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--- planning:airtight_construction:airtightness_measurements_in_passive_houses [2021/08/24 11:11] – nsukhija
+++ planning:airtight_construction:airtightness_measurements_in_passive_houses [2023/01/30 11:44] (current) – [2. Calculation of volumes] zbastian
@@ Line 15: / Line 15: @@
 ==== 2. Calculation of volumes ====
-|The air volume V<sub>n50</sub> used for calculating the V<sub>n50</sub> value inside the heated building envelope should be determined and comprehensibly documented separately for **each room**. In doing so, **the base area of the room should be multiplied by the average clear height of the room**. Overall assumptions for determining the internal volume of the enclosed space (gross volume) by means of a reduction factor are not permissible.|**Room by room**|
+The air volume V<sub>n50</sub> within the heated building envelope is the volume that will be used for calculating [[planning:airtight_construction:general_principles:blower_door_test|the n50 air leakage value]]. It is supposed to indicate the //actual// volume of air that will be heated or cooled within the building and should be calculated separately for each room. The calculation should be carried out in accordance with detailed rules given in the [[https://passivehouse.com/downloads/03_building_criteria_en.pdf| Criteria for Buildings]], section 3.2.10 Airtightness of the building envelope.
-|**Note:**\\ The base area to be used for this calculation differs from the treated floor area which is normally used. The air volume Vn50 is not the same as the "enclosed volume", nor is it the same as the volume of air in a heated zone as used in the PHPP sheet "Annual Heating Demand" (overall room height 2.5 m). For this reason, the calculated volume Vn50 from the test report must also be transferred into the PHPP. |**not TFA,\\  not V<sub>V</sub> \\  instead, V<sub>n50</sub>**|
-|Irrespective of the degree of completion of the building, **the dimensions used should always be those of the finished building** (e.g. where there is no screed). Air volumes above suspended ceilings do NOT count towards the total air volume. This is regardless of whether the ceiling already exists, is tightly connected with the wall, or has different types of holes ("acoustic ceiling"). The reduction of the volume by layers of plaster does not have to be taken into account.|**Final dimensions only**|
-|**A full and comprehensible room-by-room calculation of the volume must be provided for each airtightness measurement.** Auxiliary calculations may also be necessary; these must also be provided. For example, in the case of inclined roofs, the air volume is determined by means of triangular or prism calculations. A proportional factor such as those used in the table below (Figure 1) can be taken into account.|**Documentation**|
-[{{:picopen:figure_1_room_by_room.png?500|Figure 1: Example of documentation for room by room volume calculation.}}]
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-The **total air volume** within the thermal envelope will thus be taken into account. Special features are shown in Figure 2 for more detailed explanation.
-[{{:picopen:figure_2_volume.png?500|Figure 2: Guidelines for calculating the air volume inside the airtight layer of a building. The red dashed line all around represents the air tight layer.}}]
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-|Visible rafters, beams, plasterboard encasings, wall-mounted installations (if these do not have the same height as the room) and the like are not taken into account; in the calculation they are __not__ deducted for simplification. They are thus treated as if they did not exist (= air space).|**Rafters, beams wall-mounted installations.**|
-|The volume of window reveals (see Figure 3) is not taken into account either (measured only up to the inner wall surface). The same applies in the case of doors and openings.\\ These stipulations are for the purpose of simplification. Any deviations occurring as a result are usually small.|**Window reveals**|
-[{{:picopen:figure_3_stairs.png?500|Figure 3: The volume of window reveals is __not__ taken into account in the volume calculation}}]
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-|**Stairs**\\ The volume of a stairwell is part of the air volume and is fully taken into account. The volume of the stairs themselves (building component) is not taken into account, therefore it is not deducted. The base area of the stairwell can thus be multiplied with the clear height of the storey.|**No deduction of the stairwell volume**|
-|The volume of elevator shafts and any other kind of shafts inside the thermal envelope are part of the air volume and is fully taken into account. The volume of the elevator cabin, pipes etc. themselves (building component) is not taken into account, therefore it is not deducted. The base area of the shaft can thus be multiplied with the clear height of the storey |**Elevator and shafts count to the air volumes**|
 An overview of the distinctions between the VL value from the PHPP and the Vn50 value for the blower door measurement can be found [[planning:building_services:ventilation:differentiation_between_vv_and_vn50_values|here]].