Ventilation loss

To work out the heat required to warm up incoming cold air, we need the heat capacity of air: 1.2kJ/m3/K.

In the building trade, it's conventional to describe the power-losses caused by ventilation of a space as the product of the number of changes N of the air per hour, the volume V of the space in cubic metres, the heat capacity C, and the temperature difference AT between the inside and

kitchen

2

bathroom

2

lounge

1

bedroom

0.5

Table E.1. Air changes per hour: typical values of N for draught-proofed rooms. The worst draughty rooms might have N = 3 air changes per hour. The recommended minimum rate of air exchange is between 0.5 and 1.0 air changes per hour, providing adequate fresh air for human health, for safe combustion of fuels and to prevent damage to the building fabric from excess moisture in the air (EST 2003).

Table E.1. Air changes per hour: typical values of N for draught-proofed rooms. The worst draughty rooms might have N = 3 air changes per hour. The recommended minimum rate of air exchange is between 0.5 and 1.0 air changes per hour, providing adequate fresh air for human health, for safe combustion of fuels and to prevent damage to the building fabric from excess moisture in the air (EST 2003).

old modern best buildings standards methods

Table E.2. U-values of walls, floors, roofs, and windows.

old modern best buildings standards methods

Walls

Q.45-Q.6

Q.l2

solid masonry wall outer wall: 9 inch solid brick

2.4 2.2

11 in brick-block cavity wall, unfilled

l.Q

11 in brick-block cavity wall, insulated

0.6

Floors

Q.45

Q.l4

suspended timber floor solid concrete floor

0.8

Roofs

Q.25

Q.l2

flat roof with 25 mm insulation

Q.9

pitched roof with 100mm insulation

0.3

Windows

1.5

single-glazed double-glazed double-glazed, 20 mm gap triple-glazed

5.Q 2.9 1.7 Q.7-Q.9

outside of the building.

power (watts)

NVAT.

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Getting Started With Solar

Getting Started With Solar

Do we really want the one thing that gives us its resources unconditionally to suffer even more than it is suffering now? Nature, is a part of our being from the earliest human days. We respect Nature and it gives us its bounty, but in the recent past greedy money hungry corporations have made us all so destructive, so wasteful.

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