Section Energy efficiency development according to DSTU B A.2.2-8.2010 example

 

According to DBN A.2.2-3-2014 “Composition and content of project documentation”, the energy efficiency section is an obligation part of the project documentation. This is not surprising at the moment. In today's situation, with a significant increase in energy tariffs - of course, they pay attention to the issue of energy conservation.
And as at the design stage - the first step in the construction of a new or reconstruction of a building, the necessary solutions will lead to the efficient use of energy for heating, ventilation, lighting and so on.
A tool that will help to analyze all the inherent decisions for compliance with modern standards of energy conservation is the very section of energy efficiency in the design documentation.

So, let’s try to look at a specific example of which parts the energy efficiency section consists of.

ENERGY EFFICIENCY

1. General information.

The project provides for major repairs, thermal modernization of the building of the Sergeevsky institution of pre-school education (nursery garden) Kolosok, located at 5 Sobornaya Street, the village of Sergeevka in the Slavyansk region of Donetsk region.

The following activities are planned:

Bringing the actual resistance of the walling of the external walls to the normative by warming the EPS with thin-layer plaster.

warming the foundation of the building is not provided, since work on warming the foundations and arranging the blind areas was completed in 2017

insulation of the attic floor with Thermolife Caviti material 150 mm thick.

1. General part - describes the general data on the object of construction or reconstruction.

2. Input data - a description of geometric indicators, the building’s operating mode, as well as the general view of the object of study.

2. Incoming data

I General information about the object

Preschool educational institution `` Sun '' was built in 1983. The total building area is 498.24 m2 with a building volume of 4982.40 m3. The plan has a rectangular shape. The spatial rigidity of the building is ensured by the configuration of the building, the joint work of the longitudinal and transverse walls and hard flooring.

The estimated number of personnel is 15 people, the number of visitors is 75 people / day.

Building code according to DK 018-2000 - 1263.5 "Buildings of preschool and after-school educational institutions."

The facades of the building are presented in the figure below:

 

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3. The next part of the energy efficiency section is the input data for calculations.

Design solutions are considered here (what walls, ceilings, roof, basement consist of, which windows are proposed for installation, etc.) And of course, all the engineering systems of the building are considered.

II. Input data for calculations

Constructive decisions:

•     external walls - made of silicate brick;
•     internal walls and partitions - made of clay bricks, 420 mm thick;
•     strip foundations, clay masonry;
•     floors and coatings - precast multi-hollow concrete slabs;
•     the roof is of a hip type, the coating is a metal tile, the existing roofing system serves as a frame;
•     translucent structures are made of PVC profiles with filling with two-chamber double-glazed windows with an energy-saving coating on the inner glass (4M1-10-4M1-10-4i). The area of ​​translucent structures meets the standards of natural lighting according to DBN B.2.5-28.

Heating system.

The building provides water heating. The heat supply source is the existing modular gas boiler room. The heating system is one-pipe, with a lower wiring. Bimetal radiators without thermostatic regulators.
Influencing the energy efficiency and energy saving factors, the distribution of the heat carrier of the water heating system.

Influential energy efficiency factors for a water heating system with heating devices (radiator, convector, etc.) in rooms with a height of not more than 4 m:

 

Influential factor	Influence factor detail
Room temperature adjustment	None, with central quality control coolant adjustment
Temperature head (at an air temperature of 20 ° C	30 K (e.g. 55/45)
Specific heat through external cladding	The heater is installed near the external wall: - ordinary wall
Hydraulic setting	Unbalanced system

Hot water system. Hot water from the existing modular gas boiler room. The use of hot water is provided in the bathrooms, as well as in shower rooms.

Pipeline networks and cold water supply are mounted from propylene pipes, which are laid hidden in the structure of the floor and walls in heat-insulating material.

Influencing factors of energy efficiency of a hot water supply system

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4. Consideration of climatic parameters also has an important stage in the development of the energy efficiency section. Air temperature and cooling.

III. Estimated climatic and heat energy parameters.

According to DBN V.2.6-31, the calculated internal temperature is adopted at tv = 22 ° C, the estimated value of the relative room temperature is 50%, according to DBN V.2.6-31 and DSTU-N B.1.1-27, we take the calculated external temperature ts = -22 ° C .

In accordance with clause 5.8 DSTU-N B A.2.2-5, the duration of the heating period is defined as the duration of the period with an average daily temperature <8 ° C and, accordingly, DSTU-N B B.1.1-27 is zon = 176 days. The average air temperature during the heating period is top.per = -0.5 ° C.

According to DBN V.2.6-31, the standard value of the reduced heat transfer resistance Rq min, m2K / W, is:

for external walls - 3.3 m2K / W;
for combined flooring - 6.0 m2K / W;
for translucent walling - 0.75 m2K / W;
for entrance doors - 0.6 m2K / W;
for the floor on the ground - 3.75 m2K / W.

The maximum permissible annual energy consumption for a building according to DBN B.2.6-31 is: E max = 28 kWh / m3.

5. Determination of thermal performance for truly energy-efficient building structures that will consume a minimum of energy.

The reduced heat transfer resistance of the external enclosing structures is determined in accordance with paragraphs 5.2 of DSTU B B.2.6-189: 2013. The calculated thermal conductivity of the materials is adopted in accordance with Appendix A of the same DSTU.

Exterior walls. Characteristics of the layers:

 

  

•  Internal cement-edible plaster δ = 0.05 m, λ = 0.93 W / (mK); ρ = 1800 kg / m3;
•  Silicate brick masonry with joint filling δ = 0.550 m, λ = 0.87 W / (mK); ρ = 1800 kg / m3;
•  Glue Ceresit CT190 (not taken into account in the calculation)
                                                                  .....

Overlapping overlap

The following elements are used to calculate the thermal performance of the deliberate overlap (with some exceptions due to their insignificant effect). The design of the floor is shown in the figure below:

 

   The heat transfer coefficient of the floor over the soil U, W / (m2K), is determined by the formulas:

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6. Also during the development of this section of the project documentation, an assessment of the humidity regime of the building is carried out to prevent the formation of excess moisture in the building structures and to prevent the formation of fungus.

Assessment of the humidity regime of building envelopes.

The assessment of the humidity regime of the structures was carried out in accordance with the requirements of paragraph 6.12 of DBN B.2.6-31 for deaf sections of the main field of the external walls. The calculated assessment was carried out using the heat engineering calculator of the building envelope. The figure shows a diagram of the heat-moisture regime of wall enclosing structures of the main design solution of the external walls.

Heat and humidity condition of the structures of the external multilayer wall with mineral wool insulation.

According to DSTU-N B V. 1.1-27, the average monthly values ​​of temperature and relative humidity of external air are determined.

Month	I	II	III	IV	V	VI	VII	VIII	IX	X	XI	XII
Temperature, оС	-5,2	-4,4	0,7	9,4	15,4	19,0	21,2	19,8	14,9	8,0	1,8	-2,9
Relative humidity,	86	84	80	66	61	65	63	61	66	75	86	89

The temperature and relative humidity in the room are determined. For a building according to DBN B.2.6-31, it is 22 ° C; fifty%

According to table B.1, the partial pressures of saturated water vapor E are determined, according to formulas (6), (7), the partial pressures of water vapor are:

    for internal air: Ev = 2645 Pa, ev = 1322 Pa;

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7. The indicators of heat resistance show the ability to withstand the influence of external factors, and also show how the building reacts to changes in temperature.

           Determination of heat resistance.

Assessment of heat resistance in the summer period of external walls according to DSTU-N B V.2.6-190: 2013

Object - external wall in the climatic conditions of the city of Donetsk. Climate parameters of the construction area are given in the table.

Parameter Name	Values
The average monthly temperature in July (according to table 2 of DSTU-N B V.1.1-27)	21,2
Average amplitude of daily fluctuations in the temperature of external air in July, ° C (according to Table 2 of DSTU-N B B.1.1-27)	11,2
The maximum value of the total solar radiation that arrives on the vertical surface of the western orientation in July, W / m2 (according to table 15 of DSTU-N B V.1.1-27)	524
The average value of the total solar radiation that arrives at the vertical surface in July, W / m2 (according to table 15 of DSTU-N B V.1.1-27)	106
The minimum average wind speed in rumba for July, the repeatability of which is 16% or more, m / s (according to table 6 of DSTU-N B V.1.1-27)	3,8

 

Layer number	Designation	Value, (m2K)/W
1	R1	0,0538
2	R2	0,6322
3	R3	2,4390

Determination of thermal inertia of each layer and the building envelope as a whole.

Calculation of thermal inertia of each layer and walling given in the table:

Layer number	Designation	Value, (m2K)/W
1	D1	0,5962
2	D2	6,8908
3	D3	1,5366

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8. The determination of energy indicators is reduced to the calculation of energy requirements for heating, cooling and hot water supply. Then, due to the loss of determination, the total energy consumption is determined and the energy efficiency class is determined.

The area of ​​the external walling is shown in the table below:

№	Type of building	Total area, m2
1	Exterior walls	668,9
2	Overlap	448,8
3	Ground floor overlap	224,4
4	Unheated basement	224,4
5	Windows and translucent structures	164,5
6	Entrance doors to the building	24,1

Transmission heat transfer characteristics

The average heat transfer coefficients are determined in accordance with clause 8.2 of DSTU B A.2.2-12: 2015 

• Hx, H, for walls = 225 W / K
• Hx, H, for windows = 253 W / K
• Hx, H, for overlap = 103 W / K
• Hx, H, for doors = 48 W / K
• Hx, H, for floor = 379 W / K

When calculating heat transfer through translucent elements, the effect of night insulation is not taken into account.

The total heat transfer by the transmission is calculated in accordance with the formulas (9) and (10) of DSTU B A.2.2-12: 2015 for each place is shown in table 4.6.2 according to the heating mode.

Heat transfer characteristics of ventilation.

The amount of air exchange during ventilation is adopted at the level of air exchange rate of 1 hour-1. The presence of heat recovery installations in the ventilation system of the building is not provided. Central preheating and cooling of ventilation air is not provided. Values ​​of the overall ventilation heat transfer coefficient are:

Hx, H, for ventilation = 1,333 W / K

The total heat transfer by ventilation is calculated in accordance with formulas (22) and (23) of DSTU B A.2.2-12: 2015 for each place and is shown in table 5 for the heating mode and in table B.7 for the cooling mode.

Month of the year	Q, kW*year
	Ventilation
January	8 028
February	7 038
March	6 286
April	3 599
May	-

 

....	....	...	...	...	...	...	...	...	...
June	2 178	857	3 035	5 874	10 986	16 860	5,56	0,99	13 850
July	600	236	836	6 248	11 352	17 600	21,05	1,00	16 764
August	1 650	649	2 300	5 820	11 352	17 173	7,47	1,00	14 882
September	5 154	2 028	7 182	5 048	10 986	16 034	2,23	0,93	-
October	10 503	4 132	14 634	3 811	11 352	15 164	1,04	0,74	-
November	14 665	5 769	20 434	1 753	10 986	12 739	0,62	0,54	-
December	18 680	7 349	26 028	1 455	11 352	12 807	0,49	0,45	-
Всего за год	121 801	47 919	169 720	49 327	133 665	182 991	-	-	45 495

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Building energy efficiency

Determination of the energy efficiency class of a building according to DSTU B A.2.2 -8.2010.

1.     Energy demand for heating is 68 863 kW * h / year.
2.     The energy requirement for cooling is 45,495 kW * hour / year.
3.     The energy requirement for hot water supply is 13,463 kW * hour / year.
4.     The total energy requirement for heating, cooling, DHW = 127 821 kW * hour / year.
5.     Estimated (actual) specific energy requirement = 47.5 kW * h / m2.

The term of effective operation of the heat-insulating shell of the building and its elements is analyzed.

9. Definition of the term effective operation of the heat-insulating shell of the building and its elements.

Mineral-wool heat-insulating products are provided as heat-insulating materials of the external building envelopes.

The design of the heat-insulating shell of the houses was carried out using heat-insulating materials with a term of effective operation, which meets the requirements of DSTU B V.2.6-189. External wall constructions with facade thermal insulation use heat-insulating materials with an effective life of not less than the estimated life of the structures in accordance with DSTU B V.2.6-35, DSTU B V.2.6-36. The operating life of the heat-insulating shell and its elements is at least 50 years, which meets the requirements of Clause 1, 15 DBN B.2.6-31 and is confirmed by the test reports of tests conducted by DP NDIBK.

An important element is the assessment of the breathability of the enclosing elements in order to avoid the passage of cold air through them in winter and heated in summer.

Estimated air permeability of building envelopes.

For building envelopes of heated buildings, the following conditions are mandatory:

GK ≤ GKH,

Standard air permeability of building envelopes, kg / (m2-hour), is determined according to the table:

Type of building	The value of permissible breathability of the building envelope
External opaque structures of residential and public buildings	0,4 kg/(м2-h)
Joints between elements (panels) of opaque structures of residential and public buildings	0,5 kg/(м2-h)
Translucent structures...	4,0 kg/(м2-h)

In general, the energy efficiency section is a rather complex section using complex calculation methods. However, we have enough experience and skills to help you develop a quality project.

If you have any questions about energy saving and calculations, you can ask them through the feedback form or by phone: +380503582282 (Viber), +380975153839 (Telegram)

  

Regards, AkvilonPro Energy Efficiency Manager

Pavlo Biriukovych

[email protected]

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