This is Part 1 of a 4-Part Article about Residential Ice-Assisted A/C.  This product is starting to be manufactured in 2018.  Details about the product and the company who makes it are included within this 4-Part Article.

Al’s Plumbing, Heating & A/C in Plano, Texas provides maintenance & 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 (same company as American Standard) and Coleman HVAC (same company as York HVAC).

Al’s also provides full service plumbing maintenance, repairs and replacements for every plumbing component in your home.  Al’s sells and installs Rheem Profressional Series gas & electric water heaters, and tankless water heaters.

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, and offer 24/7 Emergency Service.

Ice-Assisted Air Conditioning

photo of the ice bear commercial ice-assisted air conditioner

Shown:  The Ice Bear (brand) Ice-Assisted Rooftop Commercial HVAC System

While this concept may sound like something from the future, it’s actually been used in commercial and industrial, large-scale settings for many years.   The purpose of ice-assisted a/c is so the system can freeze the ice at night, then use the ice (instead of running the outside a/c unit) to produce cool air during the day.

Starting in 2018, a residential version is starting to be manufactured.  It’s call the Ice Cub.  This multiple part article describes ice-assisted HVAC systems, both commercial and residential.

How Ice-Assisted A/C Saves Money For Commercial & Industrial Customers

Most industrial and commercial buildings are subject to “Demand-Charges” added to their electricity bill.  Demand-charges look at the highest 15 minutes of electricity demand for the entire day, then add a demand-charge (for the entire day) based upon that 15-minute peak demand period.  For this reason, there is tremendous incentive to reduce daytime electricity daily peak demand — and ice-assisted a/c does just that.

graphic depicting the highest electricity demand for the day

Shown:  The Graph Depicts The Period Of Peak Electricity Demand For A Structure.  This Peak Creates The Demand-Charge To Be Added To The Daily Bill.

The system can be switched to use only ice-assisted cooling during periods when electricity demand is highest during the day.  This dramatically reduces demand charges and lowers electricity charges for the entire day.  diagram of a thermal energy storage air conditioning system

In DFW the period of peak electricity demand in summer is 3 — 7 p.m. on weekdays.   It behooves operators of large buildings to reduce their electricity demand during this period, as that is when demand charges would be highest.   The number of hours the structure can use ice-assisted a/c to provide all its cooling is based upon the size of the ice-containing tanks.  The more ice, the longer the period the structure’s ice-assisted a/c can provide cooling.

Then, the ice-assisted a/c’s water is refrozen at night when overall electricity demand is lowest.  So, not only are demand charges minimized, additionally the cost to refreeze the water is minimized because the electricity rate is lowest at night for commercial structures.

Some Electricity Retailers Currently Offer Incentives To Business Customers To Reduce Electricity Usage During Peak Demand 

  • ERCOT’s Emergency Response Services Program is a demand response program that helps prevents power outages during times of peak use or emergencies in ERCOT service areas. Participants at specific load zones reduce energy consumption by a pledged amount in order to lower overall demand on the grid.
  • How much the business earns from demand response is based the number of hours they are enrolled to participate in, plus some other factors.  Businesses can earn approximately $75,000 for every 1 MW of load reduction. Participants receive payment (for the amount or energy demand they curtailed) when an event is called.
  • TXU Brighten® Reduction Rewards business customers get a market-based bill credit for reducing their demand by 2% or more.  The program is targeted toward business customers that use about 1 megawatt or more of electricity per year. Those customers get an hour’s notice of the opportunity and can choose whether or not to participate.   “This program offers easy savings participating business can spend on products and services,” said Gabe Castro, vice president of business for TXU Energy. “That can create a competitive advantage and a growing revenue stream at a time when the ceiling on wholesale electricity prices is rising. At the same time, reducing usage during peak demand periods helps ensure a reliable and an affordable electricity supply for everyone.”
  • During a test of the program, a Houston-area school district reported saving $6,000 for three hours of reduced demand.  “Trimming our usage was easily achieved by reducing lighting in noncritical areas and raising HVAC set points to reduce air conditioning load,” a school official said.


  • ERCOT Is most of Texas’ electricity generating and distributing utility company.
  • TXU is a Retail Vendor of electricity.

Ice-Assisted A/C Was Installed In Dallas’ Fountain Place Office Tower When It Was Built In 1986

fountain place office tower in downtown Dallas, TX

Shown: The 62 Story Fountain Place Office Building — 1445 Ross Ave., Dallas, TX (built in  1986)

photo of dallas' fountain place office tower plus new apartment high rise under construction in 2018

In 2018, Amli Fountain Place, A 365 unit, 45-Story Luxury Apartment High Rise Is Under Construction Where The 2nd (matching) Office Tower Was Once Planned.

map showing location of fountain place office tower and new apartment high rise in dallas texas

Shown: Map Showing Location Of Both Fountain Place Office Tower And New Amli Fountain Place Apartments High Rise Building At Field Street and Munger Avenue

Click Here To Learn More About The New Amli Fountain Place Apartment Building:  New Apartment Building Beside Fountain Place


When Fountain Place was built in 1986, an Ice-Assisted A/C Cooling System was installed.  Their website describes it as “On-site Thermal-Energy Storage allows Fountain Place to run the chillers at off-peak hours which significantly reduces electricity cost for tenants while also taking burden off the electric grid.”

Fountain Place is LEED Certified.  Leadership in Energy and Environmental Design (LEED) is an internationally recognized Green Building Certification Program.  It provides third-party verification that a building was designed and built using techniques aimed at improving performance regarding; energy savings, CO2 emissions reduction, water efficiency, improved indoor-environment quality, and stewardship of resources and sensitivity to their impacts.

An Large (c0ld) Thermal Storage System Currently In Use In A FL School District 

photo of storage tanks for ice-assisted air conditioning photo of a large trane brand chiller for air conditioning


(Left) Thermal Energy Storage Tanks               Large Chiller A/C System From Trane HVAC

Click Here To See A Video Of This Large-Scale Ice-Assisted A/C System: St. Lucie Co. FL School District’s Ice-As


Why Residential Ice-Assisted Air Conditioning Is Becoming Important

While this may also sound like something from the future, ice-assisted residential a/c starting to be manufactured in 2018.  While initial distribution will be primarily in California, this product will expand production and become available throughout the U.S. over time.  Ice-assisted a/c offers advantages in areas where the owner will save on their electric bill by using it.

Note: In later sections of this article we provide details and photos of Residential Ice-Assisted A/C.

Residential Electricity “Time Of Use” Or “Dynamic Pricing” Is Coming To Areas In The U.S. 

Why is Time Of Use or Dynamic Pricing being implemented?  By incentivizing consumers to do laundry and baking outside the periods of peak electricity demand, this limits the amount of additional electricity-generating equipment needed to ensure there is enough electricity during periods of peak demand.  Since the largest consumer of electricity in summer is cooling, ice-assisted a/c used during peak-demand periods will notably reduce a homeowner’s electric bill.

In most Power Plants, there is a lot of excess electricity-generation capacity that is being used very little.  It’s used only during those times of peak electricity demand.  This increases the amount of money invested in power plants, and results in higher electric rates.  Residential Dynamic Pricing is similar to Demand Charges for commercial and industrial customers.

Billing aside, population growth + ever increasing electricity demand puts rapidly increasing requirements on the aging Power Grid.  A Power Grid must always have a balance of electricity demand and supply.  If this balance is not maintained “The grid electrical frequency will drop and the system will collapse in a matter of seconds, resulting in a failure / blackout.” **

If a Power Grid is at its maximum electricity generating capacity, it must buy electricity from other (interconnected) Power Grids if electricity is available.  If no electricity is available (from other Power Grids) the system must then must implement emergency measures to reduce electricity demand (to match current electricity supply).  Electricity demand reduction typically occurs in the form of scheduled Rolling Blackouts.

** Source:

photo of rolling blackout

Shown: A Metropolitan Area During Rolling Blackouts

In 2019, California Will Deploy Time-Of-Use (TOU) Electricity Billing At An Unprecedented Scale 

Research done for California described “TOU rates as a type of load-modifying or (consumer) demand-response that could save up to $700 billion annually by 2025 by optimizing now limited renewable energy sources (such as solar or wind).”

Others say “California needs Dynamic Pricing,” instead of Time Of Use (TOU) rates. TOU rates are simply a price differential for each (entire) day.  Dynamic pricing involves different charges for various hours during the day.  The System alerts customers of upcoming steep increases in per-kWh rates in advance of specific peak-demand events.

Dynamic Pricing creates a larger gap between peak and off-peak pricing, and will drive more significant electricity-demand reductions during periods of peak demand.  With dynamic pricing, ice-assisted a/c becomes as attractive to home owners as it is to commercial customers (who pay demand charges).



A SIDE NOTE:  Dynamic Pricing Is How The LJB TEXpress (toll lanes) Charges

Their website reads “The LBJ TEXpress Lanes feature fluctuating congestion-management pricing.  Toll rates on the LBJ TEXpress Lanes are typically higher during weekday rush-hours, and lower during other times on week days and on weekends.”

photo of lbj express lanes toll rates in dallas texas

Shown: Fluctating Congestion-Management Toll Price Sign For LBJ TEXpress Lanes


Sometimes History Repeats Itself

For ice-assisted a/c, we can look back at the evolution of the “Ice Box” Into A Refrigerator.

photo of 1920's ice box

Shown: A 1920’s “Ice Box”.  This was used to keep food cold.  An Ice Box had no ability to create cold, that came from only the ice.


photo of some of the first frigidaire refrigerators

Shown: In 1923 Frigidaire introduced the first self-contained refrigerator.


photo of one of the first general electric refrigerators

By 1925, the first home refrigerators were being manufactured by General Electric.  Their Price Was Twice That Of An An automobile At That Time.

In The Late 1920’s DuPont Introduced Freon Refrigerant.  This Expanded Refrigerator Sales.

Nearly 100 Years Later, Ice-Assisted Residential A/C Is Coming Of Age

What Are The Major Benefits Of Ice-Assisted Air Conditioning? 

  • In areas with Dynamic Pricing for electricity, this will make ice-assisted a/c attractive to home owners.
  • Ice-assisted a/c lowers electricity bills by shifting some of the home’s cooling demand to off-peak hours.
  • Ice-assisted a/c reduces electricity demand on the Power Grid during peak-demand periods.
  • Ace-assisted a/c allows electrical generation to come from much cleaner, natural gas fired generators, rather than coal-fired units. *
  • * Coal-fired generators can be brought on line and taken off line more quickly than gas-fired generators.

At night, ice-assisted a/c creates and stores cold “thermal-energy” in the form of ice — during nighttime when there is far less demand on the Power-Grid.  During the day, Ice-assisted a/c uses the stored (cold) thermal-energy to cool the structure, eliminating the need for the outdoor a/c unit to run during times of peak-demand.

While historically limited to large-scale cooling systems, increasing electricity demand and future electricity pricing is creating a need for ice-assisted a/c at the residential level.  The cost of the thermal energy storage system will be higher than standard central air conditioning, but ice-assisted a/c will pay for itself through cooling costs savings (in areas with Dynamic Pricing).

Why Ice-Assisted A/C Will Become So Important

Simply put, Ice-Assisted A/C allows homes to cool (for several hours) from the ice-reserve within the A/C System.  This eliminates air conditioning electricity demand during times of peak-demand.  Ice-assisted a/c is particularly important if a power-grid is reaching its maximum electricity-generating capacity.

Power Grids Can Sometimes Reach Or Exceed Their Capacity To Generate Electricity

To accommodate peak-demand periods, power generation over-capacity is deliberately built  (known as the reserve margin) to ensure Power Grid reliability. The electricity generation reserve margin ensures there is enough additional electricity-generation capacity to accommodate periods of peak-demand.  This results in trillions of dollars invested in power generating equipment that is used very little (only during periods of peak demand).


photo of texas USA flag

In 2018, Texas’ Power Grid Reserve Margin Dropped Below

ERCOT’S Recommended Level

map of u.s. power grids denoted by color

Shown: U.S. Map Showing The Areas Served By Different Power Grids.  Each Power Grid Is A Different Color

The drop in reserve margin is due to the early 2018 shutdowns of 3 coal-fired plants (Monticello, Sandow, and Big Brown) plus 1 natural gas plant.  This reduced Texas’ summer reserve margin to 9.3%.  This is well below the 13.75%, reserve margin recommended by the Electric Reliability Council of Texas (ERCOT).  *

Add to that the rapidly increasing population of Texas, and electricity demand continues to also grow at a swift pace:  +4,223,918 more people began living in Texas during 2000–2017.  That is a 16.8% population increase, and it’s safe to say Texas’ electricity demand also increased nearly 17% in just over 7 years

With Texas’ reserve margin below recommended levels, an unusually hot summer could create demand beyond Texas’ power grid electricity-generation capacity in 2018.  If this occurs, electricity will be purchased from another (interconnected) power grids, if it’s available.  In past years ERCOT bought electricity from Mexico and several U.S. states to prevent blackouts — at prices some called exorbitant. ** 

Rolling Blackouts May Be Required In Texas During Summer 2018

Rolling Blackouts may be required to keep Texas’ power grid stable.  ERCOT warns of possible rolling blackouts during summer 2018.  “Texas faces; looming hot summer weather, a growing population, and reduced electricity-generation margins. That tightens Texas’ electricity-generation margins to the lowest they’ve been in years.”   ***

Part of the power crunch is linked to the recent retirements of three large-scale coal-fired plants that closed in Jan. & Feb. 2018.  The plants produced more than 4,100 megawatts of electricity — enough for more than 830,000 homes.  ***

“We did look at some scenarios and there is some risk we would have rotating / rolling (scheduled) outages.  That’s a managed process, as opposed to allowing the system to have unplanned blackouts,” said Pete Warnken, Manager Of Resource Adequacy for the Electric Reliability Council of Texas (ERCOT).   ***

Warnken said “the name of the game is the performance aspect … we need to make sure that all of our resources are available.”  If those resources aren’t available, and Texas’ Power Grid sees shortages, ERCOT said it “anticipates voluntary load reductions, and an increase in electricity purchases by ERCOT from industrial facilities.  This electricity becomes available in response to higher (ERCOT purchased) electricity prices during peak-demand.”   ***

* Source:

** Source:

*** Source:

The Power Generating Reserve-Margin Could Shrink More If Any Remaining Texas Coal-Fired Power Plants Are Shut Down

This Creates Problems On Two Fronts:

  • Note: Coal-fired power plants are closing because they are no longer profitable.
  • Future closings of coal fired plants could shrink the power generating reserve margin further.
  • Coal Fired plants (without emissions equipment) create notably more air pollution than natural gas power plants.
  • There are times when electrical generators are fired up and ready to go, but needed and used only during peak demand hours.
  • Those generator are more likely to be coal-fired, because they take less time to fire up and take back off line (than natural gas powered generators).
  • A great example is the W.A. Parrish Power Plant southwest of Houston. It is Texas’ largest coal fired power plant.  It has 4 coal-fired generators + 6 natural gas fired units.  When electricity demand is lower, the Parrish plant often uses the 4 coal units. The 4 coal-fired generators consume an average of 36,000 tons of coal a day.
  • Power generating capacity is 3,565 MegaWatts.
  • A 2013 Report showed the Parish Plant (TX) as: 5th most polluting power plant in the U.S.
  • In 2016 the Environmental Protection Agency (EPA) said the Parish Plant then met federal emissions guidelines.
  • These Emission-Control Devices Were Installed At The Parish Plant Over The Years:
  • Pollution is reduced on all 4 coal-powered units with a filtering-system that removes coal fly-ash from exhaust gases.
  • 1 of the 4 coal units has a Flue Gas Desulfurization System.  This system removes sulfur oxides from the exhaust gases.
  • In 2016, the same unit (just above) had a Carbon-Capture System installed.  This system captures 90% of the carbon dioxide from the exhaust (carbon dioxide is a greenhouse gas).
  • In January 2017 the Carbon Capture equipment became operational.
  • Texas Power Plants that met 2016 EPA Standards were identified as: Tolk (Earth, TX); Twin Oaks (Bremond, TX); Coleto Creek (Fannin, TX);  San Miguel (Christine, TX); Limestone (Jewett, TX); and W.A. Parish (Richmond, TX – southwest of Houston).

Click Here To See The EPA’s Jan 2016 Letter: Jan 2016 EPA Letter Identifies Texas Power Plants Meeting EPA Emissions Standards.

photo of w.a. parrish power plant near houston tx

Shown: W.A. Parrish Power Plant, 27 Miles Southwest Of Downtown Houston, TX.  Coal is piled at the front of the photo.


To Continue Reading Our Ice-Assisted A/C Article, Click Here: Ice-Assisted A/C Part 2 of 3



This is Part 1 of a 3-Part Article about Residential Ice-Assisted A/C.  This product is starting to be manufactured in 2018.  Details about the product and the company who makes it are included within this 3-Part Article.

Al’s Plumbing, Heating & A/C in Plano, Texas provides maintenance & 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 (same company as American Standard) and Coleman HVAC (same company as York HVAC).

Al’s also provides full service plumbing maintenance, repairs and replacements for every plumbing component in your home.  Al’s sells and installs Rheem Profressional Series gas & electric water heaters, and tankless water heaters.

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, and offer 24/7 Emergency Service.