HVAC Fans and Blowers - Insights

VFD, but people often forget that 1. VFD only pays for operating at a lower speed not at full speed At full speed why would you need a VFD! 2. Blowing into a system you have to make a static pressure before air starts to blow.

Very good insulation of the structure can make extensive duct work less important.

Low noise high air flow volume. Computer design and simulation of fan design.

They all pretty much have the same product. It's the guy specing it coming up with a better fan for his application that matters most for improvement.

Nordic Heater in Sweden

Denso, Behr, Mitsubishi

I put a small fan in a flexible insulated pipe inside my attic to move warm air from near the location of my wood stove to the master bedroom. It works! Previously we had cold drafts in the family room when the wood stove was operating, and the air was much colder in the bedrooms than in the family room, which was often too hot. Now it is much more moderated. I would like to find some high velocity fans in small diameter pipes for other rooms. It seems this could eliminate the need for expensive retrofitting of a furnace with extensive duct work.

1. Air handling units. 2. Fan coil units. 3. Fresh air handling units. 4. Extract fans. 5. CCU.(for IT server room) 6. Cooing tower. 7. Package units.

Mainly ventilation, Auxiliary mine ventilation, scrubber systems, cooling fans for alternators, traction motors, inverters, and truck radiators.

High pressure requirements using axial fans rather than centrifugal fans.

Single room heat recovery unit built inside the window frame.

To blow up a canvass cover on a 50 meter swimming pool.

A fan blew down a partition wall because there was no R/A-relief air path. A fan sucked in air handling unit walls that the R/A and O/A dampers had closed on.

Bad design of BLDC electronics leading to premature ball bearing failure with very high recall rate.

Extreme noise and vibration levels bring rapid deterioration and lower value to the property.

Efficient, vs operating at the lowest speed. High efficiency may be lost in a short time. Seals, or clearances wear so in practical terms the extra efficiency isn't here for the long run with out a continuous up keeping. Which may not be available. Thing that run slow - tear themselves apart slow. A 3600rpm fan will squeal then shortly shutdown. A low speed fan will run for days.

Square type centrifugal fans, backward curved impellers, motors installed on top.

Increased efficiencies, quieter, longer life, lower vibration levels

1. Light weight 2. Variable speed 3. Adjustable static pressure

Compact and maintenance free unrustable sound less construction.

Best efficiency in the world and the lowest noise ever.

Ease of installation (retrofit). Quiet operation.

Greater efficiency and power consumption

Compact size Low noise High air flow

Better noise criteria level

More efficient, lower noise

Fan manufacturers data

Carefully compare forward / backward curved option Check for low power consumption at low speeds Make sure bldc fans have no commutation noise

The quieter type. Soft start var operation as needed during the day.

Make sure that you nominate the fan external pressure when purchasing.

Be clear about your exact needs of the process.

Be sure that the performance curves are real.

Listen to your engineering consultant.

Ask the right questions.

Air conditioner maker

Nothing special

Buy a system

Make sure that you use total pressure to select the fan; look for system effect problems. Consider the noise criteria. Take into account the heat gain due to the heat of compression when calculating the heat load.

When fans and blowers are required to be installed as a battery, individual blower / fan must have an inbuilt non return damper.

Have good duct work. Size to the duct and present conditions. It may have changed since installation.

Fans & Blowers should be useful to serve the intended purpose without any maintenance problems.

Check for commutation noise for sensitive applications (e.g. bedroom, living room).

Always thinking about lower noise and energy consumption.

Use a correct sized motor to the fan.

Consult a knowledgeable engineer.

Try not to run pipes too long.