Regular Guest
Your house is as good as it's going to get with the builder grade equipment installed and complete mess of a all flex duct system it's a typical new construction mess. It's a ac system to get the house cool and sold and then that's all you get. But hey it's got all the pretty stuff our wives like so they are pretty and uncomfortable. 20g in flooring and a 2500 ac system typical builder.
It's time to spend the money hire a qualified contractor and plan on replacing the existing junk builder system's with correct high end HVAC equipment scrap the flex duct spider mess and design a custom duct system using quality materials that will deliver correct airflow to all areas. IE variable speed blowers, multi stage cooling or a vfd driven compressor HVAC equipment is what you need along with a correctly designed duct system will deliver exactly what you are after.
You've done about all the optimizing of your existing stuff you can. What it's doing now is all you are going to get out of it ever and as the house and equipment ages it's going to get a whole lot worse. We are ac guys our job is to deliver bad news to people who don't want to pay to fix problems on a daily basis. They all want it fixed and precious few want to pay the money to get their desired results.
Membership Chair/ARP Committee / Professional Member*
It's an oddity of hackery that it is often possible to both lower humidity and trade off sensible while actually forcing the system to perform closer to the required BTU requirements. <g>
PHM
--------
Originally Posted by Mr Bill
Ok I'll shut up, since he apparently doesn't care about any sensible heat removal loss. Carry on soldiers.
Sent from my iPhone using Tapatalk
PHM
--------
When faced with the choice between changing one's mind, and proving that there is no need to do so, most tend to get busy on the proof.
Regular Guest
Thanks for the response but no, I do not have an attic fan.
Regular Guest
Thanks for the response and suggestion.
Regular Guest
Of course I care about sensible heat removal... I'm just trying to find a middle ground between that and removing humidity.Ok I'll shut up, since he apparently doesn't care about any sensible heat removal loss. Carry on soldiers.
Sent from my iPhone using Tapatalk
Regular Guest
Hey Teddy... Again thanks for all the advice as well as thanks to everyone else who's trying to help me out.
Here are some numbers...
Outdoor Temp/Humidity = 95°/63%
Indoor Temp/Humidity = 74°/54%
I'm also noticing some condensation on the bottom of my drain pan falling on to the wood floor beneath it. It appears cold air is coming out of my secondary drain line hitting the drain pan and causing it to condensate at the bottom of it. I don't have much room to insulate this part as my pan is on a platform. The pan sticks out about an inch from the platform. I shoved some attic insulation under there in the mean time, any suggestions????
Last edited by MSanchez214; 09-17-2016 at 06:28 PM. Reason: Wrong number
Professional Member
I would be curious to know the tonnage of the unit and how long does the unit run when there is a call for cooling before the thermostat is satisfied? I've seen oversize units that don't run very long cause humidity problems. Humidity is only being removed when the compressor is running. Sometimes people think that a bigger unit is just better but if it's too big there is just not enough run time to get the humidity removed. Might not even be the issue here but just a thought.
Regular Guest
I have timed the units run anywhere from 10 to 25 minutes.
Professional Member
Seems like a reasonable amount of run time to get the humidity out. Are you getting lots of condensate out of the drain line? Not sure if it was discussed yet but what is the configuration of your return air ducting? Could you be pulling in warm humid air from a leaky return duct in the attic ? Just thinking out loud here...
Regular Guest
I checked all my returns (I have 4 12 x 12s in the bedrooms, a 20 x 25 on one side if the house and a 20 x 30 on the other) and none seemsm to be leaking at the plenum or where they meet the sheetrock. Even then, I out some great stuff on the attic side where they go into the sheetrock and all returns have mastic on the inside.
Professional Member
I know you had the humidity down some at one point. What are you currently at? Have you tried lowering your temperature set point and letting the units continue to run and see if the humidity comes down any more? I may have to ponder this a bit more. ..
Regular Guest
Yes! I currently have my AC at 75. Used to have it at 76/77 and now my wife is dying of coldness at 75! LoL. And the lowest humidity number I've seen was 53% indoors but I'm not 100% what the outdoor temp/humidity was. =/
Professional Member
Ok, if your wife was cold at 75 and 53% RH was she comfortable at 76/77? At my house, as long as my wife is happy, I don't care what the numbers are lol
Regular Guest
Lmaoooo!!!! I totally see your point. My wife loved 76/77 but what concerned me was my humidity in the low 60s. That's when I hear mold growth starts.
New Guest
I'm having the same issues. did any of these pointers help?
Sponsor & Professional Member*
I reviewed your posts.
The story goes on. Keep in mind that shot cooling cycles less than 20 mins. with a dry coil will not remove any moisture. It takes 20-30 mins. to load the coiling coil/pan with moisture to the point where moisture goes down the drain. The moisture left on the coil re-evaporates back to the home in 1 hour when the compressor is off. During repeating on/off cycles of shorter length, limited dehumidification takes place. 20 mins. on/off should remove some moisture.
I would encourage the lowest fan speed possible without freezing the coil. Expect 50-55^F +75%rh supply air temps at the close supply vents with 75^F, 55%RH return air, same as room air. Short term, do no worry about the condensation on the ducts.
After several hours continuous operation during peak cooling loads, expect approaching 50%RH. If not, start looking for duct leakage on the supply/return ducts. You may find a big air leak in the attic.
Adding dehumidifiers to a warm coil a/c will not get you low humidity during high cooling loads. Dehumidifiers will be needed to maintain low humidity during low/no cooling loads and high outdoor dew point, +60^F.
You may need an Ultra-Aire 70 H on each a/c with a good setup.
Glad to talk to your a/c tech on the phone.
Keep us posted.
Regards Teddy Bear
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"
Professional Member
The way the flex duct is installed (sad) with a pocket thermometer with a 5" long 1/8" diameter shaft, measure temps at all return air grills (in the grill) then at the return of the unit (if its flex just poke a hole in it). Do this when outside temp is 10* or better outside. See how much difference there is between RA and OA. If their not close you have a lot of infiltration. Duct leakage.
Posting Permissions
Reply
