Humidifiers and Dehumidifiers - Condensation on windows due to humidity?

I have allergies to molds and other airborne materials. I have noticed that over the past couple of years they have been getting worse when I'm inside the house. Coincidentally, I have noticed that during the warmest months the windows in our house have condensation on them and this past summer it was evident every day.

We have a den adjacent to our garage which is about 5 feet below ground level and I have started to notice my allergy symptoms getting worse while I'm down there. I've also noticed some rusting on some of our tools in the garage.

Here's my question...I am assuming this is all due to a high level of humidity in the house and am considering a whole-house dehumidifier. We are all electric and last year had to replace the complete heat pump system. Could the extremely high level of humidity this past summer be a result of the new unit's inefficiency to dehumidify? If so, is there anything that can be adjusted within the unit itself? Could something be wrong with the unit? If not, would a dehumidifier be of any real help and if so, does anybody have any suggestions?

Thanks! (sniff-sniff)

On the new equipement, does it run steady on a hot day? Or ic cycles on and off??

If it cycles on and off often, then the system is oversized..

Does it have a standard blower or variable speed.

Hmmmmm, I'm not really sure what you mean. I keep the fan on because I have a ranch-style house with 11' ceilings in the inner part of the house with bedrooms on either side w/ 8' ceilings. I have a downstairs that's partially underground that is 1/2 garage and 1/2 finished living area. I was told that the fans were manufactured so that they could run constantly and this would help balance and maintain the temp throughout the house. However it is always cooler downstairs, we usually have to close the vents in the hot months. We also have an unfinished attic area with a low slope roof line.

My compressor does cycle off and on, however, I have never seen one that didn't. If it stayed on, my house would be freezing in the summer and unbearable in the winter. Wouldn't it?

An oversized a/c on a hot day is NOT going to remove humidity if it's oversized.. over sized will lead it to cycle on and off. (Cooling down quick)

When temp gets in the mid-upper 80's my a/c pretty much run steady all afternoon into the evening. It's able to keep temp for the house as well cuz it's sized right. And when it's runnning, it's removing humidity. I get ave of 40 to 45% reading.

What is your humidity level in your home?? (Summer time? Winter time?)

How old and large is the house? Air to air exchanger? How big is the a/c unit? (2.. 3 tons?)

When you say humidity build on the window.. you mean on the glass inside outside or in between?

sounds like you have variable speed, and running the fan is good. You know if your ductwork is sealed in the garage area?

Wow! Ok, I'm going to try to answer your questions... (thanks for taking the time to help me with this!)

1. I don't have anything to measure the humidity in the house. Should I get something that will tell me and if so, what?

2. The house was built in 1980 and, is a total of about 3,200 sq.ft.

3. I'm not sure what you mean by air to air exchanger - the complete system (except ductwork) was replaced last year, the outside compressor and the air handler (fan) which is in the garage.

4. It is a Rheem 3.5 Ton, 12 SEER, Heat Pump with a variable speed air handler.

5. We have standard wood, single-glass paned windows. There is some condensation on the lower panes of the floor level windows, but most of the condensation is on the outside of the window (I assume this is due to the low insulation value of the single pane glass).

6. I don't know what sealed ductwork is, however, it looks pretty sealed to me. It's pretty thick with tape all around it.

Does this help?

Fan should not run all the time in summer! this will raise RH by up to 10% in the summer! All Basements need a dehumidifier! At least 60 pint!

Fan should not run all the time in summer! this will raise RH by up to 10% in the summer! All Basements need a dehumidifier! At least 60 pint!


How does running the fan raise relative humidity? :confused:

Wow! Ok, I'm going to try to answer your questions... (thanks for taking the time to help me with this!)

1. I don't have anything to measure the humidity in the house. Should I get something that will tell me and if so, what?

may not be bad ideal to get one. You can find one pretty much at any hardware store/home centers, or super center.

2. The house was built in 1980 and, is a total of about 3,200 sq.ft.

3. I'm not sure what you mean by air to air exchanger - the complete system (except ductwork) was replaced last year, the outside compressor and the air handler (fan) which is in the garage.

4. It is a Rheem 3.5 Ton, 12 SEER, Heat Pump with a variable speed air handler.

Sounds like the unit isn't too oversized.. Here is a link (http://www.lifebreath.com/life.htm) for the info on it.

5. We have standard wood, single-glass paned windows. There is some condensation on the lower panes of the floor level windows, but most of the condensation is on the outside of the window (I assume this is due to the low insulation value of the single pane glass).

That's your problem! Single pane window will be cooler so it will collect the humidity on the glass. (outside in warm days outside, and inside on cool days.)

What type of filter do you have?

As for airman comment about fan on in the summer, I agree.

I did a test of my own last summer to see, and sure enough the humidity goes right back up in the summer.

Why?

The a/c coil in your air handler/furnace is cool and wet when it's running. when the a/c turns off, the coil is still wet, and slowly warms up. as it warms up the humidity comes off and blows back into your home.

I had avg humidity of 45 to 52% with the fan in ON, and down to 40 to 48% with fan in auto in the summer month.

I only run my fan on in the fall/winter/spring when I used heat.

Thanks for the help! I'll stop running the fan all the time in the hottest months, maybe that will make the difference.

For now, I'll get a guage for the humidity level and maybe a portable dehumidifier for the downstairs. I'll see what comes of that and go from there. I think I'll also look into replacing the windows with more energy efficient double panes.

As for airman comment about fan on in the summer, I agree.

I did a test of my own last summer to see, and sure enough the humidity goes right back up in the summer.

Why?

The a/c coil in your air handler/furnace is cool and wet when it's running. when the a/c turns off, the coil is still wet, and slowly warms up. as it warms up the humidity comes off and blows back into your home.

I had avg humidity of 45 to 52% with the fan in ON, and down to 40 to 48% with fan in auto in the summer month.

I only run my fan on in the fall/winter/spring when I used heat.


Interesting! Never heard that before, but makes sense. Sounds like in the normal operating mode (i.e., fan goes off when compressor cycles off), the A-coil has a chance to drip-dry before the next time the compressor is called, but when the fan is on continuously, the coil doesn't have a chance to do so, and in effect becomes a "flow-through" humidifier pad!

On my new Honeywell thermostat, there is "circulation" mode for the fan, where it kicks on about 30% of the time when it would ordinarily be off. Seems like that should be OK, since it gives the A-coil a chance to dry off before the fan kicks on.

400E.

I am you have noticed in your car when your run your a/c, then you swtich it over to vent, you notice the air blowing out of your vents warms up and muggy?

I program my stat to do Circ at night in the summer since the a/c don't run much in the evening/night hours, the back to auto in the day time.

400E.

I am you have noticed in your car when your run your a/c, then you swtich it over to vent, you notice the air blowing out of your vents warms up and muggy?

I program my stat to do Circ at night in the summer since the a/c don't run much in the evening/night hours, the back to auto in the day time.


Good points -- thanks!
Steve in Omaha