops, creating suction as air passes over it. This is called the “Venturi Principle” according to the scientific relation between static pressure and velocity pressure, described by Giovanni Battista Venturi (1746–1822).

It is of course important to realize the importance of the phrase “sticking up above the rooftops”. Planners who allow high buildings adjacent to existing buildings also often destroy the ventilation systems of the neighbours.

There is a need for care and respect in Town Planning questions regarding air, and light, to neighbours. Ideally, the existing regulations in Copenhagen and St. Petersburg, which limit building height generally, are very democratic and sensible.

Of course, in our case, at the Winter Palace, is a very advanced form of chimney, as described in the section entitled “Rastrelli”, with adjustment possibilities built in, including adjustment of air entry down to zero, if the Baltic Wind was a little too eager to enter the palace.

Sometimes it is possible to create landscapes that alter the passage of the wind. Some avant-garde architects, especially in Germany, have designed houses built into the landscape specifically to create a climatic shield from the winter wind, with rooves sculptured into the surrounding earth mounds to create an illusion of open land.

In St. Petersburg the use of trees as a wind break is a common feature, which can be seen clearly from the air. This of course combines the feature of using the wind with the feature of using water—see the section entitled “Dagmar”.

But in the Winter Palace, with the site on the river bank, it is clear that the winter wind has unhindered access for its cold attacks, and the only defence available to Rastrelli was finely fitted double windows and the provision of inner courtyards. However, over the years the fit of the windows has become worn and overpainted, and attention is required.

In the summer, of course, the open windows allow excellent cooling ventilation, but in both summer and winter the fine adjustment possibility available from the “Fortochka” system has in many cases been lost owing to “modernization” without understanding.

Various methods to tighten windows are available, but the real challenge is the provision of selective tightness to allow the users to adapt the windows to either reject or accept “Astraeus” as and when required.

Various window tightening methods have been tried at the Winter Palace, but there is much study to be done so that the appropriate match between the original architectural ideas and the availability of quality modern technology create the acceptable match between old and new.

Of course, the restoration of the 800 currently blocked chimneys will also restore the lungs of the palace, so that breathing through the windows becomes easier.

Use “Astraeus”—use The Baltic Wind—harnessed, though wild.

Allow it to reach the building, by considering the landscape. Allow it to enter the building, and carry away used, polluted air.

But above all, ensure that the building users can adjust windows and shafts so that they are tight when “Astraeus” is angry, and open, when, amongst other benefits, the special fragrance of the flowers characteristic of north-western Russia is in the air.

Sergio Fox