Fiberglass insulation stops which type of heat loss from a building?

Fiberglass insulation is primarily used to reduce thermal heat loss in a building. Thermal loss occurs when heat flows from warmer areas to cooler areas, which can lead to significant energy inefficiencies. By using fiberglass insulation, the transfer of heat is impeded, helping to maintain desired indoor temperatures more effectively. This type of insulation works by trapping small pockets of air, which slows down the movement of heat through conduction and convection.

While conductive heat loss does occur, it is more accurately described as a subset of thermal heat loss. The same applies to convective heat loss; while fiberglass insulation can help in reducing this, its primary purpose relates to overall thermal performance. Radiative heat loss involves the transfer of heat through electromagnetic waves, which fiberglass insulation is not particularly designed to address. Its effectiveness lies in reducing the overall thermal transference within the building structure.