Lodging HVAC and Refrigeration

Goals

• Guest comfort

• Energy saving

• Extend equipment life

• Reduce maintenance

• Reduce service calls

What we’ll talk about

• The purpose of HVAC

• A/C fundamentals

• Basic HVAC controls

• HVAC troubleshooting

• HVAC system adjustments

• Guest room PTAC

What we’ll talk about

• Refrigeration

Walk-in coolers and freezers

Under counter reach-ins

Display coolers

Guest room refrigeratorsIce maker fundamentals

Ice maker troubleshooting

Typical Hotel Electricity Usage

49%

20%

9%

11%

11%

HVAC Room

HVAC Common

Lights Common

Lights Room

Misc.

Source: Florida Power

Comfort

• Design airflow

• Space air distribution

• Outside air proportion

Indoor Air Quality(IAQ)

• Indoor air pollution• Material outgassing• Particulates

• Ventilation• Infiltration, natural, and mechanical• Fresh air proportion required by code.

HVAC Safety

• Loose hair, jewelry, wristbands, clothing

• Situational awareness

• Disconnect OFF

• Lock-out Tag-out

• Safety glasses

• Right tool for the job

VOM Basics

Alternating current (AC)

Direct current (DC)

Continuity

VOM Basics

Measuring voltage – Select type of power and rangeIf unsure select highest rangeMeasure voltage to ground

Checking fuses – Select Continuity (diode symbol)Place probes at each end of the fuseIf the fuse is good, then tone and reading 0

A/C Fundamentals

A/C FundamentalsStraight Cooling

A/C FundamentalsHeat Pump

Operation

• Cooling

Liquid line should be warm

Supply air should be about 15F lower than return air

Condenser discharge air should be warm

Operation

• Heating (heat pump)

Suction line should be warm

Supply air temp should be 100F – 115F

Condenser discharge air should be cold

Controls

Controls Thermostat Wiring (Straight Cool)

Controls Thermostat Wiring (Heat Pump)

ControlsStraight Cooling

Red Thermostat, Air Handler, Condenser

Yellow Thermostat, Condenser

White Thermostat, Air Handler

Green Thermostat, Air Handler

ControlsHeat Pump

Red Thermostat, Air Handler, Condenser

Yellow Thermostat, Condenser

White Thermostat, Air Handler, Condenser

Green Thermostat, Air Handler

Orange Thermostat, Condenser

Black Thermostat, Air Handler, Condenser

Problems

• A/C not working (Not running)

Power

Fuses at disconnect

24VAC to control board

Control board fuse

24VAC to thermostat

Power at thermostat terminals

Problems

24VAC at thermostat terminals

R to C

Y to C in cooling

W to C in heating

G to C in fan mode

If no C terminal read between R and appropriate terminal (Y, W, G). If there is power at the terminal there will be no reading.

Problems

• A/C not working (running)

Airflow temperature

Filters

Coils

Condenser operation

Problems

• Condenser troubleshooting

Power

Low voltage terminals

Discharge air temperature

Liquid line temperature (cooling)

Problems

• Space too hot/cold (A/C working)

Check for airflow

Filters

Dampers

Controls

Problems

• “Smudging” – Dirty filters Dirty coil Particle entrainment

• Squealing

On start-up - Belts slipping

While operating – Belts too tight

Problems

• Evaporator icing

Low airflow – Dirty filters

Dirty coil

Low refrigerant charge

• Condenser icingDirty coil

Low refrigerant charge

Revisiting the HVAC Systems

• Outside air

• Diffuser vanes

• Balancing dampers

• Fire dampers

• Controls

• Air handling equipment

Outside Air

Outside Air

• Ventilation air

• Required by code

• ASHRAE 62.1-2007

• Requirements vary by occupancy

• Amount for each system found in the balancing report.

Outside Air

• Direct measurement• Temperature method• Must be 15F – 20F difference between outside air and

return air temps.

• Formula: (MA – RA)/(OA – RA)

Where: MA = Mixed air temp

OA = Outside air temp

RA = Return air temp

Outside Air

Temperature method in action

Conditions: Outside air temp: 30FReturn air temp: 70FMixed air temp: 64F

Formula: (64 – 70)/(30 – 70) = 0.15

or 15% outside air.

Diffuser Vanes

• Control diffusion and mixing in the space.

• Improper adjustment can lead to stagnant zones and drafty areas in the space.

• Usually set vanes at 45 degree angle from the center on sidewall diffusers.

Balancing Dampers

• Located in ductwork prior to grilles.

• Usually located immediately prior to grille or at ductwork branch.

• If little to no flow at grille:Verify that damper is open

Ensure that damper handle position corresponds to damper position

Fire Dampers

• Located in ductwork at fire-rated partitions.

• If there is no airflow to a space, check the fire dampers.

• Visual inspection through access doors in ductwork.

Controls

• Ensure that the thermostat is level.

• Electronic thermostats programmed correctly.

Air Handling Equipment

• Change filters every monthOrient filters correctlyMore often in dirty environments (laundry)Pre-filters in dirty environments

• Clean coils annually

• Keep fans cleanExhaust fans

Air Handling Equipment

• Make sure that belts are tight and alignedRecommended ½” deflection

Pulleys should be in alignment

Grip-notch belts may solve slipping problems

• Ensure that drain lines are clear

• Drain pans slanted toward drain line

• Install float switchesWired between transformer and control board

PTAC

• Package Terminal Air Conditioner

PowerLine fuse – 15A buss fuse24VAC to control boardControl board trouble codePower at control board terminals3A buss fuseNo power from board – replaceCompressor makes ‘chugging’ noise –

dying

Property Refrigeration

• Walk-in cooler and freezer• Under-counter reach-in• Display coolers

Not running - Power

Fuses

Running - Coils

Discharge air temperature

Liquid line temperature

Property Refrigeration

Guest room refrigerators• Power

• Coil

• Loaded

• Defrost

Ice Maker

Ice MakerFreeze Cycle

Ice MakerHarvest Cycle

Ice MakerTroubleshooting

• Download service manual from manufacturer

• Ice maker and bin may have different model numbers.

• Sequence of operations

• Trouble codes

• Troubleshooting help

Ice MakerTroubleshooting

• Leaks

Drain line intact

Over floor drain

Debris in ice bin

Water line

Ice MakerTroubleshooting

• Little or no ice

Clean condenser coil

Float switch

Ice curtain stuck

Water line obstruction

Wrapping Up

• Improve guest experience

• Save energy

• Extend equipment life

• Reduce maintenance

• Reduce service calls

• Questions?