HVAC Energy Efficiency using Mass Flow and Building Pressurization Jay Richardson Professional Supply, Inc.

Professional Supply, Inc. - PSI Professional Supply, Inc. was founded by Tom Kiser in 1979 to support Architects and Engineers in developing energy efficient HVAC designs PSI Technology has provided significant energy savings for Ford, Goodyear and Delphi Today, PSI’s innovative energy solutions extend to waste heat recovery, lighting, photovoltaic and thermal solar based on precise energy models PSI has a strategic alliance with Giffels, Inc. to create Sustainable Energy and Building Designs PSI’s Energy Service Agreement with Ford is a business model that delivers technical solutions to energy challenges with no capital expenditure by our clients based on guaranteed performance

Today’s Energy Challenge HVAC energy consumed for Commercial Buildings is 4.5 quadrillion BTU’s –13% for Heating –11% for Cooling –6% for Ventilation –6% Hot Water America’s Commercial HVAC creates 34% of CO2 emissions – 90.2 MMTCE HVAC Technology dates back 2000 years to the Roman Baths Incremental technical improvements will not solve the Global Climate Change Challenge

Laws of Physics Cold air is heavier than hot air Hot air rises, cold air falls Air is subject to the laws of mass flow and fluid dynamics In Winter, warm air rises as a result of stack effect promoting cold air infiltration at base of the building In Summer, stack effect is less and hot air collects at the roof promoting heat retention in the building

HVAC Engineering Practice HVAC Forced Air Handling Systems use a blower to push hot air HVAC designs require dampers or sized ducts to maintain pressure and velocity at the discharge vent Higher air temperatures are needed for personal comfort when air blows directly on people Temperature controlled by discharge temperature and thermostat Blow enough tempered air with volume, pressure and velocity to accommodate all possible conditions Buildings tend to draws air from outside to produce sufficient updraft and pressure differential for roof exhaust to be effective

Traditional Design 50,000 scfm Air Supply Powered Roof Exhaust Negative Pressure Updraft Ducted Supply Discharge Vent

Cool Air Heating Cool air is heavier than warm air Cool air introduced at the top of the building naturally falls to the floor This eliminates the need for ductwork This allows PSI to recover process and building heat gain to reduce energy needs Inverse stratification uses mass flow to provide energy efficiency while creating a comfortable workspace 55°F 65°F 72°F

Bigfoot Air Handler Capable of delivering 200,000 scfm of air with two 100,000 scfm centrifugal blowers Variable frequency drives give Big Foot the ability to adjust to the building air supply requirements, thus minimizing the electric and natural gas usages Fresh air and return air bypass dampers react automatically to system changes to maintain the building conditions Discharge head louvers direct air horizontally and vertically

PSI Engineering Practice Big Foot distributes air at the truss and pressurizes the building. Pressurization and perimeter relief dampers allows PSI to control air distribution Without Ductwork Big Foot modulates air flow using VFD blowers and damper control Big Foot System maintains uniform building temperature and positive pressure 55°F 65°F 72°F

Global Controls Global controls continuously monitor and respond to interior/exterior temperature, humidity and pressure as well as wind speed/direction Big Foot modulates VFD’s to adjust to building pressure In Winter, smart discharge heads respond to cold spots by directing warm air down to the floor In Summer, ventilation is increased at night to cool the building. During the day, outside air is minimized until the interior temperature exceeds the exterior, then ventilation is increased

PSI Design – Cool Air Heating Bigfoot Air Supply Diffuser at Truss Level Exhaust Louvers Monitors Positive Pressure Global Controls

Average Ford Assembly Plant PSI Energy Service Agreement Average of 8 Assembly Plants –Plant 3.1 million sq. ft. –Converted both Steam or Forced Air Gas Systems –Abandoned 182 HVAC Air Houses and numerous Unit Heaters –Installed 12 Big Foot Units and/or modified existing air handlers and 2 Direct Contact Hot Water Heater PSI Investment - $11 million Ford Guaranteed Energy Savings – $2.0 million per year at 2000 Energy Prices Energy reduction from baseline year: –54% Gas –46% Electricity ESA includes daily monitoring, new equipment warranty and monthly on site review.

Energy Performance Building pressurization, global controls and Big Foot Air Handlers reduce first cost, operating cost and provide a better cleaner work environment The PSI approach using mass flow and building pressurization allows us to heat and cool uniformly with less energy Adaptive controls respond to internal and external temperature, pressure and humidity Complete energy model allows the client to prioritize their potential solutions