If your child has recently been diagnosed with asthma or severe allergies that can affect his or her ability to comfortably (or easily) breathe, you may wonder what you can do to ease these symptoms -- as well as whether certain environmental factors within your home could be making your child's health conditions worse. In many cases, a few simple steps can be enough to purify and cleanse your home's air to provide your child with a safe, comfortable haven against the allergens of the outside world. Read on to learn more about the best heating, ventilation, and air conditioning (HVAC) options for allergy sufferers as well as the steps you can take to immediately begin to improve the quality of air within your home.

What are the best HVAC options for a home with allergy sufferers? 

If replacing your HVAC system wasn't in your home improvement budget this year, you're in luck -- even an older or less-efficient system can be modified to provide pure, allergen-free air without much of an additional cost investment. 

The hallmark of an allergen-free HVAC system includes some heavy-duty filtration that can capture any airborne particles that do make their way into your vents. Newer HVAC systems have these filters built into the vents directly, ensuring that the air coming from your home's vents is as pure as possible; however, you can also retrofit your vents so that they can easily accommodate surface air filters. Once you've cleaned these filters a few times, you'll be shocked at the amount of dirt, dust, and pollen that was previously being spewed out of your air vents each time the heater or air conditioner kicked on.

For older furnaces that run on gas or oil heat, proper ventilation of any fumes generated is also key in improving indoor air quality. If you currently have a stovepipe that ventilates just outside a ground-floor window, you may want to extend it so that the ventilated air is dispersed farther from your home. In other cases, you may even want to consider moving your child from a bedroom closest to the furnace to one that is farther away to see if this improves his or her quality of sleep. 

What can you do to immediately begin to improve the air within your home? 

There are a few things you can do to quickly reduce the amount of airborne particles and other pollutants in your home, even without making any substantive changes to your HVAC system. 

First, you'll want to take account of your home's relative humidity (RH). Keeping this humidity level below 50 percent is ideal for a number of reasons -- low RH inhibits the growth of mold and mildew, prevents pollen, dust, and other particles from being continually circulated through the air, and can even make the air within your home lighter and easier to breathe. 

To keep your home's RH levels in check, you'll usually need to purchase a humidifier, dehumidifier, and small humidity gauge. You'll be able to use the dehumidifier on humid days to wring excess moisture out of the air, and can use the humidifier to raise humidity levels on drier days (particularly during the winter months, when a central heating system can literally bake the moisture away). The gauge will give you an instant reading of the humidity level within a certain room, allowing you to tweak your humidification efforts as needed. 

You may also want to purchase a couple of HEPA filters for your home -- placing one in your child's room and another in a common area like the kitchen or living room can go a long way toward removing any particles that are already in the air.