Determining whether your heat pump has auxiliary heat is critical for understanding its heating capabilities and optimizing energy efficiency. Auxiliary heat provides supplemental warmth during extremely cold weather or when the heat pump alone cannot maintain the desired indoor temperature. This article explains how to identify auxiliary heat in your heat pump system, the role it plays, and signs indicating its activation.
| Aspect | Details |
|---|---|
| Auxiliary Heat Purpose | Backup heating during colder weather or when heat pump output is insufficient |
| Common Sources | Electric resistance coils, gas furnace, or oil furnace as supplemental heat |
| Identification Methods | Thermostat settings, inspection of outdoor and indoor units, operational noise, and energy bill indicators |
| Activation Signs | Increased electricity usage, noticeable warmth from indoor coils, system alerts |
What Is Auxiliary Heat In A Heat Pump System?
Auxiliary heat, also called emergency heat or backup heat, is an additional heating source integrated with a heat pump. Its main function is to maintain indoor comfort during extremely cold temperatures when the heat pump’s efficiency diminishes. Heat pumps operate by transferring heat from the outside air indoors, but when outdoor temperatures drop too low, the heat pump might struggle to deliver enough heat. Auxiliary heat activates to supplement this deficiency.
Common Auxiliary Heat Sources In Heat Pumps
The type of auxiliary heat installed varies by system design. The most common auxiliary heat sources include:
- Electric Resistance Heat: Electric coils inside the air handler generate heat by electrical resistance. This is the most common auxiliary heat source in electric heat pump systems.
- Gas Furnace: Some heat pumps are paired with a gas furnace that activates under cold conditions.
- Oil Furnace: In certain setups, an oil furnace serves as the backup heat source.
- Dual Fuel Systems: These systems use a heat pump for moderate temperatures and switch to a furnace as auxiliary heat when needed.
How To Check If Your Heat Pump Has Auxiliary Heat
Several approaches can confirm if your heat pump includes auxiliary heat:
Inspect Your Thermostat Settings
Modern thermostats often have an “Emergency Heat” or “Aux Heat” mode. Look for these settings in your thermostat menu. If the option exists, your system likely supports auxiliary heat.
Examine The Indoor Air Handler Unit
Open the air handler panel carefully and look for an electric heating element (a set of metal coils) near the blower fan. Presence of these coils generally indicates electric auxiliary heat.
Review Your HVAC System Documentation
Check the user manual, installation paperwork or contact your HVAC installer. These documents often specify whether auxiliary heat is present and what type it is.
Listen For Operational Cues
When the temperature drops below approximately 35°F, observe your heat pump’s behavior. If you hear a distinct buzzing or clicking sound or notice air coming out significantly warmer from the vents, it may signify the auxiliary heat is running.
Signs Your Auxiliary Heat Is Active
Knowing when auxiliary heat is running can help manage energy use. The common signs include:
- Increased Energy Consumption: Auxiliary heat, especially electric resistance, uses more electricity and can cause your energy bills to rise sharply.
- Warmer Air from Vents: The heat delivered when auxiliary heat is on is typically hotter than the heat pump alone produces.
- Thermostat Indicator: Some thermostats display when auxiliary heat is engaged.
- Outdoor Unit Behavior: The outdoor compressor might slow or shut off while auxiliary heat maintains indoor temperatures.
When Should Auxiliary Heat Activate?
Auxiliary heat generally kicks on under two conditions:
- Very Cold Weather: Typical heat pumps become inefficient below 30-35°F; backup heat maintains comfort.
- During Defrost Cycle: If frost accumulates on the outdoor coils, the system reverses temporarily to defrost, often activating auxiliary heat to keep the home warm.
How To Optimize Usage Of Auxiliary Heat
While auxiliary heat ensures comfort, excessive use increases energy costs. Here are ways to optimize its use:
- Set Thermostat Sensibly: Avoid setting temperatures very high during winter to reduce auxiliary heat activation.
- Regular Maintenance: Keep heat pump components clean and well-maintained for efficient operation.
- Upgrade Thermostat: Smart thermostats can help manage auxiliary heat more efficiently.
- Insulate Your Home: Improved insulation reduces heating demands, decreasing reliance on auxiliary heat.
Conclusion
Identifying whether your heat pump system includes auxiliary heat can improve your understanding of its heating capabilities and support energy-efficient operation. By checking thermostat controls, inspecting your HVAC units, and observing signs of auxiliary heat activation, homeowners can better manage their heating systems. Proper maintenance and smart usage can optimize comfort while controlling heating costs during cold weather.