skip to main content

Heating & Air Conditioning

Single Speed vs Variable Speed with 10 foot ceilings and 2 story foyer

6 years ago

I need some advice. I have one air conditioning company saying we need to go with single speed 3.5 ton AC unit because we have high ceilings and 2 story foyer. They say it will have to kick in high almost immediately and we will experience higher bills instead of lower. I have another company telling me that variable speed is the only way for us to go.

Sort by:Oldest

Comments (9)

mike_home
6 years ago
Two story foyers are generally a problem to heat and cool. You want a return and vents near the high ceiling. A ceiling fan will help circulate the air.

The variable speed is probably better since it will run longer and allow more time for air to circulate the the top of the two story foyer. But this assume you have vents high enough to move the hot air sitting at the highest point.
PRO
Austin Air Companie
6 years ago
Location?
Related Discussions
Trane or Amana; Single stage vs 2 stage
Q
Comments (3)
Is the trane single speed or two speed? If it is single speed, and the price isn't that much different, go with Amana If the trane is two speed, and the price isn't that much different, go with trane. Trane is a high end unit, but two speed is alot better than single speed as far as efficiency.
...See More
Variable Speed / TWo stage...come on!
Q
Comments (15)
"Variable speed will make me more comfortable and is more efficient---still no explanation as to how" - In the summertime, a fan running on lower speed for longer times pulls more humidity out of the air. In the winter using the heat pump, you don't get the blast of cold air at start-up because the fan gradually ramps up. These are the "more comfortable" part. Since it is a DC (direct currrent) motor, it costs less to run than the typical AC (alternating current) motor. This is the "more efficient" part. Not sure that the variable speed motor will help you at all with floors seeing different temperatures as Daddo stated previously. Ceiling fans will help this and so will running the furnace fan all the time in the summer. The key is to circulate air thru the house to try and equalize temperature. "Variable speed is a gimmic that actually costs more to operate." - This is Bob Brown's opinion. They cost more to repair for sure, but you have to do some experimenting to figure if they cost more (based on run time, power consumption, and cooling effect). I chose not to get a variable speed with my new heat pump. The air handler that I bought has 3 fan speed settings so I get to play with only 3 speeds. The Goodman variable speed air handler has dip switch settings for 4 fan speeds for each mode: heat pump/ac, heat pump + electric back-up, and electric emergency only. It also has a trim adjust dip switch of +15% or -10% CFM for the 4 settings for each of the 3 modes. For this variable speed motor, running the unit in "fan only" on the thermostat sets the fan speed at 30% of the heat pump/ac setting. You get a lot more to play with with variable speed motors. Hope this helps.
...See More
What is variable speed?
Q
Comments (12)
We are in Alabama and the temps have been 95-105. It is a 2.5 ton, but our invoices says we paid for a 3 ton. As for the fan being variable have no idea, I just know that the installer said he could not make it go at different speeds, but variable is what is on our invoice and what we though we where getting when we did the upgrade. The 3.5 downstairs for the entire 2200 square feet with a 20x20 den with a 18 foot vault is cool as a cucumber and keep the temp at 68, 70, 72 74 and not run for more than about 40-50 mins at a given time if it was on 72 and we move it to 68. Vents are in the floor of the main level. Upstairs the vents are in the ceiling and I have to go to a vent, and see if I can feel the air moving. There are are 3 bedrooms, large playroom and heated and cooled storage. Each bedroom has an intake and and one flow vent in the bedroom and one flow vent in the bathroom. Playroom has 2 flow vents and 2 intakes and storage has two flow vents (storage seems to be the least cooled area, that is ok). My husband just went under the house to look at the furnace numbers but said the tag is messed up, but the numbers he got are. I looked them up but they make no sense to me and I cannot find anything on any of these numbers xv95 model # 4TXC8048BC3hCAA the first 8 could be a b serial # 10294X0B5G date of manufacturer 7/2010
...See More
Going against the grain...two story family room vs 10' ceiling.
Q
Comments (40)
I love a two story room with a wall of windows. I designed my current home with ten foot ceilings on the main floor, and I would like them higher. I would have gone two story but couldn’t swing it because I was unable to free up space on the second story due to constraints with stretching out the first floor (creek in the way). I think though that 15 or 16 feet might give you the feel you’re looking for if you made sure to add lots of windows. We custom built one house where the family room had 15 foot ceilings and it totally satisfied my need for a two story. Loved that room....it had floor to ceiling windows. Many say they don’t like tall ceilings due to a lack of coziness and intimacy . Tall ceilings never strike me that way. I LOVE the space and open feeling....especially with lots of windows. What I don’t care for is a two story room with large swaths of sheetrock where windows could have been installed. That, to me is a total waste....tall ceilings need tall windows.
...See More
sktn77a
6 years ago
There's something missing here. What are you trying to accomplish and what was the alternative to a single speed 3.5 ton unit? Higher bills than what?
Ed Levy
Original Author
6 years ago
I live in NC and I am simply trying to replace an old unit. One contractor say variable speed is the only way to go and another one says since we have 10 foot ceilings and 2 story foyer that single speed is the only way to go. I have no idea.
Ed Levy
Original Author
6 years ago
One more note, we have a 4 ton unit that handles the second floor
mike_home
6 years ago
It would help if you gave us more information about your house. How big are the first and second floors and what is the current size of the first floor AC. Where is the first floor thermostat located in relationship to the foyer?

When your first floor AC was working, were you having problems keeping the foyer cool?
sktn77a
6 years ago
last modified: 6 years ago
A "variable speed" blower will perform exactly the same as a fixed speed blower with a single stage AC except that it slowly ramps up the speed (over about a minute) so that you don't get an immediate blast of air. It will make no difference to the overall cooling. If you have a suitable thermostat it may be able to slow the speed down to improve dehumidification.

You won't experience higher bills - the VS motors are more efficient that PSC motors so they are talking rubbish. For some reason, they don't want to install a VS blower (maybe their profit is lower?)
mike_home
6 years ago
I think variable speed here also means a 2-stage condenser. One guy is saying the AC needs to always operate at it maximum capacity in order to cool the two story foyer. The other is saying operating in the low stage will help move the air in the foyer.
jln333
6 years ago
last modified: 6 years ago
It is all rubbish. I have a 2 stage, variable blower and many of my neighbors have single stage. We all have 10 foot ceilings and we are in Cary NC. Some of us have 2 story foyers. None of it matters.

10 foot ceilings are absolutely no big deal. 2 story foyers are not nearly as bad as 2 story great rooms. All HVAC contractors are liars and will tell you anything to sell what they are selling.....jk (that is nod to the pros here but I really am not).

ARS tried to sell me a single stage to replace my 2 stage without telling me....

Related Stories

LIFE That’s a Talker: 10 Stories You Had Lots to Say About This Year

By Erin Carlyle

The world’s ugliest color, tubs vs. showers, and TVs over fireplaces had readers talking in 2016. Tell us what you think

HOUSEKEEPING How to Speed-Clean Your House

By Leslie Reichert

Short on time but still want to keep up appearances? Discover these tricks for making your house quickly presentable

MOST POPULAR Heads-Up Hues: 10 Bold Ceiling Colors

By Jennifer Ott Design

Visually raise or lower a ceiling, or just add an eyeful of interest, with paint from splashy to soothing

COLOR Speed-Dial Color Selection to Get the Best Result

By Kimberly Collins Jermain

You’ve belabored your color decisions and are still stuck. Here is how to evaluate your space and make choices that are right for you

LIFE Is Cabin Fever Real? Share Your Story

By Mary Jo Bowling

Are snow piles across the U.S. leading to masses of irritability and boredom? We want to hear your experience

HOUZZ TOURS Houzz Tour: A Three-Story Barn Becomes a Modern-Home Beauty

With more than 9,000 square feet, an expansive courtyard and a few previous uses, this modern Chicago home isn't short on space — or history

REMODELING GUIDES 10 Tips to Maximize Your Whole-House Remodel

By Ventana Construction LLC

Cover all the bases now to ensure many years of satisfaction with your full renovation, second-story addition or bump-out

HOUSEPLANTS 10 Top Plants to Grow Indoors

Brighten a room and clean the air with a houseplant that cascades artfully, stretches toward the ceiling or looks great on a wall

ARCHITECTURE 10 Things to Know About Prefab Homes

By Laura Gaskill

Are prefab homes less costly, faster to build and greener than homes constructed onsite? Here are answers to those questions and more

TRENDING NOW The 10 Most Popular Home Entryways on Houzz Right Now

By Erin Carlyle

Abundant storage and attractive designs have the Houzz community saving these photos

Sponsored

NME Builders LLC

2 Reviews

Industry Leading General Contractors in Franklin County, OH

More Discussions

A/c making humming sound

4

Engineered vs. Solid Hardwood over radiant floor heating

8

Replace rusted swamp cooler panels with aluminum sheeting?

2

is this leak due to condensation?

23

HVAC condensate pump issue

7