How variable-speed HVAC systems work and why are they more efficient

Are you frustrated with your utility bills? Electricity prices have been slowly increasing for homeowners throughout the country. Thankfully, there are a number of modern HVAC technologies that can reduce your energy usage. In this article, we’ll review variable-speed HVAC systems. These energy-efficient air conditioners, heat pumps, and furnaces are capable of operating at different speeds, allowing them to “slow down” to maintain the temperature in your home.

Allbritten is your team for new air conditioners and furnaces here in Fresno and the Central Valley. To get a free in-home estimate on a new variable-speed HVAC system for your home, call us today.

The difference between standard and variable-speed technology

Standard air conditioners and furnaces are connected to your thermostat. When your thermostat sends a signal, your AC turns on at 100% until your home reaches the desired temperature. This all-or-nothing approach uses more energy than a variable-speed alternative.

A variable-speed HVAC system—such as this heat pump—can save you hundreds on your energy bills.

A variable-speed HVAC system—such as this heat pump—can save you hundreds on your energy bills.

Short cycling is a common issue with the old, single-speed AC units. This can be caused by choosing an improper AC unit for your home. The result is a unit that continues to quickly turn on and off and use significant amounts of electricity.

How variable-speed fan motors and compressors work

A variable system precisely controls the compressor and fan motor to create more energy-efficient cooling. Variable compressors can cycle between 30% and 100% capacity to keep your home cool without expending additional energy.

Similarly, fan motors that are adjustable use various speeds to reduce energy usage. Installing a variable-speed fan motor allows your blower to improve the efficiency of both your AC and your furnace.

The Office of Energy Efficiency and Renewable Energy found that even at half speed a variable-speed motor uses 75% less power than a single-stage alternative. Even with a speed reduction, your new fan can still reach your ideal indoor temperature.

Benefits of a variable-speed HVAC system

At Allbritten, we’ve installed variable-speed HVAC systems from Carrier throughout Fresno and the surrounding area. Here are some of the benefits you can enjoy by switching to a variable-speed system.

  • The most obvious benefit will be reduced energy costs. The peak energy usage of older HVAC systems is the moment it turns on. Turning a blower and compressor on at full power uses significant amounts of electricity.
  • Variable-speed systems, however, don’t start immediately at 100%. By building up to full power, these systems save you significant amounts on your electricity bill.
  • A variable system also prevents excess moisture in the air. If your air conditioner is constantly running, you may need to use a dehumidifier. A variable fan motor can balance the humidity and temperature in your home and avoid the use of a dehumidifier.
  • Finally, a lower speed fan causes your AC system to operate for longer periods. This increases the amount of time that your indoor air is filtered through your system. If you’re sensitive to pollen, dander, or other allergens, this increased filtration can reduce the effects of allergens in your home.
  • Low-speed operation reduces stress and strain on your fan motor and compressor. While a compressor typically has a long service life, a fan motor can wear out with constant use at 100% power. Enjoy an extended motor lifetime with your variable-speed system.

Contact Allbritten for more information

Contact us at Allbritten today to discover how you can enjoy variable-speed heating and cooling in Fresno, CA. Work with our leading HVAC company to find the best model for your home and enjoy hassle-free installation from our friendly team.

Here are 5 different heating noises and what they mean

All furnaces, regardless of their age, condition, or model, make some noise. It’s that steady hum you hear as your furnace runs. Over time, these heating noises should just become background noise in your home. You might notice it in the dead of the night, but—otherwise—it shouldn’t be too recognizable.

When it comes to strange furnace noises, follow your gut. If something sounds out-of-the-ordinary—when with your newly installed furnace—your ears are probably picking up an important change in the furnace’s sound output. While this could be nothing, there is a chance that you’re hearing the first warning bells that something is wrong with your heating system.

In this article, we’ll run through some of the most common furnace and heating noises, as well as what often causes them and what they could mean for your system. Again: if you’re hearing anything unfamiliar coming from your heater, it’s better to be safe-than-sorry and get it looked at soon. Call a local HVAC professional for furnace repair.


Is your furnace constantly starting-and-stopping?

While you’re listening to your furnace at night, do you notice that it starts up, runs only for a short time, and then stops?

This is known as short cycling, and it could be putting extra stress on your furnace and wasting you money. Learn more about heater short cycling and how to fix it.


Heating noises that you should not ignore

Furnaces make all kinds of noises. There’s that steady hum as they run, or that sudden “bang” as chilled air ducts are first filled with heated air. But, not all noises are so innocent. Here are a few common heating noises that you should be listening for when things are quiet at night.

1. Buzzing noises

No, it’s not bees in your heater. A loud buzzing typically means something that shouldn’t be vibrating has started vibrating. As furnaces run and age, parts and components can shake loose and start to rattle, buzz, and vibrate. A buzzing sound could also be an indicator that something is wrong or off about the capacitor or fan.

If you’re hearing a loud buzzing noise coming from your furnace, call a local HVAC expert in for a closer look so they can diagnose the problem and put an end to the noise.

2. Vibrating noises

Similar to buzzing, vibrating noises include shaking, rattling, or rhythmic thumping. In addition to all the causes listed above, vibrating sounds can also be caused by an imbalanced motor or an unbalanced blower wheel. A shift in the balance of either can impact the entire system and create loud sounds that will be heard throughout your home.

3. Squealing noises

A squealing noise can occur for many reasons. An experienced technician will need to use specialized tools to find out the exact cause of the squealing noise.

One common cause of this noise is a lack of lubricant in the shaft bearing. Or, the noise could indicate a problem with the blower motor. Finally, a loose blower belt can cause a squealing noise, too. You’ll need the help of an experienced expert to help you sort out what is causing the squealing and—in the interest of getting you some sleep this winter—how to make it stop.

Replacing a furnace belt is complicated. Instead of opening up your furnace, bring in an expert who can first make sure that’s the core issue and, if it is, help you safely and accurately replace the belt.

4. Banging noises

As we’ve already discussed, some banging sounds are pretty innocent. As chilled air ducts are filled with heat energy, the metal warps and flexes. It’s similar to how an icy plastic water bottle can sometimes “pop” when left in the sun. However, not all banging sounds are so benign. Sometimes, banging noises can caused by:

  • A delay in ignition due to dirty burners
  • The excessive buildup of gas inside the chambers
  • A fault in the heat exchanger

If you’re hearing loud, repeated “popping” every time the furnace switches on, this could indicate an issue with ignition. In most cases, this problem may be accompanied by the furnace flame sensor shutting the system off. You’ll need an HVAC technician to help you get your furnace back up-and-running again.

5. Rumbling sounds

A loud rumbling sound coming from the furnace is usually due to an issue with the blower wheel. A faulty burner could be causing the noise, or, again, the noise could also be caused by rapid expansion and contraction of the air ducts. The issue is common when the ducts are made of metal. An experienced technician will inspect the furnace and perform the necessary repairs.


Listen to your senses!

You won’t hear some furnace problems—you’ll smell them. Check out this article to learn more about what strange furnace odors mean for your system.


Have a professional listen to your system

If you’re hearing heating noises that you believe are out-of-the-ordinary, now’s the time to act. Call a local HVAC professional (and contact Allbritten!) and have them out to take a closer look—and listen.

An experienced heating expert will often be able to diagnose the problem right away. After all, they’ve likely heard the exact sound before while fixing hundreds of similar furnaces. Ask them what it will take to fix the system and if there’s anything else you should watch and listen out for in the future.