Ultra Low-NOX Furnaces and the Future of Gas Heating in California

With a new decade comes new regulations. And although most of these regulations will not affect you, there is one in particular that could change the way you heat your home. San Joaquin Valley Air Pollution Control District’s regulation known as Rule 4905 requires a reduction of the amount of NOx produced by natural gas furnaces; after March 31^st of this year, everyone in the San Joaquin Air Quality District will be required to install an Ultra Low-NOx (ULN) furnace when they replace their system, instead of standard low-NOx furnaces.

As a quick primer on what these terms mean: nitrous oxide (NO) and nitrous dioxide (NO₂) are pollutants that are the byproduct of combustion from nautral gas furnaces and are commonly referred to as NOx. This NOx produced from the furnace combines with other volatile organic compounds (VOC’s) to produce ground-level ozone (a carcinogen), and to combat pollution, the Air Quality District has lowered furnaces’ allowed NOx emissions from ≤40 ng/J (nanograms per joule) to ≤14 ng/J.  Rule 4905 declared this standard (one that no manufacturer could meet at the time) in 2015, but allowed for an interim product development period in which manufacturers could sell continue to sell standard low-NOx furnaces by paying a mitigation fee.  That interim grace period ends this year on March 31^st; on April 1^st, we will only be able to set an ULN furnace in the Central Valley.  To date, almost all manufacturers have introduced a line of furnaces that comply with the new requirement.

Unfortunately, we have found several problems with these new compliant furnaces.  Not only are they nearly twice as expensive, but they were also rushed into production with little actual testing.  Although every manufacturer claims their ULN furnaces are reliable and robust, the word on the street is that they all have problems due to  being reliant on stable and consistent gas pressure to and within the home. Standard low-NOx furnaces, on the other hand, are very forgiving in response to the normal fluctuations most homes have with their gas pressure.  Think of how the water pressure drop from flushing a toilet can cause a shower’s hot water to become suddenly scalding- this same type of pressure drop in the gas line when, say, the water heater comes on, detrimentally affects ULN furnaces and causes a multitude of problems, including premature failure.

Because of these issues, we have decided it is not in our customers’ best interest to install ULN furnaces and as such, we will instead be installing all-electric heat pump systems from April forward. Even though heat pumps currently cost more to install than systems with standard low-NOx furnaces, they will nonetheless still be less expensive than the ULN furnaces, and come with the peace of mind that only tried-and-true equipment can.

The real reason for this post is to let our customers and readers know what will happen next month so that you have the option: if your system is older and you have been thinking about replacing it, we will still be able to get and install a standard furnace until March 31^st. We urge you not to wait and to get pricing on a low-NOx furnace before the ban takes effect.