Resources & HVAC forum
Hydronic Pressure Loss & Pump Head Calculator
Estimates hydronic-system pressure loss and total pump head across pipework, fittings, coils and plant components.
AS/NZS 5149 Refrigerant Charge Calculator
Assesses maximum refrigerant charge limits for occupied spaces using toxicity and flammability criteria.
NCC Section J Pipe Size Calculator
Selects compliant copper or steel hydronic pipe sizes and reports velocity and pressure loss for the NCC index run.
Hydronic Pipe Size Calculator
Sizes chilled-water and heating-water pipework from design flow, velocity and pressure-loss criteria.
NCC Fan Efficiency Calculator
Checks fan-system power and efficiency against National Construction Code Section J requirements.
Duct Size Calculator
Sizes circular and rectangular HVAC ducts from design airflow and velocity for supply, return and exhaust systems.
AS 1668.2 Table D Multiple Enclosures
Estimates common exhaust airflow for multiple enclosures using the simultaneous-use factors in Table D.
Supplementary A/C Calculator
Estimates supplementary cooling capacity for equipment-dense spaces and other internal heat loads.
Expansion Tank Size Calculator
Estimates hydronic expansion-tank volume from system volume, temperatures, static head and fill pressures.
Condensate Pipe Calculator
Sizes condensate-drain pipe capacity for air-conditioning equipment and connected systems.
Cooling Tower Water Usage Calculator
Estimates evaporation, drift, blowdown and makeup-water demand from tower load and cycles of concentration.
Cable Size Calculator
Sizes the smallest active cable that satisfies current-carrying capacity and voltage drop, with the applicable table reference returned alongside the result.
Questions from the industry, answered in the open.
Practical discussion of building-services problems — plant replacement, heat recovery, electrical sizing and lessons from operation and delivery.
Chiller replacement
Building a defensible replacement case from measured load, plant condition, access constraints and whole-of-life cost.
Runaround coil
Applying runaround heat recovery where supply and exhaust air streams are separated or cross-contamination must be avoided.
HVAC wire sizing
Coordinating mechanical selections, circuit capacity, voltage drop and protection before equipment is ordered.
Low-load chiller
Keeping chilled-water plant stable and efficient when most operating hours fall well below peak design load.
Chilled water bypass lines
Selecting and sizing decouplers, minimum-flow bypasses, condenser-water bypasses and flushing provisions in chilled-water systems.
Supplementary air conditioning
Sizing independent tenant systems for equipment, occupancy and outside-air loads beyond the base-building allowance.