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Questions and answers

10 most common questions and answers about the need of the chimney remediation.

Why is it now necessary to renovate the chimney, and for 30 years everything was fine?

Like all things in the world so the chimney gets old, erodes, cracks, becomes porous, worn out, starts to collapse. The reason is the aggressive composition of flue gases and moisture.
Humidity is 70% in the composition of the flue gases.
Smoke is measured and expressed in grams per second, so if you turn it into a kilo per hour, it would be that in one kilogram of flue gas there are 7 dcl water. Sve te činjenice pa puta vrijeme učinile su da takav dimnjak postaje neupotrebljiv. All these facts times the weather have made such a chimney unusable.

What's the matter if I change a boiler, so now I have a chimney too?

Chimney that you have is designed for gas appliances which then had a flue gas temperature of 150 ° – 170 ° C or more. Then the chimney made of the bricks (the bricks) or slag concrete had a chance to heat up and thus pull smoke out of gas appliances and drag it to the top of the building.

Replacement new devices due to better utilization and lower power consumption have a flue gas temperature of 90 ° – 120 ° which is not enough to warm the chimney, so that the chimney is always “withdraws”, and new sensors in the apparatus register that and do not let the device to work resulting to a frequent shutdown (user is dissatisfied). At the same time, a large number of users change their windows and doors, and they disable the air intake into the space (flat) so that no smoke can go out of the chimney unless the air has entered the space before.

I need to change the boiler, and the neighbor in the same smoke channel does not want to. I'm a hostage?

This is the problem of not knowing regulations. The chimney in the building is a common part of the building and so it needs to be watched as such. When the chimney is out of service all the tenants need to repair it together. Unfortunately all boilers have to be changed in such a solution.

Why do we all have to have the same gas boilers in one of smoke flue vertics? Monopoly?

No, it is not a monopoly or someone’s “sake”, but it is the only possibility is to do it without making a mistake due to the non-return damper being made by different manufacturers of different constructions and working at different pressures. The non-return damper serves in cases where there are more gas boilers in the same smoke channel that the smoke of one boiler does not enter the space of the other, but only on top of the object.

Why are there different prices of chimney repairs?

Prices differ mainly due to the type of material. Postoji „čudna“ roba na tržištu koja je jeftina. There are “strange” commodities in the market that are cheap. Manufactured reputable materials are certified (tested), and most commonly the German ones are more expensive.

There are “black” businesses without bills, so when these two components are united “black business and non-certified material”, then the prices are significantly lower, but the security and quality of living in the spaces where the materials without the certificate, the duration of such materials, as well as the contractor’s warranty are questionable.

What kind of materials exist for the sanitation of the chimney?

Usually two types of remediation material are used:

  • Inox (rostfrei) – for wood stove, pellet, and for gas boilers of older generators with higher flue gas temperature.
  • PPS polypropylene – the type of plastic that has the highest application in new boilers with low flue gas temperatures and a lot of moisture (condensation technology).
Why do we have to bring air from the outside?

Because of the better energy efficiency of apartments, frequent changing of windows, doors and facades, the apartment loses air, and we know that fire burns only if there is fuel and air.

Since we prevent air intake through porosity of windows, doors and walls we have to bring air to the boiler independently of space.

Why do we need to set up a condensing boiler?

Condensing boilers are best suited for chimney repairs because the pipe flue profiles are the smallest.

When there is not enough flue gas channals can the chimney go over the façade?

There is a possibility of drainage of smoke gas pipes with vertical pipe to the top of the building but this requires greater intervention because the pipes must be double or double insulated. The scaffolding and sometimes the consent of the Ministry of Construction are required.

How to build and strengthen chimney?

Mounting of smoke flue sanation pipe can be made by pulling from the top of the object to the lowest connector where a “T piece” is needed to be strenghtened beside each connector and the “T piece” in front and back allow the pipe dilution due to high stretching. This can be demanding, and in the apartment itself, it requires the dumping and expansion of the current connector.

There are a number of technical solutions where the chimney is secured with stainless steel cables and does not require the opening of the connector more than 130 mm. There is a need to mention the drain of condensate where the condensate from each boiler must be connected to the sewerage system, and the drainage from the chimney itself depends on the chimney manufacturer, not necessarily connected to the sewerage system.

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