HVAC Equipment Basics: Know Before Buying


The lungs of your house i.e. the Heating, Ventilation and Air-Conditioning (HVAC) system need to be in shipshape in order to ascertain that both your house and its occupants breathe healthy! Gharpedia brings you a guide on HVAC equipment which are commonly used in your home.

Well, let’s accept that house breathes, if not physically, at least figuratively. The logic is that air from outside wafts into your house and internal air gradually vents out. Now doesn’t that sound like inhale and exhale process that living beings do? On a serious note, practically all households would have equipment to condition the air and the heating, ventilation and air-conditioning in a home are termed the HVAC System. According to Shaimaa Seyam (Author of the article namely – Types of HVAC Systems), the basic goal of an HVAC system is to provide thermal comfort to building occupants by modifying and changing outdoor air conditions to the desired conditions. We at GharPedia, aim to provide you basic information on different types of HVAC equipment.

A good feature about modern constructions is that a large portion of the HVAC ductwork is hidden behind walls, floors and ceilings. Unfortunately the same doesn’t hold true for old homes where components like window air-conditioners and radiators are glaringly obvious.

Window Air-Conditioners

From the broader perspective, there are three energy sources that fuel heating and cooling systems – natural or propane gas (which is carried via the medium of underground lines into your house), fuel oil (these demand good ventilation) and electricity. Before proceeding further to the types of HVAC equipment, let’s look at the dos and don’ts for HVAC systems.

Dos and Don’ts for HVACs

Technical Inspection of HVAC Equipment

One needs to treat these systems properly and refrain from trying to figure out things on one’s own when they conk off. Professional technicians are the ones who can resolve the fault without playing havoc with the internal wiring of the system. However, a basic thing that all members of the household need to learn is how to shut down the system. Take the case of gas furnaces. They generally have a shut off valve right in the gas line leading to the furnace, plus a main shut off valve at the meter.  Electric systems have a switch along with a dedicated or single breaker or fuse for that appliance in your electrical system and in case of a fuel oil tank the shut off valve is mostly located near the bottom.

Quality Ratings of HVAC System

The HVAC equipment are assigned ratings based on their efficiency. They are as follows:

  • AFUE: The acronym AFUE (Annual Fuel Utilization Efficiency) rates how efficiently the furnace unit delivers warmed air into the house. An AFUE of 78 per cent denotes that 78 per cent of the heat that the furnace produces gets into your house, and the balance 22 per cent goes up the flue
  • SEER: The acronym SEER (Seasonal Energy Efficiency Ratio) for cooling equipment follows the same idea. A higher number translates into sturdier cooling efficiency. A minimum SEER of 13 is highly recommended for central air-conditioning systems.

After having basic information on HVAC systems and their ratings, let’s  now have a glance at different types of HVAC equipment that are popular.

Different Types of HVAC Equipment

There are various types of HVAC equipment available in the market. The following are the popular ones:

01. Hot Water Radiator and Steam Heat Radiator

Hot Water Radiator

Both hot water radiator and steam radiator systems operate on the same principle. The water heated by the boiler is pushed through pipes in the form of steam or hot water to radiators (or convectors) spread across the house. Their biggest plus is their durability (one can see eighty-plus-year-old boilers merrily chugging away heating houses) alongside the moisture content of the heat they provide to our bodies.

02. Gravity Furnaces

Gravity Furnaces

Gravity furnaces follow the principle that warm air rises and cold air falls. This HVAC equipment resembles a giant octopus with tentacles extending in every direction from a huge, stocky, impressive belly which is the heat exchanger. Gravity furnaces were popular in houses built in the thirties and forties, but are no longer manufactured owing to the fact that they are not very efficient.

03. Forced Air System

Forced Air System

Adaptability and affordability are the major advantages of forced air system. The process involved is pretty simple. Just like most heating systems, this too has a thermostat at its core. Once the thermostat is set to the required temperature, the furnace swings into action by heating air in a chamber, which is then forced into rooms through ductwork.

Ductwork running through the house is a blessing in disguise, specifically if one is looking at central air-conditioning; for the simple reason that the existing ducts and registers from your heating system can be deployed to deliver air-conditioning.

04. Radiant Heat System

Radiant Heat System

According to Robert McDowell (2007) (Author of the book – Fundamentals of HVAC Systems), radiant heat is the heat that is transferred from a hotter body to a cooler body without any influence on the space between. Radiant heating systems directly supply heat to floors or panels in the wall or ceilings of a house.  Radiant heat system will help you do away with slippers. There are two types of radiant heat systems, which are:

Hydronic Radiant Heat Systems

In hydronic radiant heat systems, plastic tubing termed PEX (PEX is an acronym for Cross Linked Polyethylene) is installed atop the subfloor. Hot water is pumped through the tubes, which heat your floor, rising to warm the air in the room. These are best installed when the house is being constructed; albeit they can be retrofitted also but it would turn out to be extremely expensive. Ascertain that you commission the task to someone who holds a rich experience in installing this type of system.

We have a detailed article on PEX pipes:

Electric Radiant Heat Systems

Electric radiant heat systems too operate on the same pattern as their hydronic counterparts; the only difference is that here the heat source laid on the subfloor is a pad or other flat material which is fuelled by electricity. In case you intend to opt for this system for your entire house, then be warned that the cost would be pretty hefty owing to the stupendous charges of electricity compared to gas. In case you’re extending your house with a room, then it would be more economic and less cumbersome to use radiant heat instead of extending the existing ductwork. These systems are best suited for bathrooms, owing to their small size and the fact that electric radiant heat systems work best under ceramic tile floors. Last, but definitely not the least; bathrooms are a good place to have warm feet!

05. Heat Pumps

Heat Pumps

This may sound confusing, but ‘heat’ pumps are air-conditioners in actuality! Yes … but hey hang on they can operate in reverse and provide heat too! Magical … eh? Well, there’s no rocket science involved here, but a valve that allows it to swap from the air-conditioning mode to the heat mode. According to James E Brumbaugh (2004) (Author of the book: HVAC Fundamentals, Volume 3: Air Conditioning, Heat Pumps and Distribution Systems), heat pumps are designed to alter the action or direction of heat transfer based on whether heating or cooling is required. These HVAC equipments are a must-have for zones where the temperature rarely drops below freezing level; because with the fall in the temperature, the efficiency of the heat pump too drops. Then again, with innovative concepts like ‘booster’ compressors, heat pumps too can become cold weather-efficient.

06. Evaporative Coolers or Swamp Coolers

Evaporative Coolers

In parched weather, the most efficient method to cool a home would be adding water to the air. The evaporative cooler operates on this basic premise. It basically pulls in the sultry outdoor air and distributes it over special pads soaked with water; this leads to the evaporating water cooling the hot air… and this cool air is then passed inside the room. A USP with swamp coolers is their cost-efficacy vis-à-vis expensive air-conditioners, which not only cost a bomb but also hike your electricity bill. Gone are the days when coolers came in bulky sizes, which made them a deterrent for smaller houses; now they too come in sleek models and can also be moved from one room to the other.

07. Indoor Comfort Systems

Indoor Comfort Systems

As most of us are aware, modern houses are constructed with the objective of being weather friendly. Now, this has both good and bad repercussions. Let’s start with the positives. It can help us conserve on our utility costs; on the downside, these houses are so airtight that residents end-up getting weighed down with indoor pollutants (like pet dander, smoke, mould and pollen). This gives rise to stink! In order to combat this, the innovative market has come up with an entire array of ‘comfort equipment’, which aims to custom condition the air that you breathe. Many of these HVAC equipments mandate the ductwork as a delivery system.

There are certain enhancers that are attached to the HVAC equipment, let’s have a glance at them:



With the same temperature feeling different in various places owing to the humidity of that particular place, it’s no small wonder that a few forced air systems come fitted with humidifiers. The other pros of enhancing the humidity in your air, especially during winters include – alleviating chances of electrostatic shocks and protecting wood from turning excessively dry and splitting. A point to be taken care of with humidifiers is that one needs to religiously check their evaporative pads at the commencement of each heating season and replace it if needed– this is to ascertain that they don’t get clogged with mould and mildew.

Air-to-Air Exchangers (Heat Recovery Ventilators/Energy Recovery Ventilators)

Air-to-Air Exchangers

The best part about these HVAC equipment are the double duties they perform – alongside ushering in fresh air into your home and throwing out the stale air, they also ascertain that your house doesn’t lose its precious heat. These units are a boon for those weather-tight houses which do not facilitate the exchange of indoor and outdoor air. Another alternative is opening the windows … but a good question to ask here is that would you like to do so when the temperature outside is below zero degrees?

Whole House Electronic Air Cleaners

Whole House Electronic Air Cleaners

During the yonder days, one could hear the crackling of the smoke eating equipment when a person lighted a fag, especially in a drinks bar. Something akin to this can be smoothly installed in your house’s HVAC system, that too sans the noise element! Termed an electronic air cleaner these quietly and efficiently demolish lots of nasty things like mould, spores, smoke, dust, pollen and pet dander to ensure that your ductwork unknowingly does not disseminate these thereby polluting the fresh air of your home sweet home!

This HVAC equipment, when attached to your furnace guarantees fresh, clean air for the entire house. A word of counsel – do remember to regularly change or clean the filter (refer to the manual)

Important Points to Keep in Mind for HVAC Equipment

  • With HVAC equipment fitted with filters – say forced air systems and whole-house air cleaners – it’s critical to change these filters at regular intervals. So, in case you are absent-minded, please mark it on your calendar.
  • More and more countries are harnessing free sources of energy like sun, wind et al for their HVAC Systems like HVAC systems made by the professionals from RMS heating and cooling, boosting the alternative energy market in times of skyrocketing prices of fuel and electricity.
  • An innovative technology that has come up in the last decade to vanquish mould is ultraviolet lights. This comes in handy in those hot and humid zones where air-conditioning is more of an essential than a rarity, as it may be required for a major part of the year. So go ahead and destroy those dirty mould spores by retrofitting ultraviolet lights and that too at a reasonably decent cost.

Summing up,

The above HVAC equipment help to keep your house ventilated and healthy. Hope you are now in a better position to ensure that the ‘lungs of your house’ i.e. the HVAC system is all pumped up, irrespective of the weather outside.

Before leaving, make sure to check out our articles on HVAC:

How to Choose the Right HVAC Company?
4 Tips for Hiring an Air Conditioning Installation Contractor!

Image Courtesy: Image 2, Image 5, Image 7, Image 9, Image 10, Image 11, Image 12, Image 13

Author Bio

Huta Raval – An English Literature and Journalism Topper, Huta Raval has graduated from the L D Arts College, Ahmedabad. Post serving for 23 years in the NBFC and Public Library Sectors her desire for ‘writing the unwritten’ brought her to the creative field of content writing. Her clientele comprises of NGOs, Blogging Platforms, Newspapers, Academic Institutions, et al.

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