New member with HVAC problem

[Bricks stoner]

Just joined last night, I hope someone out here can give me some advice on a HVAC system I have on a 1500 sf cabin with a 4' crawl space that is insulated very well in crawl space and house.
i have a 8-9 yr old 2.5 ton heat pump 12 seer, with a air handler in crawl space. This is in a weekend house on Arkansas/Missouri boarder.
When I leave to head back home I leave the thermostat at 76-77 degrees , the temp shows 82 regular degrees in house with a humidity at 89% +, I'm having a hell of a time trying to get the humidity out of my house! and get the a/c to cool it off.
i had a new company come out to look it over , he found a large cold air return on top of my duct work in the crawl space pulling air from there into my first floor, so I will close that off for good this weekend, he thought maybe in the future to change entire system to a 3.5 ton heat pump or just regular electric heat and a/c unit with all new 8" round insulated duct work with larger vent added to my main room which has 16' ceilings, rest of bedrooms and baths are regular 8' high.
i would like anyone thoughts on this, would anyone also recommend a whole house dehumidifier for my house. - it's driving me crazy, I just can't get the house to cool off and get the humidity down below 80% .
thx in advance for any help

[jnaas2]

Need a lot more information, The moisture is removed by the a/c unit running, if its not cooling the house down thats the first thing I would look at. What all did they do, Did they check for proper air flow across the coil, Did they clean the outside unit did they even make sure the charge was right. Did they install gauges and check pressures and the subcooling and superheat, Whats the temp split between air entering a/c coil and supply air, NEED MORE INFO

[Bricks stoner]

I was not there when the first guy came out, but my neighbor was, he said they checked the freon, hooked up the gauges and everything seemed good, he check the air handler in the crawl space and that's where he found the hole on top of the duct work about 16". Away from air handler, the opening was 17"x 21" which he thought that it's pulling the moist air from the crawl space I through the main floor of the house, that's where he thinks most of the humidity is coming from
I clean out the outside unit every year, and also change me Air Bear filter every 6 months.the guy who originally installed the system that I was pissed at, looked at few weeks ago, when I first turned on the a/c unit outside, and when I was there I had it set at 65 degrees trying to cool off the house, he checked the temps from the floor registers and the cold air returns and they were off a few degrees each. I didn't understand all that BS. Out of all the years we had this system, I know it usually takes a good day to get the house cooled down, and the humidity is always high , this year it's crazy high, and taking forever for the system just to cool off the master bedroom where the thermostat is located.
i hope it helped you, and I appreciate your help

[HayZee518]

did you seal up that hole? cold/warm air should come from the returns to the system. also check all the joints. you'd be surprised how much air comes from the joints. use a quality duct tape or non drying caulk. the a/c is nothing more than a super big dehumidifier. air flow across the evaporator has to be even as it removes the latent heat from the room air.
If your system's size was initially calculated at 2.5 ton then why would someone try to get you to increase to a 3.5, unless to make a quick buck! Was any room expansions performed?

[Bricks stoner]

I sealed the hole with a PC of insulation , but will head there this weekend and cover it with a PC on tin, tape and caulk it also , in also going to use a large dehumidifier to get as much as I can out of that house.would you recommend a full house dehumidifier system to add to what I have now ????and if u think that would help me, tell what what brand and size I would need and what you think it may cost me labor and system?
Thx for everyone's help

[HayZee518]

just went to a site that had an online calculator for cool and heat.
ark-mo border is split between two zones. right on the line, 2.5T for cool is good for 1251-1550 sq ft. heat 3.0 is for 1501-1850 sq ft and 1601-1900 sq ft for ark.
52500 Btu heat @ 35% times sq ft
64500 Btu heat @ 43% times sq ft.
the cool calculation takes into account 6 air changes per hour with a setpoint of 72 degrees.

[Lone Star Charles]

The only way to get an accurate design for HVAC is to do a Manual J calculation. That being said, I have found that older homes with average insulation, infiltration, and single pane windows will come out around 500 sqft/ton. Newer houses with R-19 or better insulation, extra effort on sealing around windows and doors and other penetrations, thermo pane windows, etc. will be in the 600 sqft/ton range.

Infiltration usually causes the biggest heat load on an AC system. Make sure that your cabin is sealed properly and that all of your ductwork, including the return air ductwork is properly sealed. Just guessing, I suspect that your current system will struggle a little bit during the heat of the day, but it should be comfortable enough in the evening if all is working properly.

[Bricks stoner]

I appreciate all the help so far, I did contact another HVAC company that my builder uses and going to meet with him Friday morning, I explained what my problems are and he will check everything out with his gauges etc and see what the problems and solutions will be. I'm also bringing Dow a industrial dehumidifier to run when I get there Thursday late morning and run it 24/7 till I head back home on Sunday . I will pass on his recommendations to all you guys once I find out what he thinks.
again thank you for your help and ideas so far, I just want this to be over with and run the right way.

[Bricks stoner]

Lone star, my house is very well insulated with r-19 in walls /R-50 I believe in ceilings of my bedrooms all walls between rooms were also insulated for sound and extra for cold and heat, that was all professionally done from my buddy's company, I we all made sure everything was filled correctly .
like I said house before, custom built ranch style house with all brick veneer , well insulated crawl space etc. Pella windows, insulated front doors and 2 large sliders.it was very well built for a 1500 sf house

[Lone Star Charles]

Bricks - It really does sound as if your system should be adequate. There must be something amiss somewhere. BTW, can you give us the manufacturer and model number of your heat pump? I look forward to the HVAC company's report.

[Bricks stoner]

Lone star, I'll be heading down tomorrow am, with the large dehumidifier , I will get whatever info from the system I got and also tell you this HVAC guy says also. Thx , and talk with you all soon

[Bricks stoner]

I just lost what I wrote out for you Lone Star, so I will re-write it again and hope I get everything in here. I borrowed 2 industrial dehumidifier a from a restoration company I do brickwork for and they pumped out the humidity out of my house within a day from 80% down to 45% which I guess is normal??, so I met the second HVAC guy Friday afternoon, we first started on the air handler, he showed me a few problems with the existing duct work, thin cheaply put together also a small opening for the cold air return back to handler of approx 6"x6"- ish which he said should be much larger, I did cover the hole that was on top of the duct work I told you all before with with a PC of tin with caulk and tape- all solid , and he showed me other places to tape , which I did. We then went to main floor, showed me 2 large cold air returns and 3 very small cold air returns, he thought that the large air return in my main room is not working fully with the system, it's just above our front door approx 8' off floor , he said it should have been installed as close to the ceiling height as possible , which the ceiling height in that room is 16' , and the rest of the smaller cold air returns should also be larger. He thought that with all the floor registers that system is maxed out with the 2.5 ton heat pump system I have now.
He also said he would also change out my old style thermostat to a new digital one.
so this is how he is going to figure out my options,
1: rework what we have now to get the system at is real potential and energy savings
2: price a complete new system /possible a 3 ton outside and 3 ton air handler unit with all thicker insulated ductwork throughout, rework cold air returns, thermostat etc and Heat Pump system
3: all new with regular a/c outside unit 3 ton , new regular heat strip furnace/air handler etc, rest same as #2 option.
the system info I have now is a Copeland Scrull / Goodman Company
model #GSH140301A. Serial #0807150533
i did not get any info off my air handler since I had it covered with insulation - sorry about that - I hope this help you out with any more info or your thoughts on this . Really appreciate everyone's help.
again the house is approx 1500 sf with 8' ceilings with the main largest family /kitchen room which is about 35' long x 27' wide with 16' ceiling .
look forward to any info/help you have for me

[Lone Star Charles]

It sounds like you are on the right track with this new contractor. A 6"X6" return air duct sounds awfully small and would certainly restrict airflow. Ductwork leaks will also seriously degrade performance. Getting those issues fixed will help you to get all the AC that the system makes into your home.

I looked up the technical manual for your system Download Goodman Mfg GSH140241A, GSH 14 SEER, GSC140421A, GSH140301A, RT6213004, GSC140601A, GSC140481A, GSH140361A, GSH140181A manual / user guide for free. . If you will look on page 10, it shows that at 95°F outside and 75°F inside your system will only deliver between 25,900 BTU and 28,100 BTU of cooling. The Goodman systems with the Copeland Scroll compressors are really good systems; however, yours does seem a little marginal for your size house, especially if it is installed with a marginal ductwork system.

Option #2 sounds like the best solution, but it is probably the most expensive. Before you spend your hard-earned cash on this one, I would recommend that the HVAC contractor do a Manual J analysis on your home. Let's make sure that the application is correct.

Everybody is using a programmable, digital thermostat these days. It does make the system a little more intelligent and effective.

One other option would be to seal up all your leaks and fix up the ductwork. Your current system might still be comfortable enough, especially in the evenings when it is a little cooler outside.

[Bricks stoner]

Thx for the info lone star , I'm just waiting for what the new guy puts together, as soon as I get his info and figures I will pass them on to you guys to see what you all think. I with you on the option 2 , if the figures come in reasonable , hopefully better than the first contractor that came out or at least in the same area he was at . I will stay in touch with you soon. Thank you again for taking time out of your day to help me out , we shall see !!!!