Page 9 of 10 FirstFirst ... 2345678910 LastLast
Results 105 to 117 of 122
  1. #105
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,104
    Teddy, your pushing thermostore so hard, your sounding like a snake oil salesmen.





    Contractor locator map

    How-to-apply-for-Professional

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

  2. #106
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
    Posts
    6,446
    Originally posted by beenthere
    Teddy, your pushing thermostore so hard, your sounding like a snake oil salesmen.
    Thanks for all good comments. I realize that my critics are sincere. Pushing hard enough to sound like an "efficient dehumidifier" salesman is what I had in mind. I have made the development and benefits of humidity control my lifes work for the last 15 years. I use a Infinity VS furnace with a tuned 2 ton a/c on 2400 sqft. home to max moisture removal. The air flow is slowed to the point that freexe-up occurs below 73^F. I could not provide <50%RH during all weather conditions we experience here in WI without a 100 pint dehumidifier. You are right, I do not install any a/cs except my own. But I am involved a desinging several dehu add ons to 2 speed vs a/c every week to provide <50%RH. Some houses have special problems but most simply do not have enough a/c load during wet cool weather to provide <50%RH. Keep in mind we should be providing 50-75 cfm of fresh air ventilation which makes the <50%RH objective impossible during wet weather without dehumidification. Testing in Houston by Building Science on +20 homes proved that Homes without supplemental dehumidification had significant time with +60%RH. This study inculded an "I" 2 speed a/c. The year of the test, 2002, there were only 15 rainy days in Houston. The year before, there were 20 straight days of rain in Houston. If the test would have been the year before, Many of the test homes would have had serious mold problems. To my critics, answer this question. It rains for 10 days straight with a top temperature of 75^F. Explain to us how your favorite system provides <50%RH with 4 occupants doing normal activity. After that, add 50-75 cfm of infiltration/fresh air ventiltion(new ASHRAE 62.2). After you post comments, review to see how easy it is to sound like "snake oil" salesman. Thanks again! TB

  3. #107
    Join Date
    Apr 2002
    Posts
    11,808
    I firmly believe that well built homes can get by with heating and cooling systems that are drastically reduced in capacity, compared to what is viewed as the norm.

    I have worked on many R2000 homes in Canada, which were extremely well built and tightly sealed and their cooling loads per square foot were not as low as this virtual home and a big reason for this was a lot of glass was used for passive solar heating in the winter.

    The latent load stated in this virtual house just seems too low for me even if the ambient humidity is 47 grains higher than the indoor humidity.

    This house is two floors at 35x70 with 9 ft and 10 ft ceilings so it is like 4900 square feet at 9.5 ft ceilings. If there was 0.3 air changes then that is equivalent to 233 CFM woth of infiltration.

    The LOW latent load stated in the OP makes me wonder if it was based on a Colorado elevation of 5000 feet. The latent load carried seems low for the infiltration rate, never mind the effects from 6 occupants in a 5 bedroom home.

    I never really use manual J software but there has to be more than just entering different design ambients when you change loactions, there must be a correction for latitude which would also have an effect on solar gain through windows. So if it was possible that the virtual house was run under a Colorado elevation, it could have also been run at a Colorado lattitude.

    A big problem with using design dry bulbs and coincidental wet bulbs which manual J seems to incorporate in the "Grains for 50%", is the most humid times of the year do not correspond to the hottest time of the year.

    As stated before, typically Houston can have worst case humidity levels of 137 to 147 grains ( 72 to 82 for 50%) while dry bulb temperatures are in the low to mid 80s and this is not a hurricane.

    In reality the virtual latent load could be double and the fenestration load could be higher as well. I would be impressed to see a comfortable 4900 square foot home in Houston with only a PAIR of 3 ton systems.


    The way we build has a greater impact on our comfort, energy consumption and IAQ than any HVAC system we install.

    http://www.ductstrap.com/

  4. #108
    Join Date
    Apr 2002
    Posts
    11,808
    Originally posted by beenthere
    Teddy, your pushing thermostore so hard, your sounding like a snake oil salesmen.





    Lol using the words 'pints' and "year round less than 50%" are sure signs of dehumidifier salesmen
    The way we build has a greater impact on our comfort, energy consumption and IAQ than any HVAC system we install.

    http://www.ductstrap.com/

  5. #109
    Join Date
    Aug 2003
    Posts
    626
    Carnak you have a very valid point. No system, no matter how good at latent removal can help if the run times are short. That is why the Building America homes use whole house dehumiifyers even though they are tighter than .3 nach. I also recommend them in hot humid climates.

  6. #110
    Join Date
    Apr 2002
    Posts
    11,808
    I am obviously south of Houston, more humid location but it does not get as hot.

    Year round cooling.

    It does not really matter how hot it is outside, its more a matter of how sunny it is and how humid it is. I would suspect this would be just as true in the cooling season up north, considering all the insualtion in homes these days.

    Almost all the load is from the ambient air and the sunshine. It is a pretty small portion through insulated walls and ceilings.

    ICF homes are diminishing returns down here, I think they are great in Canada where you have a 100 degree differential in the winter.
    The way we build has a greater impact on our comfort, energy consumption and IAQ than any HVAC system we install.

    http://www.ductstrap.com/

  7. #111
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,104
    Teddy, my point is that your answer to everybody is a whole house dehumidifier.

    In one post, the guy has 2 new systems over sized for his house by perhaps more then a ton, and your answer is install a whole house dehumidifier.

    Shouldn't the answer be, have the contractor install the correct size units?

    Not put a band-aid on it.
    Contractor locator map

    How-to-apply-for-Professional

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

  8. #112
    Join Date
    Aug 2003
    Posts
    626
    While ICF homes are strong, moisture and termite resistant, the cost/benefit ratio on energy savings is very hard to justify. Concrete here is expensive!

  9. #113
    Join Date
    Apr 2002
    Posts
    11,808
    Concrete is the way to go if you are prone to hurricanes.
    The way we build has a greater impact on our comfort, energy consumption and IAQ than any HVAC system we install.

    http://www.ductstrap.com/

  10. #114
    Join Date
    Jul 2004
    Posts
    253
    Originally posted by uktra
    While ICF homes are strong, moisture and termite resistant, the cost/benefit ratio on energy savings is very hard to justify. Concrete here is expensive!
    Uktra, I will have to ask my builder what the exact incremental cost of ICF was over 2x6 framed construction. The last time I spoke to him about it (after we decided to go with ICF), he said the cost differential had shrunk since the first time we talked ( a period of about a year ) because of rising wood prices. He has an interest in a concrete company I beleive so the increase in the price of concrete was probably less than for most people. We did it because of reduced termite issues and for the potential energy savings - whether we save on energy remains to be seen and will probably be hard to evaluate.

  11. #115
    Join Date
    Aug 2003
    Posts
    626
    Key thing on ICF construction is the roof. Make sure you airseal and insulte well.

  12. #116
    Join Date
    Apr 2002
    Posts
    11,808
    There used to be a guy called "mark" something on here who worked for an ICF co. They even had an ICF roof system.
    The way we build has a greater impact on our comfort, energy consumption and IAQ than any HVAC system we install.

    http://www.ductstrap.com/

  13. #117
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
    Posts
    6,446
    Originally posted by beenthere
    Teddy, my point is that your answer to everybody is a whole house dehumidifier.
    In one post, the guy has 2 new systems over sized for his house by perhaps more then a ton, and your answer is install a whole house dehumidifier.
    Shouldn't the answer be, have the contractor install the correct size units?
    Not put a band-aid on it.
    Yes, the dehumidifier solves most of the "cooled before dry" problems in green grass climates. If the a/c is big enough to handle the sensible cooling, the dehumidifier handles any remaining latent load to maintain less than <50%RH regardless of the oversize. Many times there is only a latent load. With a slightly oversized a/c, we are able to set the t-stat up when the home is unoccupied and maintain <50%RH with minimal operating cost. If the home will cool down in a hour or less, whats the problem. No a/c for 10 hours every day or weeks with no threat of mold or dust mite growth. This is a tremendous opportunity to save energy and improve temperature/rh control of the home. Dial in the %RH desired, cool to the temperature when occupied. If you away for a day, week, or a month, no a/c requied to maintain <50%RH. Humidity control with a dehumidifier gives ideal temperature with no over cooling and reduces operating cost significantly.

    I agree, grossly oversized a/c are not ideal but after after paid for, replacing with a smaller unit is expensive and does not solve the latent load problem totally. We have leading a/c contractors, distributors, and equipment mfgrs. handling our systems. There is nothing like setting your %RH and temperature indepently with a minimum investment and operating cost. After 15 years of pioneering this concept, Aprilaire, Lennox, and several others are joining us in providing this solution to humidity control.

Page 9 of 10 FirstFirst ... 2345678910 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