Calculation of heating, calculation of heat loss and optimization of energy consumption at home Zx60 - 167 m2

 

Checking energy consumption for heating and domestic hot water, determining the type of heating appliances.

Purpose of calculation:

  1) Determination of energy consumption for heating and cooling

    2) Determination of consumption for domestic hot water and electricity

    3) Assessment of the need for a solar system for domestic hot water.

    4) Selection and comparison of different energy supply systems.

    5) Determination of the monthly balance of energy consumption (heating-cooling)

    6) Comparison of the cost of heating with different sources of fuel.

    7) Calculation of heating and determining the optimal solution for the heating system at home.

The initial data of the basic calculation:

• Two-storey house with a building spot of 130 m2 and a total area of ​​167 m2

•         Number of permanent residents - 4 people

•         The entrance to the house is west.

•         Walls - aerated concrete block with insulation of 100 mm

•         Foundations - monolithic, with insulation of 50 mm expanded polystyrene

•         PVC windows - Rehau Rehau Euro Design 70, double-glazed window (44mm) 4-14Ar-4-14Ar-4і

•         Overlap of the 2nd floor - wooden beams 200 mm, insulation - 250 mm mineral wool.

•         Ventilation system - forced with heat recovery system

•         In the calculation, the VENTS VUT / VUE 270 V5B EC ventilation unit of 87% efficiency was used.

•         Heating systems - electric boiler or heat pump.

•         A hot water system with the possibility of using a solar system (covers 40% of energy costs for hot water supply, appropriateness assessment).

The house corresponds to a building with energy efficiency class “C” according to DBN V.2.6i31: 2016

Distribution of maintenance costs:

Heating - 19 589 kW * h / year,

DHW - 3544 kW * h / year,

Possible solar system coverage -

1523 kW * hour / year,

Cooling - 329 kW * h / year,

Power supply - 9 085 kW * hour / year

Total: 34,070 kWh / hr

 

Having all the numbers, we can determine the energy efficiency class of a building

Next, we determine the costs of heating and air conditioning using different systems. A comparison is made regarding electrical heating. In this case, there was no possibility of gasifying the site, therefore this option was not taken into account in the calculation.

Testing solutions for incremental improvements in energy efficiency:

1.  Improving the tightness of the building

2.         Application for warming PSB-S 25 or Neopor 18 expanded polystyrene

3.         Additional insulation of the floor of the 2nd floor

4.         Additional floor insulation 1st floor

5.         Using windows with an installation width of 80 mm and a double-glazed window 4і-16Ar-4-16-Ar-4i

6.         Assessment of the appropriateness of the use of remote installation of window structures

7.         Using an intelligent thermostat to control climate

8.         Evaluation of the economic feasibility of a ventilation system with recovery

The appraisal of the feasibility of decisions to improve the energy efficiency of a building is determined using the DPP discounted payback period

1) Estimated additional costs for sealing the building, sealing films, cement-sand plaster ... - 40,000 UAH

The payback period of investments is 6.8 years. The event is recommended for implementation.

2) The transition to thermal insulation with PSB-S polystyrene 25 - 200, Neopor 18 - 150 or 200 mm instead of mineral wool 100 mm

a) Polyfoam PSB-S 25 - 200 mm

Savings in investments when using the solution - (-15000 UAH)

Annual savings from improving energy efficiency - from 4227 UAH / year (recommended economy solution)

b) Eco expanded polystyrene with graphite Neopor 18 - 150 mm

Savings in investments when using the solution - (-6342 UAH)

Annual savings from improving energy efficiency - from 3871 UAH / year

c) Eco polystyrene foam with graphite Neopor 18 - 200 mm

Additional investments - 9903 UAH

Annual savings from improving energy efficiency - from 4967 UAH / year

Payback period - 2 months (recommended environmentally friendly solution)

3) Additional, 250 mm insulation of the ceiling of the second floor

Estimated additional investment - 41700 UAH

Payback - 14.24 years.

Given the capital investment, an event is recommended.

4) Additional insulation of the floor of the first floor

a) The total thickness of the insulation - 150 mm PSB-S 35

Additional investments - 16910 UAH

Annual savings - UAH 1751, Payback period - 10 years

b) The total thickness of the insulation - 200 mm PSB-S 35

Additional investments - 26090 UAH

Annual savings - 2585 UAH, Payback period - 10 years

c) The total thickness of the insulation - 250 mm PSB-S 35

Additional investments - UAH 35,280 (recommended solution)

Annual savings - 3121 UAH, Payback period - 11 years

d) The total thickness of the insulation - 150 mm Neopor 25 (eco)

Additional investments - 26340 UAH (recommended eco-solution)

Annual savings - 2343 UAH, Payback period - 11 years

f) The total thickness of the insulation - 250 mm Neopor 25

Additional investments - 51625 UAH

Annual savings - 2343 UAH, Payback period - 14 years

5) Using more energy efficient windows

The project includes windows of the Rehau Euro Design 70 type with a double-glazed window with one energy-saving glass

U - 1.19 W / (m² · K) and two sealing circuits in the sash

It is proposed to install windows of the Rehau Synego MD type with an installation width of 80 mm, a double-glazed window with two energy-saving glasses and a warm distance (4i-14Ar-4-16Ar-4і)

Investments - 51648 UAH

Annual savings - from 3117 UAH

Investment payback period - 15 years

Recommended Investment

6) Installation of windows in the insulation layer (remote installation)

Investments - 80 036 UAH

Annual savings - from 286 UAH

The payback period of investments is not rational

7) Using smart thermostats

Nest, Tado, Netatmo or similar

Investments - 10000 UAH

Annual savings - from 2400 UAH

Investment payback period - 4.5 years

8) Use of ventilation with recovery

Investments - 128 000 UAH

Annual savings - from 1477 UAH

The payback period of investments is not rational.

But there is no other way to get fresh air at the right time.

The recommendation is to use.

 

The ratio of heat loss and heat gain after applying the recommended solutions.

The house corresponds to a building with energy efficiency of class “B +” without the use of a heat pump according to DBN V.2.6i31: 2016.

Distribution of maintenance costs:

Heating - 8 482 kW * h / year,

DHW - 3550 kW * h / year,

Cooling - 592 kW * h / year,

Power supply -8 740 kW * hour / year

Total: 21,364 kWh / year

40% reduction in energy costs without using a heat pump

Using a soil-water heat pump by 66%

Schedule of energy consumption at home for heating and cooling after improving energy efficiency

Building energy efficiency class after optimization

Payback analysis of the use of a heat pump for heating and cooling.

 

After performing all the calculations, the following decisions were made:

1. Increase the thickness of insulation relative to the base project.
2. To heat the house, use the underfloor heating system.
3. For ventilation, use a supply and exhaust system with heat recovery and the introduction of a heat exchanger for heating and cooling the air.
4. Starting the house into operation is done with an electric boiler, but provide for the possibility of connecting a ground-water heat pump.
5. By improving the energy efficiency of the house, the required power of the heating system was reduced to 5 kW

Calculation of heating and calculation of heat loss with optimization see here

Read all about calculating heat losses and energy efficiency of houses here.