Mitsubishi PMFY-P15NBMU-E- User Manual

Falmouth Elementary School

Project Location:

Stafford, Va.

Completion Date:

July 2012

Project Team

Owner:

Stafford County Public Schools, Stafford, Va.

Architect:

Hayes Large Architects, LLP, Reston, Va.

Mechanical Engineer:

b2E Consulting Engineers, P.C., Leesburg, Va.

HVAC Contractor:

ACME Mechanical Contractors of Virginia, Inc.,

Manassas, Va.

General Contractor:

Kenbridge Construction, Kenbridge, Va.

HVAC Distributor

AIRECO Supply, Inc., Savage, Md.

Mitsubishi Electric Equipment Installed

(1) PURY-P240YSJMU-A R2-Series Outdoor Unit

(2) PURY-P120YJMU-A R2-Series Outdoor Units

(3) PURY-P192YSJMU-A R2-Series Outdoor Units

(2) PURY-P96YJMU-A R2-Series Outdoor Units

(1) PEFY-P48NMAU-E Ceiling-concealed Indoor Unit

(3) PEFY-P24NMAU-E Ceiling-concealed Indoor Units

(1) PEFY-P18NMAU-E Ceiling-concealed Indoor Unit

(1) PEFY-P15NMAU-E Ceiling-concealed Indoor Unit

(1) PEFY-P12NMAU-E Ceiling-concealed Indoor Unit

(30) PLFY-P15NCMU-E Ceiling-recessed Indoor Units

(9) PLFY-P12NCMU-E Ceiling Cassette Indoor Units

(2) PMFY-P08NBMU-E Ceiling Cassette Indoor Units

(9) PMFY-P06NBMU-E Ceiling Cassette Indoor Units

(4) CMB-P1016NU-HA Branch Controllers

(53) PAR-F27MEA-US ME Remote Controllers

(2) GB-50ADA Central Controllers

(2) BAC-HD 150 BM Adapters

Timm Guyer, project manager for Acme

Mechanical Contractors of Virginia, Inc.,
Manassas, Va., installed the system. “The
Mitsubishi Electric VRF zoning system was a
perfect fit for the Falmouth ES installation. It

was easy for us to install, is super efficient, and
we have had zero warranty issues,” said Guyer.

From a utility bill comparison, Horan estimates
a 25-30 percent average reduction in energy
use. “This is impressive when you think that we
increased the building area by about 20 percent,
or 13,000 square feet,” said Horan.

The team included b2E Consulting Engineers

(b2E), Leesburg, Va., to help them find a solution.

“We wanted a design team with a track record

of bringing huge energy savings to outdated
school buildings. b2E is known in the area for
applying the latest technology to reduce energy
consumption in buildings with optimal results,”
said Horan.

b2E and SCPS decided on a new mechanical
system that included a Variable Refrigerant Flow

(VRF) zoning system from Mitsubishi Electric US

Cooling & Heating Division (Mitsubishi Electric).

b2E Founder, Bruce E. Beddow, PE said, “As
a result of installing the Mitsubishi Electric VRF

zoning system, we were able to keep the original
ceiling heights and planned suspended ceiling

heights, improve lighting levels, reduce sound
levels in classrooms to NC [Noise Criterion] 30
or quieter, and improve occupant comfort.”

An important consideration for a school

system is the automatic control system. The
VRF zoning system comes on line at start-up.

The system controls do not need to have the

Energy Management System (EMS) tested and
commissioned prior to opening the school. The
system is fully operational upon start up. The
EMS allows the system to be controlled from a
remote off-site location via the internet.

case study

www.mitsubishipro.com

May 2014

Built in 1963, the 75,778-square-foot Falmouth
Elementary School (Falmouth ES) in Stafford, Va.,

was in urgent need of renovation by 2010. The

Stafford County Public Schools Division (SCPS)
had begun a shift towards sustainable building
practices, including an emphasis on LEED

®

and participating in the Go Green Virginia Green
Public Schools Challenge. The SCPS decided that
Falmouth ES should be renovated with energy
reduction as a top priority.

One of the critical challenges to the energy-
efficient renovation for Falmouth ES was the
selection of a new cooling and heating system.

The existing through-wall unit ventilators on a

two-pipe system were not working. The existing

units did not have proper dehumidification
capacity (cooling coils were not deep enough)
and there were no dehumidification cycle
controls, which contributed to poor indoor air
quality and a constant battle with mold. The
school also maintained a building housing the
central boiler and an adjacent chiller garden that

was inconveniently located in the school’s parking
lot, which made student drop off and pick up

complicated. Lastly, the system was inefficient.
Records show that Falmouth ES was operating
at 90 kBtu/sf per year before the renovation –
30 percent higher than the average* for
educational facilities in that climate area.

Scott Horan, SCPS assistant superintendent for
facilities, knew that creating a high-performance
HVAC system in Falmouth ES was going to be
problematic. The school’s structure was a very
complicated pre-stressed precast plank design

which meant that there was little room for

ductwork or piping above a suspended ceiling.
Using a traditional VAV air-handling system

would not be the most viable method for this

project, he said.

Solution

The Mitsubishi Electric VRF zoning system

conquered the school’s very complicated pre-

stressed plank design and helped cut the operating

energy costs by 40 percent and energy costs by 25

percent - saving $70,000 per year.

Challenge

Selecting an energy-efficient HVAC system for an

outdated building unable to accommodate ductwork

because of its tongue and groove, pre-stressed

precast concrete structure.

VRF Zoning Turns

1960s School Into High-

Performing, Smart Building

* According to the EPA’s ENERGY STAR

®

Small Business Guide