#heating

I know, I know. You came here for HVAC content, so why are we talking about pool heaters? Since we live in Florida and don’t have that much of a heating season, we have to look for other forms of work during the winter months. Pool heaters fit the bill quite nicely since they’re actually […]

If you’ve been following my writing for the last couple of years, you know that I like to blather on and on about combustion analysis. Now, I am by no means an expert on the subject, as I live in North Texas (which is not known for its intense heating season), but I love using […]

We’ve entered that season of service calls for “smoking heat pumps,” and I figured now is as good a time as any to share a few quick tips for troubleshooting defrost. Of course, the “smoking heat pump” calls can be solved over the phone with a quick explanation of normal defrost conditions—as can the service […]

This tech tip came from an email sent by Adam Blunkall, a Tennessee-based HVAC technician. He shared some tips to help overcome this issue in his market, and we appreciate his insight. Thanks, Adam! If we’re draining our 90% furnaces (or any condensing heating system) outside the structure in a similar fashion as we would […]

Just like Shrek, I like to think about the heating sequence of operations as an onion—it has layers. And each layer builds upon the previous one. We have written previously in great detail about gas furnaces, from top to bottom. I want to focus today on why there is a sequence of operations and how […]

If a furnace runs for years and years while tripping the limit switch but satisfies the thermostat, will it ever be noticed? The answer is most likely “no,” but it will depend on whether the furnace utilizes soft or hard lockouts when the limit switch trips. So, what is a soft lockout vs. a hard […]

This tech tip recaps the livestream by the same name, featuring HVAC School contributors Matt Bruner and Adam Mufich and special guest Ty Branaman. You can watch that livestream on our YouTube channel HERE and visit Ty’s at https://www.youtube.com/@love2hvac. While 80% gas furnaces are relatively commonplace in the Southeastern United States, where HVAC School is […]

Last year, I bought my first combustion analyzer. I had just started my own company and felt the additional weight of responsibility to sit down and determine the best way to verify that the furnaces I was servicing were working safely. In the past, the most extensive testing I had done was a visual inspection […]

Enthalpy is easy. It's just a state function that depends only on the prevailing equilibrium state identified by the system's internal energy, pressure, and volume. It is an extensive quantity. Simple. Like most things, the scientific definition is as clear as mud. In HVAC/R, we use enthalpy measurement to come up with the total heat […]

 In this short podcast episode, Bryan talks about the standing pilot gas systems and the ignition strategy in gas-fired appliances. Standing pilots are very simple devices that are common in fuel logs, water heaters, and some pool heaters. These devices have a thermocouple or thermopile; in a thermocouple, two dissimilar metals are connected at […]

 Jim takes us all the way through the history of furnaces, from the Stone Age when he was a child to modern modulating condensing types. The goal of a furnace is to move heat, so a furnace uses heat exchangers to facilitate heat transfer. Furnaces have primary and secondary air. The primary air goes […]

 In this short podcast episode, Bryan talks about heat exchangers and temperature rise in gas furnaces, especially 80% open-combustion gas furnaces. Temperature rise is the difference between the return air temperature and supply air temperature; in cooling, we usually refer to this difference as a delta T or temperature split. The manufacturer sets a […]

 In this short podcast, Bryan talks about evaporator coil placement based on a question submitted by a listener, John. Evap coil placement differs in furnace applications versus air handlers. When we use air conditioners with furnaces, we usually put evaporator coils on the positive side to protect the heat exchanger from rusting out during […]

 Bryan and Craig Migliaccio (AC Service Tech)dive deep into the complexities of managing condensate drainage in high-efficiency (90%+) gas furnaces. The conversation begins with a clear explanation of why these furnaces produce condensate in the first place – they have two heat exchangers that extract so much heat from the combustion gases that water […]

 In this short Q&A podcast, Bryan answers a listener-submitted question about sizing heat pumps for heat load in heating mode, something that we haven't talked much about in the past due to the greater need for cooling in our market. In most cases across the country, a heat pump's heating loads will be greater […]

 In this short podcast episode, Bryan talks about when to switch to emergency heat. He talks about coefficient of performance (COP) and how it's a deciding factor when to run emergency heat, which is when a system ONLY runs the backup heat; it doesn't use it as supplementary heat. When we have a heat […]

 In this short podcast episode, Bryan talks about the four different combustion venting categories for gas appliances as set by ASHRAE and where you'll see them. He also shares some notes about pressurization. These categories deal with the pressurization and temperature ranges of the vents. Category 1 venting is used for old-school open-combustion gas […]

 In this short podcast, Bryan dives into a gas heating topic: primary & secondary air in combustion. Primary air is the air and oxygen content that enters the furnace BEFORE combustion. In older furnaces, prior to induced combustion, air was drawn in through the front. These older furnaces had adjustable shutters that we could […]