ASHRAE 189.1

I recently read an article discussing ASHRAE 189.1 and its many requirements. At first I thought, "not a another green building standard" but as I dug into it further I discovered that it was a practical guide for implementing many of the requirements of LEED V3.0. One big advantage I saw was its prescriptive language and how if followed could yield energy savings around 30% over a building designed to ASHRAE 90.1. Apparently ASHRAE worked with USGBC in evaluating the results of energy saving measures provided through LEED building case studies and condensed them into a standard written like a code. I for one welcome the standard and look forward to using it in my practice. I found the following article helpful in learning more: http://www.eco-structure.com/green-standards/natural-progression.aspx

They can use the gym

The last two work days were reminiscent of my days at South Pole where we were readying the facility for the design team visit. We would work and work hoping to get things perfect. In the most recent case we needed to get the DEW P.E. Complex a certificate of occupancy so they could use it when classes start on August 16. We thought we had everything ready but then a control board suddenly failed and the state fire inspector cancelled. At best we were going to scramble and with the two problems it looked unlikely the school could use the complex. Fortunately the controls tech used a creative solution to get all the air handlers operating. Both air handlers serving the locker rooms had the same sequence of operation so the tech mapped the air handler 4 devices to the air handler 3 board and the two would track together until a new board arrived. It was a good temporary solution that provided the locker rooms with code required ventilation and exhaust.

The fire inspector showed on Friday, one day late, spent 20 minutes testing the safety devices and handed the project manager the paper work he needed. He went to an office, scanned the documents and emailed them to the state in hopes that on Friday in August enough people were in their offices to process the paper work and issue certificate of occupancy. Late in the afternoon the schools facility manager received a calling saying they could use the building.

Hats off to Design Mechanical, Lon Kersting and the electrician Perry for getting it going

BVHS Mechanical & Electrical Upgrades.

The summer has brought construction of a project at the local high school. It started as a boiler replacement that removed an old steel tube boiler and replaced it with two condensing gas boilers. To make maximum use of the boilers condensing features, the school also replaced the existing blower coils with new semi custom air handlers. The School originally did not have the funds to start the project so it was put on hold for about year and during that time we were tasked with writing a grant application to The Governors Office of Energy Efficiency which resulted in a $130k award for the project. Now it is a year latter and the contractors are finishing the controls in time for school.

Mmmmm pretty stainless steel!

New fan room on the second floor to house the new Temptrol air handlers and new supply air duct constructed of fabric (notice the new fabric duct in the gymnasium also!)

LEED AP BD+C

Yea, Kirk passed the LEED Building Design and Construction Exam.

UFAD

Challenging week! A customer came to me with a request to design an Underfloor Air Distribution System. I had never designed this type of system before except while working as a design build engineer where I "red lined" several to the schematic design level. Good thing those systems were never built because the design procedures have changed since the scheme was introduced to engineers in America. Not sure why the same problems never occurred in systems in Europe where the scheme was developed but the Center for the Built Environment has introduced a rather simple design procedure based on experimental data.

Underfloor air distribution pressurizes the area under a raised floor causing air delivery to occur using high induction diffusers in the floor to condition air in the occupied zone, usually 67" AFF. The people and the equipment are cooled by convection of air as it moves up the occupants or surface by thermal buoyancy. The heated air continues to rise gaining additional heat as it rises past the lights and other loads above the 67" height. The benefit of the system is instead of contaminates (viruses, bacteria, pollutants, gases) mixing throughout the space they rise out of the occupied zone causing fewer sick days and higher productivity of the building occupants. Other benefits include better system efficiency because the fans require less static pressure and the less energy usage because the air is supplied at 65F instead of 55F.

In designing the system I read the design guides provided by the Center for the Built Environment and Price. I also had some help from my local Price sales representative. Based on the reading and recommendations I broke out the perimeter loads from the space and calculated the air required at the perimeter using a supply air temp of 65F and a space set point of 79F. I then selected higher velocity diffusers to wash the walls with cool air that will (hopefully) travel up the wall and out of the space taking the heat with it. The interior loads I calculated the total load including lights and equipment and multiplied it by a factor of 0.65 and calculated the air flow using the same 14 degree delta T I used to calculate the perimeter air flows. I then selected a round swirl air diffuser to deliver air to the space.

The best part about the project is I learned some new information and increased my knowledge base. Another consultant and I also worked on selecting water cooled air handling units that will utilize a ground source well field to reject and absorb heat. More on that latter.....

Following is a Youtube video I found discussing underfloor air distribution and some of the other advantages. Skip to 2 minutes 43 seconds to skip to the underfloor discussion.

Under Construction

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