How to inspect furnaces covers a large amount of material but can be summed up as follows. Furnaces can be described by fuel type, ignition, efficiency, distribution, and airflow. Within each of these categories there are several different types of each. For example a furnace can be fueled by gas, oil, electricity ect. Heat can be distributed by gravity or forced air and so on. An inspector is required to inspect the system using normal operating controls, to identify the energy source, and heating method.
This is a York model TG9S040A08MP11B, 40,0000BTU input and 38,000BTU output, gas-fired, direct vent forced air up-flow lowboy furnace. It is 95% “steady state efficient”, relatively new, well maintained and in good condition. It is configured as an up-flow unit with the supply plenum above the unit and the return plenum low to the side of the unit. The supply diffusers are ceiling mounted and has a high return grille. This is an ideal configuration for summer cooling. A possible upgrade to the design for winter heating, would be installation of a low return with a damper to close during summer cooling, to draw the high warm air supply down through the space into the low return.
I appreciate the variety of systems covered during this course. As an inspector in Florida different varieties of heating systems are uncommon and often forgotten. Refreshing information is always a good thing.
This article from the library is an overview of the various types of furnaces an inspector can expect to encounter during an inspection and various ways to describe the furnace which was covered in this (Inspecting HVAC Systems) course. They include fuel type (coal, oil, gas, electric), air distribution method (gravity, forced), air flow (Up, Down, Horizontal) capacity (BTUs) and efficiency rating (AFUE). It stresses that inspectors are not required to operate the system during an inspection other than by normal operating controls, if weather conditions permit.
This is a picture of a portable cooling unit. I find this a lot more useful because you can just take it wherever you go and plug it in, and use it. Rather than an exterior cooling unit, you know, the one that connects to the house and since it goes throughout all the house and rooms, you have to wait until it gets to yours. And the article I chose to read about is called How a Home Inspector Can Stop Defamation. Basically, a home inspector can do so by writing a letter and having his/her lawyer review it. Failure to do so will mean you are automatically guilty of defamation and will award the plaintiff for the damages done.
The window pictured below is from a recent inspection. It appears to have an unfinished trim on the exterior. Upon internal inspection the wall containing the window was bulging inward at the window and was marked for further evaluation by a licensed professional in my report. The carpenter that looked at the window later told me that the window had been set in place by attaching it the the drywall with no detachments to and structural members.
For this research project I chose dryer vent safety. I chose this because I had a friend who left his house to go shopping and turned the dryer on. He returned to a plethora of emergency vehicles at his burning house. The fire investigators determined the fire starting in the dryer vent.
It is important the dryer vent be properly installed, not restricted and free of lint. Lint is an extremely flammable substance. When combined with a restriction in the dryer vent it is a recipe for disaster.
The furnace heater in the pic below is a Concord model. It’s a forced air furnace with an AFUE rating of 80.0, which makes it a Mid-efficiency furnace. BTU output is 80,000 and input admission is 100,000. Fuel source is natural gas. As a modern higher efficiency rated furnace it has an intermittent-pilot that does not burn continuously. The plenum that supplies and moves the heat to all the supply registers appears in good condition. The air filters are dirty and need to be replaced, at least once per month.
This here is a flexible connector at the supply plenum of a gas heater. It’s coming apart at the corners and leaking warm air back into the heater room. It has to be repaired.
For my assignment for this course I took two pictures. One of the Baxi propane condensing boiler for our forced hot water heating system and the second picture is the venting for this boiler. My primary concern was the clearances for the venting. As noted the venting is located near a basement window, which is a finished room. I am pleased to report that the venting is 19" away from the window and 30" above finished grade. Both dimensions exceed the requirements which are at least 12" from any opening and 12" above grade.
In the article library I checked out the Water Heater dating chart. I have not needed a dating chart for water heaters yet but I’m glad to know it’s available. I often have to look up a home heater number online. I promptly forgot the website that was shown on the video, but at least I can look it up again. It may be in the study guide. I post all my study guides to the cloud so I can pull them up for reference if on an inspection, lots of good stuff.
For my research assignment for this section I chose to review the oil storage fill and vent piping issue. I reviewed the gallery as well as reread the course section and I take issue with the course material. In the course material the text calls out that the fill pipe should be a 2" pipe and the vent should be a 1 1/4" pipe. This is not correct and actually a dangerous combination.
I have 15 years installing heating and cooling equipment experience. The code, at least in NH, calls for a minimum of a 2" vent pipe. As well as no vent pipe shall be smaller than the fill pipe. The reasoning behind this is in the truck delivery system. New modern delivery trucks are equipped with high volume pumps to deliver oil quicker. If the vent pipe is of a smaller diameter than the fill pipe, and smaller than 2", the tank will pressurize while being filled with oil. Especially when the tank becomes 3/4 full. At this point the pressurization of the tank can blow out the bottom of the tank. If the tank has some age to it, this can be more likely to occur. Some of our local oil companies will not fill an older thank that still has 1 1/4" vent pipes for fear of liability.
This section should be revisited by the folks at InterNACHI.
Hello InterNACHI and friends:
I’m beginning course talk to you again when done.
Gary Jameson
After removing the front cover panel of this Goodman brand gas furnace it was easy to defect rust up inside the burner tubes. (Not able to see rust in pic) This unit was not the old but was in a basement with lots of moisture and water intrusions. Recommended a HVAC tech evaluate the furnace
This is a picture of a Rheem condenser installed in 2010.
I found a couple of problems on it. The conduit is loose at the side of the condenser exposing the wires, the dryer vent is close to the condenser, it was not installed on a concrete pad.
The condenser was in good condition but those problems can cause damage to the unit.
I reviewed an article about Central Air Conditioning System Inspection.
This article states that the System must be periodically inspected and maintained to function properly.
I will add something else about the Air Handler, this unit should be inspected for air leaks, sweat, and the most important verify that there is not mold.
This condenser unit was operating normally. But minor clicking was heard from the fan. This could indicate damage to the fan, fan imbalance, or problems with the housing. Recommend further inspection by a licensed professional.
Just read about common home repair rip-offs. It is good knowledge to have for yourself and to share with clients. The most common are roofers, driveway sealers, and termite exterminators. Their scams can very. But it seems that the smartest thing to do with any home repair is, do your homework. A scam artist can’t really fake cold hard facts.
Evaporative coolers, also known as swamp coolers, create coolness through the evaporation of water. Air is drawn from outside though wet soaked cooler pads. The water turns into a vapor creating a lower temperature indoors. Cooling the air in this manner is a cost effective way to maintain comfortable temperatures vs. using a HVAC system, which can be twice the cost. Evaporative cooling units work best in drier climates. If the the humidity is too high the evaporative cooler will not cool the air and begin to feel muggy indoors. Maintenance costs are also lower because the parts are few and can be replaced at lower cost. Although, the pads for Master coolers are more expensive but they can be used two or three times depending how well the mineral content in the water is managed. The advantage of evaporative coolers is the lower operating costs. The downside is that in high humidity, they quit working.
Hydronic heating is becoming more popular in my region, so the teaching on this type of heating until was very helpful. How the water expands in the tank as it heats and flows through the tubing was enlightening