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  1. Replies
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    Measure the discharge air temperature at a grill...

    Measure the discharge air temperature at a grill close to the unit. Subtract the room temperature. This delta T should be in the 20-30 degree range. The installation manual for your unit will specify...
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    An air source heat pump can probably be installed...

    An air source heat pump can probably be installed for half the cost of a geothermal. The coefficient of performance of a modern air source pump at -10 degrees is between 2 and 3 meaning you get 2-3 x...
  3. In a previous post you stated that an independant...

    In a previous post you stated that an independant thermometer didn't indicate a drop in temperature as you noticed the comfort level change. If this is true even when the independant thermometer is...
  4. http://www.energy.wsu.edu/Documents/10_spr_iaq_nl....

    http://www.energy.wsu.edu/Documents/10_spr_iaq_nl.pdf

    This article gives a good explanation of comfort vs temperature, humidity, wind, etc.

    When an AC unit starts running it begins to lower...
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    You might consider an air to air heat pump. The...

    You might consider an air to air heat pump. The new high efficiency units are pretty efficient. I installed a 5 ton unit to get away from LP which was costing me $4000 / yr to heat the house. Most...
  6. Vinegar and citric acid are the reason deli cases...

    Vinegar and citric acid are the reason deli cases have more coil leaks than other cases. Attach a zinc sacrificial anode to the coil piping and / or put a box of baking soda in the case on a regular...
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    I would install an EPR and use it to control the...

    I would install an EPR and use it to control the case temp. This will keep the temp steady and also the evap temp higher so you get less frost. Most of the walmart's we install and service use air...
  8. I would just strap an A19 johnson controls...

    I would just strap an A19 johnson controls thermostat to the return pipe. Set it for 70 degrees and use it to open a 24v motorized ball valve or zone valve to bypass.
  9. You would need to assure that the returning water...

    You would need to assure that the returning water was mixing with enough water from the bldg heating zone to keep the temp actually entering the boiler high enough. If your 10 gpm limit is too high...
  10. When I worked in hospitals we had a sensor that...

    When I worked in hospitals we had a sensor that measured the air velocity thru a fixed oriface that was used to assure that negative air pressure was maintained in patient isolation rooms. If the...
  11. Load limit

    Install a gpm flow limiting valve in the line to the pool. That will limit the maximum amount of btu that you can divert to the pool.
  12. I am using java 7 ver 21 with windows 8 64 bit...

    I am using java 7 ver 21 with windows 8 64 bit and it works fine. You need to disable the java auto update and use either mozilla or chrome with the allow outdated plugins switch as posted earlier....
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    You need 3 logic boxes. A greater than 70 degrees...

    You need 3 logic boxes. A greater than 70 degrees , A less than 75 degrees, then a logical AND to combine the two outputs if they are both true.
  14. Another factor is that some server rooms include...

    Another factor is that some server rooms include high speed printers and decollators. The paper absorbs moisture and swells or shrinks accordingly. This causes jams in the machines. So old school...
  15. I am controlling 4 ultras from a metasys...

    I am controlling 4 ultras from a metasys UNT1144-0 It has 4 0-10vdc outputs which we use to control the firing rate of each boiler. We also monitor the alarm contact on each boiler so the EMS can...
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    I have a customer with an old 8 story bldg. that...

    I have a customer with an old 8 story bldg. that has poor insulation on the steam pipe risers and condensate return runs. They used to turn the steam on and off several times a day by hand because...
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    Most of these additional energy costs are...

    Most of these additional energy costs are associated with moving BTu's from a physical plant equipment room to the occupied space that it is needed in. The distance is the variable that eats up your...
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    Pump power is largely determined by the length...

    Pump power is largely determined by the length and rise of the run. VFDs can help with energy costs but every installation will be different in its requirements.
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    Leakage current during the heating season is not...

    Leakage current during the heating season is not a serious issue because the waste heat does go towards heating the building and is unlikely to drive temps beyond their control setpoints. During the...
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    I had to retrofit an enviroguard rack from a...

    I had to retrofit an enviroguard rack from a Johnson Controls board to CPC. Had to enter a program in CPC's einstein to handle the enviroguard. Whenever a compressor is running, refrigerant is bled...
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    The link below has a pdf with the manual and...

    The link below has a pdf with the manual and wiring diagram.
    ...
  22. You can squirt some nitrogen into the fittings...

    You can squirt some nitrogen into the fittings before you braze. Even though it is not flowing it will still prevent oxidation. Also the small amount of oxidation created would be blown out by a...
  23. Make sure that the solenoid valve is closing...

    Make sure that the solenoid valve is closing completely as well. Sometimes old ones leak by and that will cause the icing too.
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    Most compressor manufacturers cut open a number...

    Most compressor manufacturers cut open a number of their warranty returns to perform an inspection to determine the cause of the failure. You can usually request that they inspect your unit and let...
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    If the rotating valves are still operable, then...

    If the rotating valves are still operable, then you would need a 24volt solenoid valve for each station. Then control of those solenoid valves would require 8 digital outputs from a controller on...
  26. This time of year with high humidity and probably...

    This time of year with high humidity and probably more beer moving in and out of the walk in. Your thermostat is probably not cycling very often. A box can defrost during the off cycle IF it gets a...
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    Most of the R12 drop in replacements raise the...

    Most of the R12 drop in replacements raise the head pressure significantly. It is a good idea to change the whole condenser when dealing with a dead compressor on one of these old beasts. You can...
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    Power surge / lightning most likely.

    Power surge / lightning most likely.
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    By hydraulic I assume you mean the rotating valve...

    By hydraulic I assume you mean the rotating valve that selects the next zone everytime the water is shut off and back on again. You would not have to replace that. A custom control routine could be...
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    EasyIO controller

    Anyone have any experience with these?
    What software is required to set these up in a stand alone application?
    Is the software (if any) free or is there a cost involved?
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    Pilot positioners are used for two reasons. The...

    Pilot positioners are used for two reasons. The most common reason is to adjust the spring range, ie the pressure at which the actuator is fully open or closed. I've seen them most often on steam...
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    Triatek makes the alarm unit and sensor. Talk to...

    Triatek makes the alarm unit and sensor. Talk to them about adding a delay or filter to screen out nuisance alarms. Those alarms are made for safety and if you modify them w/o the manfacturers...
  33. Not sure if this will solve your problem, but the...

    Not sure if this will solve your problem, but the FX60 likes devices to be imported with a resource file to set things compatible with johnsons way of doing things. I've made my own from a list...
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    For each upgrade calculate the payback period....

    For each upgrade calculate the payback period. Prioritize the projects and do the ones with the fastest payback first. Try to talk management into using the savings to do additional projects.
  35. Nu-Calgon makes a pan cartridge for ice machines...

    Nu-Calgon makes a pan cartridge for ice machines that's food safe. But it might be too large for a WIC pan especially if you have defrost heaters. Health dept. would probably make you toss the food...
  36. Did you import the device using a resource file...

    Did you import the device using a resource file provided by Carrier, or are you manually creating the points from a list?
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    The distributor has an oriface to make sure that...

    The distributor has an oriface to make sure that the liquid/gas mixture flows evenly to all of the tubes. Probably was enough of a restriction to make it work sort of.
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    Freeze cycle is about 12-15 min, harvest 3-4 min....

    Freeze cycle is about 12-15 min, harvest 3-4 min. Depends on ambient temp and/or if it is a water cooled unit.
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    I think this model has a software algorithm that...

    I think this model has a software algorithm that looks at the water sensor and the pattern of the dropping ice to determine the thickness. Sometimes they get confused and you have to shut off power...
  40. Putting tablets or pads in the drain pan will...

    Putting tablets or pads in the drain pan will also kill algae in the drain line and help it stay clean. Spraying the coil with a coil cleaner at the beginning of the season is also a good pm step. If...
  41. If installed as recommended it will indicate...

    If installed as recommended it will indicate liquid. The turbulence caused by the small lines and curves will cause liquid with low subcooling to flash in the glass more than the relatively open path...
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    http://www.national.com/mpf/LM/LM34.html#Overview...

    http://www.national.com/mpf/LM/LM34.html#Overview

    The above chip is a low cost temp sensor that produces a linear voltage in response to temperature so it is easy to map into a 0-10vdc input.
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    We are seeing these high mass temp sensors being...

    We are seeing these high mass temp sensors being installed in a convenience store chain that we service. The control scheme is to pair the high mass sensor with a traditional air temp sensor and...
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    http://cgproducts.johnsoncontrols.com/MET_PDF/1201...

    http://cgproducts.johnsoncontrols.com/MET_PDF/12011406.pdf

    This Johnson controls supervisory controller can give you web access to all of the data on your metasys network. It can also send email...
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    Be carefull with large pneumatic valves. The...

    Be carefull with large pneumatic valves. The spring is very powerfull and can cause serious injury if not secured properly. Get the disassembly instructions and make sure you understand them before...
  46. Agree with your analysis as to temp. ranges and...

    Agree with your analysis as to temp. ranges and customer satisfaction. Would add that Rh can be used in combination with temp to get a comfort number, but that is as complex as I think it should be...
  47. You need an occupant mass sensor too. The more...

    You need an occupant mass sensor too. The more massive the occupant the cooler they like it.:grin2:
  48. One thing that is sometimes missed. Check the...

    One thing that is sometimes missed. Check the condenser capacity at your summertime peak temps. Also the sizing of the lines to the condenser.
    Just having the compressor capacity isn't all of it....
  49. My difficulty is with making a simple problem...

    My difficulty is with making a simple problem overly complex. It is easy to reset temperature setpoints based on Rh. or enthalpy. It is easy to control CO2 within acceptable ranges. Mass sensors can...
  50. This is a meanless specification without the...

    This is a meanless specification without the sensors needed to implement it. It reflects thinking that optimum comfort levels for all occupants is possible without creating cubicle level zoning....
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