April 10, 2023 – The receipt of new applications for this advice has been suspended. Consultancy concerning protection against WMD is available to a limited extent.

Consultancy concerning air filtration

After buying filter ventilation equipment, the majority of people usually think that it is enough only to use it when necessary, and that everything is solved. Such an approach can often work safely for only a few days, and in some cases even for a shorter time. In particular, carbon filters (containing activated carbon) designed to capture toxic substances would have a relatively short operation time in real conditions. In general, the more air that passes through such filters, the sooner their life will end. The filters will therefore lose their ability to function after a certain period of use and harmful substances will then pass through them without restriction. Therefore, it is necessary to change the activated carbon filters more often.

With our Zeus filter ventilation equipment we give detailed recommendations on how to ensure the longest possible use of filters in real conditions with regards to a number of parameters (outdoor temperature, filtration speed, amount of carbon dioxide in the shelter, physical activity, weight, age, health and sex of sheltered people, etc). The clear tables we supply are unique in their scope and we are unaware if similar tables have been developed by any other company, army or civil defence units. They are the result of our research.

As, along with other filter ventilation equipment and filters, people do not receive detailed and practically usable instructions for their operation during times of war from the manufacturers, we also offer recommendations for arbitrary filter ventilation equipment. These recommendations are not only compiled into customized tables, but also into an assessment of the surroundings of the planned sheltering place with respect to a possible chemical attack or industrial accident.

With our recommendations, it is possible to manage with only a few replacement filters, compared to a few dozen filters that might be needed if they were used inappropriately during filtration.

Our consultancy concerning ventilation without filter ventilation equipment (FVE) is also included in the price.

For whom the consultancy is important

Those who do not want to spend tens of thousands of dollars on replacement filters for their filter ventilation equipment, or those that do not have that much money for them, they should possibly consider the consultancy on air filtration. Of course, if they have only one filter and do not plan to buy any more, they must filter only with the one and hope that there will not be any chemical attack etc. in the area.

The consultation therefore makes sense especially for those who have bought or will buy at least a few replacement carbon and other filters for their filter ventilation equipment.

What you will learn from the consultancy service

What the consultancy does not address

This consultancy does not deal with the calculation of the effects of nuclear explosions (these are dealt with in detail in the consultancy focused upon the effects of nuclear explosions) and does not address possible biological contamination in the given area. In addition to the replacement of filters in the event of a chemical, nuclear or toxin attack, it also addresses the approximate replacement time of filters designed to catch viruses, bacteria, and spores.

Consultancy procedure

After receiving the necessary information (electronically, by regular mail, or in person by prior arrangement), we will contact the manufacturers of the filters used in your filter ventilation equipment and ask them for detailed information about filters. We will then inform you when everything should be ready for you. You will be asked to pay just before we prepare our recommendations and tables.

Comprehensibility of the obtained information

The tables and recommendations should be well understood by everyone who has completed basic education.

Necessary information

We need to know the location of the planned shelter so that we can make detailed recommendations. As you know the area well, it is also necessary that you provide us with a list of critical objects and their location, if they are within a distance of 20–30 km (12–19 mi) from the shelter. Looking at larger cities (approximately over 100,000 inhabitants), chemical plants, waterworks, large industrial centres, swimming and winter stadia, fertilizer and fuel depots, refineries, power stations, civil and military airports (including former ones), radar stations, air defence systems, military bases and ammunition depots, military fallout shelters, larger dams etc. This detailed information will allow us to assess the possible impact of the environment on the planned sheltering place. We are also interested in the type of filter ventilation equipment, information about filters, the air flow during filtration and ventilation (filter ventilation equipment blows air into the shelter without the use of filters, which is usually only suitable for peace conditions), pipe length, diameter, and the number of rectangular bends. If filtration and ventilation airflow values are not available, appropriate anemometer measurements must be made. In this case, we will agree on how to proceed further.

Answers to some of the questions

Are the tables “tailor made”? And what about the recommendations?

A part of the tables are adapted towards the given area and the recommendations we supply indicate how we ourselves would proceed in that given area.

Will not the tables be damaged during frequent use?

All tables and instructions are laminated. They are moisture and grease resistant and can withstand 'less than gentle' handling.

How accurate are the tables?

The final table values take into account a number of parameters. However, a more fundamental change of each parameter can significantly affect the outright result. The tables only need to be used for a rough estimate, i.e. they cannot completely replace the measurements made on site, but if it is not possible to measure the necessary data, they will at least serve as a point of reference. If you follow these tables, you should “proceed with confidence”.

How can I verify the values from the tables?

Very difficult. It is a question of trust. We spent a lot of time on the calculations. We do not say that a stated filter will last three months, half a year, etc., because that is ridiculous. It always depends on the given conditions. Therefore, we have incorporated more than ten parameters into the calculations in order to be able to get as close as possible to the real conditions. It is also worth adding that we have also processed similar tables for our own use.

Why do not other manufacturers of filter ventilation equipment supply similar tables?

A filter ventilation unit is a technically demanding device. In order to be able to supply similar tables, the manufacturer would also have to have relatively large knowledge not only in the field of weapons of mass destruction, but also, for example, in medicine or meteorology. In addition, he would have to manage to develop extensive simulations and make a number of measurements. He would also need to obtain information regarding the lifespan of the filters directly from their manufacturer, who does not know it however as he does not deal with such things. He is only interested in whether he conforms to the standard for the amount of captured pollutants. Plus moreover, only very few people count on war. Unfortunately, the approach of some filter manufacturers is that there will be no judge after the war.

Why is not the price for tables lower?

Some tables are customized. In addition, we also address the surroundings of the shelter (the distance from strategic targets in the area, the climatic conditions in the given area, etc.), so it is a detailed assessment of the situation. We also need to obtain long-term detailed temperature measurements for the given area, which is in some cases relatively expensive. It takes a relatively significant time to put all the tables and recommendations together.

Is it possible to book a personal evaluation of the performance of a filter ventilation unit with filters etc.?

We do not perform such measurements due to time constraints.

Will I know from the tables when, at the latest, to start filtering to avoid high levels of carbon dioxide in the shelter?

Yes. The tables also show how long you can remain safely in isolation mode, which is the time when no filter ventilation equipment is used and you have to manage only with the air in the shelter. The reason for this may be due to outdoor smoke, an attempt to extend the lifespan of the filters, to prevent the disclosure of the shelter if there are strangers nearby…

Which areas of the world are most at risk from a chemical attack?

These are mainly in Europe and the Middle East, however industrial accidents can also pose a significant risk.

What are the possible sources of exposure to harmful chemical substances?

The risk of air contamination with harmful chemicals outside that of a chemical attack or various fires, is represented by, for example, chemical plants, waterworks, swimming stadia, various refrigeration equipment used mainly in the food industry and winter stadia, fertilizer depots, etc. Accidents at these facilities can in some cases endanger the health and lives of residents even within a distance of several dozen kilometres (miles). It depends upon the amount and type of pollutants released, the meteorological conditions etc.

Delivery time

The tables and recommendations are compiled according to a waiting list, and the current lead time is about 3–4 months.
(April 10, 2023 – We are no longer accepting new applications for this advice. Consultancy concerning protection against WMD is still available to a limited extent.)

Delivery method

We send tables and recommendations by registered mail by Czech Post, but personal collection is also possible by prior arrangement.


Payment is made by bank transfer or in cash by prior arrangement (some other payment methods are possible). We send the request for payment shortly before we start processing the tables and recommendations. After receiving the payment, everything is dispatched or ready for personal collection within about a week.


The price for tables and recommendation concerning a suitable method of filtering and working with filter ventilation equipment in the given area is 9,699 CZK (approx. 454 USD or 416 EUR). The price in USD or EUR depends on the current rate of exchange of the Czech crown on the date of payment. Postage or personal collection, by prior arrangement, is without charge. Information are in English (translation into other languages is possible).

If an order is cancelled prior to payment, no fee will be charged. If the order is cancelled within two days after payment, the fee is 20 %, within three days 50 %, and over three days 100 % (in this case, everything will be delivered).

By purchasing, you agree to the terms and conditions.