Ventilation

Ventilation (the V in HVAC) is the process of "changing" or replacing air in any space to provide high indoor air quality (i.e. to control temperature, replenish oxygen, or remove moisture, odors, smoke, heat, dust, airborne bacteria, and carbon dioxide). While heating and air-conditioning are relatively straightforward operations, the more complex processes involved in ventilation are the most important in determining the quality of our indoor air.

It is one of the most significant engineering controls available to the industrial hygienist for improving or maintaining the quality of the air in the occupational work environment. It is a means of controlling the environment with air flow. Ventilation also assists in removing unpleasant smells and excessive moisture, introduce outside air, to keep interior building air circulating and to prevent stagnation of the interior air. Ventilation is addressed in specific standards for houses, offices, general industry, shipyard employment, long shoring, and the construction industry. Currently a number of well-identified illnesses, such as Legionnaire’s disease, asthma, tuberculosis, the common cold, influenza, meningitis, hypersensitivity pneumonitis and humidifier fever, have been directly traced to specific building ventilation problems. These are called building-related illnesses and are increasingly predominant in common buildings and workplaces today. Most of these diseases are treatable but some pose grave health risks and may require prolonged recovery times, most often long after the person has left the building.

There are many types of ventilation options –

Single - Sided Ventilation: limited to zones close to the openings

Cross - Ventilation: two or more openings on opposite walls - covers a larger zone than the single-sided openings

Stack Ventilation: Buoyancy - driven gives larger flows

Windcacthers: Wind and buoyancy driven-effective in warm and temperate climates

Solar - induced Ventilation: using the sun to heat building elements to increase buoyancy – more effective in warm climates

Mechanical or forced ventilation: through an air handling unit or direct injection to a space by a fan. A local exhaust fan can enhance infiltration or natural ventilation, thus increasing the ventilation air flow rate.

Natural ventilation: the airflow is due to wind and buoyancy through cracks in the building envelope or purposely installed openings.

Mixed Mode Ventilation or Hybrid ventilation: uses both mechanical and natural ventilation processes. The mechanical and natural components may be used in conjunction with each other or separately at different times of day.

Mechanical exhausts control odors and humidity in kitchens and bathrooms. Ceiling, table, floor fans circulate air within a room for the purpose of reducing the perceived temperature because of evaporation of perspiration on the skin of the occupants. When creating an energy-efficient, airtight home/ workplace through air sealing, it's very important to consider ventilation. Unless properly ventilated, an airtight home can seal in indoor air pollutants. Opening doors, windows, and using ceiling fans are all ways to maximize natural ventilation and reduce the risk of airborne contagion. Natural ventilation requires little maintenance and is inexpensive. Ventilation also helps control moisture, which is another important consideration for a healthy, energy-efficient home.

Good ventilation is matter of great criticality, ISO 16813:2006 is one of the ISO building environment standards, applicable to new constructions and the retrofit of existing buildings.  “It considers the need to provide a healthy indoor environment for the occupants as well as the need to protect the environment for future generations and promote collaboration among the various parties involved in building environmental design for sustainability.”

If you or others at your home/office are experiencing health or comfort problems that you suspect may be caused by indoor air pollution, you can talk to other family members or colleagues to see if similar problems are being experienced by others and contact a HVAC specialist immediately.

Never be a victim of cheap HVAC services

When you entrust the job of repairing or maintaining your HVAC system to a contractor who offers low cost services, you need to think twice before handing it to him. These so called low cost deals are often underhanded practices of unscrupulous HVAC companies who employ contractors that are not professionally qualified, trained or possess the skill of undertaking repair or replacement on your heating and air conditioning systems. We all know that a great doctor is never cheap, so it goes to say that contractors who offer quality services for your HVAC units are definitely not giving you a very cheap bill.

Most homeowners have been victims of cunning marketing strategies put for by the salesmen of unreliable HVAC service companies. These companies have in fact become gimmicky and dishonest when it comes to offering their services and sales. This is especially prevalent in the residential and commercial service industry. The salesmen are employed intentionally by these HVAC companies. They do not have enough experience in the HVAC trade, but the company believes in them to generate more sales for their HVAC equipment and product line. This according to them makes up for their lack of technical expertise. There are also reports carried out that justify that these HVAC companies train their staff by conducting mock sales interactions that teaches them to hook the customer and avoid technical questions.

If you have been a victim of all these, you are not alone. There are probably thousands of homeowners across the country who have been duped by these conniving salesmen, whose only purpose is to generate profits and not worry about the customer’s requirements. These so called contractors are shrewd enough to catch you at your most vulnerable point, especially when you are in desperate need of repair or replacement of your heating/air conditioning unit.

The point we are trying to make here is that homeowners and businesses need to seriously consider what kind of a service company they bring to their front door. A reliable HVAC company cares about the customer’s requirement and takes extra precaution when it comes to selling their product or when offering any service. Only then will your HVAC unit be guaranteed to a long and efficient working life, free from unnecessary repairs. It is not difficult to find a reputable company in your area who offers quality services. All it takes is a little common sense and the willingness to communicate with the company you are planning to approach. Just as you would get a lawyer’s second opinion in a trial, you need to apply the same strategy in this case. Then you can be assured that your HVAC unit is in good hands.

The same applies to choosing the right product or equipment for your home or office. You can’t just walk into a store, select a unit and then walk out. It takes a lot more time and effort to finding the perfect heating and cooling system that is the right fit for your home and your budget. Make sure that the unit is of the right size. For this, you need to measure the total square footage area of your indoor space. Also, ask your dealer to conduct an energy analysis of the building to determine the operating cost. This process will also help in preventing uneven temperature fluctuations and air stratification indoors by installing products for that particular purpose.

Saving Energy this Winter

To keep your energy bills under control this winter, make sure you properly prepare your home for the cold weather. This will help you save energy, money and keep your family comfortable indoors when the temperature drops. There are no cost and low cost ways to save on your energy bills this winter. Have a look at them below for some helpful tips.

Heating – For optimum heating and warm comfortable conditions, install a programmable thermostat. This way, you can lower the settings when the house is unoccupied and also during the night when everyone is asleep. You can save 10 to 20 percent on your heating bill by lowering the temperature by 10 degrees. You can also save on energy use by upto 3 percent if you wear socks and sweaters indoors to keep warm and then lowering your thermostat settings. However make sure that the thermostat is installed properly, programmed correctly and not situated in a heated area. Only then the thermostat can sense the average temperature indoors. Make sure to inspect your air filters and ducts before the cold season, if you have a forced air furnace. Replace or clean them to prevent dust build up and increase heating efficiency. Indoor heating can make the air inside very dry. For this, you can get a humidifier installed to add moisture to the air. Even if the thermostat is set for a lower temperature, heated air with moisture will make the indoor area feel warmer and more comfortable. If you need supplemental heating, you should never use a traditional fireplace. When the fireplace is not in use, you need to close the damper and seal the opening. That’s because the fireplace sucks warm conditioned air out of your home’s indoors to fuel the fire and then exhausts it through the chimney. Your furnace has to do double work by turning itself on and then replacing that warm air. 

Windows and doors – To prevent cold air from entering and warm air from escaping, you need to keep your windows tightly shut and doors closed as much as possible. Look for drafts, cracks and openings in your windows and doors. Have someone help you in checking the doors by having them stand on the other side and shine a flashlight around the door’s perimeter. If you can see the light through any openings or cracks, then the door definitely needs to be sealed. Another thing you can do is to hold a piece of paper between the door’s frame and then shut it. If you are able to pull the paper out without tearing it, then it needs to be weather-stripped. You can caulk windows as much as needed. Install storm windows, open up south facing drapes and curtains during the day to let in warm sunlight and close them at night to keep the heat in. Other things you can do is to seal off all unused rooms in your house as long as it is not the place your thermostat is located and is less than 100 square footage in area.

Water heater – You can save a lot on energy bills by making sure to set the temperature of your water heater no higher than 125 degrees. To remove sediment that will interfere with the efficient working system of your heater, drain off a bucket of hot water from it annually. If the water heater is older than 5 years, you can install a water heater blanket. Also it makes sense to insulate pipes around the heater as this will be really helpful if it is installed in an unheated space.

Other ways to lower energy costs – Consider upgrading your home’s insulation if it is less than R-38 in rating, which is the standard requirement for homes. You should also check your attic’s insulation and seal areas which could have leaks like basements, garages and crawlspaces. If you are using special lighting for the holidays, make sure you buy new LED holiday lights. Dispose of older strings of incandescent lights as they can use up to 99 percent more energy than new ones. Switch off holiday lights before going to bed or when you are leaving the house. Make sure you don’t use them for more than six hours in a day to keep energy usage down. For this you can install lighting timers to make them turn on or off automatically.

Heating and Cooling Of Yesteryears

Do you wonder how people kept themselves warm or cool as the case may be in houses of yesteryears? No one can imagine themselves living in conditions with an air conditioner in summer and a furnace/heater in winter. The first thing that flashes through your mind is,How can I live inside my home when it is so hot or so cold? 

About a century ago, people were accustomed to living without heating and air conditioning units. There was no technology or the HVAC systems that we have and are taken for granted during these past few years. Electricity was also not available and yet, people lived comfortably and remained healthy. Houses were designed to keep cool in summer and warm in winter. To know about the way houses were designed and built hundreds of years ago, take a look at some of the essential features that were addressed by architects.

• Natural resources – For those who lived centuries ago, the absence of electricity did not pose a problem for keeping warm or cool during the changing seasons. Houses were naturally insulated thanks to the structure and materials used to build them. Every home had a fireplace which was religiously lit at dusk to keep warm. The fireplace would always have sufficient amount of logs that lasted the entire night. The warmth which was derived from the fire would be absorbed by the walls made of stones or bricks, which had strong energy retention capacity to keep the warmth inside and the cold out.  
• Structure – The structures of old houses speaks a lot about keeping the inhabitants comfortable indoors. The walls were very thick which prevented warm air from seeping out and the cold air from entering inside. Some homes had double walls for extra insulation and it was not an uncommon sight to see people building wooden walls inside and concrete walls outside. The double wall served as an excellent insulator for the home.
• Bricks – Walls that were built by bricks were thick and very large. Another interesting fact is that bricks take a long time to heat and also a long time to cool. That’s why, during winter months when the house is warmed, bricks can retain the heat without losing it too quickly. This of course functions the other way during summer when hot air is prevented from entering inside.
• Glass – Glasses were placed in homes all around the south side during the construction process. Sunlight enters the house from the south side so the rays would penetrate through the glass and warm the indoors. This is indirect heat energy from the radiation of the sun’s rays used to keep the house warm and cozy. Temperature inside slowly increases as the warmth of the sun’s rays moves indoors to every area. Drapes and thick curtains are also used to retain heat inside without losing it too quickly.
• Paint – The difference with painting your home with dark colors compared to that of light colors is that dark colors absorb heat more efficiently and quickly. Light colors reflect sunlight and thus cannot retain the heat from the sun’s rays. That’s why old houses are usually painted with dark colors so that the radiation from the sun is absorbed outdoors and the dark color of the paint locks the heat in.
• Heat retention methods – To reduce heat transfer indoors, windows play an important role. Cement filling was used to seal the gaps between the window frames to keep warm air inside and prevent cold air from seeping in. This helped in heat retention and decreased air flow between the outside and inside. Ancient History says that the Romans used advanced heat retention methods to keep warm. They used hypocausts which was an under floor heating method where floors were raised above the surface of the ground by pillars with a layer of tiles, a layer of concrete and then another layer of tiles on top. Spaces were then left between them so that smoke or hot air from the furnace would pass through these enclosed areas and then out through the roof. This ensured that there was no pollution in any interior areas of the house but only efficient heating.

Significance of maintaining the Air Conditioner during winter

The air conditioning is one of the most overused electronic gadgets in any household. Since it starts running from spring, the machine hardly gets any rest throughout the summer and is switched off only when winter approaches. Seldom people bother about its maintenance until an emergency situation arises. This is turn results in additional expenses and hassles too. Rather than waiting for an emergency to happen, it is advisable to take proper care of the air conditioner during winter so as to ensure its peak performance during the spring or summer months. If this explanation doesn’t sound motivating enough then discussed below are few reasons which should encourage you to maintain the AC unit in spite of the freezing weather.

Ø  Utilize the winter month to carry out a thorough inspection of the cooling unit

If last summer you were troubled with exorbitantly high electric bills, then utilize this resting period to take a close look at what is bugging your cooling unit. Is it because of accumulation of too much debris or a clogged filter which is causing the problem? Do you feel any component of the AC unit is damaged or rusted and hence causing over expenditure? Then it is time to give a call to the HVAC unit so that they can do a detailed inspection of the air conditioning system and suggest necessary measures.

Ø  Regular maintenance of the AC unit ensures prolonged life and round-the-year smooth performance

If you have invested thousands of dollars just a year back to purchase the new air conditioning unit, then it is natural that you would like to retain it for few more years and that too in perfect condition. By following a proper maintenance regime, it is possible to ensure a smooth and extended performance of the AC machine. In fact specialists suggest inspection and tuning of the cooling unit by an HVAC professional, at least once or twice in a year. So why not schedule the winter time for yearly inspection thus ensuring the AC runs uninterrupted during peak seasons!

Ø  Make sure that the air conditioning unit looks its best

While you just can’t avoid having an AC condenser which looks large and bulky, the best you can do to improve its look is by keeping it dirt and rust free. Clean and dry it thoroughly and then cover it up properly before the winter sets in. This way you not only protect the machine from extreme weather and critters but also make sure that the unit looks spotlessly clean when you uncover it to use.

Now that you know why you need to winterize the air conditioner, the next thing to decide is how to do so. While some basic cleaning acts or covering the AC unit can be performed at home, for specialized assistance you should get in touch with an Air Conditioning specialist. One good idea is to look for a certified service provider which has all-round expertise in installation and maintenance of cooling units.