1/15/2013. HVAC Maintenance Repair or Replace & Planned Replace Initiative. Reduce Operating Costs. Improve Comfort / Process Conditions

15 

Loading....

Loading....

Loading....

Loading....

Loading....

Full text

(1)

HVAC Maintenance Repair or

Replace & Planned Replace Initiative

Greg DuChane, Retail Vertical Market, Director, TRANE Jack Rehder, Western Territory Manager, TRANE

Reduce Operating Costs

Improve Comfort / Process Conditions

Why Maintain Rooftop Units?

Why Maintain Rooftop Units?

Improve Comfort / Process Conditions

Extend Equipment Life

Tough Life for a Rooftop Unit

Tough Life for a Rooftop Unit

Regarded as Semi‐Disposal Pieces of Equipment

Operates in a Harsh Environment

High Ambient Temperatures

Brutal Radiant Heat

(2)

Reduce Operating Costs

Field Tests Have Shown that Rooftop Units Operate  Well Below Stated EER Levels if Not MaintainedA “Tune‐Up” Can Improve the EfficiencySavings Averaged 11% on 25 Rooftop Units in New  England StudySavings Ranged from 22 ‐42% on 23 Rooftop Units in  Louisiana study

Air-Side Vs. Refrigerant-Side

Two Fluid Loops to Deal WithAlways Do Air‐Side Maintenance & Repairs Firsty pThe Air‐Side Can Effect the Refrigerant‐Side, Such as  Proper Air Flows

Air-Side Focus

FiltersEvaporator CoilFanBeltsMotorOutside Air DampersCabinet Integrity

(3)

Filters

Maintain Indoor Air QualityProtect Downstream ComponentsProtect Downstream Components

Filters

Changing FrequencyMaintain Air FlowReduce By‐Pass AirIndoor Air QualityFilter Structural FailureClean Vs. Dirty FiltersEffect on Energy Consumption

Norminal cooling capacity (tons) a 10 10 10 Compressor input power (kW) a 9.8 9.75 9.67 Condenser fan input power (kW) a 0.56 0.56 0.56 Gross cooling capacity (Btu/h) a 112.79 110.10 105.14 Latent/sensible cooling ratio a 0.095 0.129 0.159 Total unit economics

Total unit power (kW) d 12.42 12.27 11.70 EER (Btuh/W) e 9.08 8.97 8.98 Annual run time (hours/year) f 2,000 2,048 2,146 Annual energy use (kWh/year) g 24,840 25,129 25,102 Total annual cost (US$) $1,987 $2,010 $2,008

Annual dirty filter penalty Base Line $23 $21

Notes:

a: Operating data from Carrier Corporation for unit # 48HJDO12 with standard fan. b: Assumed static pressure increase from dirty filter. c: Based on motor efficiency of 80 percent and belt drive efficiency of 95 percent. d: Sum of supply fan, compressor, and condenser fan power. e: Gross cooling capacity divided by total unit power.

f: Assumed run time of 2,000 hours for a clean system; dirty systems run proportionately longer due to reduced cooling capacity.

g: Total unit power times annnual run time. h: Electricity price; 8 cent per kWh.

(4)

Filters

Filter TypesFilter Depth (1,2 or 4 Inch)Filter MediaFiberglass MattPolyester MattPleated

Filter Material Options

Filter material options

Pressure drop Lifetime

Filter type Average efficiency a (in. wg-new) b (months) c Unit cost d Annual cost e One-inch filters Fiberglass matt <20% 0.07 2 $0.94 $82.56 Polyester matt <20% 0.08 2 $0.94 $82.56 Environmental "EP40" 25% to 30% 0.22 3 $3.26 $92.16 Farr 20/20 pleated 20% to 25% 0.19 4 $4.25 $82.20 Farr 30/30 pleated 30% 0.23 3 $4.60 $113.60 Two-inch filters Fiberglass matt <20% 0.09 2 $150 $96.00 Polyester matt <20% 0.15 2 $1.50 $96.00

Environmental "EP40 pleated 25% to 30% 0.16 4 $3.51 $72.12

Farr 30/30 pleated 30% 0.14 6 $5.15 $61.20

Notes:

a: Efficiency based on ASHRAE Standard 52.1.

b: Pressure drop: Fiberglass and polyester information based on satalog data at 300 feet per second face velocity. All others based on independent test data at 375 feet per face velocity.

c: Lifetime based on recommendations from filter vendor. Lifetime of fiberglass and polyester filters is short to prevent migration of dirt through the filter into the coil. Lifetime of pleated filters is based on changeout at a specified pressure drop.

d: Single filter unit cost based on HVAC contractor order, case-lot purchase (at least a dozen filters), FOB Denver, size 20 x 20 inches. e: Annual cost based on replacement for a typical 10-ton unit at end of relative lifetime, four panels (20 x 20 inches), $10 labor cost for each filter change.

How To Determine Filter Change

Frequency?

Time & Experience

Measure Pressure Drop

Install Transducers & Tie to EMS

(5)

Evaporator Coil

Dirt on Evaporator CoilReduces Air FlowReduces Coil’s Capacity to Transfer Heat Louisiana Field Test87% of Units Needed Evaporator Coil Cleaning Clean Evaporator Coil Yearly?Measure Fan Amp Draw & Pressure Difference

Dirty vs. Clean

Evaporator Coils

TONNAGE KWH WITH CLEAN COILS 1 KWH WITH DIRTY COILS 2 Savings/Yr @ $ 0.04/kwh Savings/Yr @ $ 0.05/kwh Savings/Yr @ $ 0.06/kwh Savings/Yr @ $ 0.07/kwh 3 8200 11400 $ 128.00 $ 160.00 $ 192.00 $ 224.00 5 11000 16200 $ 208.00 $ 260.00 $ 312.00 $ 364.00 7.5 14800 22400 $ 304.00 $ 380.00 $ 456.00 $ 532.00 10 24600 33600 $ 360.00 $ 450.00 $ 540.00 $ 630.00 15 32000 48800 $ 672.00 $ 840.00 $ 1,008.00 $ 1,176.00 20 41600 64800 $ 928.00 $ 1,160.00 $ 1,392.00 $ 1,624.00 25 54000 81600 $ 1,104.00 $ 1,380.00 $ 1,656.00 $ 1,932.00 30 61600 97800 $ 1,448.00 $ 1,810.00 $ 2,172.00 $ 2,534.00 40 83000 132800 $ 1,992.00 $ 2,490.00 $ 2,988.00 $ 3,486.00 50 104200 164600 $ 2,416.00 $ 3,020.00 $ 3,624.00 $ 4,228.00 60 126000 197200 $ 2,848.00 $ 3,560.00 $ 4,272.00 $ 4,984.00 1.Unit operating at 80*F ambient temperature, 45*Fsaturated suction temperature (standard design), F22 refrigerant, 2000 hours of operation.

2. Unit operating at 140*F-144*F saturated condensing temperatures at 45*F saturated suction temperature (337-354 psi head pressure) to stimulate dirty condenser operation multiplied by required hours to give the equivalent cooling in the above table.

Fan

Bearing Lubrication

Blade Cleaning

Blade Rotation

(6)

Belts

5‐10% Loss in Energy TransferProper Belt Tension, Change Belts RegularlyBelt AlignmentSpare Belt in UnitStandard V‐Belt Vs. Cogged V‐BeltsIncrease Drive Efficiency 2‐10% with Cog Belts

Motors

Sealed BearingsSpecify Energy Efficient MotorsNewReplacement

Comparison of Standard vs.

Premium Efficient Supply Fan Motors

Standard-efficiency motor Premium-efficiency motor Motor specifications

Norminal size (hp) 2 2

Motor efficiency a 82.50% 90.20% Motor power (watts) b 1,938 1,795

Motor cost c $325 $410

Marginal upgrade cost n/a $85 Economic comparison

Annual energy use (kWh) 9,691 8,975 Annual energy cost d $775 $718 Annual energy cost savings n/a $57 Payback (years) n/a 1.5

(7)

Outside Air Dampers

Economizer Cooling

Dry Bulb Sensor

Increase Set Point to Save Energy

Enthalpy Control (Reference & Comparative)

Ultimate in Energy Savings

Old Versions are Hard to Maintain

Cabinet Integrity

Many Access PanelsToo Many ScrewsOld Gaskets & SealsLeaks in Cabinet Costs More than $100/Year 

Refrigerant-Side Focus

Refrigerant ChargeCompressorCondenser CoilCondenser Fan & Motor

(8)

Refrigerant Charge

Undercharged Systems‐Caused by LeaksReduces Energy EfficiencyLow Pressures on both High & Low SidesFrosting on Evaporator EntranceWarm Suction Line, Cool Liquid LineWarm Supply AirContinuous Compressor Operation

Refrigerant Charge

Overcharged SystemsCaused byCharging Method

Air‐Side Problems

ff ff

Does Not Effect Efficiency as Severely

Effect of Refrigerant Charge

on Efficiency

90 95 100 y 65 70 75 80 85 90 80 85 90 95 100 105 110 115 120 % of Charge Eff ici en c y

(9)

Field Test of Refrigerant Charges

10 12 14 U nit s 52% 0 2 4 6 8 >-30% -16 to -30% -6 to -15 % +/- 5% >+6% Refrigerant Charge Nu m b er o f U 12% 16% 12% 8%

Charging System Correctly

Measure Superheat & Sub‐CoolingWeighing Refrigerant Charge

Compressor

Meg Test MotorTest oil for acid, especially after compressor failuresMeasure Compressor Heat with EMS SystemLow Voltage

(10)

Condenser Coil

Exposed to the Outdoor ElementsA Dirty Coil Raises the Condenser Temperature by 10  degrees Can Cost Over $250/Year in EnergyBest Money You Can Spend on MaintenanceClean Coils Annually

Condenser Fans

No Maintenance RequiredWatch Out for Rapid On‐Off Cycling of Fan

Repair or Replace

Points to consider when evaluating Repair or  Replace

The life expectancy of HVAC Equipment is 12 to 15 years

What is the condition of your HVAC

What is the condition of your HVAC

Due to recessionary issues routine maintenance has been lax

This reduces life expectancy

Is your equipment R22,  refrigerant price escalating

New HVAC is far more energy efficient and will save you 

(11)

Repair or Replace

Establish a History Data Base on Your HVACIf history does not exist perform an accurate survey of your 

HVAC

Build a data base of asset information

Installation date, brand, model, serial # capacity, voltage, type 

and capacity of heat, blower motor hp.

Additional information to meet municipality codes

Maintenance records and warranty information

Repair or Replace

Current Condition of HVAC Perform an  Inspection

Cabinetry must be intact, fastened properly to minimize air 

leakage leakage

Quality of equipment, reputable brand, or builders model 

Number of breakdowns, keep records

Poorly maintained, inferior quality, and frequent breakdowns 

Replace

If Rooftop Unit costs more than 50% to fix…replace the 

rooftop unit

Planned Replacement Program

Something You Should Consider

(12)

Planned Replacement Program

Market Data

Industry shipments & construction starts indicate that  the HVAC replacement market has been on a growth  curve since 2009.  Traditionally this has not been the case, HVAC  shipments would track with commercial building starts.  This data points to a strong replacement market in both  Unitary & Applied unit shipments. During the recession maintenance took a back seat.

Planned Replacement Program

Planned Replacement Program Benefits

The Planned Replacement Program is designed to  address HVAC equipment that was installed in the mid‐ to late 1990’s. Most equipment is nearing the end of their service life  of 12 to 15 years in retail applications.   Older units were also developed prior to significant  advances in efficiency technology. New HVAC  equipment can lower energy costs by up to 40%. 

(13)

Replacement Program Cost of

Older Equipment

Older equipment is more prone to breaking down, repair costs are also 

generally higher and more frequent with an older system. Spending capital 

to patch an older system – whether it’s for a $1,500 condenser coil or a $500 

blower motor, plus labor costs – adds up over time and doesn’t improve 

operational efficiency

operational efficiency.

Avoid spending more money repairing old equipment, which may require 

only more repairs with age. Invest current and future repair costs in new 

equipment, which has the added benefit of higher efficiency, increased 

durability & service‐friendly features.

Planned Replacement Program

Key Benefits

Avoid Expensive Emergency Replacement Situations Lower Replacement Costs Control the Timing of Capital Expenditures High‐Efficiency Equipment Offsets the Rising Costs of  Energy  Replacing older units from the 1990’s with new  equipment delivers instant energy savings. As energy  costs escalate, the return on investment is quicker.

Planned Replacement Program

More than Efficiency

Replacing older equipment can also help improve  comfort & indoor air quality. Proper sizing & duct design eliminate hot & cold spots,  while humidity control equipment & high‐efficiency  filt     i i i   ld g th th t   t igg  h lth  filters can minimize mold growth that can trigger health  concerns.  Enhanced comfort & air quality deliver a better customer  experience & satisfaction and increased sales. Between higher efficiency, reduced costs and better  environment, a planned replacement unit is the smart  and affordable decision.

(14)

Planned Replacement Program

Utility Inflation

Projected electric rates also play into the Planned Replacement 

process.  Industry projections notes gradual increases in electrical 

rates through 2030. 

Within modeling programs there is typically an input that allows 

for projected increases in electrical rates to be factored into the 

for projected increases in electrical rates to be factored into the 

ROI calculation.

Planned Replacement

Program Mechanics

Program Mechanics  Facilities teams need to identifying older equipment  (>12‐15 years) on active properties.  Prioritization of HVAC assets can have many drivers  Prioritization of HVAC assets can have many drivers  (repair cost, operating hours, equipment age, & facility  remodeling) however the metric is determined the  financial calculation begins to take shape.

Planned Replacement Program

Modeling Tools

Restaurant (3,000 S.F.)

25 Tons (3‐5 Ton RTU’s) 6.0 EER Existing Unit

(15)

Replacement Program Implementation

HVAC fleet management is a constant issue for retail facilities  teams & also represents approximately 30 to 40 percent of  electrical consumption.  The Planned Replacement Program  should become an annual process should become an annual process. The timing of your program is set to coincide with the  restaurateurs capital funding processes & sustainability  planning.

Percentage of Existing Programs Which Include Incentives

Packaged Units – 79%

Controls – 77%

Unitary – 73%

Typical Payouts

f h l f i h ffi i i d d

Rebates

 

&

 

Incentives

50%‐90% of the Incremental Cost of Higher Efficiency Equipment Vs. Standard

10%‐20%, or more, of the Equipment Cost

Usually Capped Out at 50% of the Total Installed Cost

Goal is to Buy Paybacks Down to 2 Years or Less

Purpose is to Reward Improvement of Local or ASHRAE Code

Who is Eligible?

All Rate Payers Paying the “Systems Benefits Charge” Government Entities are Eligible

Figure

Updating...

References

Updating...

Related subjects :