# Variable speed heat pump installation in Memphis

> A sticky house at 72 degrees: variable speed heat pumps in Memphis run longer at low speed to pull more water from the air and even out rooms and floors.

URL: https://blufflinememphisheatpumps.com/variable-speed-heat-pump/

Service

Long, slow runs that pull more water out of a Memphis summer and keep two-story houses even.

(901) 657-2200

Last Updated: November 12, 2026

1 visit

before a written estimate with load numbers, model numbers and price

95° / 20°

Shelby County design temperatures we size for

In writing

start-up readings for charge, airflow and backup heat

## When 72 degrees still feels sticky

A Memphis house can sit at 72 degrees and still feel clammy, with damp sheets and a musty closet. The temperature is right; the humidity isn’t. That is the problem a variable speed heat pump solves best.

[Bluffline Memphis Heat Pumps](https://blufflinememphisheatpumps.com/) installs variable speed heat pumps across Memphis and the suburbs, and we price them beside single-stage so you can see what the step buys.

### Two kinds of load

A cooling system removes two things: heat you can feel, and water in the air. The second is the latent load, and Memphis summers carry a lot of it. A system can satisfy the thermostat on heat and leave the water behind.

## How variable speed works

A single-stage heat pump runs at full speed or not at all. A variable speed heat pump has an inverter-driven compressor and a variable speed blower that can run anywhere from roughly a third of capacity to full.

### What that changes

- **Longer runs at low speed** keep the indoor coil cold for longer, so more water condenses and drains away.
- **Steadier temperatures**, because the system matches the load instead of overshooting and shutting off.
- **Less noise**, since most hours are spent at low speed.
- **Better heating on mild days**, with fewer strip-heat calls when it ramps up gradually.

On the hottest afternoons it still runs near full speed. The gain is in the many hours when the house needs less than full output.

## Where it earns its cost

Variable speed costs more than single-stage. It pays back best in a few kinds of houses:

- **Two-story houses on one system**, where upstairs runs warm and damp and downstairs cool.
- **Houses that stay humid** at a normal setpoint, even with a correctly sized unit.
- **Bedrooms close to the outdoor unit**, where a quieter compressor matters at night.
- **Houses that run the AC hard**, where the higher SEER2 rating cuts the summer bill.

In a small single-story ranch with good ducts and normal humidity, a correctly sized single-stage or two-stage unit may do the job for less. The comparison table above shows the trade-offs.

### Sizing still matters

A variable speed unit that is far too big still spends its time at minimum speed cycling on and off. We size it from a load calculation for Shelby County’s 95-degree summer, and for two-story houses we look at each floor. The [sizing guide](https://blufflinememphisheatpumps.com/guide/heat-pump-sizing-manual-j/) explains how.

## Collierville, Germantown and the upstairs problem

Many newer two-story houses in [Collierville](https://blufflinememphisheatpumps.com/service-areas/collierville/) and [Germantown](https://blufflinememphisheatpumps.com/service-areas/germantown/) have one system per floor or one system for both. Heat rises, attic ducts gain heat, and the only return may be downstairs.

A bigger unit rarely fixes an upstairs that feels hot and damp. Variable speed upstairs, with a properly sized return, often does. The [humidity guide](https://blufflinememphisheatpumps.com/guide/heat-pump-humidity-control/) explains why.

## Ducts and airflow

Variable speed systems need ducts that can carry full airflow on the hottest days. If the static pressure is high, the blower works harder, makes more noise and loses part of the benefit.

We take a static pressure reading on the first visit. If the return is small or the trunk leaks, the fix goes on the estimate as its own line. See [heat pump ductwork](https://blufflinememphisheatpumps.com/heat-pump-ductwork/).

## Thermostats and wiring

Many variable speed systems need the maker’s communicating thermostat to use their full range. That can mean running new thermostat wire from the air handler. Some systems work with a standard thermostat at reduced range.

### Setting it up for Memphis

At start-up we set the airflow and turn on the dehumidify mode, which slows the blower when humidity is high. We show you the humidity reading on the thermostat and what range to expect. The [thermostat guide](https://blufflinememphisheatpumps.com/guide/heat-pump-thermostat-setup/) covers the settings.

## Efficiency ratings and rebates

Variable speed heat pumps carry the highest SEER2 and HSPF2 ratings, which matters most in a house that runs the AC from May to October.

TVA EnergyRight pays $500 for a qualifying heat pump at 15 SEER2 and $800 at 17 SEER2, installed by a participating contractor in TVA’s Quality Contractor Network, and most variable speed models clear the higher tier. [SEER2 and HSPF2 explained](https://blufflinememphisheatpumps.com/guide/seer2-hspf2-explained/) covers what the numbers mean.

## What it costs

Bluffline’s typical range for a whole-home ducted heat pump system is $8,000 to $16,000, and variable speed systems sit in the upper part of it. Your written estimate after the visit sets the price.

Replacing only the outdoor unit isn’t usually possible, because the outdoor unit and air handler have to be variable speed partners.

### What moves the number

- Capacity, set by the load calculation.
- The maker’s matched air handler and thermostat.
- New thermostat wire.
- Duct fixes found in the static test.

The [cost page](https://blufflinememphisheatpumps.com/heat-pump-installation-cost/) has every range.

## Living with it

A variable speed system behaves differently from the one it replaces, and it helps to know what normal looks like.

- **It runs almost all the time.** Long, quiet runs at low speed are the point. A system that rarely shuts off on a July afternoon is doing its job, not struggling.
- **The supply air feels less cold.** At low speed the air leaving the registers is a few degrees warmer than a single-stage blast, but it carries less water.
- **Humidity drops over days, not hours.** After start-up, give the house a week of summer weather before judging the humidity reading.
- **Winter mornings recover slowly.** Deep overnight setbacks make a variable speed system ramp up for a long time, and can bring the strips on. Smaller setbacks work better.

### If the house is still damp

After a week of real summer weather, a house that still reads above about 55 percent humidity needs a look at the airflow and dehumidify settings, which can be adjusted without changing any equipment.

## Placement and noise

A variable speed outdoor unit is quieter most of the time, which helps on narrow side yards where sound bounces between brick walls. We still keep it off the bedroom side where the lot allows. [Placement and noise](https://blufflinememphisheatpumps.com/guide/outdoor-unit-placement-noise/) covers clearances and sound.

## What's included

- Load calculation for the house or the floor it serves
- Static pressure test on the ducts
- Variable speed heat pump and matched air handler
- Communicating thermostat where the system needs one
- Thermostat wire run where required
- Raised pad and electrical disconnect
- Dehumidify mode and airflow set with you
- Start-up readings in writing

## Single-stage, two-stage or variable speed

|  | Single-stage | Two-stage | Variable speed |
| --- | --- | --- | --- |
| How it runs | Full speed or off | Low or high | Anywhere from about 30 to 100 percent |
| Moisture removal | Short runs, less | Better on low stage | Best, long low-speed runs |
| Room-to-room evenness | Swings | Better | Most even |
| Noise | Loudest at start | Quieter on low | Quietest most of the time |
| Price | Lowest | Middle | Highest |

## Drying out a Collierville upstairs

A 2002 two-story near the Town Square has two systems. Downstairs is fine. Upstairs sits at 72 degrees and 60 percent humidity, and the bedrooms swing three or four degrees. The upstairs heat pump is a 3-ton single-stage unit, half a ton bigger than the floor needs.

Where

Collierville, near the Town Square

The house

2002 two-story, about 3,200 sq ft, two systems

Price

$15,600

Time on site

2 days

1. Load by floor The calculation for the upper floor alone comes to 2.5 tons. The old 3-ton unit cooled the air fast and shut off before it pulled the water out.
2. Variable speed upstairs only A 2.5-ton variable speed heat pump and matched air handler replace the upstairs system. The 2017 two-stage downstairs stays.
3. New wiring The communicating system needs new thermostat wire, run from the attic to the hall.
4. Set it to dry At start-up we set the dehumidify mode and the airflow, then check the upstairs readings the following week: 72 degrees, under 50 percent.

## Related resources

- [Learn**Does a heat pump remove humidity from a Memphis house?** Why 72 degrees can still feel clammy, where the water goes, and the four things that decide how dry a heat pump keeps the house.](https://blufflinememphisheatpumps.com/guide/heat-pump-humidity-control/)
- [Learn**What do SEER2 and HSPF2 mean on a heat pump?** The two numbers on every heat pump quote, what changed when they got a 2, and how much a higher rating is worth in a Memphis house.](https://blufflinememphisheatpumps.com/guide/seer2-hspf2-explained/)
- [Learn**Where should a heat pump's outdoor unit go, and how loud will it be?** Clearances, pads, drainage and sound on narrow Memphis side yards, and when it is worth moving the unit at replacement time.](https://blufflinememphisheatpumps.com/guide/outdoor-unit-placement-noise/)
- [Learn**How should a heat pump thermostat be set up in Memphis?** The handful of settings that decide whether a heat pump saves money: the equipment type, the outdoor sensor, the lockout, setbacks and the fan.](https://blufflinememphisheatpumps.com/guide/heat-pump-thermostat-setup/)
- [Decision Guide**How do you buy the right heat pump for a Memphis house?** The whole decision in the order you meet it, from the system you have now to the readings you should get at start-up.](https://blufflinememphisheatpumps.com/guide/memphis-heat-pump-buying-guide/)

## How a job runs

### Call or send the form

Tell us what heats and cools the house now and what's going wrong.

### One visit

We look at the equipment, ducts, panel and the spot outside and run the load numbers.

### Written estimate

Load figures, matched model numbers, scope and price on one page.

### Install and start-up

Permit pulled, system set, line set tested, and the start-up readings handed to you.

## Variable speed heat pumps: questions

### Does a variable speed heat pump really control humidity better?

Yes, when it is sized correctly and set up for it. Running at low speed for long periods keeps the coil cold longer, so more water condenses out of the air. A dehumidify setting slows the blower further when humidity is high.

### Is variable speed worth the extra cost in Memphis?

It earns most in houses that feel damp at a normal setpoint, two-story houses with uneven floors and bedrooms near the outdoor unit. In a small, well-sealed ranch with good ducts, a single-stage unit sized right may be enough.

### Do variable speed heat pumps need special thermostats?

Many need the maker's communicating thermostat to run at their full range. Some work with a standard two-stage thermostat at reduced range. The estimate names the thermostat and whether new wire is needed.

### Are variable speed heat pumps quieter?

Most of the time, yes. They spend most hours at low speed, which is much quieter than a single-stage unit starting at full power. They still run near full speed on the hottest afternoons.

### Will a variable speed heat pump work with my old ducts?

It needs ducts that can carry full airflow on the hottest days. We measure static pressure first. Restrictive ducts limit the benefit and can make the blower work harder, so the estimate lists any duct fix.

## Related services

- [Service**Heat pump replacement** Your heat pump is near the end and you want the next one to last. We size it from the house and match both halves.](https://blufflinememphisheatpumps.com/heat-pump-replacement/)
- [Service**Duct work** A heat pump can only move the air the ducts let through. We measure first, then fix returns, seams and crushed runs.](https://blufflinememphisheatpumps.com/heat-pump-ductwork/)
- [Service**Air handlers** The indoor half decides airflow, drainage and backup heat. We replace it with a matched unit and keep a sound outdoor unit.](https://blufflinememphisheatpumps.com/heat-pump-air-handler-replacement/)

## Get an estimate for variable speed heat pumps

Tell us what heats and cools the house now, what's going wrong and roughly where the house is. Photos of the outdoor unit and its nameplate help.

(901) 657-2200