Choosing a Heat Pump – Ductless vs Central

Typical Cost To Install a 2-zone Ductless Heat Pump Average: $5,830 - $9,760
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When selecting a heat pump for your home, we feel it is important to clearly know what your expectations are:

1 – do you want just a very efficient Air Conditioner (cooling)?
2 – you are also interested in Heating your home with the heat pump?

Let’s that a look at both use cases.

1 – Heat Pump for COOLING

Most heat pumps are good at cooling – your main concern here should be the Price to Efficiency ratio and your cost of electricity. For example – if your electricity costs $0.10 / kWh, and you want to get an 18 SEER heat pump, your ROI or payback will be very long compared to a 14 or 16 SEER AC / Heat Pump. However, if you pay around $0.30 (30 cents) per kWh, then your payback will be MUCH faster, and it makes sense to pay $2000-3000 more for the 29% more efficient system.

To put this in real numbers:

Below is the way most contractors price their heat pump installs, with approximate price ranges. However, if you want to get an accurate estimate, use our Heat Pumps Size & Cost Calculator.

A 14 SEER 4-ton (48,000 BTU) AC / Heat Pump will cost about $591 per season to operate at 10 cents / kWh and $1,772 per season at 30 cents.

Same 4-ton AC / Heat Pump which has 18 SEER efficiency, will cost about $408 per season, at 10 cents ($183 saving vs 14 SEER) and $1,224 at 30 cents – a $548 annual saving.

As you can see it will take many years to see the economic benefit, if your electric cost is low … about 10-15 years. However if you are paying 30 cents (this is VERY real, as I’m paying 35 cents per kWh in Massachusetts, and it’s only going up), payback or ROI in now only 2-4 years, after which your more efficient Heat Pump will be “paying for itself”.

To estimate the electric cost and savings with higher SEER Rating with our AC SEER and Energy Cost Calculator.

With all of the above said – if your primary interest is cooling, that maybe you don’t even need a “heat pump”. Just get a regular 18 SEER central AC, preferably with Inverter compressor for smoother / quieter operation.

2 – Heat Pump for HEATING

If you also want a heat pump for Heating – next step is to look at where you live, how much electricity costs there, do you have or plan to get Solar, etc.

Do you live more in the south, or the north, and how cold your winters get: If you live in the south, and it does not get very cold – than you can get away with a non “Low Temperature Heating” capable heat pump. However keep in mind: Even in the hot Texas, you often get brutally freezing winters – albeit very seldom.

Some heat pumps are very good for heating, and can replace your main gas / oil / propane Furnace (forced warm air) or Boiler (forced hot water) heating system even in colder climates like Massachusetts / New Hampshire / Illinois / Montana, etc. Even in Canada, heat pumps can perform well as primary heat source – however, I feel that winter temperatures in Canada are too cold even for the most efficient heat pumps, and it will cost you too much to heat your home that way.

How Much do Heat Pumps Cost?

A low end Central Heat Pump – a single speed 16 SEER system, which is essentially is just an Air Conditioner, as its “heat pump” capability is very limited and requires adding very expensive “communicating” thermostat, indoor coil and either communicating furnace or electric heat strip (and still it will not heat your home below freezing temps – see our Warning here).

Cost of such 16 SEER central heat pump would be about $6,000-$7,500 installed – HVAC system only, excluding furnace / heat strip, and usually reusing your existing copper line set and electrical connections.

18 SEER Central Heat Pump (with Communicating Thermostat & Coil) will cost about $8,500 to $14,500, and again it is not capable of cold temperature heating. Communicating Furnace will cost additional $4,000-6,000.

21 SEER Central Heat Pump Communicating Coil, Furnace & Thermostat will cost $19,700 – $36,500

Cost of Ductless Heat Pumps:

Above we priced 4-ton Central systems. Ductless HVAC systems do not need to be so big as their ducted counter-parts, as they do not have duct heat losses, which can add up to as much as 25% loss on the high end, and as much as 10% loss on the low end (very rare).

Typically you want you ductless system to have 10-25% fewer BTUs capacity. However because most modern ductless systems have variable speed inverter compressors, they can easily “dial down” their output to meet the demand, whereas single-speed compressors have only two modes – ON & OFF. They will pump until demand is met, and then stop.

Bottom line – we don’t need 4-ton ductless system to replace same size central unit. But for accuracy, we will do just that.

Normally low to mid range ductless systems cost $3200-$4000 per zone, and each zone is usually about 7000-9000 BTUs (8K BTUs average). Therefore, a 6-zone ductless system with about 8K BTUs per zone (48000 BTUs or 4-tons) will cost about $19,300 to $24,000 and will typically have 16 to 18 SEER rating in Cooling Mode. These ductless heat pumps usually can work in Heating Mode down to +5°F (-15°C). Not exactly extra low temperatures, but will do just fine in most southern states, where heating demand is rare. With these systems, you don’t need a buck heat source.

A high efficiency ductless heat pump with Low Temp Heating operating range that goes down as low as -15°F (-26°C) and SEER Rating between 18-20, will cost about $4,000 to $4,800+ per zone, thus about $24,000 to $29,000 for a 6-zone, 48,000 BTUs.

NOTE: If you live in colder state, you will likely want to oversize your heat-pump for HEATING operation. Heating BTUs demand is ALWAYS higher than Cooling BTUs. Think about it:

Let’s say our target indoor temperature is 72°F. In the summer 100°F heat, your delta T is 28° which your heat pump must provide.

In the winter, when temps drop to say 0°F, your Delta T is 72°F or about 3 times more than in the summer. As outdoor temps drop, heating capacity of a heat pump also goes down. Typically, at 5°F, heating capacity drops to about 80-90%. At -5°F, it’s about 70%.

Thus, to have enough heat, it is recommend to use say two 3-ton condensers, each with 3 zones of about 12K BTUs. In heating mode, ductless heat pumps have about 10-20% more capacity than in their rated cooling mode. So we would have about 80,000 heating BTUs with our 2x 3-ton systems. The cost now would increase by about $600-$750 per zone, to make up cost difference in equipment. Labor is the same, so really it just the extra material cost. Thus, overall the exra cost would be about $3600 – $4500 to upsize your heat pump for extra heating capacity.

NOTE 2: For heating mode, you want your condensers mounted at least 18″ above ground, so they would not be buried in snow. Mounting 270 lb. condenser on a wall mount is asking for troubles. Therefore, I strongly recommend installing it on a concrete footing, and a metal stand:

Heat Pump on stand

Doing this myself several times – it takes a few days, and is actually very labor intensive – so expect to pay at least $900-$1100 for the footing and stand.

This actually include building a form, pouring concrete, drilling 16 holes and anchoring down the stand. While footing concrete is curing, which takes 2-3 days, you can’t install the condenser, and do most outside work, so this extends the whole project. In my opinion $900-$1100 is fairly inexpensive, after doing this by myself – it’s not fun, but very important part of the project.

What are the main types of Heat Pumps?

There are two may types – A) DUCTED also known as “central”, and B) DUCTLESS also known as “mini split”.

Both of these have their main unit – outdoor Compressor/Condenser that is always installed outside, and they also have an indoor unit know as air handler, evaporator coil or simply “coil” that is placed inside your home / building.

Ductless Heat Pump Heating Operation

The main difference between ducted ad ductless is happens inside:

A) Ducted or central system has one “central” EVAP coil that is usually installed in the basement or attic of your home. From there, cold or warm air is delivered into your rooms using air ducts.

B) Ductless systems does not have a central indoor unit which is connected to ducts. Instead you have an individual air handler in each room that you want conditioned – this is called a “multi-zone” mini split system. You can also have a single zone, where only one indoor unit is/can be connected to the condenser outside.

Ductless air handlers can only heat or cool air in the room where they are installed. This gives homeowners extremely flexible zoning – if you are sleeping in your bedroom, there is no need to cool or heat the whole house – run only one zone at a time, or however many you need. You do not get same zoning options with central system, which are made to push air through the entire duct system.

To cover my grounds for the “grammar police” type of readers:

You can have a ducted indoor unit for a mini-split system (called concealed duct or slim duct), but these are made to be used for say master suite, where you connect small ducts to your master bedroom and master bathroom. These are typically NOT used for the whole house.

You also have “zoning” options for central duct systems with dampers (mechanical or electronic). But these systems never give you full control or proper zoning. As you can see in this video produced by “this old house”, instead of dampers, they used 3 “central” indoor coils – one for each floor. And guess what – it is really a 3-zone ductless hybrid system 🙂

IMPORTANT: Not All Heat Pumps are Made for Heating!

There are plenty of horror stories about home owners installing new heat pumps, and ending up with $1000/month electric bill. There are several reasons for this. Four main reasons are:

1) Homeowners’ lack of knowledge and research.
2) Most CENTRAL HEAT PUMPS are not designed/made to HEAT your home in outdoor temps below 35-40°F
3) Manufacturers’ misleading and predatory advertising of their “heat pump” products.
4) Contractors/installers’ lack of knowledge, and willingness to install a product that’s not right for the client.

We will try to briefly cover these, to guide you in the right direction, but generally this topic is outside the scope of this calculator’s how-to guide.

TLDR: Central Heat Pumps are not capable of heating your home during the winter! You need a Heat Pump that is made for Low Temperature Heating (-15°F) and it also needs to have a bas-pan defroster / heater & be installed at least 18″ above ground.

In most cases you will need a DUCTLESS heat pump with “Hyper Heat” OR “Extra Low Temp Heating” label. We recommend Fujitsu, Mitsubishi and LG models.

1) Homeowners’ lack of knowledge and research into heat pumps

In many cases it is partially homeowner’s fault so to say, because many are not willing to spend 3 hours on basic research OR listen to the estimator / contractor.

When I was selecting a heat pump for my home, I literally spent about 4-5 weeks on research – obviously not full time, but still – many many hours. Now I have the answers and will lay them out for you. Here is what you need to know:

Your Heat Pump must be capable and designed for LOW TEMPERATURE HEATING. It need a number of special sensors to detect outdoor temperatures as well as the temperature of the refrigerant, and to direct the refrigerant flow in the right direction, to provide heating.

Your Heat Pump must also have adequate heating capacity AT low outdoor temperature, and be able to seamlessly go into defrost mode when outdoor coil is iced-up, and your thermostat is calling for heat.

Finally, your Heat Pump needs a bas-pan defroster, to melt the ice build up that occurs inside the condenser unit regularly, during heating operation.

MOST Central Heat Pumps are not capable of doing most of these tasks, do not have proper sensors, equipment and capacity. This brings us to Reason #2.

Most CENTRAL HEAT PUMPS are not designed to HEAT your home in outdoor temps below 35-40°F

As the heading says – do not buy a CENTRAL HEAT PUMP if you plan to use it for heating. They are not made for it. In temps below 35-40°F, Central Heat Pumps rely on backup heat – either a Gas Furnace or Electric Resistive Heat Strip! They also need a proprietary communicating Thermostat ($700), Communicating Coil & Furnace. These will cost (equipment only) anywhere from $15,000 to $27,000 for a 2000 sq. ft. home!

If you want a your heat pump to be primary heating system – get a Ductless Heat Pump with Low Temperature Heating mode, that operates down to -15°F or below.

Why there is so much confusion and so many unhappy homeowners? This brings us to reason #3.

Manufacturers’ misleading and predatory advertising of their “heat pump” products.

HVAC manufacturers in US caught a new “heat pump” trend that helps them sell ancient & inefficient equipment if they rebrand it as HEAT PUMP. What they do – add a few more refrigerant lines and a reversing valve to their old Central Air Conditioners, and now they can legally call it a heat pump! They use homeowners’ lack of knowledge to sell a “heat pump” that can’t actually heat below freezing temps – even if you add $5000 worth of communicating equipment to it.

Even the high-end models costing $15,000 to $27,000 for equipment alone (before cost of installation), cannot adequately heat your home in freezing temps, because their heating capacity drops to less than 10% when outdoor temps get into +10°F to +20°F.

At 47°F which is a standard temperature used for rating HVAC equipment in heating mode, the heating capacity is around 60,000 BTU/h for a 5-ton heat pump.
At 15°F, the heating capacity drops to around 5,000 – 10,000 BTU/h for a 5-ton heat pump.

Compare this to about 5000 BTU/h for a standard 1500W space heater that costs $30 – $70. This may be enough for 1 room, but not the whole house.

Because of such drastic heating capacity drop, central heat pump manufacturers limit heating mode to outdoor temps ABOVE freezing (32°F). Since they don’t need to provide heating in freezing temps, the do not install any of the sensors & equipment that is needed to run in freezing temperatures.

Thus your central heat pumps is essentially a glorified Central AC that costs 3-5 times more!

Now, if these “heat pumps” cannot heat – why do we have so many horror stories? This brings us to reason #4 – unscrupulous & uneducated HVAC contractors.

Contractors/installers’ lack of knowledge, and willingness to install a product that’s not right for the client

Unfortunate reality is that many HVAC contractors / salesmen do not have the knowledge AND/OR simply do not core for their clients. As soon as equipment is installed and is working “properly”, they are off the hook.

You bought a “heat pump” and that’s what was installed. Is it the right size? In cooling mode – it is. Therefore – there is no real liability on the part of the installer.

Did they install the right product for you? It doesn’t matter for most contractors/salesmen.

Will it cost you $1000/mo in electricity to heat your home, because you got an electric Heating Strip for a backup heat? Well – that’s your problem, and you won’t find out, until it’s mid winter and you get your electric bill and go like “WHAT IS THIS? WHY SO MUCH?”

Optionally they will install an expensive “communicating” Gas Furnace for you, and you will have a “DUAL FUEL” setup at a cost of $5000-$10,000 more that it should have cost, had you gone with a basic 16 SEER Central AC and a 96% AFUE Gas Furnace.

In a way (in certain cases) – it’s not the contractor’s fault, as many homeowners refuse to listen and do the research. I personally had many interactions with clients that get completely disinterested, when I begin to explain technical details to them. They read somewhere on “treehugger” or saw on CNN that heat pumps are good, and green new deal is providing rebates for heat pumps. It is very difficult to relay important but boring details to such clients.

Oh, and on rebates topic – your basic heat pump will typically not qualify for a rebate, or you will get at most $500. But you won’t find out, until you actually apply and get denied.

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