MEP 123 Steve Carlson, FCSI, LEED Robert Rippe & Associates April 20, 2012

2. MEP 123 Steve Carlson, FCSI, LEEDRobert Rippe & Associates • April 20, 2012

3. What We’re Going to Cover • Electricity • Plumbing • Water • Gas • Drains/waste • Steam • Refrigeration • Exhaust

4. Electricity • Electrical Terms • Voltage is a measure of potential energy • Current is the flow of electricity • Amperage is how current is measured • DC - direct current-batteries • Used for some elevators in Chicago Loop area • AC is alternating current • Hertz is the frequency of alternating current • 60 in US, 50 in Europe & Asia • Hot (X), Neutral (N) and Ground

5. Voltages • 120/1 = 120 volts, single phase • 208/1 • 120/208 • 120/240 - residential • 208/3 = 120/208/3 • 277/1 – used for building lighting • 480/3 = 208/480/3

6. 120V/1

7. 120/240V (What’s in your Home)

8. 120/208/3 – “Y” Configuration

9. 120/208/3 - “Delta” Configuration

10. Hertz

11. Ohms Law Volts * Amps = Watts

12. Use Ohm’s Law to Calculate Amperage from Wattage • P= V x I or watts = volts x amps • Example - how many amps is 3600 watts?

13. When to Use Different Voltages • 3 phase better for large motors • 480/3 better for large loads like heaters • 480/3 doesn’t need to go thru a secondary transformer • Consider availability of replacement motors or heaters before specifying 480/3

14. Water • Temperature - hot or cold • Pressure • Size - inches NPT • Quality - hardness, chlorine, etc • Protection from contamination • Flow control/shut-offs

15. Water Temperature • Hot Water • Minimum incoming temperatures for warewashing equipment • Booster heaters required to raise temperature to 180 degrees, sometimes for lower temperatures • Some elementary schools only provide 90 -110 degree hot water, always ask! • Temperature for food prep & pot washing 110 degree minimum • Chemical sanitizing needs 75-120 degree water

16. Cold Water • Sometimes cold is not so cold, find out summer water temperatures when sizing ice makers • Shouldn’t have problems with water being too cold

17. Water Pressure • Always check manufactures cutsheet • Warewashing equipment 20-25 psi • Cooking equipment 30-60 • Beverage equipment up to 80-90 psi • Ideal water pressure should be 40 -55 psi • Tell engineers what pressure the equipment needs, they should specify pressure reducing valves at equipment

18. Flow Control/Faucets • Shut-off should be provided at all water connections • Engineer to specify, mechanical contractor to install • Types-gate valves, ¼ turn ball valves, angle stops • Faucets typically furnished loose for installation by mechanical trades

19. Water Line Sizes • Usually 1/2” NPT, etc. • Difference between connection size and rough-in size, discuss with engineer

20. Water Quality • Biggest concern is hardness - check specs • Important for any equipment that heats water • Water filters can help, they take out particulate, not minerals/hardness • Reverse osmosis systems take out minerals/hardness • Water softening exchanges calcium with sodium which can still precipitate

21. Water Quality • Chlorine is a problem for ice makers • Prevents water from freezing • Affects flavor • Charcoal filter will remove chlorine

22. Protection from Contamination • Backflow prevents/anti-siphon devices • Required for “submerged inlets” like disposer water inlets, spray rinses, etc. • Prevent waste water from siphoning back into water supply if water pressure drops • Water wash hoods require “reduce pressure principal backflow device” or RPZ

23. Gas • Natural and propane • Measured in BTU’s • Sizes in inches NPT • 1 cubic foot of natural gas = 1000 BTU’s • 1 cubic foot of propane gas = 2500 BTU’s

24. Gas Pressure • Gas pressure for cooking equipment listed as inches/water column, w.c. • Typical pressures 3.5-7 w.c. • Gas piping in commercial building is 2 psi or higher • 1 psi = 27” w.c. • Engineer needs to specify a “Pounds to Inches” pressure reducing valve • Cooking equipment should have a “Inches to Inches” pressure reducing valve

25. Gas Quick Disconnects • Many details available • Should clearly state who furnishes and installs components

26. Drains/Waste Systems • Direct-hard piped • Indirect-piped to floor sink or floor drain with air-gap • Local codes determine which type of connection • Most states require food prep sinks to have an indirect waste connection

27. Direct Waste Connections • Typically for handsinks or other non-food sink • When food prep sinks are direct connected a “tell-tale” floor drain is required • Require a tail-piece and a “P-trap”, typically furnished by mechanical trades • Drain usually furnished loose by FSEC • Drain can be strainer, removable basket, lever or pop-up waste

28. Grease Traps • Put them far away from the kitchen • Required for “greasy waste” • What fixtures needs to be connected varies by code and inspector • If you can’t get them out of the kitchen try to make them flush with floor

29. Steam • Steam is water vapor • Transfers heat by condensing from vapor to water • There is five times as much heat in steam as boiling water • Steam is the most efficient way to transfer heat/cook • Steam can be hotter than 212 degrees • You can brown meat in a steam kettle with 50 psi steam

30. Steam • Steam requirements are listed as inches NPT, psi and pounds/hour or boiler horsepower • 1 boiler horsepower = 34.5 pounds/hour • Typical steam pressures are 15-45 psi • Some cook/chill projects use 100 psi steam • The higher pressure the faster the cooking

31. Steam Piping • Steam kettle detail

32. Steam Piping • Steam requires 2 connections • Supply • Condensate return • Condensate lines need to return via gravity or a condensate pump • Challenges with condensate return when on grade

33. Refrigeration • Refrigeration removes heat by “changing state” from liquid to a vapor or gas • Refrigerant boils at low temperatures, 25 degrees or -20 degrees • Liquid refrigerant can still give off heat on a 120 degree roof • Refrigeration systems work on changes in pressure • High pressure = hot • Low pressure = cold

34. Refrigeration

35. The “Low Pressure” side • The expansion valve releases high pressure liquid refrigerant into the evaporator coil • There is so little pressure in the coil so the refrigerant boiling point is so low that it absorbs heat from the air and turns into a “super-heated” gas • The refrigerant gas is “sucked” on to the compressor so this is also known as the “suction or gas” side

36. The "High” Side • The compressor “compresses” the gas which increases it temperate to 90-130 degrees • The gas proceeds to the condenser, like a radiator, and it gives off it’s heat to the atmosphere • Then on to the receiver which has a reserve of liquid refrigerant ready to meet demand • Then back to expansion valve • Condensing unit refers to the compressor, the condenser and controls

37. Pressure Controls • Refrigeration systems are activated by changes in pressure • There is no wiring required between the coil and the condensing unit

38. Defrost • Electric heaters controlled by a timer for freezer • Do need to wire from time clock to coil • Air defrost for refrigerators

39. Other Components • Suction line accumulator/filter-prevents liquid from getting into compressor • Liquid line filter/drier-collects moisture and debris before expansion valve • Liquid line site glass-for inspection • Low ambient controls • Headmaster controls-regulates how much heat needs to be given off when cold outside • Crankcase heater

40. Exhaust Hoods • Type I-grease exhaust • Type II-steam and vapor-limited uses • Hood types • Wall canopy • Island, single and double • Backshelf or low proximity

41. Exhaust Volumes • How low is low volume? • Caveat Emptor-see Fishnick.comhttp://www.fishnick.com/publications/appliancereports/hoods/disclaimer.php • The more ends of the hood that are enclosed the lower the volume can be • Island hoods require the most exhaust • Backshelf hoods use the lowest amounts - look at McDonald’s fryer line

42. Make-up Air • What goes out must come in • Make-up air has to come from the room, not the hood • Make-up air replaces the air the rises from the cooking equipment • How the make-up air is supplied affects exhaust performance more than hood design

43. Make-up Air Guidelines • The farther away the better • The lowest velocity possible • Some make-up air systems at the hood do work, but be cautious • Look at the Schlieren testshttp://www.fishnick.com/ventilation/ventilationlab/

44. Questions?