Posted by
Message
hungryone
LSU Fan
river parishes
Member since Sep 2010
10285 posts

whole house dehumidifier installed in HVAC
Considering the addition of a whole house dehumidifier to my HVAC. Anyone have one? Pros, cons, approx cost? AC company has been contacted for a quote, haven't received it yet.

Issue is that indoor humidity is hovering around 65% this mild winter. Condensation forming on window interiors. I need to get this moisture out of my house without resorting to uncomfortably cold or warm room temps.


notsince98
Missouri Fan
KC, MO
Member since Oct 2012
11347 posts

re: whole house dehumidifier installed in HVAC
have you tried a portable dehumidifier to see if it makes any difference?


ItzMe1972
Member since Dec 2013
2926 posts

re: whole house dehumidifier installed in HVAC
Pretty common to have some condensation on north facing windows and others if conditions are right.



Replies (0)
Replies (0)
00
slacker00
Member since Mar 2011
412 posts

re: whole house dehumidifier installed in HVAC
I installed one myself recently in my mid- 90s built house. Really like it. Especially shines on days like today where outside temps are in the 70s and humidity is in the 80s.

Edited to add: not sure what installers would charge, and bet many don't have experience with them. Mine was just the cost unit, controller, and the install supplies(flex duct, take off, drain pipe, drain pan, and electrical wire).

Head over to hvac-talk if you want to read more about configurations and options.
This post was edited on 1/13 at 4:52 pm


LSUtigerME
LSU Fan
Walker, LA
Member since Oct 2012
2208 posts

re: whole house dehumidifier installed in HVAC
What unit do you have and how is it installed?

I’m in similar spot as OP. These mild humid days are keeping my house fairly humid without the AC needing to run.


slacker00
Member since Mar 2011
412 posts

re: whole house dehumidifier installed in HVAC
I have the ultra-aire xt105h. It has it's own dedicated return but the supply feeds into the HVAC supply ducting so the dry air is pushed throughout the house. There's a butterfly check valve on that supply feed.


Replies (0)
Replies (0)
30
hungryone
LSU Fan
river parishes
Member since Sep 2010
10285 posts

re: whole house dehumidifier installed in HVAC
quote:

have you tried a portable dehumidifier to see if it makes any difference?


No, I'd rather just bite the bullet and get the whole house installed on the HVAC. House is exceptionally well insulated...in mild temps (like this non-winter), the unit will not run for days at a time. House is sitting around 65% when outdoor humidity is 75%-100%. I live fairly close to the MS river, so we have beaucoup heavy fog for much of late winter/early spring when temps are mild. I need to dry the house out---and I don't want to bother with a noisy, stand alone unit that will require emptying & take up space. Decent whole house units seem to cost nearly as much as the in-HVAC versions (not counting installation, of course).

It is pretty much NEVER dry in my locale unless we're in a severe drought. Lot is adjacent to pasture/fields & a large utility servitude that holds water, I can see swamp from my back porch.


CrawDude
LSU Fan
Baton Rouge
Member since Apr 2019
1074 posts
 Online 

re: whole house dehumidifier installed in HVAC
Sounds like you are a perfect candidate for a whole house dehumidifier - it is these transitional weather conditions in the Deep South that these units supposedly shine. I to plan to have one installed as well but haven’t gotten pricing yet, as I had planned to have it done when replacing my older HVAC, but I may have to re-think this.

The equipment cost is not particularly high (depending on size), and watching YouTube videos on their installation is simple pretty straightforward, particularly if an electrical outlet is located in the attic near where the unit will be placed. Only a guess, but I suspect or would hope installation cost would/should likely be about equal the cost of the equipment.

As another poster said, any post on the HVAC-Talk forum on this topic answered by “Teddy Bear” who is a guru (retired engineer who was instrumental in the design of the Aprilaire whole-house dehumidifiers) is very informative (pricing is not discussed on that site as per forum rules).

Should you get cost estimates and go forward with this, I hope you’ll update this thread.


hungryone
LSU Fan
river parishes
Member since Sep 2010
10285 posts

re: whole house dehumidifier installed in HVAC
quote:

Should you get cost estimates and go forward with this, I hope you’ll update this thread.

I will....calling around for quotes later this week. Dunno if the local guys will be of any help or not, guess I'll find out.

I replaced all ductwork due to mold late last year. Upgraded bath vent fans to higher CFMs, and duh...realized I was actually pulling in more moisture than I was venting, since the system isn't really running right now.

I want a dry house, dammit.


CrawDude
LSU Fan
Baton Rouge
Member since Apr 2019
1074 posts
 Online 

re: whole house dehumidifier installed in HVAC
quote:

I want a dry house, dammit.

I’ve been monitoring living area and attic humidity in my house 24/7 with a couple Bluetooth humidity/temp meters. for the past 1.5 years. Wanted to know what I’m dealing with before I replace my HVAC.

I can really feel the decrease in comfort level when humidity exceeds 55%, and the highest I’ve measured is 58% when AC is not operating in rainy weather. If your at 65% that’s almost unbearable - almost like having a broken AC.


TD SponsorTD Fan
USA
Member since 2001
Thank you for supporting our sponsors
Advertisement
hungryone
LSU Fan
river parishes
Member since Sep 2010
10285 posts

re: whole house dehumidifier installed in HVAC
quote:

If your at 65% that’s almost unbearable - almost like having a broken AC.

It's not unbearable--I lived for years without AC--but it certainly would help allergies, comfort level, etc.


baldona
Auburn Fan
Florida
Member since Feb 2016
11126 posts

re: whole house dehumidifier installed in HVAC
I've seen just standard plug in humidifier's installed underneath an AC return. They are super quiet actually, more quiet then the AC running. They have humidity sensors, so you can run them to run anytime the humidity is over a certain percent. They also have drain lines, so you could run it into your AC drain, that's what most do. There's almost always an extra outlet in the AC closet.

Not sure if this is an option for you, but its basically like $250 or less and you are all set with nothing to do.


hungryone
LSU Fan
river parishes
Member since Sep 2010
10285 posts

re: whole house dehumidifier installed in HVAC
quote:

There's almost always an extra outlet in the AC closet.

No AC closet....return register is in ceiling, in the middle of a hallway. Unit is in attic. Open plan house, so not very many convenient places to "hide away" a large capacity dehumidifier. I can't seem to find one that won't fail after a few years....literally the best rated one on Amazon was being recalled/bought back by Honeywell due to failures. If the local AC guys are clueless, I might try out the portable....or if I find a super good deal online.


shell01
Texas A&M Fan
Marianna, FL
Member since Jul 2014
369 posts

re: whole house dehumidifier installed in HVAC
quote:

Unit is in attic.

Is your attic a conditioned space (inside the housing envelope)? If so, perfect to put the whole home dehumidifier up there too. Check out Matt Risinger on YouTube and search for dehumidifier on his channel.


Stexas
LSU Fan
SWLA
Member since May 2013
3101 posts

re: whole house dehumidifier installed in HVAC
I did it two years ago in November and it's been amazing. We put in a new 5 ton unit and added a 3 ton equivalent dehumidifier. The dehumidifier's exhaust empties into the A/C air return and will slowly increase the temp near the thermostat kicking on the A/C so the A/C will then pull the dryer air and circulate that. It's made a huge difference on the overall comfort of the house and while I can't quantify it I'm pretty sure the showers and tubs are much easier to keep mildew free. I keep the humidistat on about 53%.

Installed cost added about $2,300 to the overall cost of what we did to the project, including plumbing and pulling new power to operate the unit.


hungryone
LSU Fan
river parishes
Member since Sep 2010
10285 posts

re: whole house dehumidifier installed in HVAC
quote:

Is your attic a conditioned space (inside the housing envelope)? If so, perfect to put the whole home dehumidifier up there too. Check out Matt Risinger on YouTube and search for dehumidifier on his channel.

Nope--it's not. It's a passively vented attic with ridge vent. My better half is encouraging the trial of a plug in dehumidifier, since we only have this problem during mild temps. 6 months of the year, the AC runs and we are fine.


Replies (0)
Replies (0)
02
XanderCrews
LSU Fan
Member since Mar 2009
728 posts

re: whole house dehumidifier installed in HVAC
Can you give a shout out who did this?

I tried to give money to someone to do it and they just keep telling me 58% humidity is ok. I would love to give someone my business who is wanting to stand behind whole house dehumidifier installs.


Stexas
LSU Fan
SWLA
Member since May 2013
3101 posts

re: whole house dehumidifier installed in HVAC
I live in Jennings, the shitehole that serial kills and produces great RBs. You don’t want me to shout out anyone from here....


Replies (0)
Replies (0)
00
hungryone
LSU Fan
river parishes
Member since Sep 2010
10285 posts

re: whole house dehumidifier installed in HVAC
Bought a 70 pint portable GE dehumidifier at Home Depot.....plugged it in yesterday. Amazing how much water that thing pulls out of the air. Haven’t yet hit the 24 hr mark, but it isn’t too loud. Planning to let it run until it actually reaches 50% humidity.....dunno how long it will take. Unit is rated for 1500 ish square feet, and I’ve got 2100....

Local HVAC guys didn’t know much about installing or performance of a whole house dehumidifier. So I’m using the portable until I find a service provider who has actually installed one.


LSUtigerME
LSU Fan
Walker, LA
Member since Oct 2012
2208 posts

re: whole house dehumidifier installed in HVAC
quote:

hungryone


I did the same thing. I picked up a 70pt Fridigdaire from Best Buy.

It’s amazing how much water I’ve emptied from that thing. I’ve run it for about 12 hours or so now, and it’s taken about 4 gallons of water from the air. My Ecobees were showing 65%+ on both of them, and now read around 53%.


Replies (0)
Replies (0)
20
first pageprev pagePage 1 of 2next pagelast page

Back to top

logoFollow TigerDroppings for LSU Football News
Follow us on Twitter, Facebook and Instagram to get the latest updates on LSU Football and Recruiting.

FacebookTwitterInstagram