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…
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…
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?