HVAC Myths, Fables and Fairy Tales

We would like to put to rest some of the most common HVAC myths and misconceptions and replace them with good habits and best practices. We all have our own ways of doing things, whether it’s a good way, a bad way, the right way or wrong way. Or simply just the way you’ve always done it for reasons unknown, and that’s fine it’s human nature. In this section we would like to address some of the questions we get asked most often and examine some of those thought processes.

The number one piece of generally accepted misinformation:

“Hey, I heard if you close all the vents in the basement it will make the upstairs colder! It also saves money by not cooling that space!” This statement is incorrect. Your ductwork and HVAC equipment are specifically designed to work together as a system, so closing off outlets for air to escape only increases the pressure inside the ducting. Thus, causing the circulation blower and other components in your furnace or air handler to work harder with less effect.

Another common misconception:

“Yeah…we don’t use that room anymore so we keep the door shut, and I also shut all the vents in there to save money!” Again we can see where some of the logic lies but the science just isn’t there. Realistically you are removing that part of your home from the air distribution system which can lead to hot and cold spots which can result in condensation and mold and other adverse effects. Also, If you have hot and cold spots in your home, there are a few common factors as to why. Poor insulation, older construction and insufficient ductwork (which most times means a lack of cold air return ducting in both the upper and lower levels) All problems that can be diagnosed and sometimes remedied.

Bad Practises:

How the air conditioner works:

The principal function of your air conditioner is to remove heat from where it is unwanted (inside your home) and transfer it to a place where it makes little or no difference (outside your home). As a by-product of this action, you get de-humidification.This is when we start to feel cooler and more comfortable. If the air is saturated with water vapour, it becomes very difficult to absorb any more. At that point, your skin is unable to release the heat from your body and you will never cool off. The air conditioner removes moisture directly from the air, allowing your skin to release or give off the heat from your body through the natural process of evaporation or more commonly, sweating. Before the “sensible” or actual temperature goes down, the latent or “hidden” heat must be removed (by de-humidifying and lowering the moisture content of the air itself). This may take some time at the beginning of the cooling cycle, and why it is important to let the air conditioner run for extended periods to do its job. Many people shut their unit off at night and open the windows just because the feels cooler outside. You are not wrong, however, by doing this you are actually inviting more moisture in, and the entire process has to begin all over again the following day.

In this exercise you are not saving money or energy. In all actuality, you are creating more work for the air conditioner, most likely during peak energy “time of use” hours. By allowing the air conditioner to operate and cycle on and off as needed, it will reach a comfortable humidity level, and once level is achieved, it is essentially in maintenance mode and therefore not working as hard as it has too upon start up. So when you are staring at your thermostat wondering why the A/C has been on  for two hours and the number on your T-stat hasn’t drastically dropped 4 degrees, just give it time to work its magic and dehumidify your home, chances are you feel cooler already and you don’t even realize it.