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  1. #14
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    34,607
    Isn't the loop water usually separated from the tower water by a heat exchanger or a closed circuit tower?

    I'm with you, hound. If they can't have cooling year round, doesn't sound like a heat pump.

  2. #15
    Join Date
    Aug 2003
    Location
    Fort Worth, TX
    Posts
    11,376
    Bald One, you would think there would be an intermediary heat exchanger. I haven't worked on water source buildings in a long time so I'm admittedly a bit rusty there.

    But thanks for the reminder...I still think the OP's building has a chiller; was just covering the bases. If he can gain access to the condo he wants to buy, he might ask if he can get info/photos off the equipment in the unit and then share that here.
    • Electricity makes refrigeration happen.
    • Refrigeration makes the HVAC psychrometric process happen.
    • HVAC pyschrometrics is what makes indoor human comfort happen...IF the ducts AND the building envelope cooperate.


    A building is NOT beautiful unless it is also comfortable.

  3. #16
    Join Date
    Jan 2012
    Posts
    11
    I don't have access to post in the condo's forum, only read access. I will see what more I can find out and will post in here again soon. Thank you Shophound for your thorough replies as well as everyone else for their thoughts!

  4. #17
    Join Date
    Jan 2012
    Posts
    11
    So I got more information from the property manager. Looks like its basic heat coil in the winter and chilled water in the summer. Any thoughts?

    The HVAC system in the building features hallway on lobby heating and air conditioning as is the case of most “make up air” systems in the city. The individual units have a heat pump system whereby the air conditioning unit on the roof supplies cooled water to the unit (s) within the individual condominium units for cooling. These very same units have electric heating elements that heat the units during the winter. There is no hot water supplied to the units for heating during the (non-cooling) month of the year. Obviously the electricity for the heat and the operation of the heat pump cooling is individually metered for each unit and is the sole responsibility of the unit owner.

  5. #18
    Join Date
    Dec 2007
    Location
    houston, texas
    Posts
    3,787
    Sound to me like standard fir down air handlers with chill water coils and electric heat strips. Maybe the "solvent" lines they were refering to were the condensate drains and unit drain pans.
    I'm not tolerating Political Correctness anymore, from now on it's tell it like it is.

    Veto Pro Pak - The best tool bag you'll ever own






  6. #19
    Join Date
    Aug 2009
    Location
    Prattville, Alabama
    Posts
    2,145
    Quote Originally Posted by BaldLoonie View Post
    Isn't the loop water usually separated from the tower water by a heat exchanger or a closed circuit tower?

    I'm with you, hound. If they can't have cooling year round, doesn't sound like a heat pump.
    A few years ago, I was on a call as "back up" for a co-worker who had a similar account. My memory's a little fuzzy, but maybe this will help. Like BaldLoonie suggests, the loop water was separated from the cooling tower by a heat exchanger. There was also a bank of small boilers (or water heaters, I can't remember). I "THINK" the loop water after leaving the load, or all the heat pumps, went through the heat exchanger, then through the boilers, then back to the load. Of course there's also a pump in there somewhere. Maybe there was a second heat exchanger to isolate the boilers from the loop water. Anyway, the tower heat exchanger was the heat sink for when most heat pumps were cooling, and the boilers (or their heat exchanger) were the heat source for when most of them were heating. I understood that site maintained the loop temperature such that each individual heat pump could run in cool or heat mode (after all, isn't that the reason for such a system?). Is it possible that this site here runs the loop temperature extra high for heating? And that is too high for cooling? Wasn't there a high pressure issue? Maybe they have to run it higher because they have heat transfer problems, perhaps due to scaling (lack of chemical control). Also, maybe they can only cool when they drive the loop temperature extremely low, also to compensate for heat transfer, to prevent high pressure trips. Having to run the loop very high for heating and very low for cooling could explain the reason to "switch over to cooling". Also, maybe the comment about sludge and the solvent line was just talking about a condensate drain- hard to tell using second hand info originating from someone unknown. Without knowing more, I would be very hesitant to move here, unless the owners showed a change of direction in their maintenance.
    Last edited by Nuclrchiller; 01-25-2012 at 03:35 PM. Reason: I'm slow- missed last two posts.

  7. #20
    Join Date
    Aug 2003
    Location
    Fort Worth, TX
    Posts
    11,376
    Quote Originally Posted by kevk773 View Post
    So I got more information from the property manager. Looks like its basic heat coil in the winter and chilled water in the summer. Any thoughts?

    The HVAC system in the building features hallway on lobby heating and air conditioning as is the case of most “make up air” systems in the city. The individual units have a heat pump system whereby the air conditioning unit on the roof supplies cooled water to the unit (s) within the individual condominium units for cooling. These very same units have electric heating elements that heat the units during the winter. There is no hot water supplied to the units for heating during the (non-cooling) month of the year. Obviously the electricity for the heat and the operation of the heat pump cooling is individually metered for each unit and is the sole responsibility of the unit owner.
    I find the property manager's response the most informative yet, but still the inclusion of the terms "heat pump" seems misleading, if I read his/her description correctly. Could be they need to learn what the term "chiller" means so they're not throwing the phrase "heat pump" around like it means anything for their building. A heat pump creates cooling in summer and heat in winter, using the compressor and refrigeration components. A chiller chills water and circulates it around the building, where individual blowers in each condo blow over coils filled with the chilled water to accomplish cooling. The heat strips are for winter heating, since no hot water is circulated, just like the manager said.

    If the building had water source heat pumps, water would be circulated year round, and each condo unit would have an air handler with a compressor and coils inside.
    • Electricity makes refrigeration happen.
    • Refrigeration makes the HVAC psychrometric process happen.
    • HVAC pyschrometrics is what makes indoor human comfort happen...IF the ducts AND the building envelope cooperate.


    A building is NOT beautiful unless it is also comfortable.

  8. #21
    Join Date
    Aug 2009
    Location
    Prattville, Alabama
    Posts
    2,145
    Could their "chiller" be a cooling tower? Is there such a thing as water cooled dx a/c unit? Or maybe water source heat pumps with heat mode disabled and using strip heat as primary heat?

  9. #22
    Join Date
    Aug 2009
    Location
    Prattville, Alabama
    Posts
    2,145
    I can't help but think that at best, the property manager is over simplifying in trying to explain what he believes to be an over complicated system, or he doesn't know the system or the terminology. Either way is a big red flag for me.

  10. #23
    Join Date
    Jan 2012
    Posts
    11
    Hi all, I went back to the building tonight for a second look at the unit. This time I took some pics of the roof unit from the deck. Also the air return in the condo was covered by a flat tall piece of metal without open grills with the air being sucked in around the edges; I've never seen an air return like that before. Feedback appreciated!







  11. #24
    Join Date
    Aug 2003
    Location
    Fort Worth, TX
    Posts
    11,376
    The item on the roof in your photos is a cooling tower.

    Wish you would have flipped open the thermostat cover to reveal the controls. If you did but just didn't photograph it, do you recall any switch on there that said "emergency heat"?
    • Electricity makes refrigeration happen.
    • Refrigeration makes the HVAC psychrometric process happen.
    • HVAC pyschrometrics is what makes indoor human comfort happen...IF the ducts AND the building envelope cooperate.


    A building is NOT beautiful unless it is also comfortable.

  12. #25
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    34,607
    I'm guessing what they are calling a heat pump in the units is a fan coil with electric heat not hot water heat.

    People on the inside of those buildings sure don't have any view

  13. #26
    Join Date
    Jan 2012
    Posts
    11
    Quote Originally Posted by Shophound View Post
    The item on the roof in your photos is a cooling tower.

    Wish you would have flipped open the thermostat cover to reveal the controls. If you did but just didn't photograph it, do you recall any switch on there that said "emergency heat"?
    Actually I did flip the thermostat cover because I wanted to see if there was anything different function-wise from the one at my rental. I didn't see an "emergency heat" function. That being said I'm guessing from whats been said in this thread that this building has water cooled AC with coils for winter?

    The Realtor confirmed that the heat IS included in the assessments and that I would just be paying to operate the blower unit. The condo is a concrete loft. approx 1250 sq ft with 12ft ceilings, SW corner with a unit above and below. The current owners average about fifty dollars a month for electricity.

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