Healthy Homes 12: Heating, Air Conditioning, and Ventilating Course

This thread is dedicated exclusively for those students currently enrolled in InterNACHI’s free, Healthy Homes 12: Heating, Air Conditioning, and Ventilating Course.

Upon successful completion of this course, students will be able to: identify the different types of standard fuels for heating; determine the general safety risks of inadequate heating systems; identify the various cooling systems used in homes; describe the maintenance requirements of various types of cooling systems; and examine the safety risks associated with fireplaces.

Students are free to pose questions and comments here and join in the conversation with other students. The thread will be monitored by the course instructor.

Contact: Chief Academic Officer, Ben Gromicko ben@internachi.org

Inspection & Writing Assignment:

The condensate pump is a critical piece of the HVAC system. When correctly installed, the float which rises if the pan accumulates water will shut off the power to the system. This will insure that there is not a water loss resulting from HVAC malfunction.

Research & Writing Assignment:

I chose the article on Inspecting Ducts for my review. First of all, I knew there was a formula for figuring the sizing, capacity, etc… of an HVAC system. This article covered the sizing of duct work and clarified how the sizing was determined.

Inspection & Writing Assignment:

The top of the chimney that vents two solid fuel (wood) burning fireplaces has a chase cover dented and with peeling paint and a metal cover over the two flues that is not secured to the chase cover. There are no caps. The condition of the two covers can allow rain to enter the chimney flues and chase. I recommend the chimney flues be inspected and cleaned if necessary by a chimney sweep. I also recommend chimney cap(s) and replacement of damaged chase cover.

Research & Writing Assignment:

I read over the article on inspecting evaporative cooling systems. The article went over the various types of evap cooling systems from swamp coolers to indirect evap cooling and the concepts behind how they work - transfer of heat energy from outdoor air through a water soaked medium lowering the air temperature entering the home. They also add humidity to the indoor air. Evaporative cooling systems are not energy efficiency rated like conditioning systems are rather they are cooling efficiency rated based on a formula using dry bulb, wet bulb, and supply air temperatures. Evap cooling systems use less energy, but do utilize water supply. Home inspectors should be aware of style and size of homes when evaluating a systems effectiveness. To size a cooling system for a home, home inspectors can get close by understanding the manufacturer’s air changes per hour need for the appliance associated with the volume of the home (sqft x ceiling height) divided by 60 which will provide the cubic foot per minute maximum air flow. The manufacturer’s plate then can be compared to see if the appliance is right sized for the home.

Inspection & Writing Assignment:

The image is of the outdoor condensing unit of a split system. While clearly in need of maintenance or replacement there are some items that stand out. The first being the lack on insulation where the line enters the unit. This lack of insulation will reduce efficiency of the unit and cause condensation. Additionally, the conduit box on the side of the unit is not securely mounted.

Research & Writing Assignment:

The image selected is the vapor compression air conditioning cycle. Of particular interest is the expansion valve and evaporator coils. This is where the inside air in the home is cooled, or rather has the heat taken out by the evaporator. The liquid refrigerant passed through the expansion valve and expands into a gas, cooling while doing so. The inside air is then passed over the evaporator coils where heat is taken from the from the air, raising the temperature of the gas and lowering the temperature of the air.

Inspection & Writing Assignment:

Pictured is an older (1970s vintage) oil fired burner. The most obvious problem is the leaking oil filter. This is a fire hazard as there is combustible fuel dripping inside the furnace. I recommend that this leak be fixed and that the burner be evaluated by a competent HVAC professional.

Research & Writing Assignment:

I read the article about the different types of fireplace fuel. While wood burning stoves are often used as multipurpose incinerators, care should be used in the selection of fuel. Burning painted or treated wood can release harmful gasses into the house or into the environment. The best fuel choice is dry split wood, with a mix of soft woods and hard woods.

Inspection & Writing Assignment:

The attached photo is of a gas, direct vented fireplace with ceramic logs. It contains an electronic ignition pilot, has a glass enclosure and a circulating fan. This type of fireplace is generally more efficient, does not emit embers and provides supplemental heat for the room it is installed.

Research & Writing Assignment:

The article on fireplace fuel educates the reader on what types of wood can be used as a fuel for a natural fireplace and how they effect the fireplace flue and environment. There is also a detailed list of what NOT to burn to avoid environmental pollution and negative health aspects of burning treated woods, trash, lint and a litany of other products. This is a valuable article for anyone who currently has a fireplace or is considering adding one.

Inspection & Writing Assignment:

The photo shows the outside condenser unit which is 1/2 of an HVAC split-system with a warm air furnace located in the garage. The reason for taking the picture is to show that the electrical disconnect located on the wall next to the condenser unit is coming loose from the wall. It was recommended that a licensed electrical contractor be called to correct the problem.

Research & Writing Assignment:

The article “Ceiling Fan Inspection” points out that the function of a ceiling fan is to circulate air within a room. The direction of ceiling fan blades can be reversed depending on the season. In the summer months, the fan blades should turn counter-clockwise and in the winter months, they should turn clockwise to ensure the proper direction of the air flow. Ceiling fans can be an efficient and economical way to move air.

Inspection & Writing Assignment:

A Split System Air Condition system. Is one of the most popular heating ventilation and air condition systems in the United States. Inspection of the exterior unit is a fairly simple process by ensuring that unit is damage and dirt free, at a proper distance and free from obstruction, and the service disconnect is within sight of the unit.

Research & Writing Assignment:

While performing an inspection on the proper operation of a gas-fired furnace unit should be checking for exhaust leaks should be one of the most important systems checks performed. Using a simple Combustion gas detector around the joints and seems on the exhaust line.

Inspection & Writing Assignment:

This is a great place to show off my home hacks! I have long had a interest in energy efficiency and indoor air quality. My house is a two story, daylight basement design, that often has a 10* temperature differential between the upper and lower floors. To help mitigate this temperature difference I like to turn on the circulating fan on the forced air heat pump system. For years I would turn it on in the morning and off at bedtime. 8-10 years ago I bought an old yard light timer and disconnected the transformer and now use it to switch the fan on and off. We heat the house with two natural gas direct vent stoves, not the heat pump so the fan being on spreads the heat to all rooms and provides air circulation for better indoor air quality. The fan is a little noisy with the metal ductwork, I do wish it had a very slow “circulation” speed.

Research & Writing Assignment:

I read an article about properly fitting HVAC filters. I have never seen a filter on a fresh air duct although it certainly makes sense. I like to encourage people to have air filters installed on return air grills as it keeps the return air ductwork clean. I also learned that higher MERV ratings have more resistance to airflow and can potentially damage HVAC equipment.

Inspection & Writing Assignment:

fireplaces. most of the fireplaces that I have run across are not in working order in fact upon inspection of these units you will find that they have not been working for some time, therefore, the maintaining of these units have been delayed for a great deal of time.

Research & Writing Assignment:

The Chimney, as it is call . the chimney is indeed a separate structure from the home or property that it is attached to, the chimney is a free-standing independent unit from the home. it has a primary purpose and that is to act as a Heating element for the occupants that are inside the home.

Inspection & Writing Assignment:

The attached picture shows a DMO Industries, oil fired, warm air furnace. It had a listed firing rate of 1.00 gallons per minute of #2 fuel oil at the time of the inspection. The discoloration of the housing to the right of the inspection port appeared to be soot escaping in that area. The material could be removed by wiping so most likely the discoloration was not due to overheating of the metal. The presence of soot is indicative of products of combustion appear leaving the combustion chamber and entering the building envelope. Carbon monoxide (CO) is one product of combustion which is very dangerous and should not be entering the building. It was recommended the furnace be evaluated by a licensed technician to determine if there is still a problem with combustion gasses leaving the furnace.