media filter and effect on heating/cooling bills?

[DJCooleo]

sorry, this is a newbie ? but what effect would placing a media filter be on bills? Does it decrease efficiency by having to push through the thicker filter? Are media filters worth it (currently just have the standard filter).

[amd]

All filters restrict airflow.

For a given level of filtration, media filters are far less restrictive than their 1" counterparts due to higher surface area.

The objective of using a filter is to keep the equipment clean; the lowest level of filtration which can keep dust from accumulating on blowers and coils should always be used. (Fiberglass MERV 1-2 for conventional/mid efficiency furnaces with no a/c, maybe Merv 5-8 for high efficiency furnaces and a/c or heatpump systems)


On air handlers/furnaces with standard multi-speed/belt drive blowers, filters reduce air flow resulting in less efficient heating or cooling. (lower airflow = less work = lower motor amp draw but higher overall energy consumption)

On air handler/furnaces with variable speed ecm blowers, the fan speed increases in the presence of a restrictive filter to maintain airflow as the media gets dirty. (Noise and energy consumption increase, motor lifespan declines)

Have a contractor check the external static pressure of your duct system to determine which type of filter is appropriate.

[sktn77a]

The objective of using a filter is to keep the equipment clean.

Well, that's one objective.

[yourairman]

sorry, this is a newbie ? but what effect would placing a media filter be on bills? Does it decrease efficiency by having to push through the thicker filter? Are media filters worth it (currently just have the standard filter).

There are several things to factor as this is not a yes or no answer. First of all is the airflow ok with the standard filter you have in place. And by ok I mean is the system moving the amount of air it is designed for. The biggest benefit, from what you are asking, that you will receive is the media filter allows you to trap more dirt without reducing as much airflow. So as the filter loads up with dirt you will stay closer to designed airflow requirements which will keep efficiency closer to what is spec'd. Also you will not strain the equipment as much which will in turn increase the life span.

[amd]

Well, that's one objective.

I haven't seen a single study which demonstrates that furnace filters can improve IAQ.

Bypass HEPA filters aside, residential equipment was never designed to clean the air. Good IAQ is best maintained with proper ventilation and source control.

[yourairman]

I haven't seen a single study which demonstrates that furnace filters can improve IAQ.

Bypass HEPA filters aside, residential equipment was never designed to clean the air. Good IAQ is best maintained with proper ventilation and source control.

I do not to see any study from someone else on this. I have learned from first hand experience. Pretty much all of the new homebuilders expect to run their furnace in the winter in the KC area to heat the home during construction. This plays havoc on a new heating and cooling system. Sometime between 2002-2004 Carrier/Bryant started supplying furnaces with a 4" media filter cabinet in them. The company I was working for at the time decided to use this to their advantage and installed them on every new home and change out. After doing so we did not replace a single blower motor due to failure because of the damage sheet rock dust can do to a system. It does not take a study by a third party to confirm this is a good thing.:)

[adamt56]

(removed)

Admin, please delete

[amd]

I do not to see any study from someone else on this. I have learned from first hand experience. Pretty much all of the new homebuilders expect to run their furnace in the winter in the KC area to heat the home during construction. This plays havoc on a new heating and cooling system. Sometime between 2002-2004 Carrier/Bryant started supplying furnaces with a 4" media filter cabinet in them. The company I was working for at the time decided to use this to their advantage and installed them on every new home and change out. After doing so we did not replace a single blower motor due to failure because of the damage sheet rock dust can do to a system. It does not take a study by a third party to confirm this is a good thing.:)

Yup, that would fall under protecting equipment.

Not sure if media filters actually improve iaq.

Ideally builders shouldn't be allowed to run hvac equipment during construction.

[yourairman]

This post is about efficiency with media filters not IAQ. If you keep dirt and debris out of the furnace blower and indoor coil wouldn't you also be keeping it out of the air supply? The answer is yes. And to answer the original post you will not achieve higher efficiency with clean versus clean. As the filters load with dirt the media filter will not lose as much air flow which in return maintains efficiency of the equipment.

[sktn77a]

Unfortunately, "Indoor Air Quality" is hard to define. If it's hard to define, it's hard to measure. If its hard to measure, then its hard to improve. That's probably why the studies are unable to come to any useful conclusions one way or another.