Everything You Need To Know To Find The Best Leading Technology Heat Pump Solutions
Best Heat Pump Buying Guide
Size (Capacity)
A heat pump thats too small for your needs will struggle to keep your home comfortable. On the other hand, an oversized unit will cost more, and if it isnt a variable-speed model, it will cycle on and off more often than it should. This decreases efficiency, stresses components, and leaves your home less comfortable.
A heat pumps cooling capacity is measured in British thermal units per hour (Btu/hr.). Btu/hr. can also be expressed in tons, with 1 ton equaling 12,000 Btu/hr. To ensure that your heat pump is sized correctly, make sure your contractor does a load calculation based on a recognized method, such as the Air Conditioning Contractors of America (ACCA) Manual J. The calculations should be done after any air-sealing or insulation upgrades are made to your home and should be done whether youre replacing a unit or installing a new system.
One nuance to consider: If youre planning to keep a backup heating system alongside your heat pump, consider getting an undersized heat pump. A contractor can help you figure out whether this makes sense in your home.
Note that heat pumps need far less capacity to heat a space than a furnace or boiler would because theyre much more energy-efficient. For example, if your home needed a 100,000-Btu/hr. furnace, it may need only a 36,000-Btu/hr. heat pump.
Compressor Type
The compressor is the heart of a heat pumpits the part that actually pumps the heat. Basic heat pumps have a single-speed compressor. Its either on or off. This system works well enough, but the temperature and relative humidity in your home will swing up and down with the cycles. Some compressors have two speeds, which mitigates the swings, but theyre still present.
The gold standard is a variable-speed compressor. Its designed to run almost constantly, adjusting itself over time to deliver only as much heating or cooling as it takes to keep your home comfortable. Its also much better at keeping relative humidity under control than single-speed models are.
Variable-speed compressors not only keep your home more comfortable but also are more energy-efficient. It may seem counterintuitive, but it takes much less energy to move a tiny bit of heat all the time than to move a lot of heat quickly.
Efficiency
Some heat pumps use less energy than others to deliver the same level of comfort. In cooling mode, efficiency is commonly expressed as the seasonal energy-efficiency rating, or SEER. The higher the SEER, the greater the efficiency. In heating mode, the measurement used is the heating seasonal performance factor, or HSPF. Again, the higher the number, the more energy-efficient the unit.
As of January , the Department of Energy adopted new testing methods for energy efficiency, replacing the SEER and HSPF values with SEER2 and HSPF2, while also increasing efficiency standards.
Heat pumps with higher SEER/SEER2 and HSPF/HSPF2 ratings tend to cost more, but theyll often pay for themselves over time through lower energy costs, and they may be eligible for better tax incentives or rebates than less efficient models. Heat pumps with higher SEER ratings also tend to have higher HSPF ratings, though theres no direct relationship between the two. If you live in a warm climate, pay closer attention to the SEER. In cold climates, look for a higher HSPF.
Climate Performance
If you live in a region with cold winters, youll need to either pick a heat pump thats rated to work well in the lowest temperatures that your region regularly experiences or have a secondary heating system to back up your heat pump.
All air-source heat pumps struggle to perform as temperatures drop; the space they can effectively heat shrinks and they dont work as efficiently. The threshold for poor performance varies from model to model. Some heat pumps falter at 25° F, others at 17° F or lower.
Models marketed as cold-climate heat pumps can work to their full potential all the way down to 5° F and may deliver some heat even down to -20° F or lower. The best course is to work with a qualified local contractor who knows what kind of equipment works well in your area.
If you live in an area where the temperature rarely or never drops below freezing (32° F), a basic heat pump can handle the bulk of your heating and cooling needs. You can keep a simple electrical-resistance backup system (sometimes built into the heat pump itself) for unusual cold snaps.
Noise
Manufacturers publish the noise levels of their products in the user manual and often on their websites. They tend to include noise estimates across a variety of outdoor temperatures and fan speeds, measured in decibels. A lower rating is better, especially if the heat pump will be installed near a bedroom window.
Reliability
In our member survey, heat pumps from eight brands were judged highly reliable, but only two of them also got top marks for owner satisfaction. Consumer Reports members can see the predicted reliability and owner satisfaction ratings for 29 brands of heat pumps, based on data that CR members have shared about 10,158 heat pumps they bought new and installed in their own homes between and . Those findings are summarized in our guide to the Most and Least Reliable Heat Pumps.
Heat Pumps: Everything You Need to Know
Theres a whole HVAC language to describe all the different types of heat pumps and how they work. Here are some of the terms youll probably come across in your journey, defined briefly.
Mini-split
Its basically another name for a high-performance air-source heat pump: More efficient, more flexible, and more comfortable than basic duct-only systems.
Theres some disagreement in the HVAC industry about the precise definition. A lot of people use mini-split and ductless interchangeably, though thats not quite right.
Heres a way to think about it: Ductless heat pumps are (almost) always mini-splits. But mini-splits arent always ductlessplenty of brands sell ducted systems that they call mini-splits, too. You dont need to worry too much about the specifics, though. Mini-split is a marketing term more than a technical term.
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Ducted / ductless
This tells you how a heat pump moves conditioned air around your home. They use the same underlying tech to generate warmth or cooling, but they deliver it differently.
Ducted systems, naturally, connect to ductwork through an air handler that usually has a large fan.
In a ductless system, youll usually have one air handler (or head) per room, attached to the wall or ceiling, and connected to the outdoor unit by a long tube running through a 3-inch hole in the wall.
Air source / ground source / geothermal / water-source
This tells you where the heat pump collects or rejects heat. Air-source heat pumps are by far the most common, practical, and affordable type of heat pump in the U.S. They look and mostly work like central ACs. When people talk about heat pumps broadly, theyre almost always talking about air-source heat pumps.
Ground-source heat pumps, sometimes called geothermal heat pumps, rely on hundreds of feet of tubing buried in your yard (instead of one mid-sized box installed next to your house). Its a great technology if you can afford it and your property can accommodate it, though its a high-stakes purchase.
Water-source heat pumps work like ground-source systems, except the heat-exchanging tube sits in a body of water, usually a pond or lake.
Air-to-air / air-to-water
These are subtypes of air-source heat pumps. Air-to-air systems distribute heating and cooling into your home through a forced-air system, either ductwork or ductless heads. Air-to-air heat pumps essentially replace a furnace and central AC.
Air-to-water systems distribute heat through hot-water radiator systems, essentially replacing a boiler. (Cooling is trickier.) Air-to-water is the norm in Europe, and while theyre not exactly common in the U.S., theyre available if you look hard enough.
Single-zone / multi-zone
These terms describe the number of air handlers or ductless heads connected to one outdoor unit. If its a simple one-head, one-compressor system, thats a single-zone system.
If multiple air handlers are connected to a single outdoor compressor, thats a multi-zone system (sometimes called a multi-split). Single-zone systems are more efficient. But if you need HVAC for multiple rooms (and don't have ducts), its usually more practical to install a ductless multi-zone system. Most multi-zone heat pumps can accommodate up to five heads, though theres some evidence that its better to stick with a maximum of three heads per outdoor unit.
Warm weather / cold climate
Basic warm-weather heat pumps work very well until the temperature drops to about 32 Fahrenheit. In many parts of the U.S., it doesnt get much colder than that very often, so basic heat pumps can get the job done (usually with some kind of simple, cheap backup). These are generally single-speed systems.
Cold-climate heat pumps can work well down to 0 Fahrenheit and below. The more often it drops below freezing where you live, the more it makes sense to look into a cold-climate heat pump. (They work well in milder temps, too.) These are almost always inverter-type heat pumps, or at least multi-speed systems.
Backup heat / heat strips / hybrid heat pumps / dual-fuel:
These are all variations on the same basic idea: A secondary heating system that can take over for the heat pump. Its almost always possible to rely entirely on a heat pump, but sometimes its more practical to keep another heater.
For the rest of this guide, we'll be focusing primarily on air-to-air heat pumps.
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