Monday, April 22, 2013

CSHQA Concrete Pour - Last Look at the Radiant Floor System

Radiant floor system before the concrete pour.
Last week the second of two concrete pours covered the final section of radiant floor system at CSHQA's new offices at 2nd & Broad and marked a major milestone in this 5-month construction project.  Crews started at 6:30 am and by 10:30 the initial pour was nearly complete (to be followed by many hours of detailed finish work.) 

The yellow, lego-like substrate of interlocking panels provides built-in spacing and fastening for the PEX tubing, plus insulation for heating and cooling functions.  The system extends throughout the entire office except for a few spaces such as walls and the entryway foyer.  Nearly 5 miles of PEX were covered by approximately 2-7/8 inches of concrete.

Once connected to Boise's geothermal system the radiant system will provide low-cost heating; in warm months cold water will be pumped through for cooling.  This comfortable, energy efficient system completely replaces convential furnace and forced-air systems and the operational savings are expected to be significant. 


Pre-cut sub-structure boards are used as guides for an even pour.


Using their boots the crew works the concrete into the panel system. 

Smooth floor wall to wall.


Monday, April 15, 2013

Integrated Design + Six Tactics for Saving Energy

Energy Saving Tactics in Integrated Design
Energy efficiency has become a pre-eminent theme and yardstick of value for today’s generation of architects, engineers and builders.  Private, government and institutional owners alike are demanding buildings that exceed code, achieve energy certifications and deliver ever lower operating costs. 

The graphic above simplifies energy saving into six tactics.  In reality these tactics overlap, interact and can even be counter-productive when designed incorrectly.  The real strategy is Integrated Design. 

Integrated Design has replaced the traditional hand-off from discipline to discipline with an approach that features multi-disciplinary collaboration from concept to completion.  Although listed separately, the following tactics are each part of an interdependent system.

Reduce / Manage Loads
Consciously reduce the day to day energy demands.  A simple technique is set point management:  Set the heat a little lower and the AC a little higher.  Combine this with computerized management (much like the digital thermostat at home) and you can also manage start of day and end of day settings as well as weekends and holidays. 

Common sense lighting design with the appropriate watt/sq. ft. applied in each space reduces loads, as does the right building envelop.  Low-emissivity (Low-e ) windows, quality insulation and well-designed wall/roof/ceiling systems are required.

Passive systems
Passive systems are built into the building.  Daylight harvesting through skylights and light tubes brings in natural light and reduces the demand for artificial light.  Reflective roofing lowers cooling costs.  Better insulation reduces heating costs.  Natural ventilation often improves air quality and reduces air handling.

Active Systems
Each component of the HVAC system is evaluated for its energy efficiency rating.  Electrical systems including lighting controls and occupancy and daylight sensors help manage energy consumption.

Energy Recovery
When a by-product of energy use is a further source of energy, we call that recovered energy.  An example is the work station.  Computers use energy to function and to operate a cooling fan.  The heat expelled via the fan can be used to warm incoming air and reduce energy used for heating, or exhausted to reduce the cooling load.

Renewables
Solar, geothermal, bio-mass, wind and hydro-power energy.

Other
An example for our desert climate is the nighttime purge during hot weather.  Summer temperatures often become quite comfortable between 3 and 5 am, even after a hot day.  Automated purging, bringing in the cool outside air, pre-cools a space before the workday starts.

CSHQA began designing for energy efficiency long before it became standard ops.  It helped that we had clients who demanded buildings with low operating costs (grocers in particular); it also helped that we’ve always sought ways to design better buildings.  As CSHQA converts a 56-year-old warehouse into our new Boise office (See 1.31.13 post), check back for in-depth posts on these tactics as we learn from architects and engineers on the project.