Useful information when choosing window frames


This is strictly an individual decision. The choice of window frames depends a lot on the region where the home is located. What are the climatic conditions there? Is it subject to high wind pressure? On which floor is the apartment located? What is the exposure of the rooms? That’s why our specialists are at your disposal and will offer you the best option for you. We have distributors in almost every neighborhood of Varna to make it convenient for our customers to contact the office nearest to them.

In addition, we offer a brand new service for our city – a mobile office. After a call and a visit request from you, our specialists will visit you at a location of your choice. In a specially equipped van you will be able to see, see the qualities and try samples of our windows, our consultants will advise you on the best type of window frames to order and prepare a quotation.

We recommend you choose a company that has an office, has samples where you can go and see the products they offer.

Require documents for the right to manufacture joinery – certificates, references. Any self-respecting company that offers a quality product should have them.

The windows must have a CE marking, which is a guarantee that all requirements have been met.

Sign the contract! It will describe the terms, conditions, penalties, guarantees, etc.

Always ask for proof of payment. It is your guarantee to claim your rights in case of a problem.

Require warranty service. By law, the warranty of the windows is five years. Don’t settle for less.

Choose a company with a manufacturing facility near you, because that way they will respond faster in the event of a problem.

It might shock you, but the best season to replace your windows is winter. We know this will make you uncomfortable, but let us tell you why we think so. First, in winter, since it is not the season of renovation works and the demand for window frames is less, companies make promotions and are more willing to discounts. So you will get a better price for your chosen window frames.

Second, the foremen are freer because of the reduced workload, they will be more careful and do their work more accurately, and they won’t “overwhelm” you by rushing to the next customer.

Thirdly, you will find out at the moment if there is a problem with the joinery. Usually when you install it in the summer, the problems shine through in the first heating season, but it’s been months. And now it will immediately become apparent if there is any problem and will be responded to immediately.

The biggest concern customers have is how they will leave their home open in the cold. In Varna, winters are not very cold and even December sometimes has plus temperatures. In addition, once the old windows are removed, the new windows are installed immediately. So your home will not be left unprotected. On the inside, you can start finishing immediately. The concern of most customers comes from not being able to do the exterior window insulation. Usually, a 3-4 cm gap is left on the outside, which is filled with polyurethane foam that keeps out rain and snow. And now in spring you can call a company to do your insulation.

That’s why we recommend that our customers replace their windows in the winter.

Usually in new construction, after the windows are installed, they are tensioned and plasterboard is put on the inside and insulation on the outside. The warm air passes through the plasterboard and reaches the cold foam, where it condenses. The accumulated moisture beats under the windows at both ends. We have a solution for this problem and it is the placement of a vapour diffusion membrane around the perimeter of the windows. The membrane is similar to a textile tape that is placed around the perimeter of the window frame and it prevents water vapour from passing through.

It can, but it is a sign that the glazing is defective. The solution is to replace it. In our company we give a warranty of 5 years and if this problem occurs within this period, the replacement is at our expense. Like anything, glazing has a certain lifespan. If it’s manufactured according to the rules, you may not have a problem with it for over 10 years. How long it will last depends on many factors – method of manufacture, number of barriers, type of adsorbent, gauges, etc.

Condensation worries every person who decides to replace their windows and the first question customers always ask is: will I have condensation when I replace my old windows with new plastic or aluminium ones.

Condensation is a problem that occurs in windows that insulate well. When we change our windows we literally seal our home and if there is no good ventilation, condensation occurs.

What are the solutions?

The first is to ensure a flow of fresh air into your home. This happens if there is a good ventilation system in place, but this is rarely an option in our homes. Public buildings usually have one.

That is why we offer the installation of dampers in the window frames to ensure fresh air flow. The valves are of two types: manual by Renson and automatic by Aereco.

How do they function?

You must have noticed that when the windows are closed the screen and the fan in the bathroom do not work effectively. This is because underpressure is created. The valves we offer support the efficient operation of these appliances. How does this happen? Usually they are installed at the top of the window frame, and there in the upper third of the room is collected the warm and humid air. By drawing in dry cold air it pushes the moist air to the vents and they suck it in.

Many customers worry that their room will get cold this way. Actually through the flaps, which open a very small slit, the air enters at a low speed and when it comes down it has already warmed up and so you don’t feel the cold air.

Manual dampers allow you to decide when to ventilate.

With Aereco’s automatic ones, the principle of operation is different. When the humidity in the room gets above 35-40%, the sensor built into the dampers gradually opens them and lets fresh air in. When the humidity returns to normal it closes the valves. The valves operate without current, are silent and have a sleek design.

You can have the flaps fitted when the windows are manufactured, but this can also happen at any subsequent stage.

We also offer a micro-ventilation feature that we can insert into the casing to provide fresh air into the room. What is the action of this function? When you turn the window handle at a 45-degree angle it creates a small slit through which fresh air enters.

The other direction we are taking to solve the condensation problem is to make the window warmer. Why is this necessary? According to the laws of physics, when warm moist air touches a cold window – it condenses. So making your window warmer will reduce this condensation. This is done by installing special glass – K-glass or all-season glass. The choice of glazing is therefore important. K-glass, by comparison, increases the thermal insulation of a window compared to two plain white panes by almost double. The coefficient of thermal conductivity of the glazing with two white panes is above 2.5. If you put only one K-glass and put argon between them this coefficient becomes 1.1. Or to put it another way – putting only one K-glass is like putting two windows one after the other.

Four-season glass has the same coefficient only it additionally has a solar factor i.e. it stops solar energy. By increasing the temperature of the glazing we reduce condensation. If we put triple glazing coefficient of 1.1 becomes 0.6 -0.8. Four-season, white, K-glass has a heat transfer coefficient of 0.6-0.8. For comparison, the heat transfer coefficient of a brick wall with insulation is 0.3-0.5. The triple glazing with two special four-season glass panes and a K on the inside approaches the thermal insulation almost like a wall.

There is one more thing that can be done to reduce condensation. Invariably dewlap begins to appear around the perimeter of each glazing unit. The reason for this is the spacers. They are made of aluminium and the perimeter of the window frames is the coldest and therefore moisture condenses there first. To avoid this, specially designed plastic spacers are now available on the market. By using such a spacer we make the whole glazing equally warm and dew on the perimeter is avoided.

Other tips to help you deal with condensation are:

  • Install heaters under windows. This way, the warm air rising up will raise the temperature of the window frames and there will be no cold surface for the warm air to condense against.
  • Whenever you can, it’s a good idea to pull the curtains and raise the blinds from the windows so that the air around the window frames can move around and there’s no chance of condensation.
  • Ventilate properly! This is done by opening the window wide for a few minutes. If it is 20 degrees in the room and you open the window wide for a few minutes, the warm air, which is high in humidity, is replaced by cold air, which is generally dry. It heats up quickly and when you close the room it will be 20 degrees again. What’s more, the walls and furniture don’t have time to cool down in a few minutes.

The glazing we use is of high quality. They are extremely important because they occupy 85% of the window opening and the comfort of our homes depends on them. We offer 32 mm and 44 mm triple glazed units. There is a wide variety of glass currently on the market that we can use to achieve maximum comfort in our homes.

Let’s start with the most familiar – low-emissivity K-glass. This is float glass, which in special chambers is “bombarded” with ions of titanium or silver and thus forms a thin metal film. This film increases the temperature of the window when heated or when the sun’s rays heat it. K-glass has a high absorption and reflection coefficient of long waves, which are actually the waves of the heaters. This is exactly the reason why a glazing unit incorporating K-glass has 30% better thermal insulation properties than a glazing unit made of two ordinary panes. We recommend that you do not install double-glazed windows in your home, because in this case the condensation will be very high. It is best to put K-glass on the inside of the room, which will save you money on heating and at the same time, as the window gets warmer, you will not have a problem with condensation. The cost is negligible, but the benefit is great. K-glazing is a must in northern exposures. It is not good to place at western as it can create a greenhouse effect.

In recent years, four-season glass, also known as all-season glass, has become increasingly popular. This glass has a solar factor, i.e. it stops about 50-60% of the sun’s energy. It is recommended for southern or western rooms where summer sunshine is intense. By placing this glass on the outside of the glazing, it will not allow the room temperature to rise and cooling will be easier. In order to achieve this solar factor, a special film is applied that reduces the light transmittance of the window, which some customers do not like. But there is a solution for that too. The Four Seasons SUN system is now available on the market where this blackout is not present.

In recent times, the most recommended and, it turns out, the most effective is the glazing made of:

four-season glass outside

white in the middle

k-glass to the room.

The choice of glazing depends a lot on the exposure of the premises and what we aim to achieve by changing the windows. We provide a variety of glazing combinations and will offer the best solution for you.

Very often our customers are worried about the appearance of condensation after replacing the windows. We have a solution for this problem as well. In fact, condensation occurs because good window frames literally seal our homes. The lack of fresh air and ventilation for the rooms leads to a disturbance of the optimal humidity. The warm air reaches the windows, which are cold, and condenses there. To avoid this problem we offer special dampers that we install in the window frames. They provide an influx of fresh air and ensure efficient operation of the extractor fan or extractor fan in the home.

The valves we offer are of two types – manual valves by Renson and automatic valves by the French company Aereco.

The first Renson dampers are manually adjustable, i.e. you open the dampers of your own volition when you feel the humidity in the room increasing and close them when you decide.

Aereco automatic dampers are installed in the sashes of the windows. They operate fully automatically, silently and without power consumption. They have an elegant design and are suitable for all types of windows. It is best to install them when the window frames are manufactured, but they can be installed additionally. The models we offer also have manual flap closure.

When the humidity in the room increases, the built-in sensor triggers a mechanism that opens the damper and increases the flow of fresh air, while the old air escapes through the vents.

The humidity sensor is set at the factory not to respond to room relative humidity up to 35-40%. Above these values, it begins to gradually open the damper, letting in air from outside and thus creating sufficient draft to exhaust the moist, contaminated air through the vents.

Often our customers are worried about their homes getting cold. This will not happen because the flaps open a very small hole. In addition, they are placed at the top of the window frame, where the more humid warm air is collected. When they are opened, dry cold air enters and drives the moist air out through the fan or extractor. But by the time it gets down to the bottom it warms up and doesn’t feel like an influx of cold air.

Depending on your needs, a variety of combinations can be made to maximize the convenience of using your new windows. Types of opening: