How is the calculation of the heat loss of the building to make the calculation of the boiler power

When calculating heat losses, our task is to calculate as accurately as possible all heat losses and heat of receipt and, after receiving the results, already make decisions on warming and also on developing solutions to the heating system.

In order to calculate the heat loss, we need the following data:

1. Architectural project with detailed dimensions according to plans and facades
2. Cuts and units for structural elements and units with thermal insulation
3. Specifications for window structures indicating the type of window structures, glass unit formulas and mounting units
4. The master plan for placing the house on the site according to the cardinal points with the surrounding houses and their height for calculating the shading.

First of all, we calculate the area of ​​all walling according to the materials used. This means that the basement part of the foundation is considered separately, walls separately, monolithic belts separately.

This is done in order to separately calculate the heat resistance of each area, its type and orientation according to the cardinal points

Calculation of heat losses through cold bridges (if any) is also done separately, it can be terraces and balconies, uninsulated parts of foundations and parts of walls in the attic on which the roof rests.

The next step is to calculate the heat transfer resistance of each type of structure in layers. Walls of frame houses and complex sections of different materials are calculated volumetricly using 3D modeling

The following is a calculation of heat loss and heat through window structures. The calculation takes into account the type and characteristics of window frames and sashes, the configuration of windows, the type of double-glazed windows taking into account the edge zones, installation decisions and the heat transfer resistance of the installation joint.

Then we take into account the shading from the visors, awnings and neighboring buildings.

If necessary, if overheating is detected in the summer, active or passive sun protection is modeled.

The next step is to set the tightness of the house (which during the construction process will need to be checked using a blower door test) and calculate the parameters of the ventilation system. At the same time, we decide how ventilation will take place in the summer (through windows or a supply and exhaust system)

After that, we can get the final data of heat loss and heat of income

We simulate a monthly energy consumption schedule for heating

Estimate monthly cooling costs

If necessary, we simulate the work of the solar system

After completing all the calculations, we can calculate the required power of the heating system, air conditioning system. Assess the risks of local overheating and decide on the required power of the heat source for heating and choosing the power of the air conditioner.

And we can predict the annual cost of operating this house

After all calculations, we determine the energy efficiency class of the house

Calculation of heat loss of a building to make a calculation of the boiler power see example here

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