This Is Part 1 Of A 2-Part Article
How To Dramatically Lower Cooling/Heating Bills In A Large Or Quite Large Home
With Supplemental, Ductless HVAC
Part 2 of 2
This article describes how to lower cooling/heating costs with Supplemental, Ductless HVAC in selected area(s) of your home (chosen by you). The existing Central HVAC Systems remain unchanged.
Example: Instead of cooling/heating 4-6 bedrooms — a Ductless System can cool/heat can cool only the owner’s bedroom. When needed, the existing Central A/C cools all bedrooms.
Al’s Plumbing, Heating & A/C in Plano, Texas provides maintenance and repairs for all brands of; Central A/C, Gas & Electric Furnace, and Heat Pumps. Additionally, we sell and install new HVAC Systems from; American Standard (same company as Trane), Ameristar (owned by American Standard), and Coleman HVAC (same company as York HVAC).
Al’s provides full-service plumbing maintenance, repairs, and replacements for every plumbing component in your home. Al’s sells and installs Rheem Professional Series gas & electric water heaters, and tankless water heaters. Al’s is near your home in Plano, TX; Allen, TX; and Frisco, TX. We service all homes in southern Collin County, Texas, and Denton County, Texas with no additional travel charge.
Call Al’s today to discuss any concerns or problems you have with your HVAC System or Plumbing. We will arrange an appointment at your convenience.
Image Source: ShutterStock
Adding Supplemental, Ductless HVAC — To Serve Specific Areas.
The existing Central HVAC System(s) remain unchanged.
Example 1: A Ductless System can serve only the Owners’ Bedroom.
Example 2: In an open floorplan home — a Ductless System can serve only the Kitchen & Family Room.
While supplemental HVAC keeps you comfortable in the spaces you’re using — you can reduce the cooling/heating in unoccupied areas of the house. At any time, you can cool/heat the home with the existing Central HVAC System(s). When the Central HVAC is running — the Supplemental System’s won’t run. There are no changes to the existing Central HVAC System(s) — and it operates as it always has.
Quite large homes have multiple Central HVAC Systems. Each HVAC System (Zone) typically cools/heats 2,000 — 3,000 square feet. It’s common for 1 HVAC System(s) to serve the daytime living spaces AND a 2nd HVAC System(s) to serve the bedrooms. Supplement HVAC allows for additional & smaller HVAC Zones where you would like them — such as cooling only the owner’s bedroom.
Smallest & Largest Size Residential HVAC Systems — When This Article Was Written
Smallest:
- 18,000 BTU’s: Central HVAC available.
- 9,000 BTU’s: Ductless HVAC System available.
Largest:
- 60,000 BTUs : Central HVAC System = 60,000 BTUs / 5 Tons. NOTE: 12,000 BTUs = 1 Ton.
- 60,000 BTUs : Ductless HVAC System = 60,000 BTUs / 5 Tons. NOTE: 12,000 BTUs = 1 Ton.
Ductless HVAC Benefit #1: A Smaller Capacity System Is Needed (using less electricity).
Ductless HVAC System Sizing Guide *
Calculations Are For: DFW’s Climate Zone.
Square Feet — with 8 Foot Ceilings:
- 1,001 to 1,200 SF requires a 21,000 BTU Supplemental HVAC.
* Source: Mitsubishi Electric http://texasductless.com/info/what-size-system
Central HVAC System Sizing Guide **
Calculations Are For: DFW’s Climate Zone.
1,000 Square Feet — 8 Foot Ceilings.
- 1,000 SF — requires a 34,000 BTU Central HVAC.
** SOURCE: https://www.servicetitan.com/tools/hvac-load-calculator Copy The URL (to the left) Into Your Browser To Use The Calculator.
Compare System Size Need For 1,000 Square Feet
- Central = 34,750 BTU
- Ductless = 21,000 BTU
Ductless System Sizes Are Smaller — because there’ no ductwork that must be cooled/heated (& likely leaking some air) each time the System runs.
With Ductless HVAC — The Indoor Unit Is Connected To The Outdoor Unit With A Refrigerant Line.
Shown: A Very Large Home With 6 Central HVAC Systems
Image Source: ShutterStock
Ductless HVAC Benefit #2 — Far More Energy Efficient Than Central HVAC
When Comparing Central & Ductless SEER: ** Ductless Is Up To Twice As Efficient.
- Central HVAC Most Efficient: 23 SEER — Brand & Model: Amana AVXC 200241A // 22,800 BTU’s
Source: https://www.energystar.gov/products/most_efficient/central_air_conditioners_and_air_source_heat_pumps
- Ductless HVAC= 42 SEER Cooling (+ 15 HSPF Heating) — Brand & Model: Carrier 38 MPRA // 9,000 BTU
Source: https://www.carrier.com/residential/en/us/news/news-article/carriers_most_efficient_air_conditioner_you_can_buy_america_ahr_expo.html#:~:text=The%20new%20Carrier%209%2C000%20BTUh,can%20buy%20in%20North%20America.
SEER: Seasonal Energy Efficiency Rating. A standardized Cooling Efficiency Rating For Central & Ductless HVAC Systems.
HSPF: Heating Seasonal Performance Factor. A standardized Heating Efficiency Rating for Air-Source Heat Pumps (most are Air-Source). All ductless systems are Air-Source Heat Pumps that cool & heat.
Cooling/Heating One To Several Rooms With Ductless HVAC System
Ductless HVAC Systems are ideal for large homes where only a limited number of rooms are typically used.
Ductless can also replace Central HVAC — providing a home with a separate zone for each room / space the owner wants.
- 1 Ductless outdoor unit can serve up to 4 indoor units.
- 1 Ductless outdoor unit can serve up to 8 indoor units — When Equipped With Two Compressors (stacked).
- Multiple Ductless Systems can be installed in one home.
Image Souce: ShutterStock
Shown: Ductless HVAC System Double-Compressor Outdoor Unit (serves up to 8 indoor units)
- 1 Indoor unit serves each room or zone. Quite large rooms might need two indoor units.
- Each Indoor unit has a Remote Control for temperature and fan speed.
- Indoor Units Can Also Be Controlled With An Optional Wall Thermostat
Copy The Link Below Into Your Browser To Read More About American Standard HVAC’s Mitsubishi Ductless HVAC:
https://www.americanstandardair.com/products/heating-and-cooling/ductless/
American Standard Sells Ductless HVAC Systems Made By Mitsubishi
Mitsubishi Offers Various Styles Of Indoor Units For Ductless HVAC. There are several models of each indoor unit style shown below:
NOTE: Each Ductless HVAC Indoor Unit — has an Air Filter that must be cleaned. The closer the Indoor Unit is to the floor — the easier filter cleaning is.
- Recessed Ceiling Cassette — looks much like an air vent for a standard, ductwork HVAC System.
- Floor Mounted — sits on the floor.
Shown: Wall Mounted Indoor Unit Near The Ceiling.
Image Source: ShutterStock
- Wall Mounted — can be mounted at any height on the wall.
- If you live in a Cooling Climate: The indoor unit is mounted closer to the ceiling — allowing it to intake the warmest air in the room.
- If you live in a Heating Climate: The indoor unit is mounted closer to the floor — allowing it to intake the cooler air in the room.
Copy This Link To See All Mitsubishi Ductless HVAC Indoor Unit Options: https://www.mitsubishicomfort.com/products/indoor-units
(Scroll down to see various types and models of Indoor Units.)
Ductless HVAC Outdoor Unit
Image Source: ShutterStock
Shown: Outdoor Unit For A Ductless HVAC System
Note: The outdoor unit can be placed on the ground or hung from the wall.
Click To See A Diagram Of A Ductless HVAC System Installation: Installed Ductless HVAC System Diagram
- American Standard Ductless, Heatpump, HVAC Systems — Are Made By Mitsubishi (and show the Mitsubishi name).
- Their Ductless HVAC Systems range in size from: 1,600Btu to 54,000 Btu. NOTE: Each 12,,000 BTU’s is also known as: “1 Ton”.
- Supplemental, Ductless HVAC Systems are also called: “Ductless Mini-Split”.
- Indoor unit(s) is connected to the outside unit by a refrigerant line (instead of ductwork).
- The indoor unit has a coil (refrigerant flows within) and a fan. It’s very quiet indoors, generating 20 db (similar to rustling leaves).
- The outdoor Heat Pump unit for Ductless HVAC generates as little as 40-45 db of sound outside (Central HVAC system’s noise — 53db to 70db).
- Note: All Heat Pumps make additional noise in winter during their defrost cycle.American Standard’s / Mitsubishi Ductless Heat Pumps can heat your home with outoor temperatures as low as -13°F.
Click Here To See A Map Of U.S. Weather Zones: U. S. Weather Zones Map
A. Ductless HVAC Works For Locations In The Southern Third Of The U.S. (Zones 1, 2, 3)
Mitsubishi’s Standard Ductless HVAC
B. Ductless HVAC Works For Some Locations In The Center Third Of The U.S. (Zone 4 + Southern Zone-5)
Mitsubishi’s Hyper-Heating Ductless HVAC
Mitsubishi’s Split-Ductless HVAC provides cooling & heating in areas with mild winter temperatures (like DFW).
Mitsubishi’s Hyper-Heating Split-Ductless HVAC Includes An Enhanced Compressor To:
- Deliver 100% heating performance — down to +5°.” **
- Deliver 75% heating performance — down to -13° F. **
** Source:https://www.mitsubishicomfort.com/benefits/hyper-heating
C. Ductless HVAC Is Not For Locations In The Northern Third Of The U.S. (Northern Zone-5 + 6, 7)
- Traditional Central Heat Pump HVAC — typically includes Heating Strips inside the air handler (which makes it an Electric Furnace).
- When the Heat Pump can’t keep up in cold temperatures — the Heating Strips operate at whatever capacity needed to help the Heat Pump.
- When temps drop too low, the Heat Pump often shuts off — and all heating is provided by the Heating Strips.
WHY Auxilliary Electric Heating Isn’t Available With Ductless HVAC
- Ductless indoor wall units are powered by 120-Volt electricity (same as a lamp).
- Electric Heating Strips require 240-Volt electricity (same as an electric dryer).
- For Auxillary Electric Heating Strips — Ductless HVAC would 240-Volt Electricity Be Wired To Every Indoor Unit.
- This would make Ductless HVAC’s Installed Cost Too Expensive.
Thermostat Options For Supplemental, Ductless HVAC Systems
Each indoor unit has a Remote Control — so you can set temperature.
You can install a Ductless System with zones (of 1 or more rooms) — and add a thermostat to control each zone.
Example: This could work well for a home with the kitchen & family room open to each other. 1 indoor unit would be in each room — controlled by 1 thermostat.
Note: The outdoor unit runs only when one or more indoor unit(s) is running.
- A Standard or Smart Thermostat is installed for each Zone.
- A Nest (brand) Thermostat can be paired with an adapter — so it can communicate with the other Nest thermostats.
- Note: All Smart Thermostat brands require a WIFI connection.
- They go online to get the outdoor temperature. Then they know when to start running the HVAC System so the indoor temperature is what you want — when you want it..
Shown: Nest Smart Thermostat
Image Source: ShutterStock
Click Here To Learn More About Nest Thermostat: AlsPlumbing.com Learn About The Nest Thermostat
In Homes Under 3,500 Square Feet — If Replacing Your Existing HVAC System
You can upgrade to a Variable-Speed HVAC System With Electric-Dampers Zoning
Home Size:
- <2,000 Square Feet: Zoning Is Seldom Needed.
- If needed, you can partially close some air vents — to force more air into other rooms.
- 2,000 — 3,500 Square Feet:
- 1 HVAC System — Plus Added Electric-Dampers (inside the ductwork) to create Zones.
- 3,501+ Square Feet: 2 Or More Separate HVAC Systems
- Each HVAC System Serves 1 Zone.
Click Here To Read Our In-Depth Article On Zoned HVAC: Alsplumbing.com Zoned HVAC’s Many Benefits
Image Source: Amazon Embedded Link
Click On Image To; View Product From Various Angles, Read Details, or Purchase From Amazon.com
Single-Speed HVAC Systems — Are Not Designed Or Installed To Become A Zoned System.
A single-speed HVAC System was designed and installed to be operated with all air ducts open. Closing more than 10% of air vents causes the air pressure to build up inside the Ductwork. This forces too much air out ducts that are open.
This causes the System to run more frequently — and for shorter periods of time. This is known as: “Short Cycling”. This causes the home to feel too warm or too cold much of the time. Too many closed air ducts essentially creates a situation where the HVAC System’s capacity becomes too large (for the number of air ducts that are open).
Having several ducts closed can also result in an overheated furnace or frozen A/C indoor cooling coil. Both of these problems occur because too little air can move through the furnace (due to closed air ducts). Short-cycling, overheated furnace, & frozen A/C coil create tremendous strain on the HVAC System — and wear it out sooner.
Click Here To See A Frozen Central A/C Cooling Coil (inside the furnace or ductwork — and can’t be seen without removing a panel): Frozen Central A/C Cooling Coil
A Gas Furnace’s Heat-Exchanger:
- Keeps the burners’ heat (including carbon monoxide) inside the exchanger.
- The home’s indoor air flows along the outside of the exchanger.
- Each time the furnace heats — the heat-exchanger’s metal expands. When the heating-cycle ends — the metal contracts.
- Over the years, this causes stress-cracks to form in the heat-exchanger.
- A crack in the heat exchanger can allow carbon monoxide to enter indoor air.
- Once the heat exchanger cracks — the entire furnace is typically replaced.
The cost of premature failure of the heat-exchanger is more than the cooling/heating cost savings (created by closing off air ducts).
How Gas Furnace Short Cycling Causes Excess Stress & Premature Failure Of The Heat-Exchanger:
- Short-cycling causes the furnace to heat more frequently than it’s designed to.
- Short-cycling causes the furnace’s heat-exchanger to heat faster than it’s designed to.
- These 2 factors cause the heat-exchanger to fail sooner.
Click To See Where The Heat Exchanger Is Located Inside The Furnace (different furnaces have different locations): Location Of Heat-Exchanger Inside Furnace
Click To See A Diagram Showing How A Gas Furnace’s Heat-Exchanger Works: How A Heat-Exchanger Works
Click To See A Furnace Cracked Heat-Exchanger: Cracked Furnace Heat Exchanger
With A Variable-Speed HVAC System
Because Variable Speed HVAC — Slows/Speeds The System — you can close all the ducts you want. If you want different areas cooled/heated at different times of the day — you can add Electric-Dampers Zoning to do it automatically.
The American Standard AccuLink™ Zoning System
The American Standard AccuLink™ Zoning System has Electrically-Operated Dampers installed on selected ducts (you choose which ones). This allows the thermostat in each Zone or Room to open/close the damper as needed. Combined with a Variable-Speed HVAC System — the outdoor unit & furnace speeds up / slows down — based on the number of dampers that are open. A Variable-Speed HVAC System adjusts itself to hundreds of different speeds continuously — to align its output with current heating or cooling needs.
Click To See A Zoned-Central HVAC System Diagram: Zoned Central HVAC With Different Temperatures
Copy The Link Below Into Your Internet Browser For A Brochure On The American Standard AccuLink™ Zoning System
https://www.americanstandardair.com/content/dam/americanstandarair/15-4156-03_HR.pdf
This Is Part 1 Of A 2-Part Article
This is Part 1 of a 2-Part article about Supplemental, Ductless HVAC — in addition to the existing Central HVAC in large homes. This allows the homeowners to cool/heat only the spaces they use. When the entire home needs to be cooled/heated — the existing Central HVAC does that. The existing HVAC Systems remain unchanged.
Al’s Plumbing, Heating & A/C in Plano, Texas provides maintenance and repairs for all brands of; Central A/C, Gas & Electric Furnace, and Heat Pumps. Additionally, we sell and install new HVAC Systems from; American Standard (same company as Trane), Ameristar (owned by American Standard), and Coleman HVAC (same company as York HVAC).
Al’s provides full-service plumbing maintenance, repairs, and replacements for every plumbing component in your home. Al’s sells and installs Rheem Professional Series gas & electric water heaters, and tankless water heaters. Al’s is near your home in Wylie, TX; Murphy, TX; and Rowlette, TX. We service all homes in southern Collin County, Texas, and Denton County, Texas with no additional travel charge.
Call Al’s today to discuss any concerns or problems you have with your HVAC System or Plumbing. We will arrange an appointment at your convenience.