IsoDim Help Heat Loss module
Purpose
This module is used for calculating the heat loss of pipes, ducts and surfaces in technical installations.
Calculation type
You have to select one out of six categories. In pipes the media is some kind of fluid/gas, in ducts it is always air.
Orientation
When calculating the external heat transfer coefficient the orientation of the pipe/duct is needed.
Calculation criteria
There's four different options:

Insulation thickness: When you know the thickness of the insulation

Surface temperature: When you want IsoDim to calculate the required insulation thickness to achive a certain surface temperature

Heat loss: When you want IsoDim to calculate the needed insulation thickness to achive a certain heat loss

EN 12828: Uses the temperature difference (media  ambient), operating hours and energy waste factor to select one of six insulation classes. The waste factor is the fraction of heat emission considered as wasted. The default value (1) means that all heat loss is considered wasted, values lower than 1 means that some of the heat loss is considered beneficial (this can be true in heated rooms). The insulation class dictates the maximum allowed heat loss and hence the necessary insulation thickness.
When selecting options 2,3 and 4 only one layer of insulation is allowed (the first option allowes up to three layers). Option 4 is only valid for pipe and surface calculations.
Facing (outside surface)
This section sets the emissivity of the outside surface of the insulated and uninsulated pipe/duct. The droplist contains typical values for different materials.
Dimensions
Use the outside dimension of the pipe/duct (without insulation).
Conditions
Description of the conditions around and inside the pipe/duct/surface. Ambient (surrounding) nd media temperature are used in all calculations. For outdoor conditions the wind speed also has to be given. For ducts the airflow is also necessary. If annual energy use is calculated average (yearly) values should be used (if you want to calculate worst case conditions then obviously wind speed and ambient temperature have to reflect this).
Insulation
It's possible to have up to three layers of insulation (the first is the layer closest to the pipe/duct/surface). For calculation criteria 24 insulation is restricted to one layer. Select an insulation product from the droplist. One of the standard thicknesses for the product can then be selected in droplist below or you can select and enter a user defined thickness.
Calculate energy use
Annual energy usage and CO2emission due to heat loss will be calculated. Four parameters are needed to perform the calculations:

Operating hours: If the system does not run the whole year this value should reflect this. The number of operating hours is also needed when calculating necessary insulation thickness according to EN 12828.

Energy cost pr kWh: the cost of heating the media, can be a mix of electricity, oil, gas or other. The efficiency of the heater should be included in the calculation of the price (example: The heater efficiency is 80 % and the price of energy supplied to the heater is 0,15 €/kWh, the effective energy price is 0,15 / 0,8 = 0,1875)

CO2emission: Emission in grams pr kWh. The efficiency of the heater should also be included in this value (see energy cost).

Currency: Currency to be used for the calculations. Please note that the currency only changes the text in the calculated results, not the numbers (there's no automatic conversion between currencies).
Valves, fittings and flanges
Here it is possible to add equipment attached to the pipe that increases the total heat loss. The heat loss is calculated as extra uninsulated pipe length. The drop list contains a few predefined types.
Uninsulated suspensions
This is a simplified way of including the extra heat loss due to the pipe suspensions. For outdoor installations 25 % heat loss is added, for indoor installations 15 % is added.
Calculated results
Results are shown in one table, the contents change automatically as you change the input above.