skip to main content

Heating & Air Conditioning

Two stage vs full variable stage heat pump

5 years ago

Hi All,

I am looking to replace my heat pump. I have it narrowed down to two American Standard models. Once is a two stage heat pump, meaning it can operate on either high or low depending on outside temperatures, number of people in house, etc. The next step up is a full variable model, which means it has high, low, and a ton of different settings in between. Has anyone had any experience with two stage or full variable heat pumps? Any concerns from either type?

Sort by:Oldest

Comments (6)

tigerdunes
5 years ago
Your question is more about your location and summertime humidity,overall comfort, and cost difference. You have to make the decision.

IMO
Oliviag
5 years ago
we have a trane two stage compressor. with the tam7 airhandler. we are in sw florida, if that helps. i believe american standard is a rebranded trane, but im not sure of that...
we have no complaints. our home was a new build, four yesrs old extremely well insulated, great windows, obvioysly new and well sealed ductwork, in semi conditioned space. . we almost never have the second stage kick in...
if you're not well insulated, at least you will probably only run in first stage in shoulder season, saving some power and short cycling.
if you're in a high humiduty area as we are, you mught also consuder a whole house dehumidifier. we. can set the ac at 79 or 80, and feel very comfortable. reversible ceiling fans in all rooms but kitchen and dining.
Related Discussions
1 stage vs 2 stage furnace with a Heat Pump
Q
Comments (1)
What is the wattage rating of the the low and high stages? I would think the low stage of the electric furnace would be sufficient as auxiliary back up heat. But in your location it can get very cold and you may need the high stage. Can your thermostat control three stages of heat? If yes then you may want to set it as a three stage system (heat pump, 1st stage furnace, 2nd stage furnace). I am not sure how this works with lock out temperature settings. Call Honeywell for guidance.
...See More
TWO stage heat pump question
Q
Comments (2)
A 16 SEER heat pump usually has one two-stage compressor. The first stage is usually 75% (approximately) of the rated tons. The second stage runs at the full compressor rating. Not sure about the 18 SEER Amana. The Trane XL19i has 2 separate compressors. The first compressor runs at 50% of the rated tonnage and the second compressor runs at the full rated tonnage. In this set-up, one or the other compressor is running (not both). Just because the heat pumps are rated at 16 or 18 SEER does not mean that the system is rated at that SEER. The matching air handler/furnace is critical in maintaining that SEER rating. An air handler/furnace can decrease SEER, increase SEER, or support the SEER rating. This is why it is important to know thw model numbers of both the condenser (outside unit) and air handler and a/c coil if there is a furnace involved. A heat pump with either a two-stage compressor or dual compressors has 2 stage cooling. If the same heat pump has auxillary heat in the air handler (back-up electric strips, gas furnace, etc), it has 3 stage heating. FYI, you don't necessarily reduce your utility bill with a 19 SEER as compared to a 14 SEER. The Energy Efficiency Ratio (EER) determines your true operating costs, not SEER.
...See More
2 stage variable speed furnace vs. single stage furnace
Q
Comments (3)
Location?...post Mdl numbers...there are 2 major difference between the furnaces...2 stage high eff heat exchanger and the var speed blower motor...I am unaware of any measurable reliability of one furnace over another. I do recommend st steel heat exchanger on both.... While blower motors are very reliable with few failures, the var speed blower mtr model is quite expensive to replace. Just so you know, you can get a 2 stage high eff furnace with fixed speed ECM blower motor, ie not var speed. IMO
...See More
Central TX - Heat Pump vs. AC/Furnace (Propane) & 2 Stage vs. Single
Q
Comments (8)
Propane has 91K btu's per gallon input, Electric has 3400 Btu's per kilowatt. Propane gives you 72,800 btu's output at 80% efficiency. Electric aprox. 3400 Btu's output per kilowatt, (100%) with only a small amount lost. 72,800 btu's divided by 3400 btu's = 21.4 kilowatts to equal 1 gallon of propane. The average cost of 1 kilowatt in Austin - $0.1142 cents, times 21.4 Kilowatts equals $2.42 for electricty and little more expensive then propane at $2+ per gallon. But this will change drastically if Biden does ban fracking as he stated. But then what happens to the price of electricity? It's a guess, and having the ability to switch between the two may be a valuable option in the near future. But the cheapest option with a stable price for ever would be to capture the heat in the sun with active solar collectors to heat water (not to be confused with solar panels to produce electricity), and store it in insulated underground tanks to use for the winter. After the initial investment it would cost you a few dollars a month in electricity to run circulation pumps, and you could even get the electricity from solar panels for that. They do it in Alaska for building bigger than yours, easy and simple, only problem is getting insulated storage tanks in the 5K to 20K gallon range. I'd do it in a heart beat if I had some really big tanks, I have the land, backhoe and the solar collectors, 9 of them 5' x 9', salvaged from a $35,000 government subsidized program project in the late 70's. (The government loves wasting other peoples money.) Johnson controls started a line of HVAC equipment called champion about 6 years ago. Parts?
...See More
B H
Original Author
5 years ago
I know that location/cost is a factor, but I guess my question also has a reliability component or anything else I should be aware of.

I’m in Florida, btw. Currently have a single stage 2.5 ton unit. It’s fine most of the time, but struggles when I have a large group or is a very hot day. Upgrading to a 3.0 ton, but that will be oversized a lot of the time. That’s why I know I want a multi stage unit. I’ve read that variable provides the best comfort, but realibility is unknown/questionable. I couldn’t find any additional details on that statement.

also, initial cost difference between the two units is only $800, so don’t mind spending the extra money if it’s an improvement.
sktn77a
5 years ago
Most 2 stage units run 67-75% of full capacity on stage 1. So a 3 ton unit will run at 2-2.25 tons in low (most of the time - good for dehumidification) and 3 tons in high (on those less-frequent occasions when you need it). Sounds like that would suit your needs just fine without being oversized "a lot of the time". I think the most comfort bang-for-the-buck comes with the jump from single stage to two stage. Variable speed (inverter) based systems seem to be the way of the future, though.
kevinande
5 years ago
Repair and replacement parts for the multi stage units are pricey, so it's not just the initial acquisition cost. If that is not an issue for you then it may be worth it. I have heard nothing but good things about these units regarding humidity control. The technology is getting better, however they are still not as reliable as single stage systems. They have many more components and more opportunities to fail.
B H
Original Author
5 years ago
Thanks everyone. I went with the two stage as that seems to offer improvement over a single stage unit and mitigate some of the risk of pricey repairs on a full variable system.

Related Stories

KITCHEN DESIGN Remodeling Your Kitchen in Stages: Planning and Design

By Matt Clawson

When doing a remodel in phases, being overprepared is key

SELLING YOUR HOUSE How to Stage Your Kitchen for a Home Sale

By Laura Gaskill

Attract buyers with a kitchen that’s clean, bright and welcoming — no expensive overhaul required

LIGHTING Decorating With Antiques: Set the Stage With Lighting

By Mike Dietrich

Complete a vintage scene or create contrast with lamps, sconces and chandeliers that have traveled through time

MOST POPULAR Crowd-Pleasing Paint Colors for Staging Your Home

Ignore the instinct to go with white. These colors can show your house in the best possible light

HOUZZ TOURS My Houzz: Full-Tilt Reinvention for a 1950s Ranch

By Heather Merenda

Out went the dated features of this Vancouver hilltop home, and in went contemporary finishes and clean lines

GREEN BUILDING Houzz Tour: Passive House in Vermont Slashes Heating Bills

By Becky Harris

Its ecofriendly, low-maintenance design leaves a family with more time to relax and enjoy the weekend home

GREEN BUILDING Insulation Basics: Heat, R-Value and the Building Envelope

By Mariana Pickering (Emu Building Science)

Learn how heat moves through a home and the materials that can stop it, to make sure your insulation is as effective as you think

DECORATING GUIDES Houzz Tour: Couple Pares Down and Pumps Up the Style

By Becky Harris

A big transition from a large suburban house to a 1,200-square-foot urban condo is eased by good design

FLOORS Is Radiant Heating or Cooling Right for You?

By Mariana Pickering (Emu Building Science)

Questions to ask before you go for one of these temperature systems in your floors or walls (yes, walls)

SMALL HOMES Can You Live a Full Life in 220 Square Feet?

Adjusting mind-sets along with furniture may be the key to happiness for tiny-home dwellers

Sponsored

Fourteen Thirty Renovation, LLC

23 Reviews

Professional Remodelers in Franklin County Specializing Kitchen & Bath

More Discussions

Mount range hood to wall or ceiling?

19

Cooling Mini Splits

65

Moving the furnace? How difficult and how costly?

5

humidifier for a furnace in a closet

0

HVAC condensate pump issue

7