Internal heat load

Internal heating load Heat gains that occur in a space from process loads, lighting, solar gain, occupants, machines, etc. 

The high internal heat load of many modern buildings means that comfort cooling may be needed even when the ambient is down to 10°C or lower. Under these conditions, a high proportion of outside air can remove building heat and save refrigeration energy. This presupposes that ... 

The modifications were minor (e.g., increasing the capacity of the electric power supply system in response to a failure of the uninterruptible electric pxjwer supply system and moving nonessential equipment outside the operations trailer so as to reduce the internal heat load on the system) and do not affect the basic RRS operations. 

In general, thermal improvements mean the minimization of the heat flux that is normally represented by the U-value. A constant and low heat transmission results in the heat built up inside being trapped due to internal heat loads. This makes it important to consider possibilities of ventilating the building, especially in a situation where the outside temperatures are suitable. Because of changing outside conditions, natural ventilation is not always possible, or the building simply does not provide window openings, which underpins the need for a variable U-value to balance the indoor temperature naturally. 

Insolation may be ignored with regard to the temperature of accessible surfaces and account is taken only of the internal heat load. The justification for this simplification is that any package, with or without internal heat, would experience a similar surface temperature increase when subjected to insolation. 

Where the test supphes data for an analytical evaluation of the package, measurements made during the test should be corrected for non-standard initial conditions of ambient temperature, insolation, internal heat load, pressure, etc. The effects of partial loading, i.e. less than full contents, on the package heat capacity and heat transfer should be assessed. 

Heat load The heat input necessary to ensure that a treated space provides the internal design temperature at a given external temperature. 

Fig. 8.15 shows the composite curves for UA= 1.12 MW/°C among the Pareto-optimal solutions in Fig. 8.12 and Fig. 8.14. The y-axis represents the temperature profiles of the hot nitrogen process stream being cooled from 30 °C to -144.5 °C, and of the cold nitrogen refrigerant stream the x-axis represents the heat load. It can be seen that there is a very good match of the composite curves with no indication of internal pinching.

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