A heat pump is an air conditioner that’s built with a reversing valve, so it can be used to cool and heat a building. Though it sounds like a heat pump is only for heating, the term refers to the movement of heat, so a heat pump moves thermal energy from one place to another.
Heat pumps move this thermal energy against a thermal gradient. What does that mean? It means the system transfers heat from a place where there is less heat, to a place where there is more heat. In practice, this means moving heat from inside a building to the hotter exterior air. In the winter, it means moving heat from the cold outside air to inside.
Heat pumps are a common option in homes and businesses along the Gulf Coast,
The advantages and drawbacks of a heat pump system include:
1. Energy efficiency – Heat pumps are extremely energy efficient compared to any system that generates original heat for the home. That’s especially true of systems that rely on combustion. Because heat pumps move heat from one place to another via a refrigeration loop, they don’t need to generate thermal energy.
HVAC manufacturers measure efficiency by how much heat they deliver to the building, compared to how much fuel is used to create that heat. The closer a system can get to 100 percent, the better, which is possible for electrical HVAC technologies. Heat pumps, though, can achieve efficiency ratings of around 300 percent. This means for every one unit of energy spent to power the heat pump, three units of heat can be moved into the home.
This excellent energy efficiency means a heat pump costs less to operate. That should be factored in when considered an HVAC system purchase.
2. Reliable, consistent climate control – Heat pumps provide total climate control to the building in a single package. Other systems require different components to provide both heat and cooling, and those components may differ greatly in their age and model. That means the system could provide adequate cooling but inconsistent heating, and vice versa. Relying on a single HVAC system means easier maintenance, which means your system will operate reliably.
3. Better air quality – Heat pumps do not combust fuel to generate heat, so they produce no emissions. That means zero risk of carbon monoxide leaking. Further, heat pumps mix outside air with inside air when delivering heat, so this keeps air circulating through the building. Finally, heat pumps retain some of the humidity left in the air, so there’s no need to use a humidifier to keep the air comfortable.
4. Backup is needed on very cold nights – Heat pumps move heat, which means the colder it gets, the less heat they have to move. As temperatures drop, heat pumps become less efficient. If it gets cold enough (usually in the mid-30s or below), then a backup heating system may be required. This can be built into the system, usually in the form of electrical burners that can generate their own heat.
5. Heat pumps require expertise – Heat pumps are complex systems that not every HVAC technician is familiar with. It’s important, then, for property owners to find an HVAC company that works with heat pump systems regularly. For example, heat pumps require the occasional refrigerant recharge to ensure reliable climate control. An HVAC technician familiar with heat pumps will know when to expect this maintenance, and will be able to provide it when needed.
There’s a lot to like about heat pumps, especially in warmer climates like those along the Gulf Coast. Although heat pumps require a backup option on extremely cold nights, for Houston-area property owners, this isn’t a frequent concern.
There’s also an option to install a ground or water-source heat pump.
The Three Types of Heat Pumps
Although all heat pumps operate using the same principles – using refrigerant to transfer heat, where this heat is sourced from makes a difference. There are three sources that the system can draw from, including air, geothermal and water. Here’s a look at each:
1. Air source heat pumps – Air source heat pumps are the most common and the least expensive to install. They work by drawing in air using an intake fan and then exchanging heat between the outside air and the refrigerant.
Air source heat pumps are a popular option, partly because they are less expensive than other options. It’s a reliable source of heat. However, air temperatures fluctuate, so their performance dips on very cold nights.
2. Geothermal, or ground, source heat pumps – Geothermal heat pumps are installed underground, deep enough where surface temperatures have little impact on the ground temperature. The refrigerant is looped through this warmer, subsurface ground, so even when the weather is cold, there is a consistent source of heat to draw from. That means a backup system isn’t needed and efficient performance can be maintained.
The only issue with geothermal pumps is their installation cost, which is significantly higher than air source pumps. For this reason, geothermal heat pumps are usually installed when the property owner expects to occupy the home or business for many years.
3. Water source heat pumps – A water source heat pump is a middle ground between air and geothermal pumps. Water holds onto heat better than air, so water source pumps remain effective on cold nights. They are also much less expensive to install than geothermal pumps.
Water source heat pumps, though, require a nearby source of water to run through the system. That could be something as simple as a pond, but it’s still required.
Heat pumps are convenient, effective two-way climate control systems, able to provide efficient cooling and heating in a single package. They are particularly effective in Houston-area homes and businesses, where the threat of extremely cold weather is minimal. There are also several heat pump options to choose from, so there’s an optimal system for every home or business.
FAQs
Why are heat pumps much more efficient than other HVAC systems?
Most heating systems must generate their own heat, either with electricity or with fuel like gas or oil. Heat pumps do not create their own heat, but instead move heat from outside to the inside, using a refrigeration loop. This reduces the amount of energy needed to power the system considerably, to the point where heat pumps are much more efficient than other heating technologies.
What is the difference between an air, ground and water source heat pump?
Air, water and ground (geothermal) source heat pumps are identical in how they transfer heat, but differ in where they get that heat from. An air source pump pulls heat from the outside air, a water source pump uses a body of water, and ground source pumps collect heat from the Earth.
Why is an experienced HVAC technician needed to maintain a heat pump?
Heat pumps are complex HVAC systems made up of many components, so they require expert maintenance to keep running. Further, many HVAC technicians are unfamiliar with a heat pump’s operation, as they are usually installed by experienced HVAC companies.