Web Exclusive! Hydronic Heating Load Calculations and System Selection
This article will discuss the preliminary engineering tasks that underlie any hvac project: calculating the loads and determining what type of system to design. It is based on a residential project where a hybrid (in-floor radiant/baseboard) hydronic heating system was installed to heat an addition. However, the principles apply to any project. The analysis is by a practicing engineer and presents practical engineering considerations intended for fellow practicing engineers.
1. "68 degrees feels like 72 degrees." Some radiant heat proponents advocate reducing design capacity based on the claim that radiant heat achieves the same comfort as convective (baseboard or warm air) at a lower room temperature. This claim comes from the theory that radiant heat increases comfort by raising the temperature of the surrounding surfaces. Applying this philosophy can get a designer into trouble: