Q. I’m working on a new science building. As you have written on your web site, it’s gotten harder to use wheels. You wrote a while back about a proposed Addendum K to 62.1 – did that ever go anywhere? As you might know, the Konvekta system is proposed as an alternate, yet it seems… Read more »
Posts Categorized: Energy Wheels
Ask Rick: DOAS System | Sensible Wheel vs. Heat Pipe
Q. I am working on the design of a Dedicated Outdoor Air System ( DOAS ) unit. I am leaning towards using double wheel units (latent and sensible wheels). What is your opinion on this approach vs. using a wraparound heat pipe. Rick… From my viewpoint the dual wheel design is a much less efficient… Read more »
Project Snapshot | Energy Recovery Unit – Tuck School at Dartmouth College
Project Name: Whittemore Hall Owner: Tuck School of Business at Dartmouth College Project Application: Dormitory for Tuck Students Mechanical Engineer: BR+A Equipment: Energy Recovery Unit Manufacturer: Annexair Size: 15,000 CFM Whittemore Hall The Tuck School of Business at Dartmouth College in New Hampshire was founded in 1900…. Read more »
Project Snapshot | Energy Recovery Wheels For Hospitals
Walter Reed National Military Medical Center Project Overview Project Name: Walter Reed National Military Medical Center Location: Bethesda, Md. Floor area: 515,000-square-foot ambulatory care building; 162,000-square-foot hospital addition; 450,000-square-foot hospital renovation; and 943-space parking structure Number of floors: Various Number of beds: 174 (of 345… Read more »
Energy Recovery Wheel | Purge Section
There are two ways that air can leak from the exhaust side to the supply side of a wheel: Cross-Flow Leakage – occurs when air leaks from the exhaust side to the supply side through the seals or any gaps in the construction. Carryover Leakage – occurs in rotary recovery wheels as the wheel rotates… Read more »
Energy Recovery Wheels | Understanding Cross Contamination / Leakage
In many applications it is important to limit the cross contamination (leakage) from the exhaust to the supply side of an energy recovery wheel. In some applications, like laboratories, it’s critical. In other applications, like schools, it’s not a big concern. There are two ways that air can leak from the exhaust side to the… Read more »
Ask Rick: Energy Recovery Wheel | Question on ANSI/ASHRAE Standard 62.1-2010
Q. It appears that the ANSI/ASHRAE Standard 62.1-2010 restricts the use of wheels for lab use. Is this the correct interpretation? A. As it stands ANSI/ASHRAE Standard 62.1-2010 is not clear on the question of Class 4 exhaust (which includes lab fume hood exhaust). The standard reads as follows: 5.16.3.3.2 Class 3 air shall… Read more »
Ask Rick: Energy Recovery Wheels on Laboratory Fume Hood Exhaust?
Q. I am working on a laboratory system. I have several fume hoods and general lab exhaust. I need to incorporate energy recovery. Can I use an energy recovery wheel for this application? A. We have done a significant number of laboratory fume hood exhaust systems using Energy Recovery Wheels. Of all the air… Read more »
Ask Rick: Should I use a bypass damper on an Energy Recovery Wheel?
Q. Should I use a bypass damper on an Energy Recovery Wheel? A. We typically use a bypass damper around a energy recovery device for frost control and economizer. That is typical for Heat Pipes and plate exchangers. In the case of an Energy Recovery Wheel we typically slow the wheel down to minimum speeds… Read more »
Ask Rick: How much cross contamination occurs with an Energy Recovery Wheel?
Q. How much cross contamination occurs with the use of an Energy Recovery Wheel? Does exhaust air get mixed back into the supply air stream? A. Cross contamination refers to the amount of air that is leaked from one side of the wheel to the other. Leakage rates are significantly reduced by using higher quality… Read more »