PhD Researches

The inspiration to create 'tailor-made' became my PhD thesis, where I focus on analysisof the impact of multi-phasing construction on comfort, cost and power consumption in the life cycle of a residential building (LCC).

 

 

What do I do in my scientific work?

Although I am a construction designer, my attention during the study was coughtby sustainable buildings. With the favour of my university I was able to go to the University of Lulea in Sweden, where he deepened this subject.

 

What the sustainable building is?

 

In a nutshell one could say that it is way of finding a proper balance between the three aspects MAN - ECONOMY - ENVIRONMENT. Each of the three factors is equaly important. Sustainable construction is not synonymous with either building or ecological building, passive, nor of building cheap or too expensive. a house that uses the potential of the environment and does not waste energy unnecessarily and the cost and maintenance is optimized. It sounds pretty fairy tale, and indeed this is the aspect multi-threaded analyzed by a large community of scientists and to which I joined a few years ago.

Idea of sustainable development

The construction industry, the life cycle analysis?

 

The construction industry in Poland and Europeis responsible for about 40% of energy consumption, is a heavy burden, both economical and environmental. Each product, including buildings, passes through several phases during its life cycle, namely: design, construction (production), operation and decommissioning. Analysis of these phases is called life-cycle analysis LCA and has a lot of smaller studies, eg. Life cycle costs (LCC The share of costs in the case of single-family homes can be represented by a graph:

Cost allocation in the building life cycle

Schade J., Life CycleCostcalculationmodels for buildings, inpro-project.eu ,LTU Luleå, Sweden

The chart above shows that the largest accumulatedcosts during the operation and are mainly related to heating the building and hot water supply. Therefore, one should make every effort to ensure that these costs have been reduced. Note, however, that it is connected with increased initial costs. Finding balance requires individual case studies. Based on knowledge and research we propose solutions for energy savings in the operation phase, for which payback time is relatively short so that the user feels the financial benefits as soon as possible. However, there are a number of solutions of savings during the exploitation phase, at a reasonable initial outlay. Read about it in the next section.

 

What solutions are cost and energy-effective?

 

After the initial reading of the distribution of the costs in the life cycle,I would introduce fundamental principles of the optimal building performance. The main factors of energy consumption include:

 

  • House location

  • Useful area of the house

  • The shape of the building

  • Insulation of the building envelope

  • Thermal bridges

  • Ventilation system

  • Heating systems and auxiliaries

I will try to briefly explain each of these points.

 

Location of the house

This factor plays a huge role and is appreciated in Western Europe where approx. 95% of homes designed individually, in Poland approx. 5% (sic!). At the stage of locating the building it is mainly about taking into account natural conditions such as wind or sun. The basic principle is shielding the house from the cold northern winds which cool down our house, usually by means of coniferous trees or outbuildings, and ensuring the greatest possible heat gains from the sun by locating glazing facades on the south - western and reduce them from the northern side. We should also protect the house from excessive overheating of the windows in the summer using a variable sun location within a year on the horizon.

 

House size

In this case, the matter is clear, the larger house on the same parameters, it will consume more energy. A characteristic feature of Polish families are building large houses "in reserve". According to CSO data, the most commonly built houses have an area of between 120 and 140m2. As is clear from conversations with the owners is often surface too large. Big house is a large construction costs and maintenance. Often, to reduce cost saving on the material or the manufacturing of which is apparent savings. Therefore, I took up the analysis of homes for low-usable allowing for possible future expansion. In so designed home we have to deal with less randomness of space. The house was built in this way, although not impressive in size but is appreciated for the quality and solutions used in it.

 

The shape of the building

The higher the ratio of the volume of the building to the exterior surface of the wall structure is exposed to less heat loss. This principle is based mainly on simplification of  the building shape by reducing elements "sticking" from the main body of the object.

 

Insulation of the building envelope

Envelope elements, ie .: slab floor, walls and roof should be designed in such a way as to let in the least heat. The walls constructed with silicate blocks or bricks are characterized by poor insulation parameters, thus to ensure adequate heat transfer coefficient (currently U = 0.25 W / (m2 K) in 2021r - 0.20 W / (m2 K) require insulation of mineral wool or polystyrene, thereby achieving a significant thickness of about 40cm or more. in the case of the use of the timber frame of the same parameters can be achieved by wallscross-section of 28cm which in the case of a small house with a circumference of 30 meters and a building area of 60m2 gives a saving of 2.5 m2 floor. However,the most important, aspect it is possibility to eliminate thermal bridges.

 

Thermal bridges

Thermal bridge is the area in the element of the buildingwith significantly worse insulation parameters than the rest of the structure. Thermal bridges are present wherever there is a discontinuity of thermal insulation. The most common sites of occurrence is a connection of walls and foundation, around woodwork and roof connection with the outer wall of the building. Bridge between the wall and roof, as well as in the vicinity of window can be easily reversed. The most difficult solution is to maintain continuity of insulation in the case of continuous footings. You can say that no solution that fully solved by this problem. The solution is theslab foundation, which eliminates this problem. The costs of this solution are comparable with traditional continuous footing, what is more, offer more opportunities for increase of bearing capacity of building and less prone to subsidence. Therefore, in the home energy efficient it is also necessary element. It is also very cost effective for economic reasons.

 

The ventilation system

This aspect is described in the energy consulting section.

 

Heating systems and auxiliaries

When selecting the heating one must take into account many factors, but above all: the size of the building, its demand for energy, comfort, initial and operating costs, as well as the life of the system. we should also mention the rate of energy demand showing how much energy is needed to heat 1 m2 home within a year. Below change of indicator over the years has been presented:

 

200-300 kWh / (m2 year) 80'-90 '

150-200 kWh / (m2 year) 00’

120 kWh / (m2 year) now (minium)

<40 kWh / (m2 year), energy efficient house

<15 kWh / (m2 year) passive house

 

Taking into account all these factors, one can make attempt to compare several solutions. Here I would like also to mention about the hybrid systems (bivalent), a combination of two or more systems. This solution allows increasing of the comfort and reducing costs. An example might be a combination of electric heating and automatic pellet fireplace during the coldest period.

 

Man in home-user

In my research work I create algorithms that enable an assessment of all costs associated with the house for different economic scenarios and technology. An important aspect is the human factor. Seeking solutions to reduce costs while increasing the standard, or maintaining it unchanged. The most important include: thermal comfort, a sense of security (financial and sociological), functionality and flexibility of solutions.

 

I try to convey my knowledge to customers and used in the designed buildings. Feel free to personal contact, whenwe can discuss the wider issue that interest you, and help you to choose the most appropriate solutions to individual customer needs, based on the analysis of a specific plot.

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