HVAC 101 – VTM Mechanical Inc. © All Rights Reserved.

4 main types of HVAC systems

Duct-free systems

Ductless air conditioners and ductless heat pumps, also known as ductless mini split systems, can fit in any space, even where traditional HVAC units don’t. With their virtually endless configurations, ductless air conditioners and heat pumps deliver comfort with minimal visual impact.

Hybrid systems

With hybrid HVAC, the system’s computer selects either an electrically-powered heat pump or a furnace that burns natural gas, propane or fuel oil. What does this mean for you as a homeowner? Cheaper energy bills and more effective comfort in the winter and summer!

Split systems

Split Systems. A package HVAC unit combines multiple units, such as an air conditioner and heater, into a single unit. The unit is usually placed outside. Split systems, on the other hand, divide each system into its own unit, so your heater and air conditioner are separate.

Packaged systems

Packaged systems typically heat and cool your home the same way their stand-alone counterparts do. The ducting with a single cabinet system is slightly different and as well the duct work is attached to the system rather than connecting to various components.

Air Filters Explained

How often should I check my air filter?

We suggest checking filters monthly. If you have a disposable type filter, (these usually have a cardboard edge), and if it is dirty, just replace it. Don’t attempt to clean it. Some higher efficiency 1″ pleated air filters can go up to three months before needing replacement. But in the higher-use seasons, it’s better to check more often.

Different systems have different filter locations. If you don’t know where your filter is located, now would be a good time to learn! Usually, there is a removable filter access door in the return air duct next to the furnace or indoor unit. This can be in a basement, crawl-space, utility closet, garage, or attic.

Sometimes, especially with older systems, the filter is located inside the furnace itself, next to the blower motor. And some systems have a central filter grille installed in a wall or ceiling. The grille swings open, revealing the air filter.

Keep in mind, many air filters are directional – the air is meant to flow through the filter in one direction only. Look for an arrow or airflow symbol indicating direction. The arrow should point towards the furnace or air handler. If your filter does not have any arrows, see if one side of the filter looks rougher than the other side; that would be the side to collect the dust, so the other side would face the equipment.

Where is my air filter located?

All central heating and cooling systems should have an air filter, but the filter can be harder to locate on some HVAC units than others. The air filter is usually located in the return air duct or blower compartment before the return air reaches the air handler. This allows the filter to clean the air coming from your house before it enters the HVAC unit.

Common locations for air filters in HVAC units include:

On horizontal HVAC units with the return duct attached to the side of the air handler, the filter often fits in a slot on the return air (intake) side of the unit.
On vertical air handlers with the return air duct entering on the top of the air handler, the filter often slides into a slot above the HVAC unit.
On vertical air handlers with the return air duct entering below the air handler, the filter often fits in a slot located below the HVAC unit.
On other HVAC systems, the air filter may be located behind the return air grill on a wall in your home.
On HVAC systems with a return in each room, there may be an air filter behind each of the return grills.

Variables that Affect Your Air Filter

Many other factors contribute to the longevity of your air filter:

Home size. Larger homes circulate larger amounts of air which means the filter may need to be changed more frequently than those in smaller homes.
Air quality. If you live in a bigger or busier city, the air in your home may be more polluted with excess smog, dust and debris. This can make your air filter work overtime, which means it will need to be changed more often.
Pets. Since common household pets can shed and track in dirt from outside, you’ll need to change the filter regularly to keep it clear of pet hair and dander.
Allergies or medical conditions. Homeowners with severe allergies, asthma or other respiratory conditions should consider changing the air filter more often than usual to prevent flare ups.

How often should I clean a washable / permanent AC filter?

There is no one-size-fits-all answer.

The life of your filter depends on your environment and the type of filter you have installed. To put it simply, there really is no concrete answer to this question. Certain things such as:

the number of people who live in your home
if there are pets in the house
if there is a smoker in the house
if you leave the windows open
if you have pollen bearing trees or plants in the neighborhood
if you live in an area with a lot of dampness
if you live in an area that is dry or arid
plus many others

If several of these factors sound familiar, you?ll likely experience a quicker loading of particles on your filters and will consequently have to change it more often.

A good rule of thumb is to check your filter every month.

If you can hold the filter up to a light and not see through it, it is time to change your filter. At an absolute minimum, you should change your filter every three months. A clean air filter will also prevent dust and dirt from building up in the system, which could lead to expensive maintenance and utility bills.

Air Filtration Lexicon

EFFICIENCY

The ability of a device to remove particulate or gaseous material from a stream of air by measuring the concentration of material upstream and downstream of the device.

DURABILITY

Ability to retain dust in the filters with the least possible harm to the flow of air.

RELIABILITY

Filter capacity to perform its function well thanks to a construction of superior quality.

Micron OR MICROMETER (ΜM)

Unit measuring the length of the international system of 10-6 meters, which corresponds to a millionth of a meter.

Bag filters

Filter whose filter layer is in the form of polyester or fiberglass bags.

Pleated bags

Generally a filter consisting of a mixture of cotton and polyester or synthetic media folded several times to increase the filtration area.

Cleanrooms

Airtight enclosure in which the properties of the atmosphere (temperature, hygrometry, content of particles and micro-organisms, pressure and movement of air, etc.) are controlled.

Heat Pumps

How do I know if I have a heat pump or an air conditioner?

Are you ready to do some simple detective work? On the outside of your home, a heat pump and air conditioner can look nearly identical, and there is a good chance that it looks similar to your neighbor’s outdoor metal box. Although a heat pump provides both heating and cooling to your home, there is a simple way to determine if you have a heat pump by testing the unit in heating mode.

From your thermostat or control system, turn the “heat” ON. Once you feel the heat coming from your return vent, head outside to observe that metal cabinet. If it is operating and you don’t pay a gas or propane bill, you most likely have a heat pump! Case closed!

What is the lifespan of a heat pump?

It’s tough to determine the actual lifespan of a because there are many factors that contribute to its overall performance — maintenance schedule, filters changes and proper installation are just a few. Location and operational hours may also impact the longevity of a heat pump. For example, if you live in an area with long, cold winters, a heat pump will run more than in temperate climates. The same goes for warmer climates.

If you are looking for peace-of-mind, be sure your installation technician provides a limited warranty for their work and is qualified, experienced and recommended by a trusted source. Additionally, research the manufacturer’s available limited warranties, registration requirements and coverage’s for your specific heat pump.

Do I have to cover my heat pump in the winter?

No, do not cover your heat pump in winter! To function properly, a heat pump needs to pull in the outdoor air through the side vents and exhaust through the top of the unit. If you cover your heat pump, it may not operate as designed and may cause damage to the system.

Why are some rooms colder or warmer than others?

Your HVAC dealer should have properly sized your for your specific home during installation. If your heat pump is not sized correctly, it may not be able to generate the capacity required for your space or shut off before the entire house reaches the desired temperature.

But if your heat pump is sized properly, your home may have a duct issue. A poorly designed duct system may results in poor airflow, leaving some rooms colder or warmer than others. If your ducts aren’t sealed properly, or an air leak goes undetected, airflow may pass through your system unevenly. To properly determine the specific cause of a warm or cold room, contact your licensed professional HVAC dealer.

When do I need to schedule maintenance for my heat pump?

Since your heat pump is designed to heat and cool your home, it may be operating year-round. Depending on your climate, it’s a good idea to schedule a cooling checkup in the spring and a heating maintenance service call in the fall. Many dealers offer pre-season specials on inspection packages during their typical slow times of the year. Seasonal preventive maintenance on your heating and cooling system may guard against many unexpected failures and could maximize the lifecycle of your heating or cooling unit. So, if you have determined that you have a heat pump (see #1), be sure to schedule pre-season maintenance.