GEOTHERMAL CONVERSION

DAVID R. OLSON, PE, LEED-AP
In the summer of 2009 my wife and I purchased a home in a small community outside Boulder, Colorado named Niwot. Niwot was named after a 19th century Arapaho Indian chief by that name. It means “left hand”. Consequently, there are a lot of local “left hand” this and “left hand” that. Continue Reading →

Altitude Effects – Fan Sizing and Operation

ALTITUDE EFFECTS

  • FAN SIZING AND OPERATION

DAVID R. OLSON, PE

Things are different when you are over a mile above sea level. There’s less air at this altitude. The density of the atmosphere at sea level is 0.075 pounds per cubic foot. That means that every cubic foot of 70°F air weighs 0.075 pounds with a barometric pressure of 29.92” Hg (14.7 lbs/in2). In Denver, Colorado with an elevation of 5,280 feet above sea level, the barometric pressure equals about 27.8” Hg (12.04 lbs/in2).  Denver air at 70°F has a density of 0.0617 pounds per cubic foot. That means that there is only 82.3% of the air in Denver as there is at sea level locations. The air density in the Colorado mountains is even less. The altitude of Aspen, Colorado is 7,928 feet above sea level. Consequently, the air density there is just less than 0.0554 pounds per cubic foot, or about 73.9% of that found at sea level. The reduced air density experienced at high elevations does not just make it more difficult for individuals to breathe; it impacts the operation and performance of all sorts of mechanical equipment. This article will focus on the impacts of altitude on the sizing of fans.  Continue Reading →

ALTITUDE EFFECTS – GAS PIPING

  • SIZING NATURAL GAS PIPING

DAVID R. OLSON, PE

Things are different when you are over a mile above sea level. There’s less air at this altitude. The density of the atmosphere at sea level is 0.075 pounds per cubic foot. That means that every cubic foot of air weighs 0.075 pounds. In Denver, Colorado with an elevation of 5,280 feet above sea level, the air density is 0.0617 pounds per cubic foot. That means that there is only 82.3% of the air in Denver as there is at sea level locations. The air density in the Colorado mountains is even less. The altitude of Aspen, Colorado is 7,928 feet above sea level.  Consequently, the air density there is just less than 0.0554 pounds per cubic foot, or about 73.9% of that found at sea level. The reduced air density experienced at high elevations does not just make it more difficult for individuals to breathe; it impacts the operation and performance of all sorts of mechanical equipment. This article will focus on the impacts of altitude on the sizing of natural gas piping. Continue Reading →

COLD ROOM SYNDROME

DAVID R. OLSON, PE, LEED AP

It seems that there is always one room in a house that is coldest in the winter and warmest in the summer. I know – I had that room for a while as a child.

Airflow is “self-balancing” in all air handling distribution systems. That is not to say that the proper amount of airflow gets delivered to each room, but the pressure drop of each zone from the source of flow is exactly equal with each branch and/or air device. Residential air distribution systems rarely have balancing devices installed within the supply ductwork. Consequently, the airflow delivered to each room within the house, or the zone in larger systems, is equal to the proportional share of airflow based upon equal pressure drop from the fan. The pressure drop from the fan to each supply air device (grille or diffuser) will be exactly the same. This occurs automatically by the system adjusting the airflow in each branch duct such that the resultant pressure drop in that branch is equal to all the rest of the branches. Continue Reading →

THERMOSTATS – ON or AUTO?

David R. Olson, PE, LEED AP
Most thermostats utilized in commercial applications include one or more operating functions. They all can control to a heating or cooling setpoint, or both. Some thermostats include manual changeover from heating to cooling and visa-versa, and some have a setting which will permit the thermostat to determine if heating or cooling operation is necessary. Most thermostats sold today include automatic set-back features which promote energy savings during unoccupied time periods. Many commercial thermostats have an “on-auto” fan switch. In my experience, I have seen numerous examples of this control feature being mis-understood. I will attempt to clarify this confusion in this article. Continue Reading →

HVAC ENGINEERING versus HVAC DESIGN

David R. Olson, PE

I was recently asked to consider the difference between “Engineering” and “Design”. The following represents my thoughts about this important distinction.

State of Colorado Definitions of Engineering

The licensing requirements for professional engineers are defined by statute in each State. In Colorado, Statute 12-25-114 defines the minimum requirements for registration as a Professional Engineer. This statute requires that an individual first be registered as an EIT (Engineer-in-training). To obtain EIT status, and individual must have completed a 4-year engineering curriculum and successfully complete an 8-hour Fundamentals of Engineering examination. Following four additional years of progressive engineering experience, an individual may apply for admission to a second 8-hour Principles and Practice of Engineering examination. Within this application, the individual shall prove technical competence prior to admission to the examination. Upon satisfactory completion of both exams, the individual may be licensed as a Professional Engineer. Continue Reading →

SPEC BOXES – WHO KNEW?

David R. Olson, PE, LEED AP, FASHRAE August 15, 2018

Throughout my career I have conducted HVAC and plumbing design for many new and remodel projects, on virtually every sort of building type imaginable. When I am doing a re-adaptation of an existing building the first step for me is to conduct a thorough survey, focusing on HVAC, plumbing and fire sprinkler components. As part of that work, I document model numbers and serial numbers for all the existing equipment. Sometimes there are equipment installations with specific components that are less familiar to me. I wonder, is this equipment installed the way the manufacturer intended it. Wouldn’t it be nice if there was a copy of the original installation manual available for me to look at? Continue Reading →

Cleanouts – Who Needs ‘em

Cleanouts – Who Needs ‘em

David Olson, PE

When I consider the cost of a properly installed plumbing system, I feel that the cost of installing adequate floor and wall cleanouts is negligible. I have been told by building engineers that more cleanouts is always better – it allows them to maintain their plumbing waste and vent system more effectively. Unfortunately, when we introduce solid material into a plumbing system, sometimes it gets clogged up. Perhaps there is a section of pipe that is installed too steep. Consequently, the liquid waste quickly runs down the pipe, and the solid waste tends to stay behind. The presence of a properly located cleanout won’t correct the pipe slope issue, but it will make dealing with it much simpler. Continue Reading →