Keeping Clients Happy AND The Lawyers at Bay

Transcription

1 The linked image cannot be displayed. The file may have been moved, renamed, or deleted. Verify that the link points to the correct file and location. Keeping Clients Happy AND The Lawyers at Bay Kirk Mescher, PE, LEED AP CM Engineering Inc. Clients and Lawyers 1

2 Today s discussion Examine what has gone right with projects Examine what has gone wrong Understand where and when the lawyers will get called and expert witnesses get hired Full Disclosure I am married to an attorney, negotiation and cross examination are part of everyday life. Clients and Lawyers 2

3 Secrets to keeping clients Happy Support local golf charities Support local high school, community college and University activities Support local fire and police official charities Support the United way Provide logo shirts and hats Provide tickets to local events Clients and Lawyers 3

4 What really makes clients happy Over performance and under promising System installations which exceed client expectations Excellent energy performance Excellent occupant comfort Low maintenance Clients and Lawyers 4

5 Building Owner Expectations Simplicity Low maintenance Greater comfort Efficiency Environmentally Green Clients and Lawyers 5

6 School Energy Usage Heat and Cool Heat GEO Average 77 kbtu/sq. ft./yr Clients and Lawyers Construction Date 6

7 Building Energy Usage Sampling of 150 schools in Illinois v Average age of the schools sampledv 37.5 years v Average energy usage v 77 kbtu/sq. ft./yr v Average age of 20 Worst v 27.4 years v 20 Worst schools Energy Usage v 130 kbtu/sq. ft./yr v 68% higher than the average v Average age of 20 Best v 47.4 years v 20 Best energy performers v 47 kbtu/sq. ft./yr v 38.9% below the average Clients and Lawyers 7

8 Project Charge Provide heating and cooling without increasing Utility bills Scope and Cost of the retrofits Schedules Maintenance Energy usage and history Comfort Thermostats and occupants Benefits to district Unit 5 Energy Experience Clients and Lawyers 8

9 McLean Schools Energy performance Clients and Lawyers 9

10 Energy Star Results Clients and Lawyers 10

11 Clients and Lawyers 11

12 Recipe for Achieving High Performance Kavanaugh 12 steps 1. Calculate peak and OFF peak loads 2. Estimate energy to and from the well field 3. Select operating temperatures 4. Correct heat pump operation for actual conditions 5. Select HP s for peak load (heating or cooling) & minimize duct runs. 6. Arrange HP s into building circuits Clients and Lawyers 12

13 Kavanaugh 12 steps Part 2 7. Conduct investigation for Thermal Properties and drilling conditions 8. Determine GLHX arrangement 9. Calculate GLHX requirements 10. Iterate to determine optimum operating conditions 11. Layout Interior piping for minimum head loss 12. Select pumps and control methodology Clients and Lawyers 13

14 The Players n n n n n n n n n n n n n n Site Owner Architect Engineer Thermal Properties Test Firm General Contractor Equipment/Materials Suppliers Loop Contractor Driller Mechanical Contractor Controls Contractor Energy Service Contractor (ESCO) Turn-key GHP contractor Experts, seminar speakers and other suspicious characters Clients and Lawyers Kevin Rafferty, PE

15 When Do Lawyers Get Involved System performance is not as expected Communication Breakdown Over promising, under delivering Ground Loop Failures Heat pump operation Issues System issues Clients and Lawyers 15

16 Bore field Performance Indications Water temps getting warmer or cooler than expected. Why? Clients and Lawyers 16

17 Ground Loop Failures Water temperatures getting hot Short loops Improper Grouting Poor loop installation Poor grout specification Hole size coordination with u-loop size Many system reviews start with this list, what are the real problems Clients and Lawyers 17

18 Where a Bore field Design Starts to Fail Borefield Design (or lack thereof) Rules of Thumb 150 ft per ton works in our area Regardless of heat pump efficiency? For residential systems grout with bentonite chips Residential systems offer loads most closely connected with outside temperature The load is 400 Sq ft/ton Ductwork construction and location Attic mounted duct must be leak free and well insulated Clients and Lawyers 18

19 System without energy recovery System with different heat pump System with energy recovery School Located in Kansas City Clients and Lawyers 19

20 System without energy recovery System with energy recovery Calgary Raleigh, NC Clients and Lawyers 20

21 Ground loop loading Understanding the selected system and the building load is imperative Ft/ton does not work in any application Clients and Lawyers 21

22 Real problems System issues Improper application of ground source to the system Low performance HVAC system System EER very low System COP very low VAV system application Electric reheat does not allow energy extraction from the ground System temperature requirements beyond Heat Pump capabilities Supply water temperatures beyond 120F Clients and Lawyers 22

23 Managing System EER/COP Pumping Power Benchmarks Pumping Pwr /Clg Pumping Pwr / Clg Cap. Pump Allowable Pump Head Cap. Watts Hp/100 (ft) w/60% Input/ton tons Grade Eff Pump Min Max 50 or Less 5 or less A- Excellent B- Good C- Mediocre D- Poor >150 >15 F- BAD 143 Pump Heads are calculated at 2.5 GPM/ton for 3 gpm / ton reduce values by 17%. Clients and Lawyers 23 23

24 Common Mistakes Ground source touted as the most efficient system there is..almost always Minimizing the first cost premium..by under sizing the bore field. Applying ground source as a cooling tower and boiler. Trusting packaged design programs All engineers can do it We will design the inside and have the ground loop provided Design Build Clients and Lawyers 24

25 Pumping Smumping Pumping is important because It is a large factor for system efficiency Pump energy goes into the bore field as HEAT It is a constant cooling load on the ground loop. Clients and Lawyers 25

26 Ground Source Issues Excessive pumping power Poor hydraulic design of loop piping Poor grout design Lack of understanding of pressures surrounding U-loop design Improper specification No thermal conductivity testing No drilling log to describe drilling conditions Clients and Lawyers 26

27 Building Issues Ventilation Control Excessive ventilation all the time Lack of pressurization Large night setbacks for energy efficiency GSHP systems are typically right sized and setback can adversely affect bore field performance Building envelope issues Wall to roof connections Metal studs Ventilated attics with insulation on roof Clients and Lawyers 27

28 Case 1 Here are the initial facts Client Wants to Green their facility Chiller plant is under 3 years old Boiler plant is also relatively new System was designed as chilled and hot water system Chilled water design temps 45 Hot water design temps 180 Clients and Lawyers 28

29 Results Engineer selected with limited Geo experience Water to water heat pump central plant design Millions of $$$$ spent for construction Loops get hot Clients get cold Lawyers get hired Experts arrive on site Clients and Lawyers 29

30 Case 2 Client builds new multi-story office building Wants to take advantage of Green tax deductions Engineer with Limited Geo Experience Design Build Geo contractor Adds Geo to standard VAV Electric reheat system Borefield in urban setting 700 ft bores Piping materials from Foreign sources. Clients and Lawyers 30

31 Experiences On start-up 8 bores experience leak failures Replaced with 8 new bores Sand indicated in water loop Add large isolation heat exchanger to isolate bore field from building System make-up water damand goes beyond capabilities of water make-up capabilities Supplementary testing indicates that nearly 50% of bores are leaking This is the good news Clients and Lawyers 31

32 Sidebar Interesting technical issue Why did the 700 ft bores fail 40 MM DR 11 pipe Dry hole 4 Bore Thermally enhanced Grout Burst pressure exceeded? Ø 350 PSI at bottom of bore before grouting Ø -350 PSI after grouting Ø Grout sand within system Clients and Lawyers 32

33 The real problem System analysis indicated that the bore field was destined to fail, thermally. No heat extracted from the bore to provide well field recovery System EER was below 8, resulting in excess heat rejection to the bore field. Controls provided for Morning pull down which, resulted in high water temperatures Insurance company contacted Lawyers hired Experts hired Clients and Lawyers 33

34 Conclusions Design of Geo systems requires and understanding of the mechanical system, the geology and the operation of the facility Using rules of thumb can and often do result in poor client satisfaction Manage expectations by under promising and over delivering. Clients and Lawyers 34

35 ? Questions?????????? Clients and Lawyers 35