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Lodging HVAC and Refrigeration

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Presentation on theme: "Lodging HVAC and Refrigeration"— Presentation transcript:

1 Lodging HVAC and Refrigeration

2 Goals Guest comfort Energy saving Extend equipment life
Reduce maintenance Reduce service calls

3 What we’ll talk about The purpose of HVAC A/C fundamentals
Basic HVAC controls HVAC troubleshooting HVAC system adjustments Guest room PTAC

4 What we’ll talk about Refrigeration Walk-in coolers and freezers
Under counter reach-ins Display coolers Guest room refrigerators Ice maker fundamentals Ice maker troubleshooting

5 Source: Florida Power

6 Comfort Design airflow Space air distribution Outside air proportion

7 Indoor Air Quality (IAQ)
Indoor air pollution Material outgassing Particulates Ventilation Infiltration, natural, and mechanical Fresh air proportion required by code.

8 HVAC Safety Loose hair, jewelry, wristbands, clothing
Situational awareness Disconnect OFF Lock-out Tag-out Safety glasses Right tool for the job

9 VOM Basics Alternating current (AC) Direct current (DC) Continuity

10 VOM Basics Measuring voltage – Select type of power and range
If unsure select highest range Measure voltage to ground Checking fuses – Select Continuity (diode symbol) Place probes at each end of the fuse If the fuse is good, then tone and reading 0

11 A/C Fundamentals

12 A/C Fundamentals Straight Cooling

13 A/C Fundamentals Heat Pump

14 Operation Cooling Liquid line should be warm
Supply air should be about 15F lower than return air Condenser discharge air should be warm

15 Operation Heating (heat pump) Suction line should be warm
Supply air temp should be 100F – 115F Condenser discharge air should be cold

16 Controls

17 Controls Thermostat Wiring (Straight Cool)

18 Controls Thermostat Wiring (Heat Pump)

19 Controls Straight Cooling
Red Thermostat, Air Handler, Condenser Yellow Thermostat, Condenser White Thermostat, Air Handler Green Thermostat, Air Handler

20 Controls Heat 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

21 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

22 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.

23 Problems A/C not working (running) Airflow temperature Filters Coils
Condenser operation

24 Problems Condenser troubleshooting Power Low voltage terminals
Discharge air temperature Liquid line temperature (cooling)

25 Problems Space too hot/cold (A/C working) Filters Dampers Controls
Check for airflow Filters Dampers Controls

26 Problems “Smudging” – Dirty filters Squealing Dirty coil
Particle entrainment Squealing On start-up Belts slipping While operating – Belts too tight

27 Problems Evaporator icing Low airflow – Dirty filters Condenser icing
Dirty coil Low refrigerant charge Condenser icing

28 Revisiting the HVAC Systems
Outside air Diffuser vanes Balancing dampers Fire dampers Controls Air handling equipment

29 Outside Air

30 Outside Air Ventilation air Required by code ASHRAE 62.1-2007
Requirements vary by occupancy Amount for each system found in the balancing report.

31 Outside Air Formula: (MA – RA)/(OA – RA) Where: MA = Mixed air temp
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

32 Temperature method in action
Outside Air Temperature method in action Conditions: Outside air temp: 30F Return air temp: 70F Mixed air temp: 64F Formula: (64 – 70)/(30 – 70) = 0.15 or 15% outside air.

33 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.

34 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

35 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.

36 Controls Ensure that the thermostat is level.
Electronic thermostats programmed correctly.

37 Air Handling Equipment
Change filters every month Orient filters correctly More often in dirty environments (laundry) Pre-filters in dirty environments Clean coils annually Keep fans clean Exhaust fans

38 Air Handling Equipment
Make sure that belts are tight and aligned Recommended 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 switches Wired between transformer and control board

39 PTAC Package Terminal Air Conditioner Line fuse – 15A buss fuse
Power Line fuse – 15A buss fuse 24VAC to control board Control board trouble code Power at control board terminals 3A buss fuse No power from board – replace Compressor makes ‘chugging’ noise – dying

40 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

41 Property Refrigeration
Guest room refrigerators Power Coil Loaded Defrost

42 Ice Maker

43 Ice Maker Freeze Cycle

44 Ice Maker Harvest Cycle

45 Ice Maker Troubleshooting
Download service manual from manufacturer Ice maker and bin may have different model numbers. Sequence of operations Trouble codes Troubleshooting help

46 Ice Maker Troubleshooting
Leaks Drain line intact Over floor drain Debris in ice bin Water line

47 Ice Maker Troubleshooting
Little or no ice Clean condenser coil Float switch Ice curtain stuck Water line obstruction

48 Wrapping Up Improve guest experience Save energy Extend equipment life
Reduce maintenance Reduce service calls Questions?

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