Hint to save on your Air Conditioning/Electric Bills. (Phoenix: fit in, houses)

[Ponderosa]

Originally Posted by LBTRS

I just had an A/C guy come over to check out my units before it gets hot out and he took one look at the filters I was using in my house (A/C & Heating filters) and said they are way too restrictive and costing me $800-$1000 extra a year in energy costs. I've been using the expensive ones that are supposed to filter the air. He said I need to use the cheap "EZ Flow" ones that allow the proper air to move through the system and will do a much better job cooling and heating my home.

Just swapped them out and I'll let you know if it makes any difference over the summer but wanted to pass it on and see if anyone else had information on this?

When I had my AC replaced there were some problems and the factory sent out an engineer. He said the same thing, use the cheapos and change them more often for best air flow and highest cooling efficiency.

[Pink Jazz]

Originally Posted by Ponderosa

When I had my AC replaced there were some problems and the factory sent out a tech. He said the same thing, use the cheapos and change them more often.

I don't know how stupid these techs are. Here is a scientific study that proves my point:
http://media.igert.org/posters2011/pdfs/0549428.pdf

And a quote from it here:

Higher efficiency filters reduced system airflow rates slightly, but did not increase energy consumption.

[Ponderosa]

Originally Posted by Andros 1337

I don't know how stupid these techs are. Here is a scientific study that proves my point:
http://media.igert.org/posters2011/pdfs/0549428.pdf

And a quote from it here:

Yeah, I changed the post to mention that he was a mechanical engineer (I am(was) a CE and we talked shop). I guess he missed the article. He did not say it would save money. They were trying to get everything including the pressure drop across the evaporator coil to spec. He said the filter I had was too restrictive and more airflow was needed. When we went to the cheapo things came into spec.

[Zippyman]

Originally Posted by Andros 1337

I don't know why, since that is totally not the case with modern HVAC systems which are designed for MERV 6-12 filters. Unless your system is over 25 years old, don't use the fiberglass filters. If your system is over 15 years old, a fiberglass filter may work fine, but pleated filters with a MERV rating lower than 8 is optimal.

Moderator cut: snip

Trust me, I am not making this information up. You will NOT save energy using a fiberglass filter on a modern HVAC system, and you may actually spend more money frequently replacing filters.

Andros, most homes in Phoenix do not meet energy star standards, and almost every home I've seen in Phoenix had insufficient return airflow. Adding a pleated filter to an undersized return will reduce efficiency. For most people, the cheap fiberglass filters are the best bet. Hose them down with endust before you install them, and change them every month.

[Pink Jazz]

Originally Posted by Zippyman

Andros, most homes in Phoenix do not meet energy star standards, and almost every home I've seen in Phoenix had insufficient return airflow. Adding a pleated filter to an undersized return will reduce efficiency. For most people, the cheap fiberglass filters are the best bet. Hose them down with endust before you install them, and change them every month.

Not according to the scientific study that I posted.

[ReadyFreddy]

Some pro just implored me to use cheap filters, too. Same argument. Personally, I'm buying it.

[Pink Jazz]

Originally Posted by ReadyFreddy

Some pro just implored me to use cheap filters, too. Same argument. Personally, I'm buying it.

The techs here must be stupid then (or they are liars), since all the online sources contradict with this info.

[Zippyman]

Originally Posted by Andros 1337

Not according to the scientific study that I posted.

One poorly done study of 17 unidentified buildings in an unidentified climate can't overcome the basic facts. A/c units need return air - and pleated filters block airflow. You can use a pleated filter if you have enough airflow, but most homes in Phoenix don't have enough airflow with no filter at all.

I added pleated filters to my a/c system and they work great. I also doubled the amount of return air going to my a/c unit to make up for the restriction the pleated filters cause. Feel free to doubt me, but according to APS, I'm paying about $100 less than my neighbors "in similar sized homes" over the summer months, and my a/c is set cooler.

[roosevelt]

I keep my house at 88 degrees during the summer but have a roll around AC in my bedroom where my TV is. The main thing is that I sleep perfectly under a sheet if I keep the bedroom at 79 degrees. I might mention I live alone in a 4,000 sq. ft. house. In the winter the house is 68 degrees but have an electric heater for the bedroom.

[rjrcm]

Originally Posted by Andros 1337

I don't know why, since that is totally not the case with modern HVAC systems which are designed for MERV 6-12 filters. Unless your system is over 25 years old, don't use the fiberglass filters. ...

OK, but the A/C tech told me to go cheap and fiberglass just as he finished installing my brand new system late last year. You can call him ignorant, but he seemed very experienced to me.