What is Commissioning?
Quality, Consequences and the Construction Industrial Complex (part 95) - All IMHO:I saw a huge RFP recently which read like a Commissioning Management project but following a meeting it was clarified to be a TAB project with some systems validation testing. How can this confusion exist on a huge project, populated with…
VAV Box Sizing – Rules of Thumb Vs Engineering
Quality, Consequences and the Construction Industrial Complex (part 94) - All IMHO:The lack of consensus in HVAC engineering continues to surprise me. How do you size (select) a VAV box? Should be easy to answer this question considering they are everywhere, right? Actually no, answers range from “we use rules of thumb”…
VAV Box Calibration – Trust But Verify
Quality, Consequences and the Construction Industrial Complex (part 93) - All IMHO:Does a VAV box require calibration and verification in the field? Short Answer Always, YES!"Trust, but verify" is a Russian proverb, used by President Ronald Reagan in the context of nuclear disarmament. Wise words IMHO. Why? VAV boxes arrive "factory set" not calibrated. In…
Tell Me Something I Don’t Know #7
Thermal Comfort: “a condition of mind in which satisfaction is expressed with the personal environment”. Depends on environmental factors and personal factors.Thermal comfort factors: 50% Radiation - 30% Convection - 20% Evaporation. Conclusion = Mean radiant temperature mattersQuestion = Why is space comfort controlled (using thermostats) by the 30% factor only?
Two is One and One is None – Resilience
Quality, Consequences and the Construction Industrial Complex (part 92) - All IMHO:“ Two is One and One is None”, Jocko Willink, retired Navy Seal.This is a military perspective on redundancy for mission critical equipment and systems. For businesses, redundancy is a risk management issue. For example, if Amazon servers go down they lose an estimated…