HomeMy WebLinkAboutAlaska Sealife Center Seawater Heat Pump Project Economic Evaluation - Mar 2009 - REF Grant 7030017 TM YourCleanEnergy LLC
308 G Street #212, Anchorage AK 99501 907-274-2007 www.yourcleanenergy.us
ECONOMIC EVALUATION
OF
SEA WATER HEAT PUMPS
TO PROVIDE SUPPLEMENTAL HEAT FOR
MAKE UP AIR UNITS AHU-5 & AHU-6 AND
OUTDOOR PAVEMENT HEATING
FOR
ALASKA SEALIFE CENTER
301 RAILWAY AVENUE
SEWARD, ALASKA 99664 USA
FINAL REPORT COMPLETED MARCH 28, 2009
BY: ANDY BAKER, PE & LEE BOLLING
TM th YourCleanEnergy LLC
TABLE OF CONTENTS
EXECUTIVE SUMMARY HEAT PUMP ALTERNATIVES TO SUPPLY AHU-5 & PAVEMENT HEAT ............................. 3
SCOPE OF SEA WATER HEAT PUMP EVALUATION FOR ALASKA SEA LIFE CENTER ............................................... 4
INTRODUCTION ........................................................................................................................................................................ 5
SUMMARY OF ASLC HEAT PRODUCTION AND DESIGN DEMANDS (NAMEPLATE CAPACITY)................................. 6
CONCEPT GUIDELINES FOR SUPPLYING AHU-5 AND AHU-6 WITH SEAWATER HEAT .............................................. 7
EXISTING ELECTRICAL COSTS FOR ASLC IN SEWARD, ALASKA ................................................................................. 8
HEATING OIL USAGE BY ASLC ........................................................................................................................................... 10
RECENT AND PROJECTED HEATING OIL COSTS FOR ASLC........................................................................................ 11
RECOMMENDATIONS FOR INCREASING ENERGY EFFICIENCY OF ASLC FACILITY ................................................ 12
MONTHLY SEA WATER TEMPERATURES AND HEAT ENERGY AVAILABLE .............................................................. 13
EXISTING AIR HANDLERS AHU-5 AND AHU-5 IN ROOF LEVEL FAN ROOMS ............................................................. 14
HEAT PUMP OPERATION AND COEFFICIENT OF PERFORMANCE ............................................................................... 16
SELECTION OF HEAT PUMP EQUIPMENT SUITABLE TO SUPPLY AHU-5 & 6, PAVEMENT HEAT ........................... 17
RESULTS OF SIMULATION WITH ASLC SEAWATER TEMPS AND TRANE RTWD HEAT PUMPS ............................. 18
SCHEMATIC OF EXISTING CHILLED WATER SUPPLY TO AHU-5 + AHU-6 .................................................................. 19
SCHEMATIC OF ALTERNATIVE A: ONE HEAT PUMP IN ROOF FAN ROOM #1 TO SUPPLY AHU-5 ........................ 20
SCHEMATIC OF ALTERNATIVE B: ONE HEAT PUMP IN BASEMENT RM 19 FOR PAVEMENT HEAT...................... 22
SCHEMATIC OF ALTERNATIVE C: TWO HEAT PUMPS IN ROOM 19 OF BASEMENT FOR AHU-5 + PAVEMENT
HEATING .................................................................................................................................................................................. 24
MANAGING FREEZE PROTECTION OF HEAT TRANSFER LOOPS IN DUCT COILS .................................................... 26
SITE PHOTOS WITH NOTES EXISTING CHILLED WATER HX AND PUMP SYSTEM IN BASEMENT....................... 27
SITE PHOTOS WITH NOTES EXISTING CHILLED WATER HX AND PUMP SYSTEM IN BASEMENT....................... 28
SITE PHOTOS WITH NOTES AHU-5 IN FAN ROOM NO. 1 (NORTH) ............................................................................. 29
SITE PHOTOS WITH NOTES AHU-5 IN FAN ROOM NO. 1 (NORTH) ............................................................................. 30
SITE PHOTOS WITH NOTES AHU-6 IN FAN ROOM NO. 2 (SOUTH) ............................................................................. 31
SITE PHOTOS WITH NOTES AHU-6 IN FAN ROOM NO. 2 (SOUTH) ............................................................................. 32
SITE PHOTOS WITH NOTES BASEMENT AREA - SEAWATER PIPING & PAVEMENT HEATING ............................ 33
SITE PHOTOS WITH NOTES BASEMENT AREA MECHANICAL ROOM 19 & ELECTRICAL RM 18 ...................... 34
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 3 OF 34
TM YourCleanEnergy LLC
EXECUTIVE SUMMARY HEAT PUMP ALTERNATIVES TO SUPPLY AHU-5 & PAVEMENT HEAT
20 Year Life Cycle Cost Comparison Of Heat Pump Alternatives A, B, & C:
Alternative B: Alternative C:
Alternative A: One Heat Pump Two Heat Pumps
One Heat Pump In Mech Room 19 In Mech Room 19
On Roof Level Of Basement For Of Basement For
Description Of Financial Component To Supply AHU-5 Pavement Heat AHU-5 + Pvt Heat
Total Project Installation Cost -$354,760 -$396,240 -$662,350
Electricity for glycol circ pumps - Year 1 $5,620 $5,620 $7,868
Present worth of electricity for glycol
circ pumps over 20 year life cycle* -$112,401 -$112,401 -$157,361
Electricty required for heat pump - Year 1 $28,755 $23,963 $52,718
Present worth of electricty required for
heat pumps over 20 life cycle* -$575,103 -$479,263 -$1,054,366
Maintenance of glycol/heat pumps - Yr 1 $1,800 $1,200 $2,500
Present worth of glycol and heat pump
maintenance over 20 year life cycle** -$44,237 -$29,491 -$61,440
#2 heating oil saved by heat pumps - Yr 1 $61,636 $51,363 $113,000
Present worth of #2 heating oil saved
by heat pumps over 20 yr life cycle*** $1,514,765 $1,262,296 $2,777,085
Net Present Worth of Project $428,264 $244,901 $841,568
Years To Payback Initial Investment 10.8 Years 13.9 Years 10.6 Years
Notes:
* Grid electricity at industrial user rate from City of Seward, with 4% per year escalation
** Maintenance labor costs escalating at 6% per year, includes complete replacement of
heat pump compressor bearings at year 12
*** Unit cost of #2 heating oil escalating at 6% per year
- Discount rate applied to all financial components is 4% per year
- Current industrial user rate for City of Seward grid electricity is $.086/KWH
- Current cost of #2 heating oil to ASLC in Seward is $1.96/gallon
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 4 OF 34
TM YourCleanEnergy LLC
SCOPE OF SEA WATER HEAT PUMP EVALUATION FOR ALASKA SEA LIFE CENTER
1. Provide introduction to the purpose of the economic evaluation and a brief discussion of the
function and history of ASLC. Express goals that ASLC has for both increasing energy efficiency
and evaluating cost effective clean energy alternatives to fuel oil and grid electricity. Identify the
financial and public relations benefits that can be derived from pursuing these goals in the current
political and economic climate.
2. Evaluate trends of grid electricity and fuel oil costs from the past five years; and estimate
escalation rates to be used for electricity and heating oil for a 20 year life cycle cost evaluation.
3. Evaluate monthly usage of fuel oil and electricity from the past five years and estimate future
usage for a design life of 20 years. Include recommendations for increasing energy efficiency of
ASLC facility that are noted during the course of technical site visit.
4. Evaluate daily and monthly raw seawater influent rates from the past five years, total capacity of
seawater pumping, and raw seawater flow available for heat exchange to heat pumps that would
be located in roof level mechanical room.
5. Evaluate seawater temperature variations from the past five years. Estimate the B
that can be extracted from ASLC raw seawater each month using a glycol loop and plate heat
exchanger, and made available to heat pumps.
6. Identify proven heat pump systems that can utilize glycol loop heated by ASLC sea water during
the heating season to supplement air handling units #5 & #6 located in roof level mechanical
room, and pavement heating in basement area. Evaluate Coefficient of Performance (COP) of
heat pumps selected and estimated electrical energy input for annual operation. Provide results
re simulation if suitable and available.
7. Identify several specifically sized heat pump/glycol pump systems that can be integrated simply
into the existing infrastructure. Provide schematics and site photos to illustrate the location of
basic equipment; routing of piping; indicate estimated sizes and capacities of pumps, piping, heat
exchanger, heat pumps.
8. For each alternative illustrated, perform 20 year life cycle cost evaluation which compares present
worth of capital cost, electricity used by circulation pumps and heat pumps, anticipated
maintenance/replacement costs, and heating fuel saved.
9. Compile an Executive Summary which lists alternative heat pump systems, the associated
Capital Investment Required, Net Present Worth, and Years to Payback.
10. Produce deliverable report in pdf format which includes data from above items, graphs, color
photos and technical information in a simple easy to read format that begins with the executive
summary and recommendations of improvement options evaluated.
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 5 OF 34
TM YourCleanEnergy LLC
INTRODUCTION
The Alaska SeaLife Center (ASLC) is the only marine research aquarium in the State of Alaska and one
of the northern most on the planet. The Seward Association for Advancement of Marine Science
(SAAMS) is the non-profit corporation that established the Alaska SeaLife Center which was opened to
the public in May 1998. The Exxon Valdez Oil Spill Settlement Fund provided $26 million to help build the
$56 million facility. Other funding was provided through grants, revenue bonds, and corporate and private
donations. The city of Seward donated the seven-acre waterfront site for the SeaLife Center. The facility
was designed in 1996 by Livingston Slone, Inc., an architecture, planning and design firm based in
Anchorage.
While the SeaLife Center receives approximately 20% of its annual budget from visitor fees and retail
sales; the remaining portion of the financial income needed to maintain the facility is derived from federal,
private and foundation grant funding. With recent escalations in both electricity and heating oil costs, and
reductions in federal funding, the SeaLife Center is motivated to reduce its monthly operational expenses
through both energy efficiency and evaluating heat production methods that are more cost effective than
continued direct use of heating oil and grid electricty. The SeaLife Center is also interested in reducing its
current production of greenhouse gas (CO2) as part of the greater mission to preserve and protect the
fragile marine environment of Alaska.
The concept of extracting latent heat from seawater in Resurrection Bay has become of increasing
interest as the bay remains ice free through the winter, and ASLC has two 24 inch diameter seawater
intake pipes that draw flow from a depth of 275 feet. The original design flow capacity from each of these
seawater intakes is 5,000 gallons raw seawater per minute, although this capacity has been reduced in
practice to only half that due to bio fouling of the perforated openings at depth. Because the heat
exchange system in place in the basement area only removes 4 degrees F from the raw seawater while
heating a glycol loop, the raw seawater can be returned to the main life support system supply pipes for
use in various flow through marine life tanks.
Under the direction of CEO Ian Dutton and General Manager Darryl Schaefermeyer, the Alaska Sealife
Center decided in January 2009 to evaluate the use of sea water heat pumps to supplement heating
loads in the ASLC facility. In review of the existing heating equipment and design heating loads for the
facility, it is evident that the largest continuous demands during the heating season of September through
April are roof level Air Handling Units AHU-5 and AHU-6; and the 12,000 lineal feet of pavement heating
radiant heat used in outdoor walkways. YourCleanEnergy LLC was secured to evaluate the economic
benefits of seawater heat pumps to supplement demands of AHU-5, AHU-6, and pavement heating.
The concept of using heat from seawater for building demands has been employed for nearly 20 years in
northern Europe, and more recently in other locations, including southeast Alaska:
Ted Stevens Marine Research Institute (TSMRI) NOAA Marine Fisheries Juneau,
Nagoya Public Aquarium, Japan
Stockholm, Sweden = Vartan Ropsten = largest seawater heat pumps on the planet
Bodo, Norway, pop 41,000, military base, district heating w/44.6F seawater
STATOIL Research Centre, Trondheim, Norway, district heating with seawater
The basic concept examined in this evaluation is to
raw seawater at temperatures ranging from 35F to 55F, and transfer this heat energy into air
handler units and pavement at a temperature of 120F. The air handler units AHU-5 and AHU-6 are
roof level units that currently transfer heat from a boiler fired 185F glycol loop in to the supply air stream
for the building. Both units are equipped with duct coils through which a mixture of outside air and return
air is drawn. The rate of glycol supply to these duct coils is modulated to maintain a temperature of 55F
through 70F air leaving the air handler. The total design demand of AHU-5 plus AHU-6 is 3,124 MBH
(3,124,000 BTU/hour) which represents approximately 40% of the total facility design heating demand.
Accordingly, installation of heat pumps to supplement a majority of the heating demand for AHU-5 and
AHU-6 will translate to significant reduction of heating oil usage and monthly operational costs.
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 6 OF 34
TM YourCleanEnergy LLC
SUMMARY OF ASLC HEAT PRODUCTION AND DESIGN DEMANDS (NAMEPLATE CAPACITY)
SUMMARY OF ASLC HEAT PRODUCTION & DESIGN DEMANDS (NAMEPLATE)
Heat Production Equipment Delivers Heat To:MBH*% of Total Capacity
Boiler No. 1 - Fuel Oil - 87.9% Eff 185F Main Glycol Loop 2911 38.60%
Boiler No. 2 - Fuel Oil - 87.9% Eff 185F Main Glycol Loop 2911 38.60%
Boiler No. 3 - Electric - 500 KW 185F Main Glycol Loop 1706 22.62%
Electric Unit Heater (EUH-1) 14 0.19%
Total Heating Capacity 7542
*Fuel oil boilers rated at 24 gal #2 fuel oil/hr x 138 MBH/gal fuel oil x 87.9% eff = 2911 MBH
Heat Demand Equipment Receives Heat From:MBH % of Total Demand
Pavement Heating - 12,000 LF 185F Main Glycol Loop via HX-1 1204 15.27%
AHU-5 185F Main Glycol Loop 1782 22.61%
AHU-6 185F Main Glycol Loop 1342 17.02%
AHU-4 185F Main Glycol Loop 521 6.61%
AHU-7 185F Main Glycol Loop 488 6.19%
AHU-8 185F Main Glycol Loop 244 3.10%
AHU-1 185F Main Glycol Loop 144 1.83%
AHU-2 185F Main Glycol Loop 130 1.65%
AHU-3 185F Main Glycol Loop 78 0.99%
Total AHU Demand 4729 59.99%
Duct Coil HC-1 (Lobby) 185F Main Glycol Loop 170 2.16%
Duct Coils HC-1 thru HC-24 185F Main Glycol Loop 396 5.02%
Ceiling Unit Heaters (CUH -1, 2, 3) 185F Main Glycol Loop 140 1.78%
Wall Unit Heaters (UH-1, 2, 3) 185F Main Glycol Loop 74 0.94%
1" Tube Fin BB Heaters (@600 LF) 185F Main Glycol Loop 468 5.94%
1-1/4" Tube Fin BB Heaters (@200 LF) 185F Main Glycol Loop 286 3.63%
Total Unit Heater Demand 1534 19.46%
Domestic Hot Water Tank, 630 Gal 185F Main Glycol Loop 416 5.28%
Total Design Heat Demand 7883
Notes: 1. HeaƟng demands listed above taken from 1996 Livingston Slone Design Drawings
2. Max monthly fuel oil usage was 18,442 gal/mo in Mar 07 = 3421 MBH avg demand
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 7 OF 34
TM YourCleanEnergy LLC
CONCEPT GUIDELINES FOR SUPPLYING AHU-5 AND AHU-6 WITH SEAWATER HEAT
In the interest of reducing the capital cost of new heat pumps to supply AHU-5 and AHU-6, the following
suggestions were made by ASLC staff during the initial scoping site visit by YourCleanEnergy:
Make use of the existing seawater to glycol plate and frame heat exchanger (HX-2) that is
currently located in the north wing of the basement. This heat exchanger is already fed by
influent seawater piping which is pumped from the main seawater intake well. HX-2 could be
used as means of transferring heat from seawater into the existing chilled water glycol loop and
up to new heat pumps installed in roof level mechanical rooms.
Make use of the existing 20 HP, 240 gpm chilled glycol circulation pump (PMP-
-5 and AHU-6.
Make use of the cooling duct coils which are currently installed in AHU-5 and AHU-6 as a means
of transferring heat from new heat pumps into the air handlers.
Make use of existing floor space adjacent to or nearby AHU-5 and AHU-6 for new heat pumps to
be installed in rooftop mechanical rooms.
Make use of existing Motor Control Center (MCC) in Fan Room 1 and 2 to supply 480V 3 phase
electric power to new heat pumps supplying AHU-5 and AHU-6.
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 8 OF 34
TM YourCleanEnergy LLC
EXISTING ELECTRICAL COSTS FOR ASLC IN SEWARD, ALASKA
In order to plan energy efficiency projects for buildings in Seward, it is very useful to see the recent trend
of rising energy costs. ASLC is currently charged a commercial electric rate by the Seward Electric Utility
that consists of the following price components as illustrated with actual January 2009 billing:
Primary Additional Peak Demand CEA Fuel Charge Monthly Charge Total
$0.0706/KWH $0.0408/KWH $13/KW $0.0548/KWH $30/month $0.1371/KWH
It is anticipated that ASLC will soon increase its monthly electri more
favorable industrial rate, due the installation of new 500 KW electric boiler this month, and large demand
heat pumps in the near future. Thus this heat evaluation is based on ASLC receiving the industrial rate,
which is significantly lower in cost, as this estimation from January 2009 clearly indicates:
Primary Additional Peak Demand CEA Fuel Charge Monthly Charge Total
$0.00574/KWH $0/KWH $9.51/KW $0.0548/KWH $30/month $0.086/KWH
Seward Electric Utility purchases firm power from Chugach Electric Association (CEA) with the exception
of local diesel generation when Chugach power is interrupted by avalanches or other events. Therefore
future price escalations in electricity cost in Seward are closely tied to those of Chugach Electric. The
unit price of grid electricity from Chugach Electric has risen at a rate of approximately 6% per year
for the past seven years. This increase has been tempered by the fact that 15%
from hydro-electric which has stabilized the retail cost of electricity; and load sharing between utilities on
the rail belt grid of Alaska has prevented any one utility from subjecting customers to rapid price
escalations.
ity is the cost of
natural gas generation which has risen rapidly due to lack of competition in the region for this commodity.
Several large oil and gas producers have an effective monopoly on gas reserves in Cook Inlet and new
supplies have not yet been developed or transported in to reduce or stabilize the cost of natural gas.
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 9 OF 34
TM YourCleanEnergy LLC
The economic evaluations contained in this report are based on the rate of grid electricity from City of
Seward escalating at an average rate of 4% per year for the next 20 years. The addition of local hydro
electric power to the Seward City grid could further stabilize the retail price by reducing dependence on
natural gas generation by Chugach Electric and by providing some alternative to emergency diesel
generation during those times when supply from Chugach is interrupted.
Electricity usage by ASLC has little variation through the year due to the large amount of continuous
loads from HVAC, indoor lighting and life support systems. There is great scope to reduce some of this
demand through energy efficiency and reduction of HVAC ventilation rates during times of low
occupancy. Other methods of reducing electricity use is to install variable speed controls on selected
glycol pumps and exhaust fans, and placing the domestic hot water heat tape system on a timer.
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 10 OF 34
TM YourCleanEnergy LLC
HEATING OIL USAGE BY ASLC
The primary heating plant of ASLC consists of two Cleaver-Brooks Model CB 100-80-125hw #2 fuel oil
fired boilers, installed new in 2003, each with a rated output capacity of 2911 MBH. These boilers
indirectly heat a 185F loop of 40% propylene glycol (Dowfrost) that in turn circulates through the facility to
baseboard heaters, unit heaters, duct coils in Air Handling Units, pavement heating heat exchanger (HX-
1) and a 630 gallon domestic hot water tank. As shown previously on Page 5, the largest design
demands of the facility during the September through April heating season are currently AHU-5 (22% of
total demand), AHU-6 (17% of total demand), and pavement heating (15% of total demand).
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 11 OF 34
TM YourCleanEnergy LLC
RECENT AND PROJECTED HEATING OIL COSTS FOR ASLC
ASLC purchases large quantities of #2 heating oil at bulk rate, actual price paid per gallon for recent
years is shown below. While there has been an accelerated price increase for unit cost of crude oil
products in the past two years, the overall price escalation has been on a baseline of 8.2% per year from
January 2003 ($1.22/gallon) through March 2009 ($1.96/gallon). The recent economic recession and
associated reduction in crude oil demand in the USA is likely to keep heating oil prices from escalating at
the high rates of 2007 through 2008 for several years. For the purpose of economic evaluation of
alternatives in this report, a conservative escalation rate of 6% per year is used, see second graph below.
The global shortage of crude oil supplies and growing global demand, especially that of China and India,
will increase escalation rates, however it is not certain how soon or how acute this will affect actual bulk
heating oil prices in Alaska. At current retail electricity and fuel oil rates (March 2009), heating with
#2 heating oil still remains 1.5 times more cost effective than heating with grid electricity:
Cost of making 100,000 BTU of electric heat (element heater, $0.086/KWH) = $2.52
Cost of making 100,000 BTU with #2 heating oil (using 87.9% eff boiler, $1.96/gal) = $1.62
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 12 OF 34
TM YourCleanEnergy LLC
RECOMMENDATIONS FOR INCREASING ENERGY EFFICIENCY OF ASLC FACILITY
After conducting two sites visits and reviewing design drawings and reports, it is recommended that ASLC
consider the following improvements in energy efficiency prior to and/or in coordination with efforts to
install seawater heat pump systems. These improvements will provide immediate reductions in heating
and electrical costs, those with the lowest investment cost and highest payback should be done first.
Reduce exhaust fan run times and/or rates. Exhaust fans have no heat recovery systems on them
and most or all appear to running 24/7 regardless of occupation or need. Consequently a notable fraction
of building heat created by burning fuel oil is exhausted to waste unnecessarily. The most cost effective
way to reduce this loss of heat is to place fans on timer devices which restrict operation to times when the
section of the building served by fan is occupied. Another method of controlling fans is with variable
speed drive, or multi-speed drive. The effect of intermittent ventilation can be tested by simply trying
different operation schedules, making sure that air quality, odors, life safety issues remain satisfactory.
Install timer to control heat tape operation on domestic water line to labs. Heat tape is typically a
very large and continuous electrical load which can be timer controlled. At present, making heat with
electricity at $0.12/KWH is twice as expensive as making heat with boilers at 85% efficiency with fuel oil
at $2/gallon. One modification that will yield high return is to place the domestic water supply line heat
tape on a timer control. The tape extends the entire length of the domestic water supply line from the
boiler room to point of use in labs. It may be very cost effective to turn off the tape from 6pm till 6am (12
hours/day) and still deliver heated water during normal operating hours. That would cut this electrical
usage in half and still allow domestic water to preheat before use during the day.
The rate that cold outside enters the various air
handling units in the facility is based on carbon dioxide levels in the return air, to optimize the use of
already heated return air. The CO2 sensors have not been calibrated since 1998 and there is great
possibility that inaccurate sensors may be causing over or under ventilation of building interior spaces.
Control of pavement heating system. More precise control of outdoor pavement temperature will lead
to reductions in heating demand. This is attractive to address considering that any excess heat applied to
outdoor pavement is wasted outside the building envelope. Currently the pavement snow melting system
operates continuously when outside temperature falls below 32F, regardless of snow or ice accumulation.
A moisture sensor and slab temperature sensor should be added to the system so that demand of
outdoor radiant heat loops can be reduced or eliminated at times when no snow is falling.
Variable Speed Drives For Main Glycol Loop Circulation. Pumping energy can be saved cost
effectively by adding variable frequency drives to the pumps circulating heated glycol (185F) to various
heating loads in the facility. These pumps currently run at full speed regardless of heat demand.
Install insulating shroud on boiler/glycol HX. The plate & frame heat exchanger located in the
basement that transfer heat from boiler water to the main 180F glycol loop is completely un-insulated and
is continuously losing large quantities of heat to the boiler room area. Insulation will control this loss.
Install door sweeps on interior doors of main entrance. The main entrance employs an arctic entry
which can reduce heat loss significantly from a building with high volume traffic. However the interior
metal door sets have no sweep seals on the bottom of doors so cold air created by conduction through
exterior doors pours at an uncontrolled rate under interior doors and into lobby area in winter months.
Consider installing double layer cellular shades on selected north facing windows . ASLC has a
large amount of glazing area with double pane gas filled windows which contribute to building envelope
heat loss. Windows that face north, north east or north west allow indirect lighting however they do not
achieve any heat gain from direct solar exposure; cellular shades may installed and left in the down
position when the space is unoccupied. This will add an estimated R5 value to the window and reduce
heat loss during winter months. The cellular shades must fit tightly inside window frame and be
positioned no more than ¾ inch off the face of glass to reduce convection air currents.
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 13 OF 34
TM YourCleanEnergy LLC
MONTHLY SEA WATER TEMPERATURES AND HEAT ENERGY AVAILABLE
Seawater temperatures recorded for the past five years (2003 through 2008) at the Alaska SeaLife
mperature for
each month. The maximum monthly seawater temperature (56F) and minimum monthly seawater
temperature (37F) were also identified. As shown in the graph below, it is evident that the large mass of
seawater contained in Resurrection Bay is absorbing a significant quantity of solar heat during the
summer months and releasing the same heat slowly through the winter heating season.
The amount of heat contained in the influent seawater that can be used to supply heat pumps is a
function of the seawater flow rate, seawater temperature, and the amount of temperature drop achieved
in the seawater heat exchanger. The graph below shows heat available at various flow rates when the
heat exchanger lowers seawater temperature to a minimum of 36F (seawater will freeze at 28.4F). The
combined heat demand for AHU-5 and Pavement Heating is also shown for the purpose of comparison.
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 14 OF 34
TM YourCleanEnergy LLC
EXISTING AIR HANDLERS AHU-5 AND AHU-5 IN ROOF LEVEL FAN ROOMS
Design specifications for existing air handler units AHU-5 and AHU-6:
Unit Make Model Year Air Flow Fan HP Heating Coil Capacity
AHU-5 Trane MCC 66 1996 30,000 CFM 30 HP Triple Row 1782 MBH
AHU-6 Trane MCC 40 1996 22,600 CFM 25 HP Single Row 1342 MBH
Sequence Of Operation (per 1996 Johnson Control Design):
Start/Stop: AHU-5 operates based on user defined 365 day occupancy schedule and starts Exhaust Fan
EF-5. AHU-6 operates continuously. Exhaust Fan EF-6 operates continuously.
Supply Air Temperature Control: When fan is operating, Make Up Air dampers modulate as required to
maintain either 600 PPM CO2 in Return Air; or 55 deg F Make Up Air temperature set point. Heating and
cooling coil valves modulate in sequence as required to maintain discharge set point of 55 degree F.
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 15 OF 34
TM YourCleanEnergy LLC
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 16 OF 34
TM YourCleanEnergy LLC
HEAT PUMP OPERATION AND COEFFICIENT OF PERFORMANCE
Coefficient Of Performance (COP) for a heat pump is the ratio of total heat output to electricity
input. For seawater heat pump projects, a minimum COP value of 3.0 is desirable and can lead to viable
economic returns. Seawater heat pumps are water to water heat pumps that operate by using electricity
powered compressors in combination with the physical properties of an evaporating and condensing fluid
known as a refrigerant. The refrigerant used in the heat pumps in this evaluation is known as R-134a.
HOW A HEAT PUMP WORKS TO LIFT LOW TEMP HEAT TO A HIGHER TEMP
COMPRESSOR
LIQUIDHOT VAPOR
VERY HOT VAPOR WARM VAPOR
EXPANSION
VALVE
R-134a REFRIGERANT
IS USED IN HIGH
EFFICIENCY ROTARY
SCREW COMPRESSOR
HEAT PUMPS
EVAPORATORCONDENSOR
41 F
33 F98 F
120 F
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 17 OF 34
TM YourCleanEnergy LLC
SELECTION OF HEAT PUMP EQUIPMENT SUITABLE TO SUPPLY AHU-5 & 6, PAVEMENT HEAT
The process of removing latent heat from raw seawater and making that same heat useful for large air
handling units is neither simple nor conventional. The engineering challenge of achieving this for ASLC is
made greater by the requirement of using heat transfer fluid with high concentrations of propylene glycol
that increase flow viscosity and reduce heat capacity. There are only several manufacturers in the USA
at this time who have considerable experience with manufacturing water to water heat pumps that can lift
commercial quantities of heat energy from a temperature range of 35F to 50F on the evaporator side to
as great as 120F on the condenser side. In this evaluation, simulations that define the glycol flow rates,
evaporator and condenser temperatures, coefficient of performance (COP), electricity demand and heat
output, are based Trane Model RTWD Hi Efficiency 2-Pass Evaporator 80 and 90 Ton Capacity units.
These heat pumps are commercially available as compact self contained units which can be shipped to
ASLC, placed on concrete foundations, and piped and wired in place.
Design specifications for heat pumps included in this evaluation to supply AHU-5 and AHU-6:
MFG Model Capacity Heat Output Dimensions Operating Weight
Trane RTWD 80 Tons 960 MBH 480v/3ph/60Hz 7 4 5733 LBS
Trane RTWD 90 Tons 1080 MBH 480v/3ph/60Hz 7 4 5792 LBS
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 18 OF 34
TM YourCleanEnergy LLC
RESULTS OF SIMULATION WITH ASLC SEAWATER TEMPS AND TRANE RTWD HEAT PUMPS
Using average seawater temperatures dropping 2 degrees F through a plate heat exchanger with 25%
propylene glycol, simulation results were provided by Trane for their 80 Ton and 90 Ton RTWD units:
25% PG 125 GPM on evap 25% PG 160 GPM on evap
25% PG 90 GPM on condensor 25% PG 95 GPM on condensor
Ent. Evap Heating MBH kW COP Heating MBH kW COP
Jan 41.2 782.7 68.53 3.35 955.9 81.94 3.42
Feb 39.3 754.4 67.84 3.26 921.4 81 3.33
March 38.2 738.1 67.45 3.21 901.4 80.46 3.28
April 37.8 732 67.3 3.19 894.2 80.26 3.26
May 38.1 736.5 67.41 3.20 899.6 80.41 3.28
June 39 749.9 67.74 3.24 915.9 80.85 3.32
July 39.6 758.9 67.95 3.27 926.8 81.15 3.35
August 40.3 769.3 68.21 3.30 939.5 81.49 3.38
September 43.7 820.2 69.44 3.46 1001.6 83.17 3.53
October 45.8 852.1 70.2 3.56 1040.3 84.21 3.62
November 45.6 849 70.13 3.55 1036.6 84.11 3.61
December 43.3 814.3 69.29 3.44 994.2 82.97 3.51
Worst 35 690.6 66.29 3.05 843.7 78.89 3.13
Best 50 use TOPSS use TOPSS
RTWD080 RTWD090
The above results can then be applied to Alternative A of this evaluation which designates one 90 Ton
unit supplying heat to AHU-5 (AHU-5 is estimated to be 30% of the actual total ASLC heating demand).
The table below shows heat pump electricity and glycol pumping costs based on the industrial rate of
$0.086/KWH and heating oil savings based on purchase price of bulk #2 heating oil at $1.96/gallon.
90 Ton AHU-5 Heat Heat #2 #2 Glycol
Heat demand % of full Pump Pump Heating Heating Pumps
Pump Electric as 30% load heat Days Electric Elect Oil Oil Elect
Output Demand of total pump is per Usage Cost Saved Saved Cost
Month (MBH)COP (KW) (MBH/mo)running Month (KWH)($)(gal)($)($)
Jul 927 3.35 81.2 256 28% 31 16,677 $1,434 1,539 $3,016 $477
Aug 940 3.38 81.5 276 29% 31 17,811 $1,532 1,659 $3,251 $477
Sep 1,002 3.53 83.2 302 30% 30 18,056 $1,553 1,757 $3,443 $462
Oct 1,040 3.62 84.2 424 41% 31 25,535 $2,196 2,548 $4,995 $477
Nov 1,037 3.61 84.1 578 56% 30 33,767 $2,904 3,362 $6,589 $462
Dec 994 3.51 83.0 590 59% 31 36,633 $3,150 3,546 $6,950 $477
Jan 956 3.42 81.9 665 70% 31 42,411 $3,647 3,997 $7,834 $477
Feb 921 3.33 81.0 612 66% 28 36,154 $3,109 3,322 $6,512 $431
Mar 901 3.28 80.5 562 62% 31 37,323 $3,210 3,378 $6,621 $477
Apr 894 3.26 80.3 430 48% 30 27,789 $2,390 2,501 $4,902 $462
May 900 3.28 80.4 326 36% 31 21,680 $1,864 1,959 $3,840 $477
Jun 916 3.32 80.9 323 35% 30 20,529 $1,765 1,879 $3,682 $462
Annual Totals =5,344 334,364 $28,755 31,447 $61,636 $5,620
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 19 OF 34
TM YourCleanEnergy LLC
SCHEMATIC OF EXISTING CHILLED WATER SUPPLY TO AHU-5 + AHU-6
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 20 OF 34
TM YourCleanEnergy LLC
SCHEMATIC OF ALTERNATIVE A: ONE HEAT PUMP IN ROOF FAN ROOM #1 TO SUPPLY AHU-5
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 21 OF 34
TM YourCleanEnergy LLC
COST ESTIMATE - ALTERNATIVE A: ONE HEAT PUMP TO SUPPLY AHU-5
Installed Installed
Unit Total
Item Description Quantity Unit Price Price
Basement Mechanical Room at HX-2
install in-line flow meter on Pump PMP-15 discharge line 1 each $1,500 $1,500
install VFD on exist 5 hp glycol pump PMP-15 1 each $3,000 $3,000
install new 8" Sch 40 pvc piping to return seawater to process 100 LF $140 $14,000
Existing Chilled Water Lines From HX-2 to Roof
install 3" ball valves on supply and return to AHU-6 2 each $300 $600
install 4" ball valves on supply and return to AHU-5 2 each $400 $800
Shut down chilled water system, drain piping 1 day $1,200 $1,200
Re-charge chilled water system with new 25% prop glycol 1 day $1,200 $1,200
New prop glycol for 25% PG chilled water loop 500 gal $20 $10,000
Rooftop Fan Room 1 (North)
new 4" copper supply and return piping to heat pump 180 LF $100 $18,000
new 4" ball valves on supply/return piping to heat pump 10 each $400 $4,000
new glycol circ pump 120 GPM @50ftTDH w/VFD 1 each $8,000 $8,000
install new 2" ball valves on duct coil inlet piping 3 each $200 $600
in-line flow meter on 4" copper supply to heat pump 1 each $1,500 $1,500
tube & shell HX for chilled 25%PG / 40%PG transfer 2 each $25,000 $50,000
foundations and insulation for tube and shell HX's 2 each $2,000 $4,000
concrete foundation w/anchor bolts for new 90 ton heat pump 1 LS $1,000 $1,000
90 Ton Rotary Screw Hi Eff 2-pass Evaporator Heat Pump* 90 ton $900 $81,000
Ship heat pump from Seattle Dock to Seward Dock 1 LS $5,000 $5,000
Install heat pump in roof area with crane + pallet jack/rollers 1 day $12,000 $12,000
On site training session with factory rep 2 day $1,200 $2,400
Start up services/commissioning** 3 day $1,200 $3,600
Sound reduction package for heat pump 1 each $3,500 $3,500
OSHA required refrigerant monitor for R-134a 1 each $6,500 $6,500
Electrical Supply & Controls
new 480v 125 amp breaker in exist MCC 2 each $2,000 $4,000
new 480v 125 amp cable from heat pump to exist MCC 60 LF $100 $6,000
integrate controls of new heat pump with exist Trane AHU-5 1 LS $10,000 $10,000
Total Installation Price for heat pump system $253,400
15% for final mechanical design & procurement services $38,010
5% for seismic structural analysis $12,670
5% for sound attentuation analysis $12,670
5% for construction inspection services $12,670
10% Contingency $25,340
Total Project Price - Alternative A $354,760
Total Project Cost/Ton Heat Pump Capacity Installed $3,942
*Heat pump price includes 2 yr warranty on all parts, 1 yr warranty on parts and labor
**Replacement of 100,000 hr compressor bearings will be required at Year 12, present day cost of $12,000
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 22 OF 34
TM YourCleanEnergy LLC
SCHEMATIC OF ALTERNATIVE B: ONE HEAT PUMP IN BASEMENT RM 19 FOR PAVEMENT HEAT
Energy usage, production, and costs per month for Alternative B (one 90 Ton heat pump supplying
pavement heat) with electricity at $0.086/KWH and #2 heating oil at $1.96/gallon:
90 Ton Heat Pavement % of Heat Heat #2 #2 Glycol
Heat Pump Heating full load PumpElectPump HeatingFuel OilHeating Pumps
Pump Electric Demand heat Days ElectricUnitElectric Oil Unit Oil Electric
Output Demand 25% of total pump is per UsageCostCost SavedCostSaved Cost
Month (MBH)COP (KW) (MBH/mo)running Month (KWH)($/KWH)($)(gal)($/gal)($)($)
Jul 927 3.35 81.2 213 23% 31 13,897 $1,195 1,282 $2,513 $477
Aug 940 3.38 81.5 230 24% 31 14,843 $1,276 1,382 $2,709 $477
Sep 1,002 3.53 83.2 252 25% 30 15,046 $1,294 1,464 $2,869 $462
Oct 1,040 3.62 84.2 353 34% 31 21,280 $1,830 2,124 $4,162 $477
Nov 1,037 3.61 84.1 482 46% 30 28,139 $2,420 2,802 $5,491 $462
Dec 994 3.51 83.0 492 49% 31 30,527 $2,625 2,955 $5,792 $477
Jan 956 3.42 81.9 554 58% 31 35,342 $3,039 3,331 $6,528 $477
Feb 921 3.33 81.0 510 55% 28 30,128 $2,591 2,769 $5,427 $431
Mar 901 3.28 80.5 468 52% 31 31,102 $2,675 2,815 $5,517 $477
Apr 894 3.26 80.3 358 40% 30 23,157 $1,992 2,084 $4,085 $462
May 900 3.28 80.4 272 30% 31 18,066 $1,554 1,633 $3,200 $477
Jun 916 3.32 80.9 269 29% 30 17,107 $1,471 1,566 $3,069 $462
Annual Totals =4,453 278,637 $23,963 26,206 $51,363 $5,620
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 23 OF 34
TM YourCleanEnergy LLC
COST ESTIMATE - ALTERNATIVE B: ONE HEAT PUMP IN BASEMENT ROOM 19 FOR PAVEMENT HEATING
Installed Installed
Unit Total
Item Description Quantity Unit Price Price
Basement Seawater Pump Room
Tap into discharge piping of exist seawater pump 1 LS $2,000 $2,000
8" sch 80 PVC seawater piping from pump room to new HX 160 LF $140 $22,400
Flow meter for new 8" seawater piping 1 each $2,000 $2,000
New plate & frame HX (seawater to 25% prop glycol, 1252 MBH) 1 each $80,000 $80,000
in-line flow meter on sch 80 glycol piping 1 each $2,000 $2,000
5 hp glycol pump with VFD 1 each $5,000 $5,000
new 6" Sch 40 pvc chilled glycol piping (HX to Rm 19) 280 LF $100 $28,000
Along New Chilled Glycol Piping
6" ball valves on supply and return 8 each $300 $2,400
Charge new chilled glycol system with 25% prop glycol 1 day $1,200 $1,200
New prop glycol for 25% PG chilled water loop 300 gal $20 $6,000
Room 19 - Heat Pump Room
4" copper supply and return piping (pavemnt heat to Rm 19) 120 LF $100 $12,000
new 4" ball valves on supply/return piping to heat pump 4 each $400 $1,600
new glycol circ pump 120 GPM @50ftTDH w/VFD 1 each $5,000 $5,000
in-line flow meter on 4" copper supply to Pavement Heating System 1 each $2,000 $2,000
concrete foundation for new 90 ton heat pump 1 each $1,000 $1,000
90 Ton rotary screw hi eff 2-pass evap heat pump* 90 ton $900 $81,000
Ship heat pump from Seattle Dock to Seward Dock 1 LS $5,000 $5,000
Install heat pump in Room 19 thru hatch with crane 2 day $2,000 $4,000
Sound reduction package for heat pump 1 each $3,500 $3,500
OSHA required refrigerant monitor for R134-A 1 each $6,500 $6,500
On site training session with factory rep 2 day $1,200 $2,400
Start up services and commissioning** 3 day $1,200 $3,600
Instrumentation wiring, testing & commissioning 1 LS $5,000 $5,000
new 480v 250 amp breaker in exist MCC 1 each $2,000 $2,000
new 480v 250 amp cable from exist MCC to Rm 19 120 LF $90 $10,800
Sub panel with two 125 amp breakers in Rm 19 1 each $1,200 $1,200
125 amp cables from sub panel to each compressor on HP 120 LF $60 $7,200
Total Installation Price for heat pump system $304,800
15% for final design & procurement services $45,720
5% for construction inspection services $15,240
10% Contingency $30,480
Total Project Price - Rm 19 Alternative $396,240
Total Project Cost/Ton Heat Pump Capacity Installed $4,403
*Heat pump price includes 2 yr warranty on all parts, 1 yr warranty on parts and labor
**Replacement of 100,000 hr compressor bearings req'd at Year 12, present day cost of $12,000/heat pump
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 24 OF 34
TM YourCleanEnergy LLC
SCHEMATIC OF ALTERNATIVE C: TWO HEAT PUMPS IN ROOM 19 OF BASEMENT FOR AHU-5 +
PAVEMENT HEATING
Energy usage, production, and costs per month for Alternative C (two 90 Ton heat pumps supplying
pavement heat and AHU-5) with electricity at $0.086/KWH and #2 heating oil at $1.96/gallon:
Two 90 Heat AHU-5 + % of Heat Heat #2 #2 Glycol
Ton Heat PumpsPavementPvt Heat full load PumpElectPump HeatingFuel OilHeating Pumps
Pumps ElectricHeat Demandas 55% heat Days ElectricUnitElectric Oil Unit Oil Electric
Output Demandas 25%of total pump is per UsageCostCost SavedCostSaved Cost
Month (MBH)COP (KW) of total(MBH/mo)running Month (KWH)($/KWH)($)(gal)($/gal)($)($)
Jul 1,854 3.35 162 469 25% 31 30,574 $2,629 2,821 $5,529 $668
Aug 1,879 3.38 163 506 27% 31 32,654 $2,808 3,041 $5,961 $668
Sep 2,003 3.53 166 554 28% 30 33,102 $2,847 3,220 $6,312 $647
Oct 2,081 3.62 168 777 37% 31 46,815 $4,026 4,672 $9,157 $668
Nov 2,073 3.61 168 1,060 51% 30 61,907 $5,324 6,164 $12,081 $647
Dec 1,988 3.51 166 1,082 54% 31 67,160 $5,776 6,501 $12,742 $668
Jan 1,912 3.42 164 1,219 64% 31 77,753 $6,687 7,328 $14,362 $668
Feb 1,843 3.33 162 1,122 61% 28 66,283 $5,700 6,091 $11,938 $604
Mar 1,803 3.28 161 1,030 57% 31 68,425 $5,885 6,193 $12,138 $668
Apr 1,788 3.26 161 788 44% 30 50,946 $4,381 4,585 $8,987 $647
May 1,799 3.28 161 598 33% 31 39,746 $3,418 3,592 $7,041 $668
Jun 1,832 3.32 162 592 32% 30 37,636 $3,237 3,444 $6,751 $647
Annual totals:9,797 613,001 $52,718 57,653 $112,999 $7,868
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 25 OF 34
TM YourCleanEnergy LLC
COST ESTIMATE - ALTERNATIVE C: TWO HEAT PUMPS IN BASEMENT ROOM 19 FOR PAVEMENT HEAT + AHU-5
Installed Installed
Unit Total
Item Description Quantity Unit Price Price
Basement Seawater Pump Room
Tap into discharge piping of exist seawater pump 1 LS $2,000 $2,000
8" sch 80 PVC seawater piping from pump room to new HX 220 LF $140 $30,800
Flow meter for new 8" seawater piping 1 each $2,000 $2,000
New plate & frame HX (seawater to 25% prop glycol - 1230 MBH) 1 each $80,000 $80,000
in-line flow meter on sch 80 glycol piping 1 each $2,000 $2,000
7.55 hp glycol pump with VFD 1 each $10,000 $10,000
new 6" Sch 80 pvc chilled glycol piping (HX to Rm 19) 280 LF $100 $28,000
Along New Chilled Glycol Piping
6" ball valves on supply and return 8 each $300 $2,400
Charge new chilled glycol system with 25% prop glycol 1 day $1,200 $1,200
new 4" copper glycol piping from basement to AHU-5 on roof 600 LF $100 $60,000.00
new 4" ball valves on supply/return piping to heat pump 8 each $400 $3,200
New prop glycol for 25% PG chilled water loop 500 gal $20 $10,000
Basement Room 19 - Heat Pump Room
4" copper supply and return piping (pavemnt heat to Rm 19) 120 LF $100 $12,000
new 4" ball valves on supply/return piping to heat pump 4 each $400 $1,600
new glycol circ pump 240 GPM @50ftTDH w/VFD 1 each $10,000 $10,000
in-line flow meter on 4" copper supply to Pavement Heating System 1 each $2,000 $2,000
concrete foundation for new 90 ton heat pump 2 each $1,000 $2,000
two 90 Ton rotary screw hi eff 2-pass evap heat pumps* 180 ton $900 $162,000
Ship heat pump from Seattle Dock to Seward Dock 2 each $5,000 $10,000
Install heat pump in Room 19 thru hatch with crane 2 day $2,000 $4,000
Sound reduction package for heat pump 2 each $3,500 $7,000
OSHA required refrigerant monitor for R134-A 1 each $6,500 $6,500
On site training session with factory rep 2 day $1,200 $2,400
Start up services and commissioning** 3 day $1,200 $3,600
Instrumentation wiring, testing & commissioning 1 LS $10,000 $10,000
new 480v 250 amp breaker in exist MCC 2 each $2,000 $4,000
new 480v 250 amp cable from exist MCC to Rm 19 240 LF $100 $24,000
Sub panel with two 125 amp breakers in Rm 19 2 each $1,200 $2,400
125 amp cables from subpanel to each compressor on HP 240 LF $60 $14,400
Total Installation Price for heat pump system $509,500
15% for final design & procurement services $76,425
5% for construction inspection services $25,475
10% Contingency $50,950
Total Project Price - Rm 19 Alternative $662,350
Total Project Cost/Ton Heat Pump Capacity Installed $3,680
*Heat pump price includes 2 yr warranty on all parts, 1 yr warranty on parts and labor
**Replacement of 100,000 hr compressor bearings req'd at Year 12, present day cost of $12,000/heat pump
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 26 OF 34
TM YourCleanEnergy LLC
MANAGING FREEZE PROTECTION OF HEAT TRANSFER LOOPS IN DUCT COILS
Glycol solution adjustment is required: The existing chilled water system is charged with 40% propylene
glycol and 60% water by volume. While 40% propylene glycol provides freeze protection down to minus
5 degrees F, it has a heat capacity too low to allow adequate heat transfer for the rotary screw
compressor heat pumps that are commercially available and suitable for this project. In order to achieve
convergence of heat transfer in both the evaporator and condenser of the heat pumps, the
existing chilled glycol loop will have to be changed to either 25% propylene glycol or 35%
ethylene glycol by volume. Using 25% propylene glycol will be a simple adjustment; however the risk
of chilled water freezing in the duct coils of AHU-5 and AHU-6 must be addressed. This risk will be
present when ambient temperatures are below 15 deg F and the heat pumps are not circulating 90F -
120F glycol through the duct coils. A possible method of avoiding glycol freeze in the duct coils is to add
a plate and frame heat exchanger and circulation pump that circulates 40% glycol through the duct coils
and the cold side of the heat exchanger, while the warm side of the heat exchanger receives 25% glycol
supply from the heat pump by means of a second circulation pump.
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 27 OF 34
TM YourCleanEnergy LLC
SITE PHOTOS WITH NOTES EXISTING CHILLED WATER HX AND PUMP SYSTEM IN BASEMENT
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 28 OF 34
TM YourCleanEnergy LLC
SITE PHOTOS WITH NOTES EXISTING CHILLED WATER HX AND PUMP SYSTEM IN BASEMENT
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 29 OF 34
TM YourCleanEnergy LLC
SITE PHOTOS WITH NOTES AHU-5 IN FAN ROOM NO. 1 (NORTH)
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 30 OF 34
TM YourCleanEnergy LLC
SITE PHOTOS WITH NOTES AHU-5 IN FAN ROOM NO. 1 (NORTH)
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 31 OF 34
TM YourCleanEnergy LLC
SITE PHOTOS WITH NOTES AHU-6 IN FAN ROOM NO. 2 (SOUTH)
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 32 OF 34
TM YourCleanEnergy LLC
SITE PHOTOS WITH NOTES AHU-6 IN FAN ROOM NO. 2 (SOUTH)
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 33 OF 34
TM YourCleanEnergy LLC
SITE PHOTOS WITH NOTES BASEMENT AREA - SEAWATER PIPING & PAVEMENT HEATING
SEA WATER HEAT PUMP EVALUATION ALASKA SEA LIFE CENTER 3/28/09 PAGE 34 OF 34
TM YourCleanEnergy LLC
SITE PHOTOS WITH NOTES BASEMENT AREA MECHANICAL ROOM 19 & ELECTRICAL RM 18