KHS Engineering Topics

Over-design (sized) HVAC Systems – Suggestions, Solutions & Recommendations A review by KHS Engineering Topics Many HVAC systems installed in commercial buildings have more capacity than is ever required to keep the occupants/tenants comfortable and in order to provide correct conditions for particular building assets. Such over-design HVAC systems can have negative effects on the environment, on occupant comfort and on the economic outcomes (operational efficiency) of the building. What are the Symptoms of over-design? The concept of “Design Day” is the standard design practice followed for comfort HVAC applications where the design day conditions that may actually present on average 10-15 days per year. So, a HVAC system design/sized based on above conditions will operate full load or run at full cooling capacity on these 10-15 days only. These full load operation days will further reduce due to load diversity, which is often possible in any commercial building. The...

Hydronic System – TAB Procedure: by KHS Engineering Topics T esting, A djusting & B alancing ( TAB ) of hydronic system within HVAC systems; can be effectively accomplished by following the systematic methods & procedures describe in this article. The current recommended & best practices, which used in the industry for commonly installed hydronic systems, are discussed here. There are many ways to accomplish the hydronic balancing of a system. Two most acceptable and common methods are, 1.        Proportional Balancing method (Ratio method) 2.        Stepwise Balancing method   Proportional Balancing (Ratio method) The applying procedure of this method is varying based on the branches arrangement in the hydronic circuit.   Proportional Balancing Procedure – without Branch Circuits a.        Verify & ensure that all balancing, control & isolation v...