- How humidity affects the way you live?
- How does humidity get into your house?
- What to do about excessive humidity in your home?
- When replacing my A/C system how can I remove the most humidity?
- If I foam my house will humidity be an issue?
- What affect does humidity have on my allergies?
- Will a larger A/C remove more humidity than a smaller one?
Humidity affects the way you live
- Humidity is one of the reasons air conditioning was invented.
- The job of an A/C system in a humid climate such as Louisiana is one to remove humidity the other is to make the home cooler.
- Humidity is removed by the evaporator coil and heat is absorbed then brought outside and disbursed.
- When your system is low on Freon it can’t remove the humidity out of the air, because only half of the coil is sweating.
- Your home would be most comfortable between 35-50% relative humidity.
- Above 50% relative humidity is when allergens, Bacteria, Dust mites, mold And mildew become prevalent.
- Below 35% relative humidity is when respiratory problems occur, Bronchitis & Asthma.
- This is why people with respiratory conditions do not run the heater much, it dries out the air causing allergens to act up.
- If your home is too humid, you are sweating even though it may be 70 degrees in the home
- If it is too dry it could cause nose bleeds
- Optimum conditions in most homes 75 degrees and 45% relative humidity. You’re not hot, you’re not cold and you’re not sweating.
How does humidity get in your home?
- Humidity and moisture infiltrate in your home in many different ways.
- Cooking, boiling water, drying clothes, washing dishes, taking a shower, fish tanks and yes even breathing are some common ways to produce humidity.
- Air infiltration-through windows, cracks under the door, plumbing and electrical outlets, vent hoods, fire places, exhaust fans, opening and closing the door.
- As you can see it is a constant struggle to maintain our standards of living and control humidity at the same time.
What to do about excessive humidity in your home?
- First thing to do is find the reasons the humidity is there.
- We can do blower door test and find most of the air infiltration in your home.
- After finding the air leaks we can seal most of them for you.
- We can assess your air conditioner, it may be too large or you may need a two stage system.
- We can do a Manual J heat load on your home to properly size the system
- You may have return air leaks bringing in humid air from the attic
- You may have supply air leaks causing a negative pressure in your home sucking in humidity from outside.
- We can seal air leaks and prevent these problems from occurring.
- Your system may be too large for your home but it’s brand new you don’t want to change it.
- We can put in a whole home dehumidifier and you can set the humidity in your home at whatever you want it to be.
What type of A/C system removes the most humidity?
- The system that is sized properly is the best answer.
- A two stage system is the appropriate answer.
- When an A/C system is installed correctly it will cool the home properly, but can it remove the humidity out of the home effectively.
- In most cases, No is the answer.
- This is because the need for cooling and humidity removal changes throughout the day.
- It is cooler at night and morning than it is during the day.
- You may need a 4 ton system during the hot summer months between 12:00pm and 4:00pm but after the sun goes down you may only need 2.5 tons of A/C to cool the home properly.
- This can only be attained by installing a two stage A/C system
- The first stage works at 67% capacity perfect for mild days and night time when the heat is off the roof.
- The second stage will come on when the temperature in the home rises 2 degrees above set point or if the first stage can’t handle the load. (this is automatic)
- Now you have a smaller system for mild days and a larger system for hot days.
Foam insulation and humidity
- Foam insulation in a house correctly installed does not cause humidity problems.
- Incorrect installation of the A/C system causes humidity problems.
- Incorrect sizing of the A/C system causes humidity problems.
- Not bringing in fresh air into the home causes stale stagnant air in the home.
- If you decide to foam your home be sure the A/C company is familiar with this type of installation or you could have a bad humidity problem in your home.
- Foam insulation in an existing home, with existing insulation could be a problem, you should remove the insulation from the ceiling so that you will not trap the moisture in the attic.
- Foaming a roof line and leaving vents open is an incorrect application of foam, the attic should be un-vented.
- This will cause the dew point to be reached quicker on the duct work and could cause all of your ducts to sweat.
How humidity directly affects allergies
- First understand that excessive humidity and lack of humidity causes allergy problems.
- Excessive humidity in the home cause’s mildew and mold problems which cause allergic reactions.
- Absence of humidity cause asthma and bronchitis, you must have humidity in the air to breath properly (could cause nose bleeds)
- Your supply plenum is where mold and mildew grow, because of the high humidity level.
- Your supply plenum is dark, damp and cold perfect breeding ground for mold mildew.
- We can counter act this by first treating the plenum with fosters 40/20 primer anti-bacterial paint, second install a new U/V light in the supply plenum
- Now mold will not grow in the plenum and your home is a healthier place to live.
- Fact- most homes the air passes through a layer of mold in your ductwork before being delivered in your home.
- Mold and mildew are living organisms and need food and water, the food comes from lack of filtration (dust, pet dander, hair etc.…) and the water comes from the humidity off your coil.
- If you filter your system properly you could eliminate most of the food source.
- We can install one of the best filtration systems on the market a P.C.O. this has a Merv. 16 filter, 4 U/V lights and a catalyst for odor removal.
- When you keep the humidity level between 35-50% relative humidity and you filter your system properly you will greatly increase the indoor air quality in your home.
Will a larger A/C system remove more humidity than a smaller one?
- It depends on if the house is large enough for the A/C to run long enough for proper humidity removal.
- Humidity is removed when the A/C runs, a large A/C makes a system short cycle therefore not having enough runtime and humidity is not removed.
- Perfect reason to have a 2 stage A/C system when the load is low 1st stage runs longer removing more humidity; when the load increases 2nd stage comes on to bring the house temperature down to set point.
- A smaller A/C may not cool the home on high load days.
- It is very important to have a manual J Heat load calculation done to know what is the correct size A/C to put in your home.
- This will only give you the correct size for 95 degree day and your system will be oversized when the day is mild. (two stage A/C) is the best solution for the correct size of A/C on mild days and heavy load days.