Mercersburg HVAC Repair Question: What Is Refrigerant Pressure and Why Does it Matter?

Refrigerant is often called the “lifeblood” of mechanical heating and cooling devices like the heat pump and air conditioner in your Mercersburg home.  The main function of refrigerant is to transfer heat through a closed loop system. Various heating and cooling (HVAC) components require different operating pressures to move refrigerant and process the “refrigeration cycle.”

In a nutshell, the refrigeration cycle involves refrigerant, which changes from a liquid to a vapor and back to a liquid again by the addition of pressure and heat. In a refrigeration system, pressurized refrigerant passed through an expansion valve into an evaporator and pressure is reduced. The evaporator is a tube which passes by the area to be cooled. When the pressure drops, this liquid refrigerant changes into a vapor, which absorbs vaporized heat from the area around the evaporator. After the heat is absorbed by the refrigerant, it flows to a condenser, where it passes over coils, absorbs heat from the hot vapor, and condenses back into a liquid. The liquid is returned to the compressor and the cycle begins again.

Today’s refrigerants – especially those used in residential applications – are broken down into two different types, labeled R-22 and R-410A. R-22 is made up of a chlorofluorocarbon (CFC) chemical, which has been found to be damaging to the Earth’s ozone layer. It has been replaced by R-410A, which is made up of a hydrofluorocarbon (HFC) chemical and will eventually be phased out by the year 2020. One of the biggest differences between the two are their operating temperatures. HFCs operate at much higher refrigerant pressure.

This change between refrigerants has created some interesting dynamics and challenges for the HVAC trade. Gauges used to check pressure readings have all changed. And mechanical compressors do not operate with a variety of refrigerants, so the compressors and coils need to be swapped out, too. To give you an example, let’s say you are shopping for a new central air conditioner. Chances are, the new air conditioner will run on R-410A. Your old air conditioner ran on R-22. In order to “match” the compressor in the your new air conditioning unit to the existing indoor coil, you will need to replace the coil and the lines running from your outdoor condensing unit to your indoor air handling unit, which is mounted to your furnace.

You don’t have to understand the refrigeration cycle to know that today’s high-pressure HFC refrigerants require different test instrumentation and retrofitted or upgraded mechanical equipment. The change in operating pressure is a small price to pay for a safer environment.

A Hanover Plumber Guide: Plumbing Noises

Under ideal conditions, you would hear nothing from your Hanover plumbing system except the sound of running water when you turn on the tap. Unfortunately, that is not always what actually happens. In fact, your plumbing can make all types of funny and sometimes alarming noises for no reason that you can easily discern.

For instance, one common plumbing noise sounds like a hard knock or hammer blow. This usually occurs when you turn off a tap and can be rather alarming. Sometimes you can even feel the reverberation of the impact that caused the sound. But why is this happening? Usually, this “water hammer” noise is the result of the dramatic shift in pressure in the system when you suddenly stop the flow of water from a faucet.

This sudden stop creates a kind of shock wave, which then travels back through the pipes and causes the loud knocking sound that you hear. This is easily fixed with a device that is known as a water hammer arrester. These devices help to dissipate the force of the pressure shift and can keep the noise from occurring at all.

There are also all kinds of whistling, squealing and squeaking noises that your plumbing can make under certain circumstances. These types of sounds are often caused by a worn out washer somewhere along the line that is having trouble regulating the flow of water. It can be a little difficult to pin down the source of these noises sometimes, especially if they occur no matter which faucet is turned on. But with a little hunting and trial and error you can usually track down the source.

Rattling sounds are also common and generally occur when your water pipes are not well secured to a rigid surface. If this is the case, the force of the water running through the pipes can cause the pipe to vibrate, creating the sound you hear as it bangs against whatever solid surface is nearby. For problems like this, simply securing the pipes in place better can put an end to all of your rattling issues.

How Do You Measure Your Air Cleaner’s Performance? A Question from Waynecastle

Your air cleaner is designed to keep your family comfortable and healthy in your Waynecastle home, regardless of what contaminants make their way inside. This is important because homes these days are sealed up tightly to minimize the loss of heating or cooling, but as a result they have poor ventilation and frequently they will suffer a buildup of excess contaminants like mold, dust, pollen and dander.

To ensure you get the best possible air cleaner for your home, there are a number of measurements available to help you in the purchasing process. Let’s take a look at a couple of those measurements and what they mean.

MERV

MERV ratings are used to measure the ability of a filter to remove dust from the air that passes through it. The higher the MERV rating, the better the filter works at removing particles. The MERV rating scale goes from 1-16 with 16 being the best possible rating you can obtain from a residential (non-HEPA) grade filter. Usually, they are designed to measure things like dander, dust, smog, wood smoke, spores, bacteria and mold.

When choosing an air cleaner, it is recommended that you look for a MERV rating of at least 8, which is good enough to remove almost all common household contaminants. Higher MERV ratings (17 and up) are found in HEPA filters which are considered among the best on the market, able to remove particles as small as 0.3 microns.

CADR

This rating stands for Clean Air Delivery Rate and is a measurement of how efficiently the air cleaner delivers clean air for tobacco smoke, pollen and dust (the common measurements given for each device). This is not a measurement of the efficiency of the device, so much as the speed of it the device. So, the higher the CADR measurement for all three contaminants, the faster those particles are removed from the indoor air.

The best way to choose a device to match your needs is to look for a CADR rating of at least 2/3 of the size of the room you are cleaning. So, if you are cleaning the air of a 150 square foot bedroom, you should get a device with a CADR rating of at least 100.

When choosing a good air cleaner for your home, make sure you do your research and choose on the best possible option for the space you need to clean. MERV and CADR allow you to do this.

How Often Do You Change Your Filters? A Question From Mercersburg

The core component of any good air quality system in your Mercersburg home is the filter. A good air filter removes almost all of the particles that inundate your home every day – from the pet dander that flakes off of your cats or dogs to the pollen released by plants both indoors and out.

But many homeowners are not aware of when they should change the filters in their air quality system. They know it should be done regularly, but how often and when do you ignore the manufacturer’s recommendation to ensure higher quality air?

Know Your Home

The first thing to consider is the size of your home and what types of contaminants you must deal with each day.  If you don’t have any pets and don’t keep any plants inside, your biggest air quality issue is likely dust, and dust will only fill up the filters quickly if you have a large family.

However, if you have a lot of pets, multiple plants and a large family, the odds are that your filter is being put through the ringer every day – asked to filter out a tremendous number of contaminants. This is when you might need to change the filter in your air cleaner or other HVAC equipment more often.

Changing Your Filter

If you have a high quality HEPA filter, it’ll probably work for as long as it’s rated. Only lower quality filters or those not large enough for the space in which they are installed will fail early. However, keep in mind that a HEPA filter, even when it can last longer, should always be changed no later than the manufacturer’s recommended date.

For most homes that timeframe is about 6 months. However, some higher quality filters can last as long as 12 or even 18 months in the right conditions.