Page 1 of 3 123 LastLast
Results 1 to 13 of 30
  1. #1
    Join Date
    Sep 2008
    Posts
    10

    Wink Advice for planned A/C upgrade?

    I'm planning to replace my existing A/C units this spring, and this the first step of my research. From this afternoon's reading, I can tell I have alot to learn before I can feel like I'm making an informed decision. Gotta start somewhere, right?
    Some background:
    Lafayette, La, about 40 miles from the coast, hot and humid for about 8 months out of the year.
    I bought this house in June, 2.5 stories, 3500 sqft, built around 1998. Slab, with siding.
    The top floor is a greatroom, around 550 sqft, always the warmest room in the house, uncomfortably so in the afternoon.
    The second floor has about 1400 sq ft, split into 2 BR/2 BA, stays cool enough, but still warmer than the ground floor.
    The ground floor has about 1600 sq ft, mostly an open space for the kitchen, LR. Master suite is down as well. This floor is always the coolest of course.
    there are 2 units to heat/cool the house. 1 dedicated for downstairs, 1 dedicated to the upper 1.5 stories. Both of the outside units are Heil "High Efficiency 5000" units, model number CA5542VKD2.
    1st question- what is the ton rating and SEER on these units?
    The upstairs unit's fan stopped working, guy changed a capacitor and it was fine for a week. Then it stopped cooling, same tech comes by, says the coil is leaking, needs to be changed. We have him add freon, and that has gotten us by for 3 months.
    I've come to terms with the cost, I just want a system that will save me some coin when the electric bill rolls in, and keep my upstairs cooler.

    Given the state of the technology, what is the highest SEER you recommend?
    Ballparked, do my current units look appropriately sized? Should I look at a larger system for upstairs?
    Who makes a system that's capable of some basic automation, such as remote control by phone? Is there a thermastat that will integrate with a Logitech Harmony 1000 universal remote control?
    Thanks, Shell

  2. #2
    Join Date
    Sep 2008
    Location
    arlington, tx
    Posts
    225
    im a young old fashioned guy and i still cant see the higher efficiency units saving any money...its takes you 15 years to recover the cost (assuming your previous unit was at least decent) and by that time you will need another one. replacing parts will be more expensive. they seem more for bragging rights than anything i would go with a 13 seer

  3. #3
    Join Date
    Sep 2008
    Posts
    10
    I "think" my current units are around 10 SEER, as that was the requirement back then. According to the ballpark savings that SEER charts supply, I'll save around 50% on cooling with a 19 SEER unit. When you're dropping $4-500/month on electricity, with probably 2/3 of that amount paying for cooling, 50% adds up fast.

  4. #4
    SSS - We would need to know what your electric rates are in determing the payback period on a high efficency system. From the model number that you provided the units are both 3.5 tons.

    As far as the impropper cooling throughout the house, you would want a contractor to complete a manual j load analysis on your house, and make any adjustments to the ducts/balancing that would be needed.

    The system could interface with a network device, Honeywell and AprilAire both have systems that allow the user to do this. We have installed many of these systems, and the customers are all happy, however the cost is sometimes prohibitive.

    You are going to want to find a HVAC contractor that you trust, and ask them to perform the load analysis for you, and have them bid the job with the correct size systems and duct work modifications that are necessary.

  5. #5
    Join Date
    Sep 2008
    Posts
    10
    All of that makes good sense to me, I'll try to learn more about the manual j-load tomorrow.
    I guess you'd need to know my averaged annual usage, as well as my cost per kW in order to accurately judge the savings, but would you say hat 49% is a good guess for the difference from 10 to 19 SEER?
    Can someone verify he Heils were supposed to be 10 SEER when new?
    can you say how much cost caused the automation to be prohibitive or is that prohibited? how much functionality was provided? I'd just like to be able to adjust it remotely, say, from the couch and/or the car.

  6. #6
    Basically a Manual J Load Calculation takes into account all the windows, attic space, crawl space, insulation, loads in each room, etc to determine the heating and cooling needs for a home. Many contractors will use rule of thumb calculations which result in improperly sized systems.

    The 10 SEER system is about what I would expect a 10 year old system to be. When I get into the office tomorrow, I'll pull the literature for you and double check that number. The energy savings that you are going to see varies based on the load of the house. If you put a high efficiency system is a house, but it is not properly sized correctly, it will use more energy than a properly sized standard efficiency system.

    When you purchase a system, there are two numbers that you should be looking at (well as far as efficiencies are concerned). The SEER, which is the Seasonal Energy Efficiency Ratio, measures cooling from 82 degrees outside to 80 degrees inside. EER, Energy Efficiency Ratio, measure cooling from 95 degrees outside to 80 degrees inside. The EER is more meaningful in predicting your actual energy usage. Many system that are 19 SEER (Trane for example) have EER's that are in the 10's or 11's. A 13 SEER system, when measured by EER would be more efficient.

    Another thing to consider is if the unit is two stage, or if it has a variable speed blower motor. Having these features in a system could have makes the house more comfortable.

    Yes, I meant prohibitive. Depending on the interface of the system, and what models are used, you could change the temperature from any device that connects to the internet. Changing the temperature from the couch is harder, unless you have internet connections at that location. Most of our customers that have these remote access systems installation have two houses, and tell the system to change the temperature before they head out to their second home, allowing them to be comfortable upon arrival.

  7. #7
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,753
    A/C units in the 19 SEER series, will be 2 stage. And only be in even tons.(with exception to Tranes 2.5 ton 19i, and AS's 18)

    You upper 2 floors could have duct work issues causing the temp differences. Or could be undersized units.

    A Manual J will let you know.
    And they should check your current air flow through your duct systems.

    2 stage with VS blowers should improve your comfort, and save some money on operating cost.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  8. #8
    Join Date
    Sep 2008
    Posts
    10
    Man. Hadn't heard of the EER yet. I will look for that rating as well. I guess SEER gets all the publicity.
    So, I can see how you can get into chicken or egg loop with the J load and contractor estimates. The contractor doesn't want to spend all the time to calculate a j load if he's not gauranteed the job, you can't give him the job until he has a firm estimate, he can't give you a firm estimate unless he does the j load, etc... Any advice for that situ?
    are there no simple Z10 type interfaces that would allow you to work the thermostat from the couch?
    Thanks to all of you, it is a alot of help to be able to discuss this and get your input.

  9. #9
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,753
    Neither EER, or SEER are accurate.
    But I get much closer with SEER then EER.

    In my area, only 3 to 5 days of the cooling season are close to EER (95°F outdoor temp) conditions.

    How many hours (yes hours) your area spends close (or above a 60% duty cycle) to OD design temp, determines which rating method you should use.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  10. #10
    Join Date
    Sep 2008
    Posts
    10
    I would say that 95* and 90% humidity are common numbers for our long summers down here in south Louisana.
    I'll check some "official" seasonal averages and report back.

  11. #11
    Join Date
    Sep 2008
    Posts
    10
    Weather Underground reports over 3 months of +90* average temps. So I'm more EER than SEER, right?
    Are EER specs usually as well published as SEER? I suppose I could have just been ignoring them since I had SEER in mind.
    Thanks again.

  12. #12
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,753
    EER is on all ARHI certs, so its easy to find.

    My Manual J bin data, must not have your area listed. It doesn't show any Louisana area that has your weather. Of course, it only list 2 areas.

    What is your zip code.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  13. #13
    Join Date
    Jan 2002
    Location
    Ft.Worth,Tx
    Posts
    4,584

    Cool

    Here is the real deal.
    2010 all R-22 equipment will cease to be manufactured.
    2015 R-22 will decrease production by 80%

    Now you have 10 .S.E.E.R ~3.5 ton (042) units and they are not keeping up when it is hot. What about on normal day say 78-82* will it maintain the temperature?

    You want to upgrade to a good system that will provide the necessary airflow to remove the heat & humidity from those second floor areas.

    Carrier Infinity with a zoned system would be a really good choice and save you some $$$$ every month on utilities.

    Carrier Infinity Air handler/FE4BNF048
    Carrier 19.0/16.0 Heat Pump/24ANA7

    Cash back rebate of $1000.00 and financing 12 months no interest.
    "Everyday above ground, is a good day".
    "But everyday that you have made a difference in someones life, may insure you stay above ground a little longer".<aircooled>

Page 1 of 3 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event