If your old furnace or AC unit is loud and obnoxious, the blame most likely falls on the air handler. This is the enclosed series of components responsible for pushing cold or warm air into your home's ductwork. Air handlers come in all sorts of configurations to fit the specific needs of your structure.
An AC air handler may be as simple as three components hooked up to a power source: coils to draw in refrigerant from the outside unit, drip pans to collect condensation, and a blower-motor with a fan aimed at ductwork to force out the cooled air built up in the air handler. In old-style furnaces and AC units, the fans and motors are not the smoothest, most discreet operators.
"Variable" refrigerant, zonal, and fan-blower systems are now offered in new HVAC units. Electronically commutated motors (ECMs) are also fast becoming standard options in some lines of HVAC systems because they cut down on the racket that the old-school air handlers make. Both types of air-handling systems have their benefits.
Variable Ventilation Versus Traditional HVAC Blowers
In modern whole-house and split HVAC systems that use variable types of technology, blower fans are set up to respond to the temperature on the main thermostat as before if desired, or they may be set individually for each room.
If you want more heat in the dining room and less in the hallway, separate fans help accomplish this, either through a master control or custom setup. In extreme hot or cold conditions, fans are set to run at a low-flow rate so they don't have to blow excessively hard to increase or lower room temperatures.
Traditional HVAC blowers cycle on and off in response to the main thermostat. If you have a too-small system, the unit will stay on for extended periods of time to meet the comfort needs of the household. This leads to a shorter HVAC system life and large power bills. Having a system like this also means you live in a house that's always making a blowing noise.
If your HVAC unit is too large, it may cycle on and off frequently, requiring a power surge each time the motor kicks back on to heat or cool the home. The heat or cooling may be extreme right before it kicks off, and then you may begin to feel hot or cold again as you wait for the unit to fire up once more.
People with these kinds of HVAC units find themselves turning the volume on their TVs up and down often, adjusting the sound in response to their home's intermittent, loud air handler.
Variable Refrigerant Flow (VRF) and Variable Refrigerant Volume (VRV)
VRF/VRV systems are becoming popular in multi-level buildings and commercial buildings in the U.S. due to the many benefits of the technology. This cutting-edge HVAC style is nothing new to other parts of the world, however. VRF/VRV units have been popular in sustainability-conscious Europe and Japan for decades. That's because VRF/VRV systems give you ultimate control of the climate in your home. They do so while also saving you energy.
The terms "VRF" and "VRV" refer to a shared refrigerant system throughout a structure. If you use a VRF/VRV to run a heat-pump system in your home, you can provide individualized heating or cooling to each room. Different zones can have more or less heat or cooling without adding more compressors. One compressor manages an entire home or small office building.
In a VRF/VRV heat-recovery system, you can have both heating and cooling out of one unit. This is a great option if you need a cool room for computers and a hot room for proofing bread or raising exotic pets but also want the main areas of the home to be kept at a normal temperature.
Because the refrigerant is shared throughout the system in a heat-recovery unit, rooms that need cooling give up heat to warm up rooms that need warmth, and the too-warm rooms return the favor by sending back their chill.
Electrically Commutated Motors (ECMs)Traditional HVAC units operate on AC current, but DC motors are often far more efficient. An ECM is a motor that converts AC current to DC voltage to offer more efficient blower operation. The ECM is efficient at a variety of speeds, and it makes less noise than traditional motors.
ECMs also have the ability to do gradual starts and stops, and this saves energy. Slow stops also avoid the pitfalls of having excess condensation in units, which can lead to mold and other problems in ductwork and air handlers.
The ECM's ability to run at a variety of speeds makes it ideal for custom HVAC applications. Many home systems with ECMs allow you only limited speed adjustments, but the motors are still more energy saving than traditional motors. HVAC systems with ECMs are a more budget-friendly choice than some of the more advanced variable HVAC technology. One of the ECM-type units is a wise choice for anyone who wants to be a greener HVAC consumer.
Whether you want a new AC unit or an energy-efficient heat pump, HomeSmart From Xcel Energy has products to make your home your haven. Contact us today for all of your heating and cooling needs—we also offer free in-home estimates on brand-new high efficiency equipment!