http://hvac-talk.com/vbb/ FOR EQUIPMENT OWNERS ONLY Questions and discussions regarding Commercial Buildings en Fri, 24 May 2013 10:21:15 GMT vBulletin 60 http://hvac-talk.com/vbb/images/misc/rss.png http://hvac-talk.com/vbb/ http://hvac-talk.com/vbb/showthread.php?1317291-Options-Needed-to-Replace-Ancient-Apartment-Boilers&goto=newpost Fri, 24 May 2013 04:45:48 GMT I have two 8 unit buildings in Michigan. They are each heated by a large central boiler circa 1950. None of the units have A/C or individual... I have two 8 unit buildings in Michigan. They are each heated by a large central boiler circa 1950. None of the units have A/C or individual thermostats. This results in HUGE operational costs and very low occupant satisfaction, as they can't control the temperature at all. The apartments range from 650 sf to 800 sf, and are on crawl spaces with a relatively shallow pitch roof above. The apartments are in the downtown of a fairly affluent area. I need to do something about the heating/cooling situation in order to bring the rents in line with the market.

I've spent a lot of time reading about the pros and cons of different heating systems. I'd like to investigate putting a series of high velocity heat and AC units in the attic space (1 per apartment). I'm considering this because the ductwork for a LV system is not feasible given the structure I'm dealing with (I think). Both buildings are single story, and the gas and electricity are already individually metered and available at each apartment.

Okay, so now you have some background, here are the questions: Are HV systems generally suitable for an attic space for both heating and cooling in my area? All of the houses I've ever owned/seen have the HVAC in the unit or in the basement. Has anyone ever heard of such a retrofit on an apartment building? Are the issues with drainage etc. that I've read about with HV systems avoidable via a knowledgeable installer or am I looking for a problem? What type of venting would be required for such an attic installation (assuming natural gas for heat)?

Thanks for any feedback you can provide. ]]> AOP Commercial HVAC Mechblue http://hvac-talk.com/vbb/showthread.php?1317291-Options-Needed-to-Replace-Ancient-Apartment-Boilers http://hvac-talk.com/vbb/showthread.php?1316621-Beverage-Air-DD94-keg-cooler-cycling-and-not-getting-down-to-temp&goto=newpost Thu, 23 May 2013 14:32:20 GMT Ok I picked this unit up a while ago and have done some research on the issue. It seems to cycle a lot, comes on for about a minute, then turned off... Ok I picked this unit up a while ago and have done some research on the issue. It seems to cycle a lot, comes on for about a minute, then turned off for about a minute and a half then repeated. From researching it a little it said it could have been under charged.

My neighbor does commercial HVAC but not refrigeration but said he would look at it. He determined that the coil or compressor was getting too hot and that's why it kept turning off (a safety precaution) and it probably had a low charge, so he cut one of the copper tubes, evaporated the unit (he said there was probably more refrigerant in his hoses and gauge than in the unit) and brazed on a shrader valve, he then pressure tested it with Nitrogen and said it held pressure for almost an hour so didnt think there was a leak.

The unit called for 7.5oz of 134A so he told me to get the smallest can that I could so I went to the auto parts store and picked up a 14 oz can. Thats where we got into some issues, his hoses wouldnt pierce the can, and the valve that I got at the store that would pierce the can had 1/2" ACME threads that didnt match his Yellow Jacket hoses. He tried Brazing a valve to it but the valve apparently wasnt brass (he said it was a painted white metal and almost melted completely) so in a act of almost desperation we just used some of the quick steel epoxy putty to seal the a valve he could attach to on to the valve that came with the can. We put in the 134A and it "drank" a lot of it.

It seems like it ran so much better that night. The compressor stayed on for quite a while and it dropped temp down to about 44 degrees (the unit had been unplugged for about 4 days while we were gathering materials and so on) Two days later it seems like it is cycling a lot again and it doenst get any colder than 42-44 degrees, even at the coldest setting (or at 5, its the same temp)

I used a laser temp probe and the coil on the front isnt getting much hotter than 95ish and the compressor itself is getting up to 110.

Any thoughts?? trouble is a lot of people I called didnt want to work on it because it was in a residential location (I use it for my home brew beer) and the res guys didnt want to touch it because it is a commercial unit. ]]> AOP Commercial HVAC radiantdesigner http://hvac-talk.com/vbb/showthread.php?1316621-Beverage-Air-DD94-keg-cooler-cycling-and-not-getting-down-to-temp http://hvac-talk.com/vbb/showthread.php?1316451-Refrigerant-piping-fittings&goto=newpost Thu, 23 May 2013 04:37:38 GMT Refrigerant piping in many application is connected by brazing and soldering ... i need to use coupling instead of it, is it applicable for HVAC... Refrigerant piping in many application is connected by brazing and soldering ... i need to use coupling instead of it, is it applicable for HVAC applications or not ?!
if yes anyone know some supplier for HVAC piping coupling ? ]]> AOP Commercial HVAC Mohammed Nofal http://hvac-talk.com/vbb/showthread.php?1316451-Refrigerant-piping-fittings http://hvac-talk.com/vbb/showthread.php?1314981-Chiller-Secondary-Loop-VFD-Control&goto=newpost Tue, 21 May 2013 13:25:51 GMT I have a secondary loop VFD controlled with 10+ 2-way modulating valves and two 3 way valves. The VFD control is currently set to maintain a specific... I have a secondary loop VFD controlled with 10+ 2-way modulating valves and two 3 way valves. The VFD control is currently set to maintain a specific dp. In the winter time, the flow that this loop maintains is beyond what one chiller with a constant flow pump can provide (actual load in tons is ok for one chiller) so I'm forced to run two chillers and get a low delta T due a large amount recircing in the bypass line.

I am thinking about trying an alternate control method with the vfd secondary loop. Instead of maintaining a constant dp could I not use the actual % open of the valves? My control system would constantly be looking at the open % of each valve and attempt to drive the most open to 90% and stay there (by reducing VFD speed and total flow). If it gets above 90% then it would speed back up to maintain 90%. If another valve would open past 90% then that would become the new PV. Thoughts? ]]> AOP Commercial HVAC smakdown61 http://hvac-talk.com/vbb/showthread.php?1314981-Chiller-Secondary-Loop-VFD-Control http://hvac-talk.com/vbb/showthread.php?1314521-Anyone-know-who-makes-million-btu-90-gas-furnace&goto=newpost Mon, 20 May 2013 19:55:40 GMT Bidding a job to replace old oil system. Million btu propane up flow furnace? Don't even know where to look. My local supply house say no carry it ]]> AOP Commercial HVAC Iceman_pdx http://hvac-talk.com/vbb/showthread.php?1314521-Anyone-know-who-makes-million-btu-90-gas-furnace http://hvac-talk.com/vbb/showthread.php?1314401-Trane-10-ton-Hi-Eff-RTU-Model-TSC120E-nuisance-alarm&goto=newpost Mon, 20 May 2013 16:27:20 GMT I'm having an issue with a RTU sending a "Call Trane Service" alarm through our Building Automation System. The unit does not shut down, operates as normal but this alarm disappears for months but then when it starts occurring, the interval between realarms shortens from every 24 hours to every hour on the hour. Trane certified, non-Trane service tech cannot explain purpose of alarm> Trane service techs cannot help either.... Has anyone had this issue or anything similar>>>?? Thanks for any and all help... ]]> AOP Commercial HVAC Joe V http://hvac-talk.com/vbb/showthread.php?1314401-Trane-10-ton-Hi-Eff-RTU-Model-TSC120E-nuisance-alarm http://hvac-talk.com/vbb/showthread.php?1312841-I-need-HELP-with-energy-sheets-in-florida!!&goto=newpost Fri, 17 May 2013 20:49:37 GMT I do the energy sheets for the company and I have a few quistions about the loads. they are saying 1. Energy sheet needs correction. System... I do the energy sheets for the company and I have a few quistions about the loads. they are saying

1. Energy sheet needs correction. System selected appears to be over allowable limit of
115% of total equipment load of 32534 Btuh. Provide revised energy sheet or manual 'S' to
show correct sizing.

my equipment load is 32836 Btuh if you x that by 115% it comes to 37761.4 and they are saying that I can't use a 3.5 ton Carrier 14 seer system I have to use a 3.0 ton.

I know how to fix this in wright J but i want to understand why this is!!

thank you ]]> AOP Commercial HVAC TMarco http://hvac-talk.com/vbb/showthread.php?1312841-I-need-HELP-with-energy-sheets-in-florida!! http://hvac-talk.com/vbb/showthread.php?1312631-ALC-Delta-Integration&goto=newpost Fri, 17 May 2013 13:35:29 GMT I'm currently working on setting up alarms in a building with a Delta control system. There was recently a new AHU installed with an ALC control system. I can view all the ALC points on the BACnet protocol but am wondering how the Alarms are set up in ALC points. There are a lot of nuisance alarms from the ALC system that im trying to fix.

Any info on how the alarms work or how to reconfigure them would be appreciated. ]]> AOP Commercial HVAC ControlStudent http://hvac-talk.com/vbb/showthread.php?1312631-ALC-Delta-Integration http://hvac-talk.com/vbb/showthread.php?1309111-Trane-remote-zone-sensors&goto=newpost Sat, 11 May 2013 01:31:33 GMT Been working at a new place with trane voyagers, mostly YCH300B4HOHB models. First time I've come across this...all the units use BAYSENS017B remote zone sensor. The two wires from the remote sensor connects to an ajustable zone sensor module (BAYSENS008B) in the roof top's electrical compartment. This has been the facility's way of keeping employees from tampering with the setpoints...dumb, I know.

I've been told that the outdoor adjustable zone sensor has to have a resistor or something, that has to be cut so that the two zones sensors don't fight each other, and only read the remote sensor's zone temp.

Has anyone else seen or heard of such a setup? ]]> AOP Commercial HVAC Hook Echo http://hvac-talk.com/vbb/showthread.php?1309111-Trane-remote-zone-sensors http://hvac-talk.com/vbb/showthread.php?1308801-Data-Aire-Mod-DACD-4034-Condensate-Issue&goto=newpost Fri, 10 May 2013 15:56:44 GMT We use the Data Aire down flow, chilled water, CRAC units, model DACD-4034. We are experiencing an issue with the condensate dripping off of the... We use the Data Aire down flow, chilled water, CRAC units, model DACD-4034. We are experiencing an issue with the condensate dripping off of the A-Frame, chilled water coil, before the condensate reaches the condensate pan. The condensate runs half way down the coil and then drips on to the top of the fan housing.

My experience has always told me to ask the question, "what has changed?" Well recently the data center team decided to add chimney's to the top of each CRAC. The chimney is 6' tall and reaches up to with in 2' of the data center deck "ceiling" There is no drop ceiling.

Can this have something to do with the dripping condensate or is there another issue? ]]> AOP Commercial HVAC KM1400 http://hvac-talk.com/vbb/showthread.php?1308801-Data-Aire-Mod-DACD-4034-Condensate-Issue http://hvac-talk.com/vbb/showthread.php?1308681-Copeland-Scroll-Compressors&goto=newpost Fri, 10 May 2013 14:33:42 GMT Can anyone tell me what is the diffrence between these compressors? ZR125KC-TFD-950 ZR125KC-TFD-250 ZR81KC-TFD-950 ZR81KC-TFD-250 Can anyone tell me what is the diffrence between these compressors?

ZR125KC-TFD-950 ZR125KC-TFD-250



ZR81KC-TFD-950 ZR81KC-TFD-250



The diference is the 250 and the 950 at the end of the model number. I already know the zr125's are bigger than the zr81's. Just not sure what the 250 and 950 mean? ]]> AOP Commercial HVAC gbathunder http://hvac-talk.com/vbb/showthread.php?1308681-Copeland-Scroll-Compressors http://hvac-talk.com/vbb/showthread.php?1307541-Alter-cc6400-with-nst-v&goto=newpost Wed, 08 May 2013 14:40:10 GMT Assistance,please how do i alter the setpoint in cc6400 with network service tool v Assistance,please how do i alter the setpoint in cc6400 with network service tool v ]]> AOP Commercial HVAC WTC http://hvac-talk.com/vbb/showthread.php?1307541-Alter-cc6400-with-nst-v http://hvac-talk.com/vbb/showthread.php?1307521-Trane-Compressor-Leak-Is-it-fixable&goto=newpost Wed, 08 May 2013 14:18:09 GMT Hi all, We have a Trane CGWD050GCONT101 Chiller in our building. One of the two circuits is down at the moment, as the 15 ton compressor (Model... Hi all,

We have a Trane CGWD050GCONT101 Chiller in our building. One of the two circuits is down at the moment, as the 15 ton compressor (Model CSHS150J0HOF) has a rather large leak on the suction fitting, which is pretty rusty. My question is this: Is it possible to repair just the suction fitting? All the quotes we have received so far have been to replace the entire compressor, at a very large expense. I just want to know if it is even possible to repair it, as that seems like it would cost less than replacing the whole (otherwise perfectly good) compressor. The model they have quoted for replacement is a CSHA150R0*00. I have also received a quote for a Danfoss at about 2/3rds the price.

Thanks in advance for your advice!

-Mike ]]> AOP Commercial HVAC Driverfound http://hvac-talk.com/vbb/showthread.php?1307521-Trane-Compressor-Leak-Is-it-fixable http://hvac-talk.com/vbb/showthread.php?1305221-Echelon-iLon-Smartserver-2-0-assistance-in-Miami-FL&goto=newpost Sat, 04 May 2013 04:42:30 GMT Hi all, I am not an HVAC professional although I have worked with many over the years of being a chief engineer and now owning my own commercial... Hi all,

I am not an HVAC professional although I have worked with many over the years of being a chief engineer and now owning my own commercial energy auditing biz. I am new to this forum and am looking for help with with installation of a Smartserver 2.0 to monitor energy use with later plans to expand and integrate HVAC and other building equipment into the controls scheme. My target clients are not the buildings that already have BAS or EMS already in place. I am looking mainly at condominiums that have nothing but some T-Stats to control their common area HVAC.

I have the iLon units, Wattnode units and current transformers. I am OK installing the current transformers and Wattnodes, but after that I hit the wall. I read the documentation for the servers but I do not have any software for them other than what may be on them. I cannot even get my laptop to recognize a Smartserver with a direct ethernet connection. I got them from an energy company that went out of business and did not get the software disk.

Any iLon controls guys in Miami-Dade or South Broward county want to earn a few bucks hooking up my first one or tutoring me?

Thanks,
Bill ]]> AOP Commercial HVAC bill_n_miami http://hvac-talk.com/vbb/showthread.php?1305221-Echelon-iLon-Smartserver-2-0-assistance-in-Miami-FL http://hvac-talk.com/vbb/showthread.php?1304811-Auto-body-shop-to-A-C-or-not-to-A-C-that-is-my-question!&goto=newpost Fri, 03 May 2013 17:53:51 GMT Yeah, sorry for the Shakespearean slip....:gah: (got you to look though) I hope I'm asking for input in the right place--if not, I assume the mods here will move me or let me know...


Here's the story--I'll try to keep it brief.

My shop--6000 sq ft, basically a pole barn(insulated), open ceiling, 13.5ft high at the eaves. 3 phase power(240 delta)

I traded into two new(old stock)never installed/or used Carrier heat/air units, both 48TF, one is a ten ton(D012) and a 12 ton(E014). Both are 460v 3 phase. I'm in them for -0- dollars, btw. Too much temptation to make them work somehow.

I'd like to have a/c in the shop, as middle Tennessee gets hot an humid in the summer....and I ain't getting any younger....

You guys have any idea what pitfalls I'm apt to encounter? How might I make the Delta 3 phase run the 460? Is 22.5 tons enough? General advice?
Thanks in advance--I know nothing about the topic at hand(HVAC)--I do paint and body. If I can help any of you guys with questions of my area of expertise, by all means ask send me a pm and I'll do my best to help in return. ]]> AOP Commercial HVAC ealrschieb http://hvac-talk.com/vbb/showthread.php?1304811-Auto-body-shop-to-A-C-or-not-to-A-C-that-is-my-question!