Ducted Heating & Cooling

Your first defense against indoor air pollution (after reducing emissions at the source) is your Heating, Ventilating and air conditioning (HVAC) filter, your “furnace filter.” The EPA indicates that, whether installed in the ducts of HVAC systems or used in portable air cleaners, most air filters have a good efficiency rating for removing larger particles when they remain airborne. These particles include dust, pollen, some molds, animal dander, and those that contain dust mite and cockroach body parts and droppings. (Ye-uuck!)

But because these particles settle rather rapidly from the air, air filters are somewhat ineffective in removing them from indoor areas, the EPA says. And although human activities such as walking and vacuuming, or the high-velocity air exiting supply vents, can re-suspend particles, most of the larger particles will resettle before they enter the HVAC system or portable air cleaner – so they won’t be removed by a particle air filter.

The appropriate type of particle removal air filter can be chosen by looking at its Minimum Efficiency Reporting Values (MERV) rating in removing airborne particles from the airstream that passes through it, and the EPA notes that MERV ratings can also be used to compare air filters made by different manufacturers.

“What MERV you need will depend on your system,” Costanzo said. “And we often use Honeywell high-efficiency filters.” He suggested visiting www.honeywell.com for information.

Because of their compact design, particle air filters that use “impregnated media” are available for residential HVAC systems and portable air cleaners. They use sorbent particles of carbon, permanganate alumina, or zeolite incorporated into fibrous filter media, the EPA says.

Such filters provide a combination of particulate and gas-phase filtration with a minor increase in pressure drop across the filter. Their use in an existing HVAC system does not require extensive or expensive modifications to the system. However, the EPA cautions that their useful service life varies according to indoor pollution concentrations and exposure time.

But Costanzo said it’s a good idea to “replace your filter every 30 days with a high-efficiency filter.”

He added that this is especially important if you live near a freeway and after brush fires that put a lot of soot into the air. He also recommends regular visual inspections of ventilation ducts, evaporative coils and blowers. When dust builds up on these it reduces the efficiency of your HVAC system and also reintroduces these particles into the air inside your home.

Flat or panel air filters with a MERV of one to four have low efficiency on smaller airborne particles, but reasonable efficiency on large particles when they remain airborne, the EPA says. These filters have low airflow resistance and are relatively inexpensive. They are commonly used in residential furnaces and air-conditioning systems, and they are often used as pre-filters for higher efficiency filters.

“A MERV of one to five works well without getting clogged,” Costanzo said.

Pleated or extended surface filters with a MERV of five to 13 have higher efficiency ratings than panel filters. These medium-efficiency filters are reasonably efficient at removing small-to-large airborne particles. The airflow resistance of these filters does not necessarily increase as the MERV increases. Costanzo explained that if your filter has too much resistance to airflow it will reduce the efficiency of your system in its heating and cooling. He added that most home systems are not designed for ultra-high efficiency filters because of this pressure loss.

“I’d recommend a MERV of one to five for most home use,” he said. And he explained that the prices of these filters will vary according to their size.

Better air
There are three basic strategies to improve indoor air quality, according to the EPA: source control, improved ventilation and air cleaners.
Source control: Usually the most effective way to improve indoor air quality is to eliminate individual sources of pollution or to reduce their emissions. Some sources, such as those that contain asbestos, can be sealed or enclosed; others, such as gas stoves, can be adjusted to decrease the amount of emissions. In many cases, source control is also a more cost-efficient approach to protecting indoor air quality than increasing ventilation because increasing ventilation can increase energy costs.

Ventilation improvements: Most home heating and cooling systems, including forced air heating systems, do not mechanically bring fresh air into the house, the EPA says. Opening windows and doors, operating window or attic fans, when the weather permits, or running a window air conditioner with the vent control open increases the outdoor ventilation rate. Local bathroom or kitchen fans that exhaust outdoors remove contaminants directly from the room where the fan is located and also increase the air exchange.

As you might expect, it is important to take as many of these steps as possible to increase ventilation while you are involved in activities that generate high levels of pollutants – such as painting, paint stripping, heating with kerosene heaters, cooking or engaging in maintenance and hobby activities such as soldering, or sanding. And both the EPA and common sense suggest you do as many of these activities as you can outdoors or at least in the garage.

Air cleaners: There are many types and sizes of air cleaners on the market, ranging from relatively inexpensive table-top models to sophisticated and expensive whole-house systems. The EPA indicates some air cleaners are highly effective at particle removal, while others, including most table-top models, are much less so. And air cleaners are generally not designed to remove gaseous pollutants.

The effectiveness of an air cleaner depends on how well it collects pollutants from indoor air (expressed as a percentage efficiency rate) and how much air it draws through the cleaning or filtering element (expressed in cubic feet per minute). As explanation the EPA notes that a very efficient collector with a low air-circulation rate will not be effective, nor will a cleaner with a high air-circulation rate but a less efficient collector.

Eastern Hardware Ltd, a Lowestoft-based sheet metal fabrication company, has been fined £3,000 with £3,000 costs after one of its employees fell through a fragile roof while installing air conditioning ducting.

In the incident in April 2008, Paul Garrod fell a metre through a fragile roof while installing the ducting at Express Composites, in Ellough, near Beccles. He landed on internal steel duct work and suffered significant bruising as a result.

The HSE investigation found that Eastern Hardware had failed to provide adequate information, instruction and training for working at height. They had also failed to undertake suitable and sufficient risk assessments or implement safe systems of work for the job. There was no recognition that there was a fragile roof and suitable work at height equipment was not provided.

“Mr Garrod received significant injuries following this incident, causing him to be absent from work for several weeks,” said HSE Inspector, Julie Jarvey. “Had he not landed on the internal duct work, the fall could have proved fatal.”

Evaporative coolers are preferred to other forms of air conditioning for two main reasons. Firstly, they cost about half as much to install and secondly they consume less energy. It is easy to see, with the two benefits above that using an evaporative cooler makes sense. These air cooling systems work by lowering the temperature of the air that goes through the wet pads, and leads to the evaporation of water. Evaporation, in turn, makes the air cooler.

There are different ways to install evaporative coolers at home or in the office. The installation type of your chosen evaporative air conditioner will depend on the style of the cooler, the size of the area where it will be located, and the climate in that area.

There are two main ways to install an evaporative cooling system or swamp cooler: ducted system and central location installation. An evaporative cooler can be connected to ductwork so that air can be directed to different areas or rooms. This ducted system is necessary for bigger homes or offices with multiple rooms and hallways. On the other hand, the central location installation suits smaller homes.

Experts recommend that you install horizontal coolers that are mounted on the ground because they are less likely to leak and are easier to maintain than down-flow evaporative coolers that are installed on the roofs of houses.

Small and portable evaporative air conditioners are also very popular and are widely available. These cooling systems are simply placed anywhere in a room and do not require any complicated set-up. However, the price you pay for having portability and convenience is a reduced cooling ability.

Portable evaporative cooling systems are less effective at cooling when compared to other evaporative cooling systems. They can lower air temperature by 5 to 15 degrees Fahrenheit and are perfectly suited for moderate climates that don’t experience extreme variation in heat

Many ducted heating systems have problems with animal penetration, most generally caused by rats, sometimes caused by possums and stray cats. The damage can often be extensive and the first time most people discover the problem is in winter when the system gets turned on for the first time, to find there is either no airflow or very poor airflow – or dreadful odours are emitted from the system. We specialise in the repair of all systems penetrated by animals or just simply those that are worn out and need repair. Our advise is for you to turn your system on in February, well before winter, checking for signs of poor or no airflow or unusual odours. The system should then be run weekly for a few minutes to ensure continued effcient operation.

In order to maximize the energy efficient benefits of evaporative cooling technologies it is imperative that regular maintenance is done on the systems. This regular maintenance ensures optimal operating efficiencies and increases the life span of the equipment. One area of maintenance that is important to remember is the evaporative cooling media itself.  Be sure to follow our ten recommendations:

1. Reduce the total number of on and off cycles. By keeping the media from drying out too often the lifespan of the cooling pad is increased.

2. Shade the pads and sump. This prevents the sun from causing pre-mature damage to the media and increases the length of time between change outs.

3. Make sure that the pads are completely dried out once every 24 hours unless of course the building is a 24/7 operation.

4. Optimize the water bleed off of the system

5. If possible completely drain and cleanse the entire water distribution system once every three months.

6. DO NOT use abrasive cleansers or water treatment chemicals. Make sure the media is free from other harmful contaminants as well such as toxic fumes and dust.

7. Double check to make sure that the amount of water being run over the pad is in accordance with the manufacturers recommendation.

8. DO NOT allow dry spots on the evaporative cooling media.

9. Regularly check for and fix any leaks in the water distribution system.

10. Have a regularly scheduled maintenance routine where the water filters are cleansed

Here are some of the more important questions you need to ask if you are considering buying air conditioning. First, get references from happy customers.If the air-conditioning experts you are considering cannot give you references and testimonials, forget them.

How many rooms do you want air-conditioned?  If you have a large family and use every room in the house regularly then it may make sense to go for a centralised air-conditioning system.However if you live in a six room house but only two are used regularly, there may be savings in both initial costs and running costs by air conditioning only those two rooms.

If you choose centralised whole house air-conditioning, be sure to discuss with your air-conditioning how flexible the system will be once installed; can you easily shut off rooms not in use, for example? Also, the appearance of your air-conditioning may be a factor.Whole house ducted air-conditioning may look much better – window mounted air conditioners are never a work of art. In any event, make sure you discuss with your air-conditioning expert first how pleasing it will look once installed.

What will the running costs of be?  This is something you may want to consider alongside environmental aspects.Your commitment to the planet may make it worthwhile to “Go Green”.When considering running costs, you also need to consider the environment into which you are placing the air-conditioner.For example, are your windows tinted and / or is your roof insulated?If not, doing these things will result in significant savings in the cost of running your air-conditioning?

Check out the Servicing requirements.How often does your air-conditioner need servicing and is it an expensive call out?  Filters are an important part of air-conditioning and need regular maintenance; how quick and easy is this?Also check out callout times; you do not want to wait three days to get the problem fixed if you are sweltering in oppressive heat

Reliability.Remember – Quality Costs; Buying the cheapest  air-conditioner you can get may turn out expensive in the end.  Use the Internet to do due diligence on the various air-conditioner makes and types, and once you have selected your air-conditioner, you should then “Google” the make and model + complaints / problems.

What sort of guarantee will you get from the various air conditioning specialists you approach? Ensure get quotes from at least three air-conditioning companies, including not only the price but also the servicing costs and the guarantee.  And check they have public liability insurance too.

Air conditoning cleans and dehumidifies (removes excess moisture) from the air. It also has the task of keeping the air at the temperature you select. Most people think the air conditioning systems job is to add “cold” air to the room. Actually, there is no such thing as “cold,” just an absence of heat, or less heat than our bodies are comfortable with. The job of the air conditioning system is really to “remove” the heat that makes us uncomfortable, and return the air to the room in a “un-heated” condition. Air conditioning, or cooling, is really a process of removing heat from an object (like air).
Your air conditioners compressor circulates a liquid refrigerant called Refrigerant-12 “Freon,”. The air conditioners compressor moves the Refrigerant-12 from an evaporator, through a condenser and expansion valve, right back to the evaporator. The evaporator is right in front of a fan that pulls the hot, humid air out of the room. The refrigerant makes the hot air’s moisture condense into drops of water, removing the heat from the air. Once the water is removed, the “cool” air is sent back into the room.

Although evaporative cooling can provide healthy and clean air around the home, sometimes it’s not the best solution.

1. How do evaporative cooling systems work?

Evaporative airconditioning works on the principle of water saturation. Air is taken from outside, filtered and moisture is added to it. This ‘moisturised’ air is then blown into the house.

2. External evaporative ventilation

Because evaporative systems use fresh air, the space to be cooled must have ventilation to the outdoor area. This means it’s essential for doors and windows to be open while the system is in use.

3. Noise issues from evaporative systems

Evaporative cooling systems tend to be quite noisy, though some brands are noisier than others. If noise is a problem for you, make sure you research the available brands carefully in order to find the quietest possible system.

4. Are these cooling systems appropriate for all homes?

As evaporative cooling systems are ducted, a house must have a roof cavity large enough to accommodate the ducting. The systems can only go overhead; under-floor evaporative cooling is not possible.

5. Evaporative design styles

The cooling unit is placed on the roof and is not particularly attractive, but taking care with its location can make it less obvious. Units are available in a range of colours, so look out for one that blends in with the tones of your roof.

6. Benefits of evaporative cooling

Evaporative cooling systems pump cool, fresh, temperature-controlled air through the house. They are considered to be environmentally friendly and are good for those who suffer from allergies.