HVAC Horror Stories Part I

HVAC Ghosts

Tales from the HVAC Crypt

This weekend will be October 1st and it’s that time of year when the ghosts and ghouls start spreading Halloween cheer. I’ve always loved this time of year when the temperatures in Phoenix start cooling down and you can start to smell that fall scent in the air at night. Aside from the wonderful weather in February and March here in Phoenix this is probably the best time of year. October and all it’s festivities seem to bring more happiness to valley residents and once Halloween is here it’s officially the kick off to the holiday season.

As many of you know, the are a lot of elements that go into residential and commercial air and heating. Starting with your air conditioning system, to the heating system, to your air duct system and finally to the quality of your indoor air. During the month of October our blog series will be about HVAC Horror Stories and what spooky things have happened with customers air ducts, cooling and heating systems. Some say the things, such as haunting noises, were actually ghosts while others thought they had unwanted spirits living within their duct systems.

The Creepy Closing Door

No creepy ghost story is complete without the mention of doors closing on their own. Due to the layout of many HVAC systems across the country, this is a very real haunt that many of your customers deal with regularly. It’s often caused on a smaller scale by something invisible, but it’s typically a fan instead of a supernatural occurrence. The two most common places this happens are in homes with central returns and commercial kitchens.

Pressure imbalances created due to depressurization can create some pretty scary airflow situations within a building. When airflow is out of balance and out of control, the stage is set for “airflow competition.”

Central returns combined with interior door closure can cause marginally open doors to shut, simply by the fan in the air-handling equipment coming on. The positive pressure created in these rooms can be enough to close interior doors if the conditions are right. In a commercial setting, kitchen exhaust and makeup air fans that are out of balance with each other can create a similar situation. In a commercial building, however, the effect isn’t as pronounced on interior doors due to their heavier construction. Instead, exterior doors are impacted so that an airflow imbalance can cause them to be nearly impossible to open to enter the building.

While this may not actually be a specter haunting your home or office space, if you didn’t know what a pressure imbalance was you could definitely see why someone would think a ghost was responsible for the opening and closing of doors.

Loud, Haunting Sounding Registers

Just like those scary wails often heard in haunted-house movies, your customers can have mysterious wails coming from their HVAC systems. The most common sort of wail is typically tied to air noises made from the grilles and registers.

Poorly selected grilles and registers can cause excessive velocities at the face of the grille or register. As air passes through the vanes, a wail is produced due to the speed of the air. For many customers, their response can range from being annoyed to feeling like they’re on the brink of insanity.

Pay attention to the desired airflow from a grille or register and make sure it’s within acceptable velocity limits to keep the wailing sound from occurring. Design supply registers for a face velocity under 500 fpm and return grilles in the 300-500 fpm range to keep the system quiet and wail-free.

With registers and grilles being the most visible parts of an HVAC system, you can offer performance-grade grilles and registers to reduce noise issues that drive customers batty. In addition, these performance-grade grilles and registers have excellent visual appeal.

Hot and Chilly Rooms

Another problem that tends to appear and disappear randomly is an uncomfortable room in the home. This room may be comfortable at one point in the day and unbearable at another. Problems of this sort can be difficult to solve because they may go beyond the traditional side and expand into the building side of the duct system.

When confronted with resolving hot and cold rooms, begin by determining the time of day it’s taking place. This can give you a lot of clues regarding the circumstances surrounding the onset of the problem. If you’re lucky, this information will lead you to the source of the complaint.

The two most common issues tied to this problem are related to duct losses and room surface temperatures impacted over the course of the day. In your diagnosis, start with the duct system to assure it isn’t an issue with duct system losses over the course of the day. Expand into building-side issues to explore insulation and infiltration problems as contributing factors next.

As you can see, many issues you encounter are invisible in nature and have to be made visible to customers through testing and diagnostics. Unlike ghost stories and haunted houses, these issues are very real to your customers and they want them solved.

I hope you enjoyed this lighthearted look at some of the issues you encounter on a daily basis and that you take full advantage of busting your customer’s comfort ghosts. If you suspect that your Phoenix and Mesa Arizona home or office space may be haunted due to strange noises coming from your air and heating systems please contact Norris Air. We will bust your ghosts and return them back to their resting place.