The average thermostat most people encounter is designed for an HVAC system that controls the fan, power, cool, and heat. There are four wires with this type of thermostat. But a heat pump needs a special thermostat with five wires.   The fifth wire in a heat pump thermostat is the reversing or changeover wire, which controls the reversing valve, allowing a switch between heating and cooling. This wire is not an AC wire and care should be taken with connections.   Additionally, there may be an emergency wire to cut off the heat pump when needed. Also, many thermostats for heat pumps are designed to be energy efficient, leading to a lower energy bill than when using a standard central furnace.   Do your homework before settling on a new thermostat for your heat pump. Know what your lifestyle needs are, consider average temperatures, energy costs, and how your choice of thermostat model will impact your aesthetics.

Manual thermostats are usually less expensive than high-end, internet-connected devices that are programmable. Prepare to spend anywhere from $15 to $300 for a thermostat. The rates for hiring professional installation vary.   You will most likely need to employ an electrician, with an average rate of $65 to $100 an hour for rendering services. If you feel confident enough to handle installing a thermostat without professional help, you can save money.   A home's square footage also impacts the cost of a thermostat installation. The average price range for a thermostat and installation altogether is between $112 and $254. Poor installation is risky and dangerous, so hire help if needed.   If you are on a strict budget, opt for a manual or non-programmable thermostat versus a fancy smart thermostat with all the bells and whistles. A programmable electric thermostat is a middle-of-the-road choice that most will accept.

ou don't really need a programmable thermostat if you have a heat pump. Because a heat pump may need to quickly shift from heating to cooling, it doesn't make sense to set the thermostat at a set temperature for extended periods.   When a heat pump is in heating mode, there may be more energy inefficiency when a programmable thermostat sets the temperature back at designated times. However, there are newer programmable thermostat models for heat pumps.   With a programmable thermostat, you don't want to cause a heat pump to rely on backup electric resistance systems. You usually save on energy and lower bills by keeping your heat pump in cooling mode versus heat mode.   Keep your home comfortable if you use a heat pump thermostat. You may want to set the temperature at a lower point when you're away from home or asleep. A wide range of thermostat settings for a heat pump isn't as necessary compared to a furnace.   Know before you make a final decision on a thermosta...

There are three main types of heat pumps connected by ducts: air-to-air, water source, and geothermal. They collect heat from the air, water, or ground outside your home and concentrate it for use inside.  The most common type of heat pump is the air-source heat pump, which transfers heat between your house and the outside air. Today's heat pump can reduce your electricity use for heating by approximately 50% compared to electric resistance heating such as furnaces and baseboard heaters. High-efficiency heat pumps also dehumidify better than standard central air conditioners, resulting in less energy usage and more cooling comfort in summer months. Air-source heat pumps have been used for many years in nearly all parts of the United States, but until recently they have not been used in areas that experienced extended periods of subfreezing temperatures. However, in recent years, air-source heat pump technology has advanced so that it now offers a legitimate space heating alte...

Geothermal (ground-source or water-source) heat pumps achieve higher efficiencies by transferring heat between your house and the ground or a nearby water source. Although they cost more to install, geothermal heat pumps have low operating costs because they take advantage of relatively constant ground or water temperatures. Geothermal (or ground source) heat pumps have some major advantages. They can reduce energy use by 30%-60%, control humidity, are sturdy and reliable, and fit in a wide variety of homes. Whether a geothermal heat pump is appropriate for you will depend on the size of your lot, the subsoil, and the landscape. Ground-source or water-source heat pumps can be used in more extreme climates than air-source heat pumps, and customer satisfaction with the systems is very high.

A number of innovations are improving the performance of heat pumps. Unlike standard compressors that can only operate at full capacity, two-speed compressors allow heat pumps to operate close to the heating or cooling capacity needed at any particular outdoor temperature, saving energy by reducing on/off operation and compressor wear. Two-speed heat pumps also work well with zone control systems. Zone control systems, often found in larger homes, use automatic dampers to allow the heat pump to keep different rooms at different temperatures. Some models of heat pumps are equipped with variable-speed or dual-speed motors on their indoor fans (blowers), outdoor fans, or both. The variable-speed controls for these fans attempt to keep the air moving at a comfortable velocity, minimizing cool drafts and maximizing electrical savings. It also minimizes the noise from the blower running at full speed. Some high-efficiency heat pumps are equipped with a desuperheater, which recovers waste hea...

An air-source heat pump can provide efficient heating and cooling for your home. When properly installed, an air-source heat pump can deliver up to three times more heat energy to a home than the electrical energy it consumes. This is possible because a heat pump transfers heat rather than converting it from a fuel like combustion heating systems. Air heat pumps have been used for many years in nearly all parts of the United States, except in areas that experienced extended periods of subfreezing temperatures. However, in recent years, air-source heat pump technology has advanced so that it now offers a legitimate space heating alternative in colder regions. For example, a study by the Northeast Energy Efficiency Partnerships found that when units designed specifically for colder regions were installed in the Northeast and Mid-Atlantic regions, the annual savings are around 3,000 kWh (or $459) when compared to electric resistance heaters, and 6,200 kWh (or $948) when compared to oil sy...

The different types of air source heat pumps are described below. Ductless vs. Ducted vs. Short-Run Ducted Ductless applications require minimal construction as only a three-inch hole through the wall is required to connect the outdoor condenser and the indoor heads. Ductless systems are often installed in additions. Ducted systems simply use ductwork. If your home already has a ventilation system or the home will be a new construction, you might consider this system. Short-run ducted is traditional large ductwork that only runs through a small section of the house.  Short-run ducted is often complemented by other ductless units for the remainder of the house. Split vs. Packaged Most heat pumps are split-systems—that is, they have one coil inside and one outside. Supply and return ducts connect to the indoor central fan. Packaged systems usually have both coils and the fan outdoors. Heated or cooled air is delivered to the interior from ductwork that passes through a wall or...

A heat pump's refrigeration system consists of a compressor and two copper or aluminum coils (one indoors and one outside), which have aluminum fins to aid heat transfer. In heating mode, liquid refrigerant in the outside coil removes heat from the air and evaporates into a gas. The indoor coil releases heat from the refrigerant as it condenses back into a liquid. A reversing valve, near the compressor, can change the direction of the refrigerant flow for cooling mode as well as for defrosting the outdoor coil in winter. The efficiency and performance of today's air-source heat pumps is a result of technical advances such as the following: Thermostatic expansion valves for more precise control of the refrigerant flow to the indoor coil Variable speed blowers, which are more efficient and can compensate for some of the adverse effects of restricted ducts, dirty filters, and dirty coils Improved coil design Improved electric motor and two-speed compressor designs Copper tubing, groo...

Heat pumps can have problems with low airflow, leaky ducts, and incorrect refrigerant charge. There should be about 400 to 500 cubic feet per minute (cfm) airflow for each ton of the heat pump's air-conditioning capacity. Efficiency and performance deteriorate if airflow is much less than 350 cfm per ton. Technicians can increase the airflow by cleaning the evaporator coil or increasing the fan speed, but often some modification of the ductwork is needed. See minimizing energy losses in ducts and insulating ducts. Refrigeration systems should be leak-checked at installation and during each service call. Packaged heat pumps are charged with refrigerant at the factory, and are seldom incorrectly charged. Split-system heat pumps, on the other hand, are charged in the field, which can sometimes result in either too much or too little refrigerant. Split-system heat pumps that have the correct refrigerant charge and airflow usually perform very close to manufacturer's listed SEER and HSPF. T...

Geothermal heat pumps (GHPs), sometimes referred to as GeoExchange, earth-coupled, ground-source, or water-source heat pumps, have been in use since the late 1940s. They use the relatively constant temperature of the earth as the exchange medium instead of the outside air temperature.  Although many parts of the country experience seasonal temperature extremes -- from scorching heat in the summer to sub-zero cold in the winter—a few feet below the earth's surface the ground remains at a relatively constant temperature. Depending on latitude, ground temperatures range from 45°F (7°C) to 75°F (21°C). Like a cave, this ground temperature is warmer than the air above it during the winter and cooler than the air in the summer. The GHP takes advantage of these more favorable temperatures to become high efficient by exchanging heat with the earth through a ground heat exchanger. As with any heat pump, geothermal and water-source heat pumps are able to heat, cool, an...

To control your heating from your phone on a room-by-room basis, you'll need a smart radiator valve (thermostatic radiator valve or TRV). Here are our recommendations.   There’s a reason smart heating is growing in popularity. Not only will it give you more control over the temperature in your home – so it’s always warm when you want it to be – but you can easily monitor your heat and potentially make savings on your energy bills. Still, we’d advise that you take manufacturers’ money-saving claims with a pinch of salt.   If you’re buying an entire smart heating system, it’ll take some time to recoup the cost of the tech but a smart radiator valve is a much smaller investment. Each one will allow you to control a single room, which means you can schedule heating so that it’s warm when it needs to be and no heat is wasted the rest of the time.   Being able to see the temperature clearly on your phone screen or on the de...