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It’s been awhile, and it’s ultra hot in the summer of 2020.  That said, some of you may be thinking: “should I replace my a/c only or the whole system?”  Well, the answer hinges on a few factors.

1. Replacing the a/c and furnace together options up higher efficiency options which may qualify for Federal tax credits or local electric company rebates.
2. An a/c and furnace replacement together will save you at least $1,500-$2,000 in labor costs and duplicating local permit fees.
3. In North Carolina, a/c’s typically last 10-15 years, and furnaces last 15-20 years.  However, the fan blower in the furnace circulates air in your home and operates all year long.

Talk to a local pro and make sure you make the right choice.  Enjoy your Summer and stay safe!

Each year, more homeowners are choosing to seal off (or encapsulate) their crawl spaces and attics.  The process, for crawl spaces, typically involves spray foam or polyurethane which covers the floor, foundation walls, support columns and sometimes under the floor of the main level of the house.  Once completed, a qualified HVAC company will install one or two small duct vents from the existing furnace or air handler to introduce air to help condition the space.

The benefits of encapsulation include:

• Improved HVAC efficiency and performance
• Lower utility bills
• Superior air quality
• Significantly reduced possibility for mildew and mold growth
• Protection for wood flooring
• Superior protection from pests and insects
• A more comfortable home

The average cost of encapsulation can be around $5,000 depending on the square footage of your home’s footprint.

Hello HVAC world and Happy 2019.

Per appliance-standards.org, furnace fans use electricity to circulate air heated by the furnace through a home’s duct system into the living space. For homes with central air conditioning, the furnace fan also serves to circulate air during the cooling season.

In 2014, the Department of Energy (DOE) established new protocol to phase out all PSC fan blower motors in 2019, to be replaced with at least X13 hi-efficiency fan blowers.  This kicks in during the summer of 2019.  What this means is all PSC motor furnaces and air handlers will be phased out.

Why is this being done? The new standards will reduce the energy consumption of furnace fans and improve residential home energy efficiency.

It has been a few months since I last checked in and hope everyone is having a pleasant summer.  I recently had a client who inquired about ways to improve humidity in their home.

One solution is to install a dedicated whole house humidifier or dehumidifier, such as Aprilaire’s product line.  However, another often overlooked solution is to opt for variable speed air conditioners and furnaces.  Variability in a/c condensing units helps pull more moisture out of the home during the cooling season.  Variability in furnaces saves on gas/propane consumption but also dries the home out less, especially in moderate climates like the Carolinas.  Remember, there are typically more than one approach to solving in-home comfort problems.

What about that ductwork in your crawl space, or in the attic?  It’s highly probable you haven’t considered it’s impact on your home’s energy efficiency.  However, to quote Energy Star:

“In houses with forced-air heating and cooling systems, ducts are used to distribute conditioned air throughout the house. In a typical house… about 20 to 30 percent of the air that moves through the duct system is lost due to leaks, holes, and poorly connected ducts. The result is higher utility bills and difficulty keeping the house comfortable, no matter how the thermostat is set.”

Ductwork from the 80’s and 90’s was no higher than R-4.2 value.  Modern ductwork is R-8.0, almost double.  The result is significant energy and comfort gains, particularly for attic applications.  In the summer months (especially in the South), attics can reach 130-140 degrees Fahrenheit.  Imagine conditioned air circulating through this extremely hot space and the temperature of the air will increase significantly before it can get into your home.  The better the duct insulation value, the colder this air will be, maximizing it’s ability to efficiently condition your home.

Happy New Year!

Nearly the entire continental United States is dealing with frigid, record breaking low temperatures.  The drastically lower humidity levels can irritate skin, cause unwanted shocks and damage wood floors and furniture.  A common notion is gas furnaces dry out the air circulating in your home.  While this can be true, the explanation is more nuanced.

Atmospheric burning furnaces (rated between 60-81% AFUE) draw in air from the home, whether in an attic, closet, crawlspace or basement.  This air is mixed with the fuel (typically natural gas or propane) and is burned to warm the home.  For every cubic foot of air removed from the house, it is replaced with outside air (which has low humidity).

Sealed combustion furnaces (rated at 90% or more AFUE) use air from outside the home for combustion.  The end result is higher humidity and better comfort for the homeowners.

Have a happy, safe and humid friendly 2018!

Condensing furnaces come with some of the highest AFUE (annual fuel utilization efficiency) ratings, typically between 90-98%.  But what makes them “condensing?”

All furnaces use burners which convert a fuel such as natural gas into heat, which then delivers this heat to the circulating air via the heat exchanger.  This conversion process creates water vapor as a byproduct.  Condensing furnaces then have a secondary heat exchanger which further extracts warmth from this water vapor.  This increases the overall AFUE of the system.

A couple things to keep in mind… condensing furnaces should be used in crawl space or basement applications only, as freezing or leak issues can occur in attics.  Condensing furnaces require PVC instead of metallic b-vent flue piping.

Happy Thanksgiving Everyone!  I get questions all the time on utility company rebates.  Here is a quick primer to help navigate the landscape as it exists in November 2017 for the Raleigh-Durham-Chapel Hill metro region.

PSNC Rebates:

• This one is easy to decipher.  The rebate is $150 if you install a 90% or higher AFUE efficiency furnace.  This rebate applies whether you upgrade from an 80% or lower AFUE heating system or if you are replacing an existing 90%+ furnace for another 90%+ furnace.

Duke / Duke – Progress Rebates:

• Efficiency rebates are lumped into two categories:
  • 15-16 SEER are eligible for $300
  • 17+ SEER are eligible for $400
• Eligible system (see above sub-bullets) can be combined with an approved list of “smart” thermostats to convey an additional $125 rebate.  This list includes the frequently used Honeywell Lyric WiFi, Honeywell 8000 WiFi and Ecobee.
• $75 “quality install” rebate for eligible systems.

The above is always subject to change and I would refer to the utility company websites for more details, but this should help demystify some of the eligible requirements.

Cheers!

There are a few ways in which coils can become compromised.  One of the most common is formicary corrosion.  Americancoolingandheating.com defines this process as “…a chemical reaction requiring three parts: oxygen, water, and an organic acid. If any of the three parts are removed there can’t be any further formicary corrosion. Formicary corrosion only occurs in copper based alloys.”

Corrosion is most often caused by exposure to fluoride or chloride.  Fluoride is present in municipal water supplies and chloride is found in a products including detergents, cleaners, carpeting and fabrics.  Pitting occurs when chloride or fluoride ions are transported to the copper metal coils via condensate (water).  The ions attack the metal, forming pits that form pinholes, causing the coils to leak refrigerant.

In response, most HVAC manufacturers have switched or are switching the composition of their coils to 100% aluminum.

In a word… no.  Many people believe partially or fully closing off a floor or ceiling supply vent will help redistribute air flow to other areas of a home.  Unfortunately, with the way duct systems work, this typically causes unwanted whistling and static pressure buildup.

Air circulation in a home works by the difference in pressure.  Once a fan blower starts, the supply ductwork becomes a positive pressure zone and the return ductwork a negative pressure zone.  Air likes to move from positive to negative pressure.  Closing off the endpoint of a duct run causes a pressure buildup at the point of entry for air.  This air cannot reverse flow against the static pressure and will eventually leak out into the crawl, attic or cause noise as it forces its way across the closed off grille vanes.

The best solution is to close off supply ducts where they connect to your furnace or air handler, increasing the likelihood this air will be properly redistributed elsewhere in your home.