What's the Difference Between Ductless & Ducted Heat Pumps? Which One Should I Install?

Your decision to buy a new heat pump system is as easy as deciding to go on holiday. You know it's going to cost money, but the tricky part is deciding where to go. It's the same here; which type of an HVAC unit to get, and do you buy a ductless heat pump system or choose a ducted heat pump system?

There are many important decisions to make. Selecting a new heat pump system for your home is not as much fun as choosing a holiday; however, it's essential to get it right. After all, you'll be living with your system for many years to come, and your comfort will depend on it.

Professional design, planning, and installation are all critical factors to ensure your new system matches your family's specific requirements. HVAC systems are expensive and complicated. No matter which system you finally select, always start with a qualified HVAC technician to avoid costly errors.

You want a reliable system that will give you control over your home's environment year-round. If your existing furnace only handles heating through ducting, it may be possible to use that ducting with a brand new system.

What's the difference between ductless & ducted heat pump systems?

Ductless

A ductless heat pump system sends refrigerant directly to one or multiple small air handlers or blowers installed throughout your home. It does not use ducts inside the walls or ceiling space to circulate air. The temperature of each room is controlled individually with thermostats. The blowers are usually wall or ceiling-mounted.

Ducted

In a ducted air-to-air heat pump system, custom-fitted air ducts reside inside the walls and ceilings of your home. These ducts transport hot and cold air from the central HVAC unit to each room via vents.

Let's consider the benefits & drawbacks of ducted vs. ductless systems

Ductless systems - Benefits

• Modern air source ductless heat pumps can deliver one and a half to three times more heat energy than the energy they consume. The unit moves heat rather than using energy to produce it.
• Ductless installations require less construction to install. They only need a 3" hole in the wall to allow for the connections between the outdoor unit and the indoor air handlers or blowers.
• Split ductless heat pump units are capable of a higher SEER rating, up to 25, which delivers substantial energy cost savings.
• They offer excellent zone temperature control for your home. Don't pay for heating rooms that are not in use. With zoned temperature control, you save both energy and money.
• Less dust in your home because you are not forcing air through it. There are filters in each air handler unit.
• No loss of energy through ducting.

Ductless drawbacks

• The individual air handlers in a ductless heat pump system do not have the capability of removing excess moisture in an area of high humidity. They are not equipped to drain it away. This can be an important consideration.
• The aesthetic appearance of a ductless system may not appeal to you.
• With a ductless system, you have an air handler in each space, which requires regular cleaning and maintenance.

Ducted systems - Benefits

• A ducted heat pump system is more efficient at humidity and moisture control, which may be an issue where you live.
• Ducted heat pump systems will deliver more airflow throughout your home, which will help to maintain freshness and avoid stagnant air.
• With a ducted heat pump system, everything is out of sight and is unobtrusive. The air feed to each room is via vents, which can be a wall, floor, or ceiling mounted.
• Ducted heat pump systems will save you time and money on maintenance. There are fewer parts to consider, as there is only an outdoor unit and an indoor air handler, which you can have installed in the attic.
• If your home already has ducting, it's entirely possible to install a new source heat pump and link it to the existing ducting.
• Quicker installation. (If ducts are already in your home and serviceable). 

Drawbacks

• Ducting can lose efficiency as materials age. 10% to 30% of the energy (link opens in PDF) used to heat or cool the air is lost through the ducts and much more if the ducts are leaky or not insulated. 
• Your home air duct installation is a vitally important component of your system, and because it's out of sight, it's easily forgotten. If they are leaking, or the sealing is weak, old, or damaged, they will deliver higher energy bills – guaranteed. 
• Ducts also need to be correctly insulated and checked from time to time for leaks and damage. It's especially important if they pass through areas of your attic where you store stuff. It's easy to damage them and not realize it.
• Occasionally people will use floor cavities and pipe chases as ducting, but they are wholly inefficient and will cost you cash.
• If your existing ducting is unsuitable to use with a new system, you may need to replace it, which will add to the costs for the project. It's essential to have it checked before you start to avoid nasty surprises when the project is underway.
• Ducting needs to be adequately insulated, especially if it passes through unheated parts of your home.
• If the airflow is too low due to leaky ducts, occasionally alterations to the ductwork are required, which can add cost.
• Ducted heat pump systems commonly have lower SEER ratings (around 13 - 16) and will cost more to run.
• Zone temperature control using existing ducting, will require thermostats in each room and installing automatic dampers in the duct, controlling the airflow to that space.

These are the facts, so now the final choice is yours:

Conclusion

The final decision is yours, but now you have information on two possible choices – a ducted heat pump system or a ductless heat pump system. When you call in your HVAC professional, you'll be able to discuss everything in detail.

As you have read, both ducted and ductless systems have benefits and drawbacks. The final choice will hinge on your specific requirements, the size of your home, and what your expectations are of the new system. The budget will also play a significant factor in your decision, of course.

Don't forget grants, rebates, and assistance that could be available in your area. Check out local, state, and federal sources of incentives to install energy-efficient systems in your home.

Remember, if you already have a duct system in your home, it may be the best way to go forward. Always have the ducting checked out by a professional HVAC technician before you place the final order, and expect a longer installation process if you need to replace it.

Before you make your final choice, check the EnergyGuide label on the equipment you are considering. It will give you full details of the heat pump's Seasonal Energy Efficiency Ratio (SEER) rating. 

The higher the SEER rating, the more expensive the unit will be, but the savings in energy costs will return the higher outlay many times over through the heat pump's lifetime.

In warm climates, SEER is more important than HSPF, but in colder climates, always aim for the highest HSPF level you can afford.

Good luck!

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