GPG Outbrief 09: Next-Generation Chillers

GPG Outbrief 09: Next-Generation Chillers


Good morning everyone and thanks for being here, and we’ll hope we’ll get one on when we get to that portion of the presentation Before we get started. I want to go over a few logistics Today’s webinar is based on two GPG assessments they’re variable speed magnetic bearing or maglev chiller and the variable speed screw chiller and both the Full reports as well as summary findings and infographics are available and gsa.gov And today’s webinar is based as one of a series the February February Webinar will be on plug load control And it will discuss findings from GP G’s report on advanced power strips as well as well as more recent developments in the field of advanced power strips and smart outlets In March we’ll be featuring the honeycomb solar thermal collector and this solar thermal collector is particularly effective for solar hot water systems without a storage tank April’s webinar will discuss electrochromic windows in december GPG released two reports of test bed assessments of electrochromic windows in general office space and highlighting the effectiveness of these windows in glass curtain wall facades Recordings of the webinars as well as an upcoming schedule is available at gsa.gov flash GPG Today’s webinar as we’ve some of you have experienced We’ve been participants are muted and it will be in you’ll be in listen-only mode But you can submit questions using the chat box on the right side of your screen And you don’t need to wait until the QA QA session that’ll happen at the very end of the presentations in fact we encourage you to submit questions throughout the presentation and Now Mike Lowell who’s the GPG project manager for the variable speed screw chiller assessment will be facilitating today’s webinar And walking through the agenda Mike Thank You Andre next slide Here the agenda for today’s webinar Which one could a brief overview a gbg by the director program Kevin Powell? Kevin’s opening remarks We will transition the technical portion of webinar with that Kevin welcome Next slide yes dick sides, thank you very much Yes there I am crabbing ok next slide Just a couple of notes about what the aims of the emerging technology programs at GSA are and Then how this particular research supports that The they there are two programs that constitute the emerging technologies division at GSA the first is The proving ground and this is a result of we’re actually presenting results a couple of field trials from proving ground projects And then the the intent of these proving ground project is to provide real-world data That validates the performance promising technologies Technologies that do prove out and you’ll hear about two that have proved out Are ones that we then are looking to further? Deploy across our portfolio in order to improve its financial and environmental performance so next slide Next slide yeah there we are So the I think the key thing and what I hope everybody will understand on on this call is that there really? Is a lot of investment in? in in really developing next-generation building technologies The challenge for most of those technologies is that in the real world? operating environment of buildings There’s a fundamentally conservative impulse to replace things With the same things because you know they work The plaint of the proving ground program is to take out some of the risk of what? essentially the next-generation Technology because there’s some concern does it actually deliver in the real world and you know our experience is Sometimes it does sometimes it does with You know certain types of caveats and sometimes. It’s really just simply not ready for primetime So that’s what we try to do. We try to bridge that it shows on the slide the technology valley of death and The the important thing to understand is that this these results have enabled GSA to make investments in our buildings even in the fiscally constrained times That are really delivering real-world savings so next slide Our process is that every year we hold a We publish a request for information that actually has closed in December the current one that is to say as a After we receive all of our submissions. We have independent subject matter experts score them we select series semi-finalists hear from those semi-finalists Select the best of the best pilot those within our portfolio Partner with Department of Energy National Labs who really are world renowned experts in conducting these kinds of field studies? See how they how they shake out And then those that that actually deliver promising results we recommend those for deployment in our ports our portfolio and also to come up with kind of guidance that can help I Should also say that the the results from proving ground evaluations are intended to also facilitate Adoption by private sector folks so that private and we’ve actually found that there’s a there’s a fair amount of confidence that these these outcomes Generate in the private sector for exact Cleveland in the same way that that they do for us next slide And with that I’m going to turn this over to Jeremy Jenks of Pacific Northwest National Lab All righty, thank you Kevin Yeah, I actually operate in that kind of in that valley of death region working on thermally driven heat and power cycles Cooling cycles so a lot of experience and that realm based off that slighted killed earlier cabin next slide please So I’m going to present some results from a study that was conducted By staff here at P&L on a variable speed and magnetic bearing chiller That was installed side by side with a different unit we’ll talk about at a Federal Building and courthouse located in Pine Bluff Arkansas Next slide please So in general just the big picture 10% roughly 10% of the energy in offices it goes to Its base crewing and and of that 10% 32% of the commercial buildings Are actually relying on chillers to provide that space space cooling? next slide please So GSA is unique in that 80% of their their floor space is attributed to large build and Most of those buildings are cooled with water cooled chillers so looking into applications or opportunities to to reduce the power requirement for a given cooling Lotus is certainly an advantage for GSA next slide please This is the cutaway view of a Magnet variable-speed magnetic bearing chiller you can kind of look at all the different internal working parts there But speaking in general the compressor uses two impellers on a single high speed rotating shaft, which is Actually only moving part in the compressor and the two impellers provides two stages of compression which provides high efficiency And a fairly compact line The compressor has a fully integrated variable speed drives and this allows the compressor Highly efficient and Certainly relatively efficient compared to the other children. We’ll talk about in a minute especially at partial lows That’s one of the unique things with with this particular compressor the shaft with impellers is levitated during rotation using digitally controlled magnetic bearings and unique that unique feature reduces the friction heat caused by conventional bearings Adding again to the efficiency, but also eliminates the need for lubricating oil And the ancillary equipment to go into that lubricating oil system, which Reduces the amount of overall maintenance requirements so again, yeah The compressor is digitally controlled with microprocessors that manage the compressor operation and provided self diagnostics and correction So in a nutshell that is the mag? bearing magnetic bearing shield Compressor the EC right there Okay next slide, please So this was this study was conducted during a Fairly long cooling season back in 2012 the study period was Started earlier than anticipated. I believe it was in March and went on through to September so it gave the Researchers a good opportunity to look at a lot of different data This particular building is over a hundred thousand square square foot and it has to each other is located to 150 each other is located in the mechanical room So what occurred is one of the chillers was due to be replaced? It was a rotary screw chiller, and it was replaced with this magnetic bearing chiller that you can see that details on the image on the right called variable speed chiller 1 and so all the both units were Instrumented to determine the overall coefficient of performance and look at that throughout the entire cooling season Next slide please Well this other chiller was a rotary screw killer that was working side by side with the new magnetic bearing chiller It was a it’s a hundred fifty ton rotary screw chiller. It was installed in 1993 and if it really was before there was any variable speed it was installed before there was any variable speed chillers and These smaller chillers. I think more from a cost perspective than anything else needed to be rotary screw At anything below, I think 100 anything below two two or three hundred tons the Centrifugal chillers just really didn’t exist One thing to note is this is a side by side study but the refrigerants that were used were different so the r22 the the rotary screw killer was using r22 refrigerant and the Magnetic bearing chiller was using r134a now to just do a quick Look at those two refrigerants at standard state points for HVAC You’ll find that at least from my back of the envelope Calculation – so In that sense this study is somewhat conservative in the charts that are following Look if you look at the table on the right. These are just comparing the two chillers the original chiller They’re both 150 tonnes The only difference here is a new chiller Obviously has the magnetic bearing and there are two Individual compressors in that particular unit the biggest thing that you can look at the oil tank heater up There is one of those for the original chiller not applicable or the new chiller because it doesn’t require oil And you can see the difference in refrigerant there and at the bottom of course oil is not applicable for the new chiller next slide please This is showing that the overall coefficient performance versus the chiller load for both of these units The gray line is showing the old chiller performance the rotary screw chiller And then the green is showing that the new chiller, and it’s really just a lot of data That’s kind of hard it may be difficult to see a trend but What you can see? Looking at the green data for the new chiller in that. There’s a an optimal operating point when they when they Compressor RPMs are slowed down the compressor speed is slowed down and that occurs between 27 and 33 percent of full load so we’re actually seeing a theme by reducing by using this variable speed and increasing efficiency and Given that most of the time the children gonna be operating a part load. That’s a huge benefit for this type of chiller as for the old chiller you can see it drops off as you reduce the Cooling load and the reason for that is in these old Chillers that didn’t have variable speeds had to restrict the refrigerant flow in some manner And of course there’s essentially an Associated loss of work usable work Associated with that that reduces the overall coefficient And the coefficient performance for those of you that may not be familiar is not an efficiency It’s just a measure of how much power or how much cooling we can Get out of this unit versus how much power we have to put into it In general 42% what we found was 42 percent energy savings Because of this this reduction in this increase in coefficient performance as we reduce the load There’s a 42 percent energy savings from one and one chiller versus the other shoulder Okay next slide, please At the end of the study period there was a roughly a $9,000 energy cost reduction per year assuming the energy or the cost of energy electricity as shown there in the subtitle Firm it was very a lot of studies that P&L had conducted previously for a Navy program textile The payback period is strongly dependent on the installation cost but in general Throughout most of those studies it was found to be less than five years for this particular technology Next slide please Operation maintenance, I spoke to this a little bit earlier, but clearly some of the benefits It’s smaller and lighter then similar capacity compressors It’s quiet because it’s because of the mag magnetic bearings. It’s frictionless So it can be played you know these especially for new spaces they need chillers can be placed next to ox fence spaces and Of course it’s as we saw it’s more efficient cooling at lower You get more efficient coming at lower partial loads as you reduce the speed of these centrifugal chillers Next slide Alright, I’ll hand it off to one if he I don’t know if he’s available or not Yeah, yeah yeah, one Griego is a regional energy engineer for gsa region seven and he’s now going to provide insights the region’s embassy deployment and Operations thanks Ron take it over Thank you, Kevin. Thank you Mike Good morning, everyone. I’m It’s an RFA honor honor for me to be here and talking about our experiences with the deployment and operations of these mag bearing chillers next slide Since the release of the gbg reports on the mag Marion chiller technology GSA is seeing an uptick in the deployment of the mag bear and chillier technology overall GSA has deployed 210 of these nightmare and chillers region 7 At the region we have installed 68 of them with four pending next slides So the 68 mag Marion chillers represents a little more a little more than a third of our region 7 chiller inventory the range of sizes of our mag baron shows range from 60 tons one compressor to 750 ton for compressor units About 90% of these magneri and chillers are water cooled with the remaining being air-cooled Now what makes the Magnar and chilled attractive is their low IPL V values? Which are in kilowatts per ton as you can see the mag Marion chillers? The values for these madmen shows range from point three to 0.35 which are lower In comparison to what you see for rotary screw screw or centrifugal chillers a little explanation on the IPL v IPL v stands for integrated, Partlow value it is the It measures the overall average efficiency of a chilled cooling system So basically in a nutshell the lower IPL B value will look being more efficient your chiller next slide please Next slide Thank you so much. Thank you Lessons learned from being incorporates in these night variant shoulders these mega bear shows need to be operated differently since Since with this technology you maximize your energy efficiency at lower partial loads Which means that a Few things one that the onand contractor needs to be properly trained to operate and maintain these chillers and so we’ve Incorporated that requirement on in our scopes of work when we conduct these children projects The other thing that’s the other thing that we have Learned from going through these shoulder placement projects is that? Because of the energy savings of going with these mag bearing chillers that Depending on the territory in which you’re replacing these chillers that Whether it’s whether. It’s with an encore or center points or energy or whichever area in those cases these chiller replacement projects are incentive eligible so So main They’re driven off of lower IP le values when you’re replaced in Chile with a mag Marin chiller and as we’ve already shown the IPL you guys are lower or Magda Ranchos was compared to Rotary screw or centrifugal chillers and another requirement is that they have to be a h RI certified Give you a quick example we Were in the process of receiving incentive money from entering Were we we had a six hundred thousand dollar project where we had incorporated magma and chillers over at Both the a bear and tail bogs federal facilities down to Orleans It was a six hundred thousand dollar project and one the process of receiving sixty thousand dollars and incentive funding from entering So this helps for two reasons one it receiving infinite money helps in terms of shortening your payback and then secondly we can deposit the sixty thousand into which we normally do when we when we Receive incentives toward the 863 money, which we then use toward future energy projects So it’s sort of a win-win Sort of a win-win for GSA there unfortunately it took us a while to understand that If there are incentive programs out there for chill replacements So, but we are getting up to speed on on that on that Requirement next slide, please and actually the last two slides are going to be case studies This one Involves the Fort Worth federal center billing twenty-three Back in April 2015 we had installed we had replaced two chillers with mag bearing chillers both water-cooled 150 ton two compressor Now these now the training data that you see Represents the elects the month by month little electrical consumption for the entire complex not for the equipment nevertheless as you can see since we install these cnidarian chillers that we saw a 30% almost a 30% drop in our logic in our electrical consumption, and that’s why 16 from FY 15 Which equated to a reduction of almost two million kilowatt hours? we also saw an electrical utility reduction of One hundred and twenty six thousand dollars or about twenty eight percent cost reduction Partially due to the nightmare and children ology This was the best case scenario the next slide will show? the worst case scenario this was the pickle farm very complex in Austin, Texas Where the project was handled at the service center level? They had replaced the 600 ton trained chiller with a 440 ton mag bearing chiller Installed back in December of 2013 With a little or no input from our regional headquarters, and as you can see we actually saw in many cases a natural slight increase in our vegetable consumption and When we when I later took part in a an internal audit for the awesome service center back in 2015 when we talked when we spoke with the owner and contractor We found out that we found out that the O&M contractor was actually operating nine barren shows on full load. Just as that they were operating a centrifugal or screw chiller and so They weren’t provided the training on how they’re properly operates these mag there and chillers And so we had to make arrangements for that train to occur and so those are the two takeaways from from this particular case study for pricklethorns every I Think that is it on my hand I think I’m going to pass it on to Michael for our next presenter Thank you Thank you Vaughn Next we have Dan Hallett dan is an orangy staff member at Oak Ridge National Laboratory his focus is on emerging technologies that serve commercial industrial facilities and Dan’s the primary investigator for the variable speed screw chiller Dan it’s Up to you Okay, well good morning everybody on next slide, please This evaluation occurred at the Cindy 8 building in Washington DC in 2015 and 16 The building had recently been renovated and the chiller plant was about to undergo a major overhaul replacing two Overson terrifical chillers as part of this overhaul GSA chose to install a 275 ton variable speed screw chiller in parallel with a 275 tonne magnetic bearing centripetal chiller the magnetic bearing chiller is of the same type Evaluated in the previous GSA study and is widely accepted by the agency both units will be connected to the same chilled water in condenser water loops the configuration allowed GSA to evaluate their performance and their near-identical operating conditions next slide, please The original report from this evaluation was issued in December 2016 in February 2017 the manufacturer of the magnetic bearing chiller Dyken and the compressor dan Foss Raised concerns about aspects of the report as a research organization Oak Ridge National Lab welcomes fair scrutiny and GSA was through the report and commissioned additional internal and third-party reviews after six months of review three major points emerged number one the report substance and overall conclusions are unchanged number two language within the report was edited to clarify points being misinterpreted Also documentation has been added to better characterize the study as a whole number three at the suggestion of the National Renewable Energy Laboratory The third-party reviewer shown performance data was an alliance with a second method commonly used in energy savings performance Contracts this alternative analysis corroborated the reports initial findings Details of the review process are captured in a 14 page preface. That was added to the reissued report Overall the report grew from 32 to 66 pages with the added documentation next slide, please There are two key design features Which distinguish the variable speed screw chiller first the compressors are of a positive displacement? Design this allows the unit to rapidly respond to the changing cooler requirements found in reelabilities Second coin capacity is controlled by simply changing the motor speed These two features eliminate the requirements for mechanical unloaders found on centrifugal compressors and older rotary screw machines Without those unloaders their inherent inefficiencies have been removed from the refrigeration cycle Thereby increasing the chillers performance in the dynamic hold of actual buildings next slide, please Here are pictures of the tea machine in the mechanical ring of the X building They were connected in parallel to the same chilled and condenser water loops During the test the maintenance staff operated the units on a day on day off schedule for the most part The team kept track of the condenser water temperatures and percent full load such that as much as possible under field conditions The unit spent the same amount of time under the same conditions next slide, please Instantaneous data was collected in 5-minute intervals key performance parameters for the energy consumption rate measured in kilowatts per tonne and The percent full load at which the chiller was operating the team chose to measure performance Instantaneously as opposed to averaging over a five minute interval so we can truly capture how performance varied under dynamic field conditions Using average 5-minute values would have resulted in neither curves rather than the broader scatterplots this performance very enslaved and lost With each chillers data set a second-order polynomial was cur fit to the data These curves are shown on the graph I would like to clarify a point of possible confusion between this graph and the graph showed in the previous evaluation of the magnetic bearing chiller in the previous study the chillers performance curve rose asn’t went into a part load condition Whereas in this study the curve lowers as low decreases? This is because the previous graph measured the coefficient of performance in which a high curve indicates better performance Graph in this study measures the energy consumption rate in kilowatts per tonne in which better performance is shown by a lower curve it’s the same outcome showing shown using two different metrics a Weighted average was applied to the curves in order to compare each units performance At the X building the variable speed screw chillers energy consumption rate was 11% lower than the magnetic bearing chiller It must be noted that performance at other sites under other conditions can vary Therefore the reports final recommendation is that both chi’lan types can show comparable energy usage and should be considered by facility owners next slide please As mentioned earlier the National Renewable Energy Laboratory Recommended that the data be parsed in a second method in which the energy consumed by each chiller in a given hour Was compared to the average outside air temperature during that hour This method is used in energy savings performance Contracts when a contractor wants to compare the performance of two chillers before and after a retrofit These graphs capture that data and further separate them based upon the condenser entering water temperature they show that across the units operating spectrum the variable speed screw chiller consume less electricity and magnetic variant children The exception is at the right of these graphs when the outside air temperature a condenser entering water temperature were both warmer at this point the magnetic varying chiller started consuming less energy than the variable speed screw unit Overall the average Airy energy consumption indicated by this analysis method corroborated on the previous slide next slide please One performance claim from the variable speed screw vendor is that their design could easily handle swings and convention water Temperature that were outside the design parameters at the 8th building Design temperatures were 65 to 85 degrees Fahrenheit for both chillers In March of 2016 there was a stretch of sunny warm days when air conditioning was required That the cooling tower Basin was at 55 degrees Fahrenheit The variable speed screw chiller handle bestowed up without any issues When the magnetic bearing chiller bender was contacted it recommended not starting a unit until the condenser water loop had reached 65 degrees Fahrenheit This cold water condition could occur at other sites during shoulder months Or during a time when a tower base when a towers Basin heater failed? During a hot spell in the summer of 2016 we had the opportunity to test the opposite condition The operating staff allowed the condenser operating the condenser entering water temperature to rise to 95 degrees Fahrenheit This test replicated the condition that might be found at the cooling tower fan were to fail Or if a multi-cell cooling tower were to completely lose one or more cells due to maintenance or other conditions The magnetic bearing chiller tripped off at its preset high limits the variable speed screw unit operating continuously up to 95 degrees Fahrenheit without any issues as part of discussions with the magnetic bearing chiller vendors They stated that their units could be built to handle any condenser water range found at a site The operating parameters would simply have to be stated up front in the specification next slide please Historically screw chillers have a reputation for being too loud My old boss from the early 90s refused to specify screw units for that very reason Below is the manufacturer provided data That shows the sound levels across each each units range of operation As you can see they are very similar and is and you’ve already heard testimony about the quietness of the magnetic bearing chiller So the 8th building mechanical room did not allow for artistic Think I can tell you anecdotally that it was very easy to carry on the conversation in the ring even near the chillers the no indias part of the room was near the pump batteries next slide please This light shows some direct comparisons from the manufacturer’s literature The variable speed screw chiller has one 200 Sony pots and compressor The magnetic Marine chiller is built on a 400 centering and asked to 210 compressors Even though the specified cooling capacity for both units was 275 tons during the evaluation The Oakridge and GSA team had extensive email conversations with the equipment rep near, Washington, DC Who is supplying two magnetic bearing chiller? the 400 timeframe was questioned but their rep repeatedly stated that the configuration was selected as it was quote the most efficient to meet the 275 ton requirements the complete email chain is included in the final reports The two chillers have similar external dimensions, but a variable speed screw unit is heavier The variable speed screw vendor gives us a budget price of a hundred nineteen thousand dollars for their children While the NBC unit was purchased for one hundred and eighty five thousand dollars through normal GSA procurement channels both prizes included similar packages and startup support The budget price for the variable speed screw unit seemed unusually low so a third party was used to go shop the vendor The price was confirmed through this process next slide please This test wasn’t previously which focused on the magnetic bearing chiller Indicate that both technologies offer performance that is substantially better than a standard water cold chiller as defined by the federal energy management program a Facility’s HVAC needs will best be served at facility management and the design team consider both chillers when looking at purchasing new water-cooled units The needs of the specific site must be weighed against rates of individual chillers next slide please Next we had feedback from the facility operation team at the H building We receiving a feedback from Kenny Thompson. He’s the gsa property manager, and she could tell by the hat in the photo a rabid Dallas Cowboys fan We’re serving with him are Then Stewart and Randy Burgess or te LR our joint venture the Yates building podium contractor Anyhow let you and the team take it over Everybody just give a couple of things That Ken and Kari you chose, and I think they both work great, but I’m gonna turn it over to the two experts This is Glen Stewart and Randy Burgess The via the VFS runs mourne Mourne season and it does accept lower temperatures when we Randy the carrier the carrier which started about 50 degrees but the Dyken would not start under 65 degrees and after hearing from dike and they’re saying that they can build that differently for different areas and That being said has you see in the picture the cooling tower Basin is About 25 to 30 feet in the ground with no heaters, so we have no way of heating up our condenser water during start-up on cool mornings so different setups may lend better For the Dyken than our setup. I guess is what I would say to that I Would say that the carrier chiller? Is a little noisier at low loads attends a surge a little bit but both chillers are very good within noise levels so I would I would say that that both chillers have their positives, and you know they have their challenges to Do we have another slide here or Yes, we’re here now Here’s where it shows how how do you go down into the sump of the UH of the cooling tower so a little different? I don’t know if anybody else would see that out there except for for what we have here And Yeah, the screens the screens that you see are actually the intake for the air And then where you saw on the top of the brick towers That’s where the outlet is and the hole is have you access to go down to clean it or? Check the pumps or something of that nature, so But in the end in the end we give we give both We get we get we get both chillers a thumbs up in our actual daily work with both of them and Just that just add on one that we have Garrett carrier actually takes care of our carrier chiller and I can take care of our Dyke and chiller and Both of them have given us excellent service, and we plan on using both of them in the future Do you have anything? Great Thanks guys and next we’ll have Dan. How it will talk about best practices Dan Well welcome back we’re going to go through a few thoughts, that should be considered when looking at a new chiller In both evaluations of the magnetic bearing in the variable speed screw chiller focus was entirely on the chiller That piece of equipment is but one of several that make up the chilled water system There are pumps cooling towers a piping system and controls that oversee everything Perhaps circumstances of such that a heat exchanger can be added to allow free cooling also in September 2016 the GSA proving ground published an evaluation of a chiller control Optimization system that might be right for your site It is important that a qualified mechanical engineer to a thorough technical and economic analysis to determine the right combination of equipment to control us to serve your facility and And as assistance being installed perform proper commissioning to make sure all equipment is working correctly in concert with each other at Your peak was the h project having autumn listed deserves mention Hey the original chillers at the site were to 350 tons and terrifical units Reflexively the design team was steering towards in sewing units of similar capacity only after performing a heat gain loss calculation Did they learned that the building use had changed such that? 275 10 years would be much more appropriate next slide please Okay, oh yeah, that is the correct food as mentioned earlier the magnetic bearing chiller was more sensitive to condenser water supply temperatures you know I’m gonna see the slide here I Do the work profile yeah Yeah I think the mistake is to make The key point to make here is that as you’re working with you as you’re looking at your building Pay attention to the profile that that building operates that As you can see and instead of blow comes straight from me if I should provided data as you can see as The load profile changes the kilowatts per ton for each type of unit will shift Whereas at a hundred percent load the variable speed screw unit has a slightly higher kilowatt per ton rating? We’re down at fifty percent load. It starts to go a little bit lower. If you have a building that operates Consistently at a very high load rate such as perhaps a data center that Can skew your results one way or another or if you have a building that operates a lot across a wide spectrum With the large amount of time at low load or mid loads that could skew your decision in another direction It’s important to pay attention to your load profile when selecting a chiller next slide, please As Mentioned earlier the magnetic bearing chiller was more sensitive to condense your water supply temperatures that were outside its design operating range If you have a site that is likely to experience wide swings in Condenser water temperature or one where a chiller trip would be costly such as a data center Be sure to clearly specify the full range of temperatures that the chiller might experience at your site The evaluation at the eighth’s building did not measure any Marshall cost might be associated with The magnetic very children with a wide range of condenser temperatures, but these must be evaluated specified and balanced with the site’s actual requirements next slide, please In areas which have unusually high electric demand charges it might be viable to install a thermal storage system or some other met of shifting the peak tune into off-hours and Finally all children’s need maintenance Different manufacturers have different maintenance presences in various parts of the country the same can be said for the variance of item contractors who operate facilities their comfort level with different chiller brands and technologies can vary Make sure that you’ll have access to the maintenance resources when selecting your brand of chiller Mike that wraps up my portion back to you Thanks, Sam and now we’ll enter into our, QA Thank you Switch screen here And let’s see first off Zach asked if I could June continuing education credits would be offered for this training and the answer is yes You need to complete a survey to receive the credit, and you can reach out to Michael Hopson of GSA Let’s see Scott Chalmers ask the question I think JJ. This will be for you aren’t there also accelerometers and capacitors for the NBC chiller as well JJ is that the case guys I’m not sure on that one I Had to look into the Google drawings and see where those would be located. I wouldn’t be surprised Okay, and then JJ. Would you have any ideas to the required maintenance for the MBC Yeah, I think there’s another question coming up on that that I think one might answer but in general I’m not sure exactly what the manufacturer requires But as we talked about earlier the variable speed oil free centripetal chiller with magnetic bearings results may result in lower maintenance Costs as a result of elimination of the compressors oil system Take a look at actual requirements, okay? Squit has to turn down on the maglev quote unquote he says I have heard 10% I See JJ doesn’t know if someone else knows. Please let us know and and shat the answer and we’ll try to pick that up I Think the answer the cost answer was covered So I’m going to ask a question about the cost between the two and that was answered in Dan’s presentation And then Dave asked how did the payback for the NBC and DSS compare to pay back compared to a modern centripetal? Dan or JJ. I don’t know if you have any thoughts on that Yeah, Mike this is dan We’re looking at the payback for these chillers There are so many factors that go into calculating the payback your utility rates your operating profile How many hours per year do you do you operate? that is so heavily dependent on the individual site data set to try to give a you know chiller a has a You know 3-year simple payback compared to chiller be anything that I? would say to that effect Would not be valid at any given site so it’s you know to get back to one of the points that was made near the end of the Presentation each site has to really be scrutinized based on its own individual characteristics Okay, thanks And Keith has just the noise of the NBC and the higher or lower octave band and as Dan’s presentation showed Both shelters the NBC the DSS operated that 70 to 80 decibel range He’s also asked, what kind of compressor warranty does manufacturer provide and JJ didn’t have any idea. I don’t know one if you have an answer to that by chance given your elaboration of NBC’s in your region And yes, I’m I Don’t have I don’t have that information offhand, but I I can research that and provide that Okay, thanks Hey Mike this is Dan Yes, I had a comment on the issue of manufacturer’s warranty I’m prior to joining the lab I spent about two years And they specifying design engineer and my experience if a buyer wants a certain warranty you know a certain period Manufacturers are open to negotiating those again Site by site based on what the buyer wants. What would be in their best interest talk to each manufacturer and Figure out what would best serve the individual sites needs Okay, thanks Bob asks do they have chillers that are external style air-cooled Choice yeah, so you answered the chat, but why don’t you wouldn’t take that for the rest of us? Yeah, I just looked I was just looking online and yes they do have direct air-cooled chillers for I guess Is he’s speaking about MV NBC’s very If it’s for NBC the answer is yes they do yes as a matter of fact, I think as Juan mentioned region 7 has several air-cooled NBC chillers Tim asks how many manufacturers offer the NBC’s and do all major manufacturers offer them and JJ. I’ll let you in just a second but wonder again. They’ve got over 60 of these chillers in their region He said even know offhand. How many manufacturers offered the NBC’s, but they’ve installed NBC chillers from Smart York multi stack Arctic cool and Dyken in region 7 JJ. I don’t know if you’re aware of any other additional manufacturers Oh Mike I Just could say just doing a first-rate look on online that there’s a lot of chillers out there that offer NBC I don’t know the exact number Okay, thanks and my like I want I wanted to follow up that you asked as far as the warranties on the Compressors for mag bearing chillers, uh-huh and looks like and it looks like to put five-year warranty So what we what we asked normally would be a one-year warranty on workmanship in the chairs plus and extended four year warranty on compressor parts and labor Okay, thanks And then I think if next question might be four years well one you might not know But David asks regarding the incentive Do you know of an expiration date for the incentive and then you may want to qualify? I think utilities that you were talking about of course are somewhat. You need to reason 7 so There is an expiration date as to when when we complete product that we have to we have to submit the paperwork to the broker and Then typically when we perform these projects after they accept our applications They have to verify the energy savings Basically, there’s a pre inspection. There’s a post inspection, and they usually do provide a deadline on when We have to complete the project Oftentimes, it’s usually toward the end of the calendar year unit or the end of November Some there are some brokers where let’s say we aren’t able to complete the project. They’ll carry it over to the next year for the incentive Now there’s also that is also deadline on when we submit applications we unfortunately Mean we were trying to submit. Yes, we were we were Trying to submit an application for an exterior light without is different from magyar and chillers, but they had a deadline on Many application we we got into late the money had already been exhausted and so The product that our project was not considered and and we couldn’t and we couldn’t hold up the project for next year because the product is ongoing and and So we had to move forward Hope that answers your question Desk Thanks, and then I think best questions for you as well one Man asked for the whole building energy is consumption. I believe this is the to? Your presentation the whole building energy use with those graphs whether normalized Mmm. That’s a good question I Don’t know offhand if they are I can I can look through that and get back to you on it Okay Thanks, and then both Doug and Gary asked if at the Thornberry if there was improvement after training I noticed in the chat that you said, but you don’t have post training Performance data, so we don’t know yet No, but we can compile the data and provide and get that out to To the guys so yes, we don’t have it a we can compile it And then Brian cinclant asks that the chillers meet the p100 requirements and they do Who When scott shines in on the maintenance of the mbc chillers that they require quarterly mains to check accelerometers and capacitors, so thanks Scott And then he also says that the cost overall for that maintenance. There’s not that much difference compared to an annual on the centrifugal chillers Let’s see Can SRAM just kind of think of the primary presentation no get the cooling towers in the EH building of low grade and that does its impact of course the condenser water temperatures, which is why they kind of skewed towards the VSS at that site, but of course it’s all side dependent And then we have an attribution to the quietness of both chillers people still eats mechanical room a question for Dan and AJ is There any reliability data available on the VSS and NBC chillers given that they’re both relatively new We have a reliability data from the studies over a year. What is Ernie can be on that? assure aware of This is Dan. I am not aware of that, but I can look and see what’s available And I think Juan can speak to at least the dependability nbc’s one You’ve had those chillers installed for what the last three to four years. Maybe in your region Yes, correct. Yes, and operating pretty trouble-free To our knowledge I From talking with our operations we we haven’t we haven’t encountered supposedly the lower convinced or water temperature issues Although Like I’ve been hearing it here at the regional level And maybe something I need to make sure I follow up down the field level with with the Equipment specialist, and you know hunters that that actually operate the equipment on a day to day basis To verify that and make sure that this case But we have any come across like any Major Magnus issues that I’ve been brought up on with with the technology Eight one. This is Chris fumble doin McAllen I can verify that we’ve got those smart D chillers in our area And we haven’t had any problems with them And I think we got them install in 2016 so As far as those go. We’ve been good the ones that you know about in, Brownsville Super thanks great, thanks Let’s see Julian asked what is he expected equipment life for the VSS and NBC? Dan or JJ. I don’t know if you can share any thoughts on that I would imagine they’re similar uh This is Dan I have no reason to believe anything other than similar equipment lies Okay, thanks The man asked that the prices quoted where GSA priceless quotes oblique so those were market prices, right Oh At the ates building the NBC chiller was purchased through normal channels and the VSS seller because of the nature of the green crude around We were working with budget prices But they were shop third party as if it was being sold on a government contract in the price And it was listed in the report was confirmed And then Joshua The issue resolved to run multiple childers a partial load rather than loading up a single Schiller and the case of the MBC That’s right. You staged your chillers so that the chillers operate kind of in their sweet spot Julian asks Do you have sound data comparison to compare sound in the octave bands, and I will say that um We don’t have that as a part of our study, then there might be someone out there in the marketplace but not that I’m aware of Does anyone know that cost associated the service in the NBC verse was the conventional chillers I’m going to take that as NBC versus conventional centrifugal chillers does anyone JJ any thoughts on that Yeah that we in the report we as I noted earlier we didn’t have any data on that the only only only Something that it would be lower because of the lack of oil requirements for that particular chiller Right Let’s see God’s got a question JJ and Dan I’ll ask if you know what is the max cottage? Manufactured for the VSS and NBC and how easier they to get into the mechanical room are they modular? Jerry or Dan any thoughts on that I Looked up I was looking up the compressor manufacturer, and they’re making Up into the several hundred ton Compressor compressors now that you want to on those chillers, so Assuming they can operate them, you know install two two compressors, and it’s it’s approaching a thousand tons now But I know Juan do you have any one line can you off the top of your head state with the largest NBC is in their region The large the largest in our region for manga and chillers at 750 I know that when I went to an OG conference in Atlanta Smart was care was gonna. Carry my great rose. I think up to 1,200 tons What’s in them as far as if they’re the larger ones and market I’m not sure offhand, but that’s the largest one. I’m aware of Okay, thanks Dan any thoughts on the VSS. You know Yeah, the variable speed screw unit when I saw this question I just looked at their website real quick their largest unit is it five hundred and fifty tons and as far as much clarity goes But to get the units into the AC chemical room was a pretty era pretty impressive job with you They worship modular they were able to get them in place and As far as I know reassembly with well perhaps acquainted Randy could address that in more detail since they were there every day Great thanks Chad ask was a plate exchanger considered as a means to utilize low condense for water temperatures I think that might be more of a lawn or a Kenny your team question So the question was did we did we consider looking at like flat plate heat exchangers? It doesn’t specify that I would think If you don’t know that’s fine, but I actually we’d come across some some cases where we had where we had some I Think I think here in this building here in the land and building We have a flat plate heat exchanger, but we hadn’t been using and in the unit because of the because of the magma and chillers They’ve been talking with Dana I Don’t in many cases things like when we when we’ve installed these night there and chillers. We’ve In places where we where we have flat plate knee exchangers. We basically deactivated and Because apparently the night manager is a more energy efficient although I know the flat plate exchanger is beneficial in that it does provide free cooling And But apparently from from talking internally with robbers group. They’re more comfortable going with the magnet chillers In places where we have slightly heat exchangers Okay, thanks, mmm. Let’s see Okay, ask is there any independent oil and refrigerant analysis analyst analysis done after the same time any frames or at the end of test period And I’m going to prefer the our study, and maybe if you can just again talk about how we You know does our best to operate side by side stay on and day off I? Yeah the answer the questions no we did not Do any oil or refriger analysis at the end of the test period Okay, thanks. I misread that um He Um craig Campbell states that some NBC chillers can accept condenser water temps down to 36 degrees So again, I think that’s a design issue That the Danfoss Titan rats told us you know if you specify convinced for water chimps don’t design to it That’s who money ask if you can get copy the slides Andreea I assume that’s the case I’m just going down the questions Dan asks, this is kind of out of a little bit Let’s give it a shot now Dan asked a new address free cooling selection there seems to be some interest in that um I don’t know if JJ had any other thoughts on pre-cooling when having these two chillers installed Any thoughts on that given that they operate well with a low low level Yeah, this is band free cooling is very much a site-by-site Item that has to be decided utility rate structures dew points in the climate zones There are myriad variables that go into that and the discussion would be too complex for this case for this discussion here Let’s thanks And then someone asked about the lower tonnage range for the VF s. Do you recall what you found? Was a lower limit I? Don’t recall off the top of my head, okay Thanks Jose Alvarez mentions that NBC chillers can unload to less than 5% based on the manufacturer design Let’s see then gary states you believes the train offers NBC as well Zack asks JJ this question for you the table of comparison between the or know, maybe this is sorry dan for you the table of comparison between DSS and NBC the coefficient of performance shows that an official Benefits of NBC at 1% 25% loads is that for cooler weather states? How does that factor in for southern states? This is dan when When you’re looking at that load profile 100% down to 25% that is Based on a percentage of peak load and peak load is not so much a trait of the climate zone that it’s located in Peak load in the amount of time that it spends in a part load is more of a factor of What is your building? How is it operating is it a conventional office building? That goes from empty on weekends to full in the summertime, so it’s really it certainly climate is a part of What drives a decision we are looking at a low profile, but also how the building operates? Very great, thank you Joe says the comparisons with between VSS and NBC’s chillers so are there chillers that are both the SS and NBC and the answer is No We had a VSS chiller and a separate NBC chiller tunafish loose in the Yates building Let’s see Chief sim Makes the statement. Oh he’s what we’ll give him the presentation data was table ISM decibels not an octave and We use decibel range we didn’t use octave band, so So we didn’t test frequency levels I believe that’s the case right then That is correct I said okay Let’s say someone Asked the question what happens if at NBC if the power to the bearing failed either by a power outage or electronic failure and Jose answers if there’s a power failure the NBC will close down to a safe stop Let’s see And Greg from region 4 says that they’ve been installing NBC’s for 8 years So, that’s you know long time duration for dependability they seem to be happy with him See Bob Braun asks are these chillers consequentially zorkin they adjust a variable flow chilled water and convinced for water temperature flows I Don’t recall off the top of my head, okay, thanks Josh I asked a variable speeds and triples been considered for comparison and the answer is no not for these specific studies Let’s J dimension somatically chillers can be bought with knock-down kits so they can be shipped from similar smaller components So that confirms what Dan was saying I? Think Andre oh, that’s it for all the questions Feel free to Reach out to us, and we’ll see if we can get those answered and Mike said this attending Is available for continuing education credit? after the completion Shortly, you’ll be receiving a very short five question survey and by completing that survey you’ll Receive continuing education credit if you don’t receive the survey for any reason, please reach out to Michael Hopson his email is Michael Hopson at gsa.gov and He can get you set up with those continuing education credits. I’m good that should have been on the screen here I’m going to show it here from a previous webinar, so you have that information of? how to get to continuing education credits And thanks very much for all of you for participating and for all the speakers and again We hope to see you at next Thank you Thank you

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