Posts Categorized: Ask DAC

Ask Rick: Bearing Life | What is L10?

Bearing Life Bearings are a critical component in all HVAC equipment.  Bearing life is usually expressed as the number of hours an individual bearing will operate before the first evidence of metal fatigue develops.  The usual life rating for industrial applications is called “L-10” life.  Simply put the L-10 life  is the number of hours… Read more »

Ask Rick: Labratory Exhaust Fans | When should you manifold laboratory exhausts?

Q.  When should you manifold laboratory exhausts? We have been asked this questions countless times through the years.  In the past, public opinion held that you don’t know what lab chemicals are being work with so you don’t combine any lab exhaust.  All laboratory hoods were serviced by individual exhaust fans.  This was extremely expensive… Read more »

Ask Rick: What is UVC?

Q.  What is UVC? UVC is a type of ultraviolet (UVC) energy in the 260-nanometer frequency.  The “C” wavelength is the most germicidal in the UVC spectrum. UVC penetrates the outer structure of the cell and alters the DNA molecule, preventing replication and causing cell death. The UVC energy kills or inactivates microbes, eradicating surface… Read more »

Ask Rick: Fan Array | Does it make sense?

Q.  I have been looking at different fan options for my Air Handling Unit application.  What are your thoughts on the Fan Wall technology?   The technology is called by different terms;  Fan Array, Fan Wall, Fan Matrix, Multi-Fan etc.  It is a combination of smaller fans built into a wall section to replace a… Read more »

Ask Rick: Pumped glycol energy recovery systems | Reasons for poor performance in traditional systems

Q.  You have mentioned that traditional pumped glycol energy recovery systems were your least favorite choice for air-to-air energy recovery.  What are the reasons for that? A.  It starts with efficiencies.  Pumped Glycol systems in this country, until the recent introduction of Konvekta, have provided the lowest efficiencies for all choices.  The best we could… Read more »

Ask Rick: Control for Wrap Around Heat Pipes

Ask Rick Question:  I am considering putting in a wrap around heat pipe to reduce cooling tonnage and provide reheat.  Is there a way that I can control the heat pipe to reduce reheat?   The Wrap Around Heat Pipe (or Dehumidification Heat Pipe) is used in lots of applications where reheat is typically used. … Read more »

Ask Rick: Glycol Run Around Loops | What is a typical face velocity for a pumped glycol system?

Q.  What is a typical face velocity for a pumped glycol system like Konvekta? A.  Konvekta pumped glycol energy recovery coils work anywhere in the range from 50-1000 FPM face velocity.  It’s typical for coils to be sized between 350 and 500 FPM.  There is always a trade-off between face velocity ( air pressure drop… Read more »