Heat Pump Intelligent Recovery Thermostat

What is Heat Pump Intelligent Recovery Thermostat, AUX and Emergency Heat For?

A simple guide to operating your heat pump system and thermostat settings for maximum comfort and energy savings.

Three quick points:

1. Auxiliary heat is electric resistance heat to supplement the heat pump on very cold days or to quickly raise indoor temperature.
2. Lowering winter thermostat set point ( 68 or lower) will minimize use of Auxiliary heat.
3. Emergency heat is electric heat only for use when the heat pump is malfunctioning.

Heat pump systems are an efficient way to heat and cool your home. During the heating season the system “pumps” heat from outside the home to indoors. (The process is reversed to air condition the home during the cooling season) A heat pump will use 60% to 80% less energy to achieve the same indoor temperature as an electric heater.

It’s easy to blow all your energy savings from a heat pump with Auxiliary heat, which can be 3 to 5 times more costly than the heat pump. You can minimize the expense of Auxiliary heat by lowering the thermostat set point at night or when the home isn’t occupied The key to keeping energy savings from a heat pump system in your pocket is an intelligent recovery thermostat.

Air flowing out of a heat pump system is warm, not hot (like you get from a furnace), and may even feel slightly cool because of the air movement. Avoid the temptation to switch on Auxiliary (AUX) or Emergency (EMER) Heat if you expect to feel “hot” air from the system. Economical operation of your heat pump will minimize or eliminate any use of Auxiliary or Emergency heat. If you want to raise the indoor temperature, do so by 2 degree increments, otherwise the Aux heat may be activated.

Note: Auxiliary Heat operates electric resistance elements to boost the heat pump system while Emergency Heat locks out the heat pump (in case of heat pump malfunction) and operates only electric resistance heating elements.

Heat pump systems also differ from forced air furnaces in another important way – heating performance declines as outdoor temperatures drop, taking longer run times to maintain the indoor temperature set point. When the outdoor temperature drops below 30 or 40 degrees, the Auxiliary heater may be required to meet system demand. The best way to minimize expensive Aux heat is to set the thermostat no higher than 68 degrees in winter.

Auxiliary heat is designed to meet demand during extreme cold, but your heating and cooling contractor can set your system to lock out Aux until outdoor temperatures reach a preset range. Depending on your system, at times it may be cheaper to use Aux than trying to meet all the heating demand with heat pump only.

You may already be familiar with programmable thermostats to adjust indoor temperatures based on your schedule by turning down the system when you are away or at night. Heat pump systems require more advanced controls because heat pump systems take longer than furnaces to make large temperature changes without using Auxiliary or Emergency heat.

The problem with setting back the temperature – say from 72 to 65 at night or when away – is the length of time for the system to return, or recover, to 72 when you wake or return home. An intelligent recovery thermostat anticipates when to start recovering the temperature to achieve the thermostat set point at the appointed time. More sophisticated intelligent recovery thermostats have an outdoor sensor so the system can adapt to changing outdoor conditions.

The Nest learning thermostat is a WiFi enabled system you can control from a smart phone. On the high end of intelligent recovery thermostats it offers options to maximize energy savings or responsiveness.

For example, if your schedule says 70ºF/ at 7am, an intelligent recovery thermostat may start heating at 5am or 6am depending on factors such as outdoor temperature and temperature rise. Because auxiliary heat is so expensive, running the heat pump longer is usually cheaper than using Auxiliary heat.

Best of all, intelligent recovery thermostats for heat pump systems cost about the same as comparable programmable thermostats, including the new wi-fi enabled models so you can manage comfort settings from a smart phone. The most advanced home thermostat today is made by Nest Labs and is actually a personal learning robot that can intelligently manage your heat pump system.

Some additional tips to reduce energy waste include:

• Have your contractor install controls to lockout Auxiliary resistance heat when the outdoor temperature is above 30 to 40 degrees.
• Ask your contractor to show you how to operate your heat pump and thermostat.
• Ensure all ductwork is sealed with mastic and insulated to R-6

• Don’t make frequent thermostat changes. This can increase heating costs by causing the auxiliary heat to come on, and it may damage the compressor.
• Don’t close supply registers or diffusers in any room. It can damage the compressor and may increase your energy use.
• Keep furniture from blocking air returns and air supplies.
• Don’t be alarmed if your heat pump occasionally makes unusual noises or releases a cloud steam. This is the defrost cycle and is part of normal operation. The defrost cycle heats the outdoor coil during the heating mode to prevent ice buildup.