Insulation thickness is key to performance. To avoid over- or under-insulating, first determine the "economic thickness," which is the most effective thickness for the building. Economic thickness is a function of the building's U-Value and can be determined by taking the following factors into consideration:
- Maximum energy use permitted
- Energy costs
- Climate (winter and summer)
- Building end use
- Costs of purchasing and maintaining climate control equipment
- Insulation installation costs
- Finance costs (insulation installation and climate control equipment)
We use a NAIMA computer program called ESP to analyze these factors. It computes the economic U-Value from a list of U-Values based on a minimal amount of data, such as:
- Building location by zip code
- New or retrofit
- Roof, wall or both
- Heating only or heating and cooling costs
- Incremental heating costs (dollars/1,000 BTUs)
- Incremental cooling costs (dollars/KWH)
- Installation cost of metal building system
Example
Building Location: St. Louis
System Type: New
Analysis Type: Heating and Cooling
Incremental Heat Costs: $0.64
Incremental Cooling Costs: $0.09
In this example, the economic U-Value is 0.05 because the building is so inexpensive to maintain. This example illustrates how investing in insulation up front can save money in the long term.