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  1. #40
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
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    6,064
    Quote Originally Posted by beenthere View Post
    I don't sell 2 stage as cure all for humidity and IAQ problems. No one product can do that.
    Like you tend to claim.

    I can give you plenty of places to go and talk to them all about IAQ and whole house dehimidifiers.
    And then you can explain why they need it now. Even though they haven't needed one for 30 or 40 years.
    You can show them all your charts, and quote ASHRAE all you want. You might sell 1 out of 100 sales calls if your lucky. In this area.

    Your size for the once or twice a year 20 to 30 person party, or those 2 to 3 times it reaches 100 once every 4 or 5 years is propaganda to sell your product.

    You quote ASHRAE for IAQ. But no where does ASHRAE say to size for the conditions you recommend to size to.

    Selective quoting to benefit your sales.
    What do you sell to address indoor humidity and IAQ problems? I know in the past you supported VS blowers with "on" mode while cooling? I do also suggest VS "on" to dryout the ducts avoiding mold growth in the ducts several hours everyday. This elevates the indoor %RH but maybe necessary for mold sensitive people. I am posting data from a WI home with the fan "on" low speed when not cooling. The setting is 76^F with "low" humidity setting on the Infinity t-stat. The SF dehu is set at 50% RH except for a couple experiments, like max dehumidifcation. Tell me what you would do based on my data. There not enough cooling load to operate the a/c. The basement is slowly warming as we are getting hotter weather. I expect the a/c to provide more humidity control as the summer progresses. Regarding the past "30-40 years ago", I gutted this basement 2X because of the musty odors. I have not had any musty odors in my ducts or basement since providing <50% RH with a good dehu (+15 years). My family loves it. As my children leave home and get there own homes, my dehumidifiers go to their homes.
    Actually manual J has a saftey factor built in to avoid the disappointment of being able to met customers expectations. An extra .5 ton will not handle more than 6 extra people. 20-30 is an over statement on your part. My comments about full featured a/cs referred to our fellow posters in general not you specifically.
    I am trying to suppport the a/c contractors role to supply ventilation/dehumidification for the resideintal customers. That makes our dehumidifiers expensive compared to home depot. Would you be more supportive if our equipment would be available at home depot for half the price? So far there an increasing number of upscale a/c contractors promoting supplemental dehumidification. Being able to maintain the desired %RH regardless of the indoor temperature or cooling load is ideal. The ideal cooling system is a simple a/c with a whole house dehumidifier. These dehus are easy to service. I appreciate the honest feedback and understand the occasional dig. Regards TB
    Attached Images Attached Images  
    Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
    Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
    Use +Merv 10 air filter. -Don't forget the "Golden Rule"

  2. #41
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
    Posts
    6,064
    Quote Originally Posted by everythingair View Post
    Coo
    If you live in a very high humidity clime, it is not a good idea to increase the thermostat temperature in the cooling mode if you are only going to be setting it back for a few hours at a time. The higher the temperature of the structure goes, the more humidity is allowed into the air that will also permeate walls, floors and furnishings. The amount of energy saved over a brief period will be overwelmed by the amount of additional energy it will require in order to remove the additional moisture that was allowed into the dwelling during the rise in temperature period.
    .
    You state that "The higher the temperature of the structure goes, the more humidity is allowed into the air that will also permeate walls, floors and furnishings." This is not true. Moisture absorption is based on relative humidity not the water content of the air. Another point about the indoor temperature is that the lower the indoor temperature, the faster moisture moves to the cool surfaces. Warmer indoor surfaces have a lesser attraction for moisture. An example is a can of pop from the refrigerater. the moisture moves in through the wall to the cool area. The cooler the inner surfaces of exterior walls, the moisture moves into the home. No big deal but any warmup of wall and sturtural temperatures allow drying out not absorption of moisture. Regards TB
    Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
    Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
    Use +Merv 10 air filter. -Don't forget the "Golden Rule"

  3. #42
    Join Date
    Jun 2008
    Posts
    63
    Quote Originally Posted by RomulanSpy View Post
    I'll give it a shot for next week. Wanna check the meter Tue-Sat then do the same for next week.

    Thanx
    RS,
    please post back what you find that works best for you. our electric rates are rocketing (Houston you know, Rocket, yuk, yuk). never would have thought of that SPAN thing if I hadn't got the idea here. anything that might help would be appreciated mucho $$$$.

    Thanx back at you.

  4. #43
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    66,805
    I supported fan "on" until they came out with stats that could do recirc/circ control of the fan. I still support fan "on" in some situations.
    Got a couple customers that won't shut their fan off no matter what, the house temp is too even with the fan 24/7 that they won't risk using fan circ.

    Average house in this area, has enough natural infiltration that a fresh air vent is not needed.

    Those houses that have a humidity propblem do get recommended a 2 stage to help control it. Not cure it. Because the humidity problem is from too much infiltration.
    The 2 stage will have the longer run cycle to keep it to a more comfortable level.

    In this area, people use their A/Cs alot more then you use yours. So you can't compare what you call no load to the rest of the people across the country.
    Around here, at 72* OD temp, A/Cs are running. And they are able to keep the humidty under 55&#37;RH.

    If they want lower, Then I look at the house as a whole. Not just one part. If they can't tighten the house, they don't need 2 stage or a VS blower.

    If they can't tighten the house. Then its a matter of how much thet are wiling to spend on a system for improved humidty control. Weather I push to use a 2 stage, or just a VS blower.

    Improved humidity control, means improved over the old system. Not cured that it will be perfect.

    No one solution is best for every house.

    I have nothing against whole house dehumidifiers, as one of many possible aids to humidity control.
    Its just the average house already has enough infiltration, additional fresh air isn't required.
    And if those homes lowered their infiltration rate, they would have lower humidity, and still have enough fresh air, that additional ventilation is not required.

    I agree that a positive pressure home can control humidity better. But perfection isn't what the average home owner is really looking for.

    Your dehumidifiers are priced for upscale homes. Nothing wrong with that.

    A unit that is stand alone, and simply dehumidifies, no ability to bring in fresh air, would be a good line.
    So would an add on to the central air system. One that just ties into the duct system, and only dehumidifies, no fresh air intake.

    Products that tackle several task, tend to cost more then needed for many applications. And ar hard to justify to the general public.

    In the past, I had several customers interested in whole house dehumidifiers. Until they heard the price.
    Then they fell back to, never needed it before, don't think I need it now.

    Customers need to be able to see an improvment, or suffer from a condition before they will appreciate devices to minimize that condition.
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  5. #44
    Join Date
    Mar 2008
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    205

    Jax 1: a question

    Quote Originally Posted by jax1 View Post
    RS,
    please post back what you find that works best for you. our electric rates are rocketing (Houston you know, Rocket, yuk, yuk). never would have thought of that SPAN thing if I hadn't got the idea here. anything that might help would be appreciated mucho $$$$.

    Thanx back at you.
    During the hottest part of the day, where do you put your T-stat on? Or are you leaving it on your night setting of around 70*?

    I will be gettin' back w/y'all about my findings.

  6. #45
    Join Date
    Jun 2007
    Location
    Bucks Co PA
    Posts
    364
    Quote Originally Posted by jax1 View Post
    Very true! This matches exactly what I experienced in Humid Houston.

    The 'setup while out' worked until the temps went to the mid 90's. At those temps and normal stat settings, I have a 30min on/ 30min off cycle time. Like Romulan, I also keep my house at low 70* while sleeping. My AC doesn't come on until around noon and runs 2 1/2 hrs until 5pm. If I 'setup while out' the AC runs 3-4 hrs to catch up.

    Romulan should try different plans for several days, and READ THE ELECTRIC METER. Then he will know what saves the most for him. A surprise to me was changing the SPAN setting to the lowest setting (more cycles) made a 10kwh/day difference. Your mileage may vary.

    Theoretical discussions can give you ideas to try, but only the electric meter knows the truth for your situation.
    OK this may sound stupid, but is that 10 kwh/day MORE ?
    .

  7. #46
    Join Date
    Jun 2008
    Posts
    63
    Quote Originally Posted by RomulanSpy View Post
    During the hottest part of the day, where do you put your T-stat on? Or are you leaving it on your night setting of around 70*?

    I will be gettin' back w/y'all about my findings.
    During the day it's programmed at a comfortable setting for us that varies probably due to humidity. Early and late season it's mid 70's, mid-season it's upper 70's. It's programmed to drop 1 degree at dark, another degree at 9pm, then at 11pm it drops to low 70's. It seems for my system that easing into the low setting uses less kwh than slamming all at once.

    I like to experiment with the settings and find the upper limit of our comfort range without getting uncomfortable. It's curious how much difference a small change can make over a long cooling season, and the results aren't always what you'd expect. Who would have thought that leaving my AC on saves more than setting it up while out? Plus it's free tax free money!

    IMPORTANT: My settings are not necessarily how anyone else should program their settings. the message here is try many things to see what saves you the most while remaining comfortable.

  8. #47
    Join Date
    Jun 2008
    Posts
    63
    Quote Originally Posted by Jack2007 View Post
    OK this may sound stupid, but is that 10 kwh/day MORE ?
    .

    Jack,
    I got 10 kwh/day less with a smaller SPAN (shorter cycles). But it's not really important. That was just an example of how a simple change can make a big difference. Smaller is better for my system. Yours may work just the opposite. There are too many variables involved to say what works best for everyone. Try everything, anything. Stay cool! Only the Meter knows for sure.

    The Meter knows all, tells all.

  9. #48
    Join Date
    Jun 2007
    Location
    The Twilight Zone
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    2,964
    Quote Originally Posted by beenthere View Post
    Start wattage is not as great as you might think. ( this should get some talk going )
    OK - I'm getting the talk going.

    Isn't the start wattage the highest instantaneous power draw that the condenser sees?

    How much more (as a ballpark percentage) is start wattage compared to running at 95F ambient?

    Thanx (and take it easy on me )

  10. #49
    Join Date
    Jan 2004
    Location
    Lancaster PA
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    I'll let you run a spread sheet on this yourself.

    Take a unit that has a 150 AMP LRA.
    And a RLA of 25.

    Now figure out how much wattage it really draws on start. Lets say it does not have a hard start kit. So lets say it starts extra slow. And go with 5 seconds of drawing LRA.
    How many watts does it really draw in those 5 seconds.
    And then use 80&#37; of the RLA as its true amp draw when running, and see how long it takes to use the same wattage running as it does to start.

    You will be supprised how little it uses.

    When taken in the context of wattage, starting does use the most in the shortest time period.
    But the time period is small enough that its not as much as you think.
    It takes a fair amount of short cycling to increase the electric bill noticably.
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  11. #50
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    If you have troubles figuring it. Let me know, and I'll run one later.
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  12. #51
    Join Date
    Jun 2007
    Location
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    Quote Originally Posted by beenthere View Post
    I'll let you run a spread sheet on this yourself.

    Take a unit that has a 150 AMP LRA.
    And a RLA of 25.

    Now figure out how much wattage it really draws on start. Lets say it does not have a hard start kit. So lets say it starts extra slow. And go with 5 seconds of drawing LRA.
    How many watts does it really draw in those 5 seconds.
    And then use 80% of the RLA as its true amp draw when running, and see how long it takes to use the same wattage running as it does to start.

    You will be supprised how little it uses.

    When taken in the context of wattage, starting does use the most in the shortest time period.
    But the time period is small enough that its not as much as you think.
    It takes a fair amount of short cycling to increase the electric bill noticably.
    OK here are my numbers (I am ignoring the motor's power factor):

    Power draw at 150 amp LRA = (150)(220) = 33,000 watts = 33 kw.
    Running for 5 seconds (.0014 hours) = .0458 kw-hrs.

    Power draw at 80% of 25 amp LRA = (20)(220) = 4400 watts = 4.4 kw.
    Assuming a 15 min run time (.25 hours) = 1.1 kw-hrs.

    Total for 15 minutes = .0458 + 1.1 = 1.1458 kw-hrs.

    The start-up is only 4% (.0458/1.1458) of the total power draw for 15 minutes.

    The condenser would have to start and stop 24 times (1.1/.0458) to equal the same power draw of a 15 minute straight run time.

  13. #52
    Join Date
    Jan 2004
    Location
    Lancaster PA
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    Or.
    The difference between 4 CPH (96 in a 24 hour period) and 3 CPH (72 in a 24 hour period) setting on a stat, in start wattage, is equal to 12 hours of run time in a 30 day period.
    If you had a month that the A/C cycled to the stat CPH setting.

    So. By its self, a start doesn't draw as much as what most first think. But, adds up over a months time.
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