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Al’s Plumbing, Heating & A/C in Plano, Texas is near your home in Plano, Allen, and Frisco.  We service all homes in southern Collin and Denton Counties with no travel charges.  Al’s 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 Professional 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.

photo of colorful fall leaves

Image Source: ShutterStock

Is It Time For A New Furnace? 

As summer’s heat fades and fall’s cooler weather arrives, many homeowners start to consider if it’s time to replace their furnace.   As detailed below, your existing furnace’s efficiency is mostly determined by its age.   The minimum gas furnace efficiency in DFW is  80%.  In northern states, the minimum is 90%.  Homeowners in southern states have the option to buy a Hi-E furnace — but is it in their best interest?   That answer is based on the cost of the upgrade, and details about the house — we go into those details just below.

Hi-Efficiency Or Standard Efficiency In DFW?

Which One Is Best For You?  It Depends.

old gas furnace

Image Source: CanStockPhoto

A standard-efficiency furnace has open vent-holes in the front panel.  This is where it draws in combustion-air.

 

hi-e gas furnace

Image Source: CanStockPhoto

A Hi-E furnace has a solid front panel, and white plastic air-intake & exhaust pipes.  This allows it to drawn combustion-air from outdoors — and it’s notably quieter.

  • An 80% gas efficient furnace exhausts 20% of the heat with the exhaust.
  • Hi-E furnaces (90% — 97% efficient) — exhaust 3-10% of their heat.
  • 80% furnaces draw combustion-air from their immediate surroundings.
  • For this reason, they make notably more noise than Hi-E.

If a gas furnace is in the attic, noise & drawing surrounding air into the furnace, doesn’t matter.  If the furnace is in the living space — it removes heated air from inside the house to use for combustion.  The heated removed is replaced by outdoor air — typically drawn in through air leaks in the home.   A Hi-E furnace gets draws combustion-air from outdoors.  It has a sealed combustion-chamber, and is much quieter than an 80% furnace, which has an open combustion-chamber.

Which Efficiency Is Best For You?

  • If your DFW home’s furnace is inside living space, and the noise it makes is a problem — a Hi-E furnace will solve the problem.
  • If you have a large home — the upgrade charge for Hi-E will likely be repaid with energy savings.
  • With a smaller home — it’s unlikely you’ll recoup the upgrade charge for Hi-E.
  • The Hi-E’s additional equipment (inside the furnace) — costs nearly the same regardless of furnace size.

Note:  The comments above relate to the Dallas-Ft Worth area.  The farther north you live, the more likely a Hi-E furnace will save money — regardless of home size.

 

Furnace Efficiency Ratings Over The Years

Furnaces are categorized according to their AFUE (Anual Fuel Utilization Efficiency) rating.

A. 50% Efficient: “Octopus” Furnace.  Half Of The Heat Goes Up The Flue.

NOTE: Because DFW homes don’t have basements — they don’t have octopus furnaces.  This information is for readers in old homes with basements.

Click Here To See, And Read Details About An Octopus Furnace: Octopus Furnace

Click Here To See A One-Minute Video Showing An Octopus Furnace In Operation: Octopus Furnace In Operation (scroll down)

  • An octopus furnace doesn’t have a blower fan.
  • Because of no blower — the ductwork is very large.
  • Some may have been modified with an add-on blower.

Click Here To See The Ductwork Pipes Size With An Octopus (also called Gravity-Feed Furnace): Octopus Furnace Ductwork Size

  • All original octopus furnaces are nearly silent during operation.  All you’ll hear is the burners.
  • Because octopus furnaces have only a valve for gas or heating oil, and no moving parts — they tend to last forever.  Octopus furnaces can still be found in some vintage homes.
  • Because they are very hot during operation — it’s common for these furnaces to be covered in asbestos, and some also have asbestos inside them.

Click Here To See The Ductwork Pipes Size With An Octopus Or Gravity-Feed Furnace (same thing): Octopus Furnace Ductwork Size

  • If a home had an octopus furnace — return-air (cold) registers are along the outside walls because those walls are cooler.
  • With forced air furnaces, supply-air (warm) ducts are along the outside walls.

Forced Air Furnace Efficiency Ratings Over The Years

B.  60% — 72%   Extremely Low To Very Low-Efficiency Gas Furnace

  • Forced-air gas furnaces built before 1970 are around 60% efficient. *3
  • Furnaces built between 1970 — 1977 are about 65% efficient.
  • Many of these furnaces will be painted green or gold.

Click Here To See A Furnace Built Around 1970: 1970 Gas Furnace 

  • Furnaces built between 1978 — 1987 are around 70% efficient.
  • Many of these furnaces will be painted shades of beige.
  • These forced air furnaces were installed in newly built homes during the 1970’s — 1980’s.
  • These furnaces were also installed as replacement furnaces in older homes.
  • Furnaces with these low-efficiency ratings are still operational in many homes today.

These Components Will Be Found In 60% — 72% Efficient Gas Furnaces:

  • Pilot Light
  • Metal Exhaust Pipe.   The exhaust is hot enough to rise up the flue and outside.
  • These furnaces have a larger metal exhaust pipe (see photo just below).
  • This is because their exhaust is hot enough to rise out of the home on its own.
  • These furnaces send 28% — 40% of the heat out of the home with their exhaust.

*3 Source: https://htoyh.com/content/replace_your_furnace.pdf

old gas furnace

Shown: Vent Holes In The Front Of An Older Gas Furnace — Efficiency Below 78%

Image Source: CanStockPhoto

photo of properly working gas burners in a gas furnace

Shown: You Can See The Flames When The Burners Are Ignited

Image Source: ShutterStock

 

C.  78% — (marginally) Low-Efficiency Gas Furnace

  • Beginning 1/1/1987 — 78% Became Required.
  • This applied to both replacement and newly built home installations.
  • These Components Will Be Found In 78% Efficient Gas Furnaces:  (Bolded Features were not present on earlier furnaces).
  • Electric Ignition For Burners
  • Draft Motor To Move Exhaust Gasses.  At this efficiency, the exhaust gasses are too cool to rise naturally up the flue.
  • Smaller metal exhaust pipe than earlier furnaces.
  • The smaller pipe is because a fan moves the exhaust out of the house.

 

D.  80% — Standard-Efficiency Gas Furnace

Click Here To See A 80% Efficiency Gas Furnace: 80% Efficient Gas Furnace

NOTE: In The Photo You Can See:

  • The vent holes in the front panel of the furnace.  These holes are where the furnace draws air for combustion.
  • The metal exhaust vent pipe is smaller than in the photo above.
  • At the concrete block chimney, you can see the adapter than was required to connect the new furnace’s exhaust vent to the larger opening the old furnace used.
  • Many of these furnaces will be painted shades of beige or gray.
  • Beginning 1/1/2015 all new furnaces had to be at least 80% efficient throughout the entire U.S.
  • This applied to both replacement and newly built home installations.

These Components Will Be Found In 78% — 83% Efficient Gas Furnaces:

  • Electric Gas Ignition For Burners
  • Exhaust Draft Motor — This motor moves the exhaust gasses out of the home.   Once a furnace is 78% or higher, the exhaust gasses are too cool to rise up the flue on their own.
  • Metal Exhaust Pipe.

E. 90%-98.5% — High To Ultra-High Efficiency Gas Furnace

  • Beginning 5/1/2013 — 90% efficiency became required in the northern U.S.
  • Beginning 5/1/2013 — 80% efficiency continues to be required in the southern U.S.
  • This applies to both replacement and newly built home installations.
  • Most of these furnaces will be painted shades of gray.

Click Here To See A 90% or Higher Efficiency Gas Furnace: 90%+ Gas Home Furnace

Components In Hi-E Furnaces:

  • Primary Heat Exchanger — for heating the house.
  • Secondary Heat Exchanger to reclaim the heat within the exhaust gasses.   Because this heat exchanger is wet while operating, it is typically made of stainless steel.
  • Sealed Combustion Chamber.  There are no vent holes on the front.  You can see the burners’ flames by looking through a small, glass-covered opening on the front.
  • Electric Ignition For Burners
  • Exhaust Draft Motor — This motor moves the exhaust gasses out of the home.   Once a furnace is 78% or higher, the exhaust gasses are too cool to rise up the flue on their own.
  • White PVC (plastic) Exhaust pipe.  This pipe could be installed horizontally because a motor moves the exhaust.
  • White PVC (plastic) Combustion-air intake pipe.  Some of the first 90%+ furnaces had only the PVC exhaust pipe.   
  • After a few years, all High-E furnaces had the 2nd PVC pipe for air intake.

Source: https://www.thespruce.com/gas-furnace-types-and-afue-efficiencies-1824743

 

A High-E Gas Furnace Includes A 2nd Heat Exchanger That Reclaims Heat From The Exhaust**

Standard Efficiency Gas Furnaces have 1 heat exchanger.  The sole purpose of the heat exchanger is to keep home air and combustion-air separate.  A heat exchanger is a structure with metal pipes.  The heat & exhaust gases flow inside the heat exchanger to heat it.   Then the furnace blower fan moves air along the outside of the heat-exhanger — and sends the heated air into the home.

photo of heat exchanger in gas furnace

Shown: Primary Heat Exchanger Inside A Furnace

Image Source: DreamsTime

Click Here To See A Diagram Of A Standard-Efficiency And High-E Furnace: Std. & High E Furnace Diagrams

NOTE: The “Secondary Heat Exchanger” is located behind the components that are green in color.

 

If your existing furnace is High-Efficiency:

  • It will have a PVC (white plastic) vent pipe to move the exhaust gasses out of the house.
  • Nearly all will have a 2nd PVC pipe to bring combustion air in from outdoors.

high efficiency gas furnace with two white pipes visible

Shown: A Gas Furnace With At Least 90% Efficiency. 

Furnace Show Has Both A Combustion Air Intake Pipe & Exhaust Vent Pipe Made Of PVC (white plastic) 

Image Source: DreamsTime

 

IN DFW — Cost & Savings Analysis For Std-Efficiency VRS Hi-E Gas Furnace (2,000 Square Foot Home)

EXAMPLE: 

1. Heating Cost Comparison — 2,000 Square Foot DFW Home With 4 Occupants

  • Using 97% GAS Furnace: at $9.71 per 1,000 cubic feet of natural gas        $505.00 Annual Fuel Cost – 97% Efficient Natural Gas Furnace. **
  • Using 80% GAS Furnace: at $9.71 per 1,000 cubic feet of natural gas       $565.00 Annual Fuel Cost – 80% Efficient Natural Gas Furnace. **

** SOURCE:  https://www.energydepot.com/ResidentialEnergyCalculator/

 

2. High-E Upgrade Cost According to HomeAdvisor.com:

  • The upgrade charge for a replacement Hi-E furnace (versus 80%) = +$1,300.00 — $3,800.00. 
  • The actual charge is based on furnace size and how complicated the installation is.
  • Replacing a standard-efficiency furnace with another standard-efficiency typically uses the same exhaust venting.
  • Replacing a standard-efficiency furnace with Hi-E furnace requires running an intake-air pipe — and an exhaust vent pipe.
  • In an attic installation, running the vent pipes is much easier than if the furnace is located within the living space.

Source: https://www.homeadvisor.com/cost/heating-and-cooling/install-a-furnace/

 

3. At The Time This Article Was Written,  Atmos Energy (DFW natural gas supplier) Offered These Rebates:

  • $350.oo for a gas furnace with 90-94% efficiency.
  • $400.00 for a gas furnace with 95% or higher efficiency,

Source: https://www.atmosenergy.com/ways-to-save/mid-tex-appliance-rebate-program#:~:text=disqualify%20your%20application.-,Rebates%20apply%20to%20current%20Atmos%20Energy%20residential%20or%20business%20customers,2020%20and%20June%2030%2C%202021.

 

4. END RESULT: 

  • Using the lowest upgrade cost of $1300.00 (shown above) – $350.00 (rebate) = + 950.00
  • With a -$60.00 per year lower heating cost:  $950.00 / $60.00 — it takes 15.8 years to recover the upgrade charge.  
  • A gas furnace lasts around 15 years in DFW.
  • Based on the numbers presented above — there’s no benefit to upgrade to a Hi-E furnace in DFW.

 

IN DFW — Lifestyle Factors Help Determine If A High-E Gas Furnace May Be Worth The Extra Cost

Cost of the High-E Upgrade (ask your HVAC contractor for prices for both standard-efficiency and Hi-E).  In DFW, the cost to upgrade to a Hi-E furnace isn’t justified.   In many cases, the money would be better spent on Energy-Saving Home Improvements (that will also lower cooling costs).

These are the primary considerations when considering a Hi-E furnace in DFW:

  • Size Of Home.  The larger the home, the better value a High-E furnace may provide.
  • Number Of Occupants.  The larger the household, the better value a High-E gas furnace may provide.

 

In DFW — The Cost For High-E Gas Furnace Upgrade 

Is Likely Better Spent On Energy-Saving Upgrades That Will Also Provide Year-Round Savings

Adding attic insulation — up to R-38 or higher.  Since DFW is a “cooling climate” (we use A/C more than the furnace) — the Hi-E furnace upgrade cost would be better spent on energy-saving home upgrades (if needed).   The older the home, the more savings these upgrades will generate.  And these improvements will reduce both heating & cooling costs.

1. Add Attic Insulation (if under R-38)

photo of blown insulation in an attic

Image Source: ShutterStock

Texas Homes Insulation Levels That Were Common Or Became Required By Building-Code:

           Attic Insulation                           Wall Insulation

  • 1950’s: none                                     none
  • 1965-70: R-13 (4″ BATT)              R-6 (2″ BATT)
  • 1970’s:    R-19 (6″ BATT)              R-6  (2″ BATT)      *3
  • 1980’s:   R-30 (9″ Blown)            R-13 (3.0″ BATT)  *4
  • 2014+:   R-38 (15″ Blown)           R-15 (3.5″ (BATT) *5
  • *3 Source: https://snuggpro.com/blog/item/many-homes-built-prior-to-1980-were-built-without-insulation-in-the-walls
  • *4 Source: https://www.jlconline.com/how-to/insulation-code-change_o
  • *5 As required by the 2012 Edition of the International Building Code (IBC)

Does Your Attic Currently Have The Insulation Depth / Thickness Required For At Least R-38?

  • 15″ of Blown Insulation is required for R-38 — or R-2.5 per inch of blown insulation.
  • If there is an existing 4″ BATT insulation, subtract 5″ of blown insulation for R-38.  A 4″ insulation batt has an R-Value of 13.
  • If there is an existing 6″ BATT insulation, subtract 8″ of blown insulation for R-38.  A 6″ insulation batt has an R-Value of 19.
  • These insulation levels meet R-38 which is current Texas Insulation Building Code.
  • The cost to add additional blown insulation will be less than you think if done all at one time.
  • Check with your insulation contractor for pricing for R-38 and R-53 — which is an additional +6″ of blown insulation.
  • Insulating to thicker depths more than R-53 won’t produce worthwhile additional savings.
  • Cooling costs will also be lowered.
  • Attic insulation will also make your home quieter inside.  If your home is located in a noisy location — additional attic insulation will help (see link just below).

 

Click Here To Learn How Attic Insulation & Many Other Home Components Reduce Outside Noise:  AlsPlumbing.com How To Reduce Outside Noise In Your Home.

To Learn About Attic Insulation, Click Here: AlsPlumbing.com Lower Heating Costs With Attic Insulation

 

2. Ductwork Sealing

If Your Home Is More Than 10 Years Old

The HVAC Ductwork Is Likely Leaking Up to 30% Of Heated & Cooled Air

ductwork for hvac system

Image Source: ShutterStock

The U. S. Department of Energy (DOE) estimates typical homes lose up to 30% of the heated & cooled air from ductwork through holes, leaks, and loose connections. 

NOTE: If you install a new HVAC System, the contractor may want to replace existing ductwork.

  • If the existing ductwork is flexible — it needs to be replaced because it only lasts the lifetime of one furnace.
  • If the ductwork is metal — it may not need to be replaced.  If the new HVAC System has nearly the same amount of air flow when the blower-fan is running — the existing ductwork will work.  If the new System has higher air flow, the existing ductwork may be too small.   But, it may be able to be modified to accommodate the larger airflow.
  • If you don’t replace existing metal ductwork, have it tested for leakage and resealed if necessary (it likely needs resealed).  Your HVAC Contractor can do that.

Resealing Existing Ductwork Can Lower Heating & Cooling Costs By Up To UP TO 1/3!

Ductwork in older homes may not have been sealed when installed.  In other cases, duct tape was used.  Duct tape fails within days in a blazing hot DFW attic where temperatures can reach 160 degrees on a sunny summer day. **  Today ductwork is sealed with non-hardening mastic at the seams and connections.  Mastic can withstand temperatures in DFW attics during summer without failing.

Click Here To See Ductwork Sealed At Seams and Connections With Mastic: Ductwork Sealed With Mastic

 

Max Sherman & Iain Walker of the DOE’s Lawrence Berkeley National Laboratory performed a” bake-test” in which sample ductwork joints were baked at temperatures of 140 to 187F degrees to test different ductwork sealing products.  They stated: “Only one duct-tape product survived 3 months —  11 Duct Tape products failed within days.” **

**Source: http://www2.lbl.gov/Science-Articles/Archive/duct-tape-HVAC.html

 

Click Here To See Several Photos Of Leaking Ductwork: Leaking Ductwork

 

For More Ways To Lower Heating Costs Without Replacing Your HVAC System, Check Out Our 3-Part Article:

AlsPlumbing.com 20 Uncommon Ways To Lower Heating Costs

 

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Al’s Plumbing, Heating & A/C in Plano, Texas is near your home in Wylie, Murphy, and Rowlette.  We service all homes in southern Collin and Denton Counties with no travel charges. Al’s 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 Professional Series gas & electric water heaters, and tankless water heaters.  Al’s is near your home in Wylie, Murphy, and Rowlette.  We service all homes in southern Collin and Denton Counties with no travel charges.

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.