Today I'm going to discuss two aspects of Comfort from heating and cooling systems Temperature and Humidity. This is the first of a series of articles on this subject.

 

Heating, ventilating, and air conditioning (HVAC) systems used in residential, commercial, and industrial buildings provide comfort to occupants. A feeling of comfort results when temperature, humidity, circulation, filtration, and ventilation of the air are controlled. HVAC systems are designed to fulfill comfort requirements with maximum efficiency.

HVAC systems contain mechanical, electrical, and chemical components. Mechanical components include all moving parts. Electrical components include blowers, compressors, and controls. Chemical components include fuels and refrigerants. Precautions should be taken and safety rules followed when working with HVAC systems.

COMFORT

Comfort is the condition that occurs when a person cannot sense a difference between themselves and the surrounding air. Comfort occurs when no differences exist or undesirable conditions have been corrected. The five requirements for comfort are proper temperature, humidity, circulation, filtration, and ventilation. See Figure 1-1. Discomfort is the condition that occurs when a person can sense a difference between themselves and the surrounding air. It can occur when any of the five requirements for comfort are not met.

Temperature

Controlling the temperature of the human body is an important physiological function. Physiological functions are the natural physical and chemical functions of an organism. The body produces energy by digesting food. Some energy is used for normal living processes, some is stored, and some is used as thermal energy (heat). Physiological systems regulate body temperature to maintain comfort.

Normal body temperature is 98.6°F. The body has natural heating and cooling systems to maintain this temperature. These systems control heat output by responding to the conditions of the air according to the internal temperature of the body. The body responds by controlling blood flow at the surface of the skin, radiating heat from body surfaces, or using evaporation of perspiration from skin. Evaporation is the process that occurs when a liquid changes to a vapor by absorbing heat. When the body is clothed, the body's temperature control system provides comfort at an air temperature of approximately 75°F. If the air temperature varies much above or below 75°F, the body begins to feel uncomfortably warm or uncomfortably cool.

Signals (electrical impulses) from different points in the body are sent through a network of nerves to the hypothalamus, a gland in the brain. The hypothalamus regulates body temperature by controlling blood flow to capillaries (tiny blood vessels) located in the skin. Capillaries regulate perspiration flow to the surface of the skin. If the body temperature rises, blood flow to the skin increases. Blood carries heat to the skin, where it is given off to the air. A person who becomes overheated also becomes flushed because the blood flow to the skin increases. If signals indicate the body is cooling off, the system reduces the cooling effect by allowing less blood flow to the skin. In cold weather fingers and toes become cold before the rest of the body because blood flow to these areas is reduced. Cold areas also appear pale because of the reduced blood flow. Temperature control in buildings is provided by warm air from heating equipment or cool air from air conditioning equipment. Heating equipment supplies the proper amount of heat in cold weather to offset heat loss from a building.

Heating equipment is rated in Btu per hour (Btu/hr.), A Btu (British thermal unit) is the quantity of heat required to raise the temperature of 1 lb. of water 1°F. Air conditioning equipment supplies the proper amount of cooling in hot weather to offset heat gain to a building. Air conditioning equipment is rated in Btu per hour or ton of cooling. A ton of cooling is the amount of heat required to melt a ton of ice (2000 lb.) over a 24-hour period. One ton of cooling equals 288,000 Btu per 24-hour period or 12,000 Btu/hr. (12,000 x 24 = 288,000).

The operation of heating and air conditioning equipment is a function of temperature control in the HVAC system. For maximum comfort, temperature control equipment maintains air temperature in a building within 1°F or 2°F of the temperature necessary for comfort.

Humidity

Humidity is the amount of moisture (water vapor) in air. Humidity is always present in air. A low humidity level indicates dry air that contains little moisture. A high humidity level indicates damp air that contains a significant amount of moisture.

Relative Humidity. Relative humidity is the amount of moisture in air compared to the amount of moisture the air would hold at the same temperature if it were saturated (full of water). Relative humidity is always expressed as a percentage.  For example, air at 50% of relative humidity holds one-half of the amount of moisture it would hold at the same temperature if it were saturated.  Air at 60% relative humidity holds 60% of the amount of moisture it would hold at the same temperature if it were saturated.  The amount of moisture required to saturate the air changes as the dry bulb temperature changes.  In addition, the relative humidity and the capacity to hold moisture change as the dry bulb temperature changes.  Humidity is important in determining comfort.

Humidity affects comfort because it determines how slowly or rapidly perspiration evaporates from the body. The flow of perspiration is controlled by the cooling system in the body, which regulates body temperature. Evaporation of perspiration cools the body. The higher the relative humidity, the slower the evaporation rate. The lower the relative humidity, the faster the evaporation rate. For example, with no temperature change and an increase in relative humidity, a person feels warmer because of the slower evaporation rate. With no temperature change and a decrease in relative humidity, a person feels cooler because of the faster evaporation rate. A steam room is an example of an area with high temperature and high relative humidity. These conditions cause the body to have a high perspiration rate with a slow evaporation rate. A steam room is an Heating, ventilating, and air conditioning (HVAC) systems used in residential, commercial, and industrial buildings provide comfort to occupants. A feeling of comfort results when temperature, humidity, circulation, filtration, and ventilation of the air are controlled. HVAC systems are designed to fulfill comfort requirements with maximum efficiency.

Air Conditioning Phoenix AZ (480) 238-5151 Service Star Air Conditioning...

Do I Really Need to Clean My Air Conditioner Coils?

 “Do I Really Need to Clean My Air Conditioner Coils?” I hear this from home owners all the time. I know that they think this is just some needless service Air Conditioning Contractors have come with up to make more money. On the other hand some business owners do know the value, coil cleaning is the “Green Thing to Do’, because it saves energy costs. We receive requests just for coil cleaning after a dust storm.  When we get the occasional “Mud Storm”, a combination of dust with monsoon rain, an air-conditioning coil can be coated with mud, sometimes blocking air flow completely.

Just .042 inch of dirt on a heating and cooling coil can lead to decreased efficiency of 21%, according to the Environmental Protection Agency (EPA). 21% efficiency reduction is substantial and that is with only a thin layer of dust and dirt. This dirt also causes your air conditioner or heat pump to work harder which can cause parts to wear out faster and lead to more expensive repairs or premature replacement of your unit.

When our cars get dirty after a storm we wash them. When our patio gets dirty after a storm we clean it. Well, our air conditioner and heat pump coils are outside and get all the same dust, dirt and debris trapped in between the fins of the coils. Washing the car or the patio might raise your water bill a little for the day, but a dirty A/C coil cost you more on your electric bill for months.

We spray a special solution on you’re A/C coil to get to the dirt trapped between the fins but does not damage the other components. This is a job for a professional.  

So in conclusion, when the A/C serviceman advises you that your coil needs cleaning, it is needed to keep your unit operating efficiently to reduce energy costs and increase the life of your unit.

Service Star Air Conditioning, Plumbing & Electrical is located in the Phoenix Metro area, in the middle of a desert, which presents us with some regional conditions that are different from other areas like the Midwest or Coastal regions. There are other special situations I will be addressing in future blogs, so check back often for more informative articles.

Remember, you can always call us at 480-238-5151 to get answers to all your cooling, heating, plumbing & electrical questions, or check our website, www.servicestarac.com .  You can also follow us on Facebook and Twitter.

PROTECT YOUR AIR-CONDITIONG UNIT FROM COPPER THIEVES WHILE ON VACATION

Thieves are out there looking for copper to steal and your air-conditioner or heat pumps are prime targets.  No one wants to come home from vacation to no air-conditioning.  Most of us are looking forward to a good night’s sleep in our cool and comfortable bed.  The loss of air-conditioning can also be deadly to pets and plants.  Plus, it may take several days to have the unit replaced.

ServiceStar Air Conditioning doesn’t want you to be another victim of this crime and we have some suggestions to help protect you.  We all know about stopping the newspaper and the mail plus leave a light on to make the house appear occupied, but there is more that needs to be done today.  Don’t post your plans publicly on sites like Facebook or Twitter, more than your friends and family are watching.  Lock the gates to the backyard.  An additional precaution is to have your Alarm Company put a monitoring sensor or anti-tamper device on the outer shell of your air-conditioner or heat pump.  An Alarm Sticker on the cooling system may also be a deterrent to thieves.   You should also padlock you electrical breaker panel and the disconnect box near your cooling unit when going away.

Remember, you can always call us at 480-238-5151 to get answers to all your cooling, heating, plumbing & electrical questions, or check our website, www.servicestarac.com.  You can also follow us on Facebook and Twitter.

If you are planning on purchasing a home or have just moved into home, here are some items to consider.

When you move into an existing home, there are many pieces of equipment that you may not want to keep. Some of them are just old and poor quality, while others cost you a lot of money and others still may be dangerous to you or your children. Before you settle into your space, make sure you have every one of your systems checked thoroughly for potential problems including inefficient heating, dangerous parts or environmentally unfriendly components.

Energy Cost

Number one on your list should be the cost of the energy needed to run your HVAC equipment. Furnaces and air conditioners in particular have become much more energy efficient in the last 10 years so older systems routinely cost much more money to operate than new ones. That doesn't mean you should immediately rush out to replace your old furnace, but if it isn't working properly or it's costing you more money than you'd like, the cost benefit of a new system is often worth checking into.

Other things to check include your insulation, your air quality system, your ventilation system and anything used to heat or cool food in the kitchen - all of which may be less efficient than you might like.

Ozone Depleting Refrigerants

Older appliances like air conditioners may still use ozone depleting refrigerants that are no longer considered safe (or in some cases legal) for home use. If this is the case, not only does your system probably have a very low SEER rating, it likely isn't good for the environment or your own health. So, have your system replaced as soon as possible to avoid potentially negative side effects.

Dangerous Equipment

Finally, there are those pieces of equipment that are dangerous. If you find that your furnace has rust around the edges, your gas lines are kinked, or you have a dangerously out of date heat pump in your backyard, it may be time for some replacements. In general, these systems will last for years longer than they are considered safe and while you probably cannot buy a house without a working and safe furnace and air conditioner, you should still have them inspected carefully and replaced as soon as possible if you suspect problems.

Good HVAC equipment is hard to come by - if your home has it already, you're in luck, but if you happen to move into a place with poor quality materials and equipment, have it replaced as soon as possible. Your health and wallet will both benefit greatly.

What is the purpose of the air conditioning?

 

There are several routes you can take with your cooling

 Cooling your entire home.

If you want to have cooling throughout your entire home, a traditional air conditioner could be a good option for you.  Cooling for your entire home plus heating in the winter with significant energy savings, many customers choose to upgrade to a heat pump. Since it only provides cooling during the summer and also only heating in the winter along with significant energy savings.

 Cooling for a room or two.

Regardless or not you already have air conditioning, chances are that you have a few rooms that get warmer than you would like during the summer months. A great way to fix that is to provide room spot cooling through ductless mini-split systems; they will cool down the spaces that need it with much more energy savings than a traditional air conditioner.

 What is the size of your home?

A larger home means that a larger air conditioner is necessary, which marginally increases the cost.

What is the heat gain within your home?

 Heat gain is how much heat your house holds in as the day gets warmer. Insulation, windows, and age of the home contribute to the calculation.

For example, a poorly insulated home with a southern bank of windows would gain more heat throughout the day than a well-insulated home with a bank of northern windows. The more heat your house gains, the larger the air conditioning unit that is needed to be able to counteract that heat.

What is the condition of your duct work?

You should always get your ducts sealed and insulated if you have leaks or cracks in them. If you don't, your cooled air is released into your crawl space or attic instead of your home wasting energy and causing the air conditioner to run longer. Some companies compensate by giving you a larger unit. Our company will seal and insulate the ductwork for you.

What efficiency are you looking for?

 Just like you can get cars with great gas mileage or poor gas mileage the same thing goes for air conditioners. Air conditioners have various seer ratings, anywhere from 12 to 23, with 13 being the lowest energy efficiency.  With a 23 seer air conditioner you're going to have lower utility bills, which will save you money over time, but you also have a higher cost up front for the unit itself.

After taking all of those factors into account, a new air conditioning system will cost anywhere from $3,500 to $10/000 depending on what type of system you ultimately chooses to get. A visit with a comfort adviser will help you determine. What is best for your needs and what will fit within you budget.

Welcome to ServiceStar Air Conditioning & Plumbing Co. New Blog

Hello and welcome to ServiceStar Air Conditioning & Plumbing Co. new blog. We will be talking about A/C, heating, plumbing and electrical problems and issues. There will also be general safety information or whatever else you want to talk about. If you have questions, we will try to answer them.