Comfortable Ventilation

Fluid Mechanics Applications:

Another branch that civil engineers can specialize in if they wish is fluid mechanics. It is a difficult branch. There are huge special laboratories. In laboratories, models of many things are made and tested. For example, one of these is dams, and if desired, frontal water flow systems can be tested in this laboratory before dams are built on site. 

A lot of integral formulas are used in these courses for system solutions. As I said from the beginning, it is a difficult branch. In short, those who want to specialize in this subject have to risk dealing with complex mathematical formulas throughout their lives. 

When we talk about fluids, gases actually show similar properties like liquids, and gases are also examined under this branch.

In fact, in engineering subjects, some subjects are partly common between disciplines, as in fluid mechanics. For example, in the mechanical engineering department, these topics are examined in more detail than we do. Especially when it comes to heat transfer in fluids, system solutions are examined in more detail in mechanical engineering. We mostly study fluid behavior in structures such as canals and dams.

Notion of Engineering:

When we think of construction, we usually think of buildings and materials such as concrete, bricks and rebar. When we think of mechanical engineering, we usually think of factories, steel as a material, and often machines and lathe leveling. 

However, our profession is not that simple, in fact engineering is a notion, in a sense it means a perspective on the solution of all kinds of problems and we engineers work together on many issues. In fact, not only engineering branches work together, a dentist is also trained in load transfers, which we take courses in construction, the forces that occur between our teeth while grinding food and the forces that occur during a beam-column system to carry building loads are similar, system solutions are similar, solution methods are similar. In short, although education at universities varies among themselves, it is possible to make a generalization about engineering education in particular. An engineer learns to think a little differently from others at university.

Returning to civil and mechanical engineering, in buildings, we civil engineers usually specialize in the structural system of the building, while mechanical engineers specialize in ventilation and heating systems. We usually start working together at construction sites after a certain stage. Since mechanical engineers usually break the things we do, we love each other even though we argue all the time.

As I said, we know heating and ventilation systems in principle, since we have at least basic fluid mechanics knowledge at university.

What should comfortable ventilation look like?

After this long introduction, let's get to our main topic. How should a comfortable ventilation be?

Although we usually have heating systems in our homes, ventilation systems are not that important. However, I think ventilation is also very important. 

I am not talking about luxury residences, but in luxury residences, a fresh air inlet duct and a dirty air exhaust duct from the central ventilation system are brought to the entrance of each apartment. These ducts can sometimes even provide conditioned fresh air from the central ventilation system. When I say conditioned, I mean that the air is supplied from outside with special filters and then connected to the heating or cooling systems. Sometimes there is also a separate connection for cooling. We don't call it luxury housing for nothing.

But as I said, there is usually no ventilation in houses, if it is somehow taken into account, it is planned as natural ventilation. So there is a foul air exhaust duct in the toilets and bathrooms and that's it. There is no external fan at the end. If you want to install a fan, you install it in the bathroom. In other words, it is actually for dirty air, because the fan you install blows, if the duct is a common duct with other apartments, sometimes when someone else's fan works, the dirty air of that apartment can even cause odor because it comes to your apartment. 

Standardization

In the old houses there was no ventilation at all, just a small ventilation window in the toilets and bathrooms, and in the rooms the window was opened a little when needed. Then, in the hot summer weather, the window is opened wide, but we still bake inside. Also, flies and bees get in. Mosquitoes are another problem in the evenings. Since old houses are not insulated, we struggle to heat them in the winter and struggle to cool down in the summer. Some people install air conditioning inside, but it is a complete visual pollution with its outdoor unit on the facade. I also get very angry when the dripping water splashes on you downstairs, it is the situation I hate the most.

As I said, in new buildings, both the thermal insulation problem of the building is usually solved and ventilation ducts can be foreseen in the project. New types of window systems can also be comfortable with special opening systems to let in fresh air, especially in winter. 

But I think it would be useful to standardize these issues. For the time being, these details are optional or based on the project projections of the housing construction companies depending on the quality of the housing they build. Unfortunately, as always, we do not have a proper standard in this regard.

Ventilation Systems in Factories:

In buildings other than residential buildings, for example in factories, this issue is taken a little more seriously. 

Depending on the product produced, ventilation in factories is specially designed. The employer determines the ventilation conditions according to the technology. In most projects, the ventilation parameters written in the technological projects are taken into consideration in accordance with the technological requirements. 

In Russia, especially in factory buildings, the ventilation details are explained in detail in the norms, so the projects are done more seriously. Russia is already a country of norms, everything has a norm, they sat in time, they were not processed, they tied everything to a standard. The Germans have done the same, and even the United States of America, which has not even been in history for 250 years, is so advanced in terms of standards. I'm not even going to talk about France, whatever we use, from mistresses to kilos, France has had a hand in the standardization.

Anyway, back to ventilation. 

I built a steel paint shop in a project, for example, the ventilation of such facilities requires special design. In such facilities, you have to make very powerful ventilation systems specific to staged, empty, painting and drying stages. Moreover, you have to consider ecology by using special filters in such ventilation systems.

Shopping Centers:

Another special design must be envisaged for shopping centers. 

Since shopping centers are very large spaces, it is not enough to heat with radiators placed on the perimeters in winter. For a volume of that size, most of the heating has to be done through ventilation. But you have to do this very carefully. If the ventilation is too fast, the breeze blowing over your head is not very good for comfort conditions. If it is too slow, you cannot heat the air as much as you want. Ventilation should be at a level that does not disturb visitors. But due to the accumulation of hot air in high volumes, you need to ensure that the hot air can reach a sufficient distance close to the ground. In other words, the air has to be blown far enough away from the top. For this purpose, jet vents have been designed, special vents that can blow the air far enough away are attached to the fresh air inlets. 

Also, in large spaces, air needs to enter from one end and exit from the other end by licking the environment, so the design of such spaces should be made accordingly. But to prevent dusty air from entering from outside, through various gaps and doors, positive pressure must also be considered inside. In other words, the fresh air that is pumped in has to be slightly more than the air that is sucked in. Also, for reasons of economy, some of the air has to be circulated inside, otherwise, if you throw the heated air directly outside, it will cost a lot of money and waste a lot of energy.  There are also heat recovery systems, but the energy savings of these systems are not effective enough, in any case, it is more effective to recirculate the indoor air by mixing it with fresh air.  

At the time of the pandemic, these ventilation systems were asked to be adjusted again, but I never understood how they adjusted the systems that were set up for circulation from the beginning. Probably they said they adjusted it and they couldn't do it in reality, or if the circulation doors were closed, this time the comfort conditions could not be provided, ventilation could not be done as it should be, the building could not be heated enough, I don't know. The systems are very expensive systems, such deviations from the project may cause various malfunctions in the system. I don't know if anyone took this risk.

Fastfood Environments:

Let us return to the ventilation system. 

The food odor in fastfood areas needs to be cleaned and completely expelled within its own space, so it is necessary to use special ventilation plants with the capacity to expel all of the indoor air. Moreover, unlike the general building, negative pressure should be foreseen in these areas, that is, the fresh air pumped in should be less than the air expelled, so that the odor does not escape to other parts of the shopping center.

In the summer months, unlike the winter months, the interior also needs to be properly cooled. Again with the same principles.

But another problem arises while designing this complex system. In the winter months, while the building is heated from the perimeters and through ventilation, the air gets too hot in the middle of the building, so in the winter months you have to cool in the middle of the building. 

This situation can also cause a need for heating in the summer months due to the excessive cooling of the center of the building.

Also, if there is a fire, there are special ventilation fans to exhaust the smoke, they have to be specially designed fans to exhaust the hot smoke. Not only that, you have to automatically close the fresh air intakes so that the fire doesn't burn inside. At the same time, you have to supply fresh air to the escape routes so that people don't suffocate in the smoke. A fire scenario requires a completely different kind of expertise. All systems have to work in coordination with each other. Even elevators must work according to the scenario, large capacity water pumps must start automatically for sprinkler systems to be activated, etc. very complex systems.

In short, these systems are not so easily solved. We had to install special systems that cooled the middle parts of the building in the shopping center we built in the freezing city of the north in winter. It is minus fifty degrees outside, the heating systems are already working at their maximum capacity, I can almost say that the systems were barely enough because the weather outside was at the coldest possible times of the season, but on the other hand, cooling systems are also working in the middle of the building. Sounds absurd, doesn't it, running the cooling in the winter, but that's what comfortable design looks like.

Yes, our job as engineers is to create comfortable living conditions for you, or rather for all of us. We know our job. We have received a good education and the whole staff is doing what we do together for you. 

As I have explained in detail throughout the article, our job is not so easy. Even though we do these jobs, no matter how difficult they are, you, the users, also have a duty. If you want to live life comfortably, at least give the task to those who know their job. 

Making the Right Decision from the Start

As I wrote yesterday, deciding certain things is the only freedom one has. This freedom must be used. Just as for a comfortable and safe life, only meritorious cadres have to build, in the same way, only meritorious cadres have to govern this country. 

As I said yesterday, let's MAKE OUR DECISIONS OURSELVES, that is, let's think about our choices and make them ourselves, let's not be fooled by anyone, let's not let anyone fool us. 

Let's not forget that the responsibility for putting in charge meritorious cadres lies only with us, on our shoulders, and no one else.

Love and regards from Moscow.