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Thread: One for the fridgies

  1. #981
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    Quote Originally Posted by Tombie View Post
    Best way to shuffle all the way to the bottom of my list One for the fridgies

    Amazing how as kids our parents would admonish us for nagging, sooking and pestering.
    Only to continue such behaviours as grown adults.
    Hahaha, yep.

    And don't start sprouting KPI's and demanding a condition report for a recently vacated tenancy to be submitted by COB TODAY.

    I had that happen Wednesday when we're up to our armpits in alligators with breakdowns across multiple supermarkets for both Coles and Woolies, a job list that seems to scroll forever on XL and a client demanded the above for a site up the coast.
    They're still waiting, but I did start it. One for the fridgies

  2. #982
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    Apr 2008
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    Brisbane,some of the time.
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    Increasing fresh air in buildings isn't easy or straightforward, it's already very finely tuned to achieve optimum building efficiency from an energy usage POV.[/QUOTE]

    Many older systems actually have the fresh air cut back from design due to the main plant being undersized.
    We see this type of issue all day.

    And building owners,most couldnt give a rats and dont want to spend a cent on anything.

    KPI's,now dont get me started......
    Paul

    Discoless for the first time in 21yrs

    '56 S1,been in the family since...'56

  3. #983
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    Quote Originally Posted by scarry View Post

    Many older systems actually have the fresh air cut back from design due to the main plant being undersized.
    We see this type of issue all day.

    And building owners,most couldnt give a rats and dont want to spend a cent on anything.

    KPI's,now dont get me started......
    Yep, and as for landlords not wanting to spend a $...
    The tenant is a major bank on a long term lease One for the fridgiesOne for the fridgies

  4. #984
    Join Date
    Jan 2010
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    Quote Originally Posted by rick130 View Post
    ....................... some sites are now using up to 26 with 10g/kg moisture content but staff and customers aren't happy.
    Situations like hotels are pretty well sealed, so rooms have individual fan coils and only a fixed amount of outside air is introduced.
    I was in a new 3 storey police statation yesterday with a setup like this.
    Multiple VRV's with I think 70+ FCU's, a combination of cassettes and split ducted systems and just four fixed speed outside air fans pumping fresh air into the space.
    The exhaust fan in the drug room failed and everyone on the first floor ended up with a cannabis induced headache. One for the fridgiesOne for the fridgies

    Increasing fresh air in buildings isn't easy or straightforward, it's already very finely tuned to achieve optimum building efficiency from an energy usage POV.
    At most office sites I've worked at, people would start threating to walk out at 26 dgs, I've only met one young lady that liked 26 dgs but she was from Cairns I think, kept wanting the A/c made warmer, so I asked her what she had it set on in her car, and she said 26!

    Passive Cannabis Inhalation induced headache, a likely story!

    I know increasing fresh air in buildings isn't easy or straightforward, that's why it is going to cost a motza and hopefully cause big profits for refrig. companies.
    2005 D3 TDV6 Present
    1999 D2 TD5 Gone

  5. #985
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    Quote Originally Posted by RANDLOVER View Post
    At most office sites I've worked at, people would start threating to walk out at 26 dgs, I've only met one young lady that liked 26 dgs but she was from Cairns I think, kept wanting the A/c made warmer, so I asked her what she had it set on in her car, and she said 26!

    Passive Cannabis Inhalation induced headache, a likely story!

    I know increasing fresh air in buildings isn't easy or straightforward, that's why it is going to cost a motza and hopefully cause big profits for refrig. companies.
    It had permeated the entire floor even though it was behind closed doors and in a safe.
    They had to remove it to the large holding area in the basement but that used a common exhaust duct One for the fridgies

    Re the temps, the 26 setpoints are causing us huge issues as we can't adjust them, the BMS is remotely monitored and setpoints locked. One for the fridgies

    It's a certain supermarket chain, it's also putting increased load on the refrigeration so I wouldn't be surprised if they're gaining efficiency on one hand and losing on the other.

  6. #986
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    We build and supply high efficiency AC systems to optimise the dehum systems in place in most supermarkets, and we have a commissioner that is very switched on and really knows his stuff re programming.
    There are a number of companies out there that sell 'optimisation' and''efficiency' who come in and rewrite the programming all in the name of saving power.
    At quite a few sites here and through Qld a number of compressors have been lost so our blokes have had to come back in and reprogrammed everything after the compressor replacements.

    I found this by accident in a store here as I was going through the controller after the AC systems had tripped out.
    I know enough to get by, but these controllers are bloody sophisticated.

    Some of the temp inputs needed offsets, no biggie, I can actually do that One for the fridgies
    But I found two trading floor RH Inputs but only one sensor??
    As the phantom sensor was reading 0 or minus something, the site RH was being averaged and s o for a big chunk of each day there was no dehum at all, all the cases were sweating and glass door freezers icing up as well as staff and customers complaining about the temp and stupidly high humidity.
    Deleted the errant input and that helped, but it all looked odd, so I rang my boss who could dial in remotely.
    I wanted to start adjusting stuff but was told don't touch anything, there's a definite set of parameters that need inputting and this had all been loused up.
    We sent our bloke out, it cost the customer 1.5 days and overnight accomodation at commissioners rates just to reprogramme everything.

  7. #987
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    Quote Originally Posted by rick130 View Post
    The big issue with introducing more fresh air into large systems is the extra load on the AC.
    If you used the %'s of fresh air health experts are advocating we'd have massive AC systems with huge electrical and therefore CO2 loads.
    Current systems wouldn't cope, and I know building owners wouldn't stump up for the extra capital cost and power usage.

    Most large systems, e.g. department stores and shopping malls and larger office buildings with large air handlers or central plant or even larger pac units have an economy cycle that kicks in If ambient conditions are conducive.
    Various %'s of outside air are introduced up to 100%, but it's a pretty narrow range of outside air conditions that can be used.
    Think of spring and autumn as being ideal for economy cycle conditions.

    Back in the day the standard was 10% or I think it was 7l/person/minute? outside air introduced at all times in a commercial building but now we base it on an algorithm of outside air, inside air, outside and inside RH and inside CO2 levels measured in various parts of the building.
    Generally 600-900ppm is the setpoint for CO2 before the dampers start to open and introduce fresh air. On ridiculously hot days I sometimes override that to 1000ppm to reduce the load on the chillers if they are old and struggling. IIRC 1500ppm is about the limit before people start to get affected and concentration can start to drop off.
    RH levels used to be and are mostly still 55-60% as the optimum but this is starting to change to 10g/kg moisture content so that higher setpoints and wider deadbands can be used to reduce coolng costs, some sites are now using up to 26 with 10g/kg moisture content but staff and customers aren't happy.
    Situations like hotels are pretty well sealed, so rooms have individual fan coils and only a fixed amount of outside air is introduced.
    I was in a new 3 storey police statation yesterday with a setup like this.
    Multiple VRV's with I think 70+ FCU's, a combination of cassettes and split ducted systems and just four fixed speed outside air fans pumping fresh air into the space.
    The exhaust fan in the drug room failed and everyone on the first floor ended up with a cannabis induced headache. One for the fridgiesOne for the fridgies

    Increasing fresh air in buildings isn't easy or straightforward, it's already very finely tuned to achieve optimum building efficiency from an energy usage POV.

    Maybe it wasn't the fan Rick but the staff doing a physical stock take. "Hey Chuck, we better test this stuff to make sure it is still fresh & fit for purpose."

  8. #988
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    Quote Originally Posted by RANDLOVER View Post

    I know increasing fresh air in buildings isn't easy or straightforward, that's why it is going to cost a motza and hopefully cause big profits for refrig. companies.
    And power companies.

    In a central plant situation, increasing fresh air can mean another chiller, cooling tower, pumps,and on it goes.
    Many sites have no more room for increasing plant, particularly high rise buildings.
    Huge costs to the building owners unless it becomes mandatory it won't happen.
    Paul

    Discoless for the first time in 21yrs

    '56 S1,been in the family since...'56

  9. #989
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    Logan
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    24,568
    Building design must be an issue in all this?
    For example, having entrances with outside doors entering a glass area and then internal doors entering the building must make life a lot easier for the air-con, compared with a single set of doors letting hot outside air straight in.
    Also, how many buildings are properly insulated, particularly in the roofs?

  10. #990
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    Air change rates can be a can of worms! Rather than try and discuss it I just post the following link:

    Air Change Rates in typical Rooms and Buildings (engineeringtoolbox.com)

    Cruise ship have come in for some bad press, so here is another point of view:

    How Royal Caribbean will circulate air on its cruise ships to protect against coronavirus

    How Royal Caribbean will circulate air on its cruise ships to protect against coronavirus | Royal Caribbean Blog

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