In the first part of our dehumidifier buying guide, we started you out some of the basic things you need to figure out before you start checking out dehumidifier reviews and spend good money on a unit. We showed you how to figure out humidity level, air changes per hour (ACH) and how to calculate your room’s square footage. Now we are going to turn those figures into a formula that will tell you exactly what size unit you need to buy.
Calculate Your Room’s Cubic Feet
Measure the height of your room, from floor to ceiling. Now take the square footage of your room and multiple it by the height of the room to get your room’s cubic footage. For example, if your square footage is 80 feet and the height of your room is 8 feet, then your cubic footage is 640 cubic feet.
Determine Your CFM
Your CFM is the amount of airflow in cubic feet that you need in order to properly dehumidify your room. To determine this value, multiply the cubic footage of your room by the ACH and then divide by 60. For example, if your room is 640 cubic feet and your ACH is a 5, then multiply 640 by 5 and then divide by 60 (640×5=3200/60=53.3 cubic feet per minute) to get your CFM.
Determine How Much Moisture You Need To Extract From Your Room
How many pints of water you need to extract from your room depends on your ACH and your square footage. Use the guide below to determine how many pints of water you need your dehumidifier to extract from your room each day:
- ACH 6: 16 pints per 500 square footage. For each additional 500 square feet add an additional 7 pints
- ACH 5: 14 pints per 500 square footage. For each additional 500 square feet add an additional 6 pints
- ACH 4: 12 pints per 500 square footage. For each additional 500 square feet add an additional 5 pints
- ACH 3: 10 pints per 500 square footage. For each additional 500 square feet add an additional 4 pints
For example, if you have a room that is 500 square feet and you have an ACH of 6, then you need a machine that extracts 16 pints of water per day. However, if the room is 1000 square feet with an ACH of 6, then you need it to extract 23 pints per day.
Buy A Dehumidifier According To Your Specs
Now you need to find a dehumidifier that supports both your CFM requirements as well as your pints per day requirements. Make sure you read the specs of the dehumidifier you are thinking of buying to make sure that it fits your needs. However, there are a few other things you might need to consider before buying your unit. One, if your CFM requirements are much higher than any dehumidifier on the market, then you will probably have to buy multiple units to properly dehumidify your room. Two, if you CFM falls between the ranges of two different models, then you might want to buy a unit with a higher CFM and just run it less often.
This concludes our two-part article on buying a dehumidifier. I know that it might seem like there are a lot of steps and that it might take a bit of time to determine ACH, CFM and pints per day, but trust me it is worth the effort. You don’t want to buy a unit that isn’t capable of dehumidifying your room properly, but you also don’t want to buy a bigger unit (or more units than you need). By taking the time to follow these steps, you can make sure you buy the best dehumidifier for your particular needs.
Some people believe that the best dehumidifier for them is a whole-house unit. While that might be the case in some circumstances, it isn’t true all of the time. Not only are whole-house units expensive and time consuming to install, but they also require that your home has the right duct work for it to be installed in the first place. In my experience, I have found that the most cost-effective and easiest solution for most households is a portable dehumidifier.
Before you shop for a portable dehumidifier however, it’s important to know what you need to look for in one of these units. Which is the purpose of this guide today. In this guide, we are going to show you the benefits that portable units provide over whole-house units, things to consider while installing one of these units, as well as the best portable dehumidifier features. After we have covered those things, you will have the knowledge you need to look over dehumidifier reviews and make an informed buying decision.
Portable Versus Whole Home Dehumidifiers
What makes a portable unit the preferred option for most people in most situations is its cost. Portable units are a fraction of the cost of whole-house units. However, that isn’t the only reason portable units can be superior to whole-house units in most situations. Another factor that needs to be considered is ease of installation. Portable units are simply easier to install.
Installation Options For Portable Units
One thing that really needs to be considered about a portable unit is where it needs to be installed. While these units can easily be moved from room to room, you want to make sure that you when you do place them in a particular location you are installing them correctly.
Most portable units have reservoirs that capture water pulled from the air, and on these units you have to make sure you set them in a location convenient enough for you to accomplish this task. If the unit is hard to reach, then you probably won’t be emptying it as often as you should.
However, there are some units that have a continuous drainage system. With these units you have to make sure that there is an available drain for them to discharge water into. If you try to use these units without a proper drain, then you can cause flooding that may damage your floor or the unit itself.
Best Portable Dehumidifier Features
You should ensure that the portable unit you are thinking about buying has a few minimum features. Features that not only make it easier to operate but also ensure that it will run properly. Some of the features you need to consider for a portable unit include:
- Energy Star Rating
- Range Of Humidity Settings
- A Humidistat
- A Drain Connection Kit (if it’s a continuous drain system)
Finding a unit with all of the above features will ensure that you not only end up with a portable dehumidified that is convenient to use but one that is of the highest quality.
If you have areas of your home that have really moist air, then you may have thought about purchasing a dehumidifier. You thought it would be pretty easy just to go online and buy one. Yet when you started searching through dehumidifier reviews your mind was boggled by all of the different sizes, styles and features. Well, that is why I am here today. I am going to help you cut through all of the noise and find the perfect dehumidifier for your home. Just by following these few easy steps, you will not only save time and money but you will also save yourself quite a lot of frustration.
Gauge Humidity Level
You know that your home is humid, but you don’t know exactly how humid it is. That is why you probably need to purchase a hygrometer before you run out and buy your dehumidifier. A hygrometer allows you to take accurate humidity readings of your home so you know exactly what type of humidifier to buy. It is a device that can easily be found at any home improvement store or online. While you don’t necessary have to buy one if you don’t want to, it does make it easier for you to purchase the best dehumidifier possible for your home.
If you don’t want to purchase a hygrometer, then you can do a simple assessment of your home to determine humidity level. While it won’t be as accurate of an assessment as using a hygrometer, it will give you a baseline. Here are some ways to access your room’s humidity level:
- 90-100 percent humidity: Standing puddles of water in the room and/or the room is extremely wet.
- 80-90 percent humidity: Room smells and feels wet; it also has visible water or mildew stains.
- 70-80 percent humidity: No water stains but the room has a clear mold or mildew smell to it.
- 60-70 percent humidity: If the room smells slightly damp.
Determine Air Changes Per Hour
Now that you know your room’s humidity level, you can now gauge the ACH (air changes per hour) rate you need to properly dehumidify the room. You can judge your ideal ACH by checking your humidity on the following table:
- 90-100 percent humidity: ACH 6
- 80-90 percent humidity: ACH 5
- 70-80 percent humidity: ACH 4
- 60-70 percent humidity ACH 3
Calculate Your Room’s Square Footage
Now you need to figure out the square footage of your room. Using a tape measure, measure the width and length of your room and multiple the two to get your square footage. For example, if you have a 10 by 8 feet, then your square footage would be 80 feet.
Now that you’ve determined your humidity level, your ACH and have calculated your square footage, it is now time to determine your CFM, and how many pints of moisture you need extracted from your room daily. Please read Part Two of our dehumidifier buying guide to continue.