Whole house humidifier in Florida

Reply

  #1  
Old 05-17-11, 01:57 PM
B
Member
Thread Starter
Join Date: Apr 2004
Location: Florida
Posts: 310
Received 1 Vote on 1 Post
Whole house humidifier in Florida

I have single family home in Central Florida with a heat pump A/C & heating system. I would like to know the feasibility of installing a whole house humidifier in the system along with any pros and cons......thanks
 
  #2  
Old 05-17-11, 02:19 PM
M
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 47,827
Received 361 Votes on 318 Posts
What part of fla? I'd think you'd have more need of a dehumidifier than a humidifier.
 
  #3  
Old 05-17-11, 02:56 PM
B
Member
Thread Starter
Join Date: Apr 2004
Location: Florida
Posts: 310
Received 1 Vote on 1 Post
Somehow I knew someone was going to ask that question. Actually, the humidity outside is high here but when the house is closed up in the summer or winter and the air or heat is on, the air in the house gets really dry. Unfortunately that isn't very good for me because I have COPD. I've been told that a bit more humidity in the house at night might help me sleep better.

OK marksr, I answered your question .....now you answer mine.....buzcar
 
  #4  
Old 05-17-11, 03:04 PM
M
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 47,827
Received 361 Votes on 318 Posts
I used to live in fla - that's why I wondered about the humidifier. I'm not an HVAC guy but I'm sure they'll chime in shortly.

My oldest son had some breathing issues when he was young. We set up a vaporizer in his room and it helped.
 
  #5  
Old 05-17-11, 03:25 PM
B
Member
Thread Starter
Join Date: Apr 2004
Location: Florida
Posts: 310
Received 1 Vote on 1 Post
I'm sure a vaporizer would help the situation but I think I would like to do the whole house if I can. Thanks again for your input.....buzcar
 
  #6  
Old 05-17-11, 04:22 PM
hvactechfw's Avatar
Member
Join Date: Jan 2011
Posts: 6,244
Received 2 Votes on 2 Posts
where is your hvac equipment located? Closet, garage, attic, basement?
 
  #7  
Old 05-17-11, 04:36 PM
B
Member
Thread Starter
Join Date: Apr 2004
Location: Florida
Posts: 310
Received 1 Vote on 1 Post
I'm not sure what the two units are called but one is located outside and the other is located in the attic
 
  #8  
Old 05-17-11, 04:46 PM
hvactechfw's Avatar
Member
Join Date: Jan 2011
Posts: 6,244
Received 2 Votes on 2 Posts
I do not recommend installing a whole house humidifier in the hvac system in the attic even if your temps don't go below freezing. This is due to the fact that sometimes when humidifiers are not maintained on an annual or biannual basis and sometimes just because.... they leak. Having a humidifier leak in the attic would not be a good thing at all. Even if the system has a secondary drain pan it is not a good idea it is too much of a risk.

As to the feasibility of installing a whole house humidifier it is feasible depending on your ductwork situation..... There must be somewhere to mount the humidifier. It would need to be a powered humidifier. A bypass humidifier will not work due to your a/c removing humidity if you were going to try to add humidity during cooling.

BTW, outside unit = Heat pump inside unit = air handler
 
  #9  
Old 05-17-11, 05:27 PM
B
Member
Thread Starter
Join Date: Apr 2004
Location: Florida
Posts: 310
Received 1 Vote on 1 Post
Thanks for the info. At least now I know which unit is the heat pump. I'll probable have to be satisfied with a portable humidifier based of what you told me.....better to recognize a potential problem now rather than later......thanks again!
 
  #10  
Old 05-17-11, 09:03 PM
Jay11J's Avatar
Member
Join Date: Sep 2001
Location: Rochester, Minnesota
Posts: 18,427
Received 0 Votes on 0 Posts
What % of humidity are you reading in your home? What level are they suggesting for you?
 
  #11  
Old 05-18-11, 05:26 AM
B
Member
Thread Starter
Join Date: Apr 2004
Location: Florida
Posts: 310
Received 1 Vote on 1 Post
Unfortunately, I have no idea what the humidity reading is in the house nor do I know what is recommended. I only know that dry air is not good for my breathing condition and thought a humidifier would be beneficial. Why do you ask?
 
  #12  
Old 05-18-11, 06:53 AM
B
Member
Join Date: Oct 2008
Location: New England
Posts: 10,524
Received 37 Votes on 34 Posts
Jay beat me to it. Knowing the inside and outside humidity helps you understand how much you need to add. Also, if inside gets above 50% or so, you can start to have mold problems.

The humidity numbers we all use are actually relative humidity and can be funny numbers as the same amount of moisture in the air will yield different relative humidity (RH) numbers as the temperature changes. Take the heating season for example. If the outside air is 50 at 50% RH, when that air infiltrates into the house and is heated up to 70 it will have a lower RH number. Just guessing, but say 30%. In the summer, the warm humid outside air that leaks in will produce a higher RH number as the ac system cools it down. The exception being that ac systems also remove moisture. Smaller ac systems run longer and remove more moisture where larger systems run in short bursts and remove less moisture.

What all of this is introducing you to is the need to look at the whole picture and perhaps a change somewhere else will yield better results. As marksr said, Florida should normally have enough humidity, so perhaps your system is removing too much in the summer and dealing with too much replacement air in the winter. That last statement is where I'm headed. Excess air leakage can cause dry air in the winter and longer ac runs in the summer, both cases will reduce the inside humidity levels. So, a possible alternative to running a humidifier could be some simple air sealing. Lower utility costs, less pollen from outside to deal with, and higher humidity.

Bud
 
  #13  
Old 05-18-11, 07:00 AM
B
Member
Thread Starter
Join Date: Apr 2004
Location: Florida
Posts: 310
Received 1 Vote on 1 Post
Thanks Bud.....by "simple air sealing" can I assume you mean leaks in the ducts?
 
  #14  
Old 05-18-11, 07:41 AM
B
Member
Join Date: Oct 2008
Location: New England
Posts: 10,524
Received 37 Votes on 34 Posts
Every home exchanges air with the outside at a rate that is hard to imagine. I don't know what you have, but a typical home will replace all of its inside air every one to two hours. leaky homes are worse and a tight home will take three hours. If a home is tight enough to require 4 hours, it is too tight and will need an air exchange system installed.

Air ducts can be part of the problem, especially when they are outside the building envelope, like the attic. Sealing and extra insulation on the ducts up there could reduce the ac run time which is removing moisture. Also reduce the electric bills.

I have a link from efficiency Vermont that details a lot of hidden air leaks. Basically, unless the builder went crazy sealing everything during construction, which only the latest homes do, all hones look like swiss cheese. Electrical, plumbing, vents, and so on all allow air to move freely through walls and eventually to the outside. Here's the link, it opens slow but is good.

http://www.efficiencyvermont.com/ste...ide_062507.pdf

Bud
 
  #15  
Old 05-18-11, 09:44 AM
B
Member
Thread Starter
Join Date: Apr 2004
Location: Florida
Posts: 310
Received 1 Vote on 1 Post
Air ducts can be part of the problem, especially when they are outside the building envelope, like the attic. Sealing and extra insulation on the ducts up there could reduce the ac run time which is removing moisture. Also reduce the electric bills.

Is it practical to seal the ducts myself or would you recommend hiring a pro? Do they have a way to locate any leaks? From what I can see all my ductwork is of the flexible variety. Might the leaks be in the duct itself or primarily where they are joined together?

By the way, the link you provided is excellent but doesn't address leaking flexible ductwork in the attic area. It certainly is great for new construction though....
 
  #16  
Old 05-18-11, 11:18 AM
B
Member
Join Date: Oct 2008
Location: New England
Posts: 10,524
Received 37 Votes on 34 Posts
Leaks associated with flex ducts will usually be at the ends as you suspect. It's possible that there are holes elsewhere, but I haven't run into any. Flex ducts are not the best for insulation with many being just R-6 or so and with moving air inside, the heat loss or gain is high.

Does your home have a basement or crawl space? The moving force for air leakage is a pressure difference. It occurs with warm air escaping high (called stack effect) and replacement air entering low. It also occurs with any imbalance within your forced air system. If a room has a supply duct and no return, then there will be a higher pressure in that room, assuming the door is closed. That increase in pressure forces air under walls, out electrical boxes, and through all of the leaks around windows. Once any air escapes to the attic or outside, there will be a negative pressure somewhere looking to pull in the replacement air to keep the volume inside the home constant.

Wind is another contributor to the air exchange problem as it exploits any and all seams, gaps, and holes throughout the house.

You are correct that new construction is the best time to be sealing things up, but the pictures provided also help to find many of the easy to fix areas and they all add up. The hard part for you is you can't see the results where I work with the tools and meters so I can test before and after and really know what has changes. Blind faith is what you need .

You also need those RH meters to help you decide when and how much you need to change things. It is one thing to decide you need more moisture, but knowing that 35% feels ok and 30% or lower is too dry really helps. Add in the outside temperature and humidity and you will begin to isolate the conditions that contribute to the problem.

I have to admit, I've only visited Florida a couple of times so relating to your temp and humidity is difficult. Way up north we are primarily a heating area and I see the dry results of adding heat to cold incoming air. Where you are, you use far less heat and the incoming air carries a lot more moisture. That leaves me as a professional scratching my head wondering what you consider too dry.

Good luck and perhaps some of our southern pros will help sort this out.

Bud
 
  #17  
Old 05-18-11, 12:04 PM
B
Member
Thread Starter
Join Date: Apr 2004
Location: Florida
Posts: 310
Received 1 Vote on 1 Post
Bud, I can't thank you enough for all the very helpful information you have given me. Whether I install a humidifier or not, you have certainly increased my amateur knowledge of the subject. For your information, I spoke to a pro a few minutes ago and he basicly told me he can do it but would have to special order the parts because he doesn't usually install them in Florida and doesn't know anyone that does. I guess I'll have to go back to the drawing board before I do anything. From what you have told me I think I will start by checking what my RH figures inside and outside are. Thanks again for all your help.....you're a credit to the forum.....buzcar
 
  #18  
Old 05-18-11, 12:35 PM
B
Member
Join Date: Oct 2008
Location: New England
Posts: 10,524
Received 37 Votes on 34 Posts
Well thanks, but for future reference, I'm still a beginner here compared to the collection of pros. I initially joined to learn and still am. Florida has many energy auditors with the same equipment, if you ever feel you need to isolate more leakage.

There is another approach, thinking backwards, when someone has a high humidity/mold problem we advise them to eliminate as many sources of moisture as possible. Long showers, boiling water, plants, aquariums, all can add moisture in a passive fashion. Perhaps a few of these steps, can help as long as they don't aggravate the air quality.

Enjoy,
Bud
 
  #19  
Old 05-19-11, 08:32 AM
Jay11J's Avatar
Member
Join Date: Sep 2001
Location: Rochester, Minnesota
Posts: 18,427
Received 0 Votes on 0 Posts
I would get a humidity/weather station and see what you are reading in your home.. Comfort range are anywhere from 40 to 50% range. I just can't see the need for them in your area since your winters are not like mine here in Minnesota where we get down to -20˚ and leaky homes get dry!
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: