News
UFAD vs. Displacement
Both Underfloor Air Distribution (UFAD) and Displacement Air Distribution are well defined in the 2021 ASHRAE Handbook Applications, Chapter 20, Space Air Diffusion. Generally, the idea for UFAD is to have a well-mixed lower level in the occupied space up to about 4.5 feet above the floor. From the…
HVAC Ins & Outs with Dan Int-Hout - Area Factors and Free Area
Every so often, we get a request for the Ak, or area factors, or for the “Free Area” for our air…
VAV Control: Terminal Unit Sequence Affects the Entire HVAC System
Developing real estate requires millions of decisions about what the building will look like, how…
HVAC Ins & Outs with Dan Int-Hout - What is wrong with ADPI?
The Air Diffusion Performance Index (ADPI) was developed at Kansas State University in the 1960’s…
VAV Systems: Ground Control to Major Tom
Choosing the right equipment for your VAV system is critical, but it is only part of creating the…
HVAC Ins & Outs with Dan Int-Hout - Measuring Air Speeds
The 1962 Air Diffusion Council Test Code 1062 required that room airspeed measurements be taken…
VAV System Design: What is your style?
The Houston, Seattle, and Washington DC markets largely specify systems that utilize series fan-…
AHRI Recognizes Nailor for 3 Years of Success
The American Society of Heating Refrigeration and Air-Conditioning Engineers (ASHRAE) has developed…
VAV Diffusers: The solution to some issues but the cause of others?
Over-cooling in the summer or over-heating in the winter can impact occupant comfort. There are…
VAV Equipment Selection: Fan Powered Terminal Units
In many VAV systems, the exterior zones will utilize fan-powered terminal units. When compared to a…
VAV Equipment Selection: Single Duct Terminal Units
Once the building cooling/heating load has been calculated and the VAV system has been laid out,…
VAV System Design Considerations
A mechanical engineer must consider several variables and equipment types when designing a VAV…
VAV System Components
Occupant comfort is critical for the building owner’s return on investment. Chilled Water VAV…