Several options to refresh the air in a home
Q: COVID-19 has increased our awareness of indoor air quality. The air in my house often seems stale. What are efficient methods to get more outdoor fresh air indoors?
A: COVID has changed many things in our lives, including in our own homes. As we make our homes more airtight for energy efficiency, natural outdoor ventilation into houses is reduced. This does save energy and may reduce certain allergies, but it can also have some negative consequences.
The unpleasantness of stale indoor air you experience may be the least of your indoor air problems. It is not uncommon for indoor air in an energy efficient house to be several more times polluted and unhealthy than outdoor air. In addition to potential health problems from bacteria and viruses, many household products such as cleaners and synthetic materials emit unhealthy chemicals, many of which have never been tested for safety.
There is quite a range of methods to introduce outdoor fresh air into your house without wasting a lot of energy. The costs can range from basically zero to several thousands of dollars for a sophisticated, automated ventilation system.
Before making a decision on the best ventilation method for your specific house, first determine what is actually creating your stale air issue. Buy an inexpensive hygrometer and measure the indoor humidity level and see if it correlates to when you experience the stale air problem. Do the same for when you are cooking, washing or other activities which may impact indoor air.
If you find a correlation, you may be able to make some simple changes to solve your problem. In many cases, though, you may have to introduce more outdoor fresh air to eliminate the staleness. Start out the simplest, low-cost methods and give them several weeks to help until you move on to more aggressive and expensive fixes.
Although it sounds inefficient, opening a couple of windows on opposite sides of the house for a few minutes during winter does not lose much energy. House building materials don't lose heat that quickly. During summer, this is not as effective because it allows humid air to come in along with allergens such as pollen and mold spores.
If you choose to try this low-cost fresh air technique during summer, run a room-size dehumidifier in the room where the outdoor air comes in. The specific room may change based upon the wind direction. The dehumidifier pulls more moisture out of the moisture-laden air. The air conditioner will circulate the fresh air throughout the house.
The most effective method for year-round fresh indoor air is an automatic heat recovery ventilation (HRV) system. It can save more than 70% of the energy. Incoming cold fresh outdoor air captures heat from the outgoing warm stale air during winter. During summer, incoming hot fresh outdoor air is precooled by the outgoing air-conditioned stale air.
Two blowers running in opposite directions are ducted from indoors to outdoors. The air flows through a heat exchanger where heat from the warmer air is transferred to the cooler air without mixing. The outgoing stale air is drawn from bathrooms or the kitchen and fresh air is ducted into a living room or hall.
This system works well in many climates; however, in very dry or very humid climates, the fresh indoor air may become uncomfortably dry or humid. Even though the HRV system has an effective air filter, extremely dry or humid indoor air can exacerbate allergies and skin issues.
In these areas an energy recovery ventilation (ERV) system is better. An ERV is similar to a HRV except the heat exchanger also transfers moisture. This is effective year-round, but most effective during summer because outgoing cool stale air dehumidifies the incoming fresh humid air. During winter the humid outgoing stale air transfers its humidity along with its heat to the incoming cold, dry air.
The most commonly used automatic control method is a humidity sensor. Stale indoor air tends to be more humid. This sensor determines how long and how fast the blowers run. There is a manual sensor override to run it for extra fresh air indoors, but there will be more energy consumed.
The following companies offer HRV's and ERV's: Aprilaire, (800) 334-6011, www.aprilaire.com; Broan, (800) 558-1711, www.broan.com; Fantech, (800) 747-1762, www.fantech.net; Honeywell, (800) 475-7515, www.honeywellhome.com; and Renewaire, (800) 627-4499, www.renewaire.com.
Q: Our sliding glass door is getting more difficult to slide open. I found a small metal cylinder in the track. Did this cause the problem and how can I fix it?
A: The small metal piece probably was a roller from the gliding assembly. Also, it is important to fix it so that your door is aligned properly for an airtight, efficient fit.
Although most home center stores have sliding door replacement parts, in most cases, it is best to have it professionally repaired and adjusted. The door panel is heavy and difficult to handle.
• Write to James Dulley at 6906 Royalgreen Drive, Cincinnati, OH 45244 or visit dulley.com.