Media Filters & Static Pressure

[mfb]

How much static pressure change should be allowed before a media filter is replaced?


thanks

[ham&egger]

Check your blood pressure. When that gets to high your static pressure is probably to high. Let me Know what your doctor says.

[dash]

.05 to .1,however you need to stay within the limits of total ESP that the fan can deliver the air flow required.

[canquest]

Dash - (I am just a non-techy homeowner with a 58mvp and infinity stat). After reading the above post, out of curiosity, I checked the static pressure that is displayed in one of the infinity stat menus and noticed a much higher number. On High (heat), it shows approx 0.79 and on low (heat) it shows approx 0.40. I thought this was within the normal range, until I read your reply above. In it you mentioned that it should be between 0.05 and 0.10. Is the static pressure measurement than I am seeing in my infinity stat a different measurement from the static pressure you were describing? Thanks for any information.

ps. (If we are talking about two different measurements, can you tell me if a 0.40 to 0.79 range in the infinity display is within "normal"). Thanks again!

[dash]

Originally posted by canquest
Dash - (I am just a non-techy homeowner with a 58mvp and infinity stat). After reading the above post, out of curiosity, I checked the static pressure that is displayed in one of the infinity stat menus and noticed a much higher number. On High (heat), it shows approx 0.79 and on low (heat) it shows approx 0.40. I thought this was within the normal range, until I read your reply above. In it you mentioned that it should be between 0.05 and 0.10. Is the static pressure measurement than I am seeing in my infinity stat a different measurement from the static pressure you were describing? Thanks for any information.

ps. (If we are talking about two different measurements, can you tell me if a 0.40 to 0.79 range in the infinity display is within "normal"). Thanks again!

It's different numbers,the above refers to the increase in Pressure Drop accross the filter only.On Infinity you could use the ESP ,which you quoted(starting with a clean filter),"plus" the above as time to change.Of course Infinity already does that for you.


The .79 on high is likely okay,can depend on model and cfms required,most are fine at .8 or .9 or less.Recheck when the air is on ,as well.If you post the model numbers,someone can likely say for sure.


If you rework the ducts and lower the number,it will save some on the operating cost of the fan.

[mfb]

Thanks dash!
I just wanted to be able to check that my Infinity system was working properly.

[seadragon]

mfb,

Also, be aware that the filter Percent Used readout can be quite erratic. Mine has shown 0% for the last couple of days. It was reading around 40%. The filter has been in for about 6 months and I haven't touched anything to do with the furnace. This feature doesn't seem to work well.

[mfb]

My readings have been very steady.
I started at 0%.
Went to 50% when I finished sealing the ducts I could reach.
And has slowly risen to 90% now after 6 weeks.

[canquest]

Is there a "filter Percent Used readout" on the carrier infinity stat? If so, how can I see it? I have only seen the message that occasionally appears telling me it's time to clean/replace the media, but I don't think I have seen a "percentage used" number. Thanks for your help.

[mfb]

Click and hold the left side middle button.
That will get you to the screen that has the Filter and Humidifier pad percentages.

[canquest]

Thanks!

[canquest]

When and how does the infinity control (or the 58mvp furnace) establish the baseline for the "Filter Used Percentage"? I think I read that at 1:00PM each day, the infinity control checks the static pressure, and I assume at that time, calculates the "Filter Used Percentage" mentioned above. But when and how does it establish a baseline to compare against?

Is there one baseline established for the furnace? If so, then how does it take into account any unique ducting configurations in a home? Wouldn’t it be possible, if this was the case, to always indicate 100% filter used, even if the filter was absolutely clean?.

On the other hand, if a baseline is established when you do a "Reset the Filter Used Percentage" on the infinity control, then couldn’t the baseline potentially change (especially if you don't actually clean the filter, but only reset the infinity control)?

Thanks for any information you can provide.

[dash]

The "baseline' is reestablished when you "reset"/change the filter.

Yes you can fool it,but with a dirty filter,the baseline will be higher,and it will "call" for changing sooner.Eventually the static will be beyond the limits,and you'll get an error notice.

[jlk_250]

I've resurrected this old thread because it has information I was searching for but didn't exactly find. I have an Infinity MVP58-80 and am confused by the autosense dirty filter feature. Here's what I got for readings with the old filter, no filter, and a brand new filter. CFM is 1450 in all cases with the fan on high.

Old filter. 1068 RPM .76 static

No filter at all. 1038 RPM .69 static

Brand new filter. 1047 RPM .71 static.

All of this makes sense and looks more or less okay except the control is saying the filter is 100% used despite it being brand new. I have some of my registers closed (all but one in the basement and an entryway upstairs. In the summer it is 76F upstairs and 70F in the basement so I don't see the need to open those registers at all. Am I causing the problem by doing this?

Jon

[dash]

Originally posted by jlk_250
I've resurrected this old thread because it has information I was searching for but didn't exactly find. I have an Infinity MVP58-80 and am confused by the autosense dirty filter feature. Here's what I got for readings with the old filter, no filter, and a brand new filter. CFM is 1450 in all cases with the fan on high.

Old filter. 1068 RPM .76 static

No filter at all. 1038 RPM .69 static

Brand new filter. 1047 RPM .71 static.

All of this makes sense and looks more or less okay except the control is saying the filter is 100% used despite it being brand new. I have some of my registers closed (all but one in the basement and an entryway upstairs. In the summer it is 76F upstairs and 70F in the basement so I don't see the need to open those registers at all. Am I causing the problem by doing this?

Jon

Did you push"Reset Filter" when you changed the filter???

[jlk_250]

Yes, I did reset it and it does its test with the fan running on high and then goes back to saying it is 100% used.

[perel]

Originally posted by dash
.05 to .1,however you need to stay within the limits of total ESP that the fan can deliver the air flow required.

Where are you getting this from? Most medium efficiency media filters (which is what we're talking about here) are specified at a final static drop of 1.0"wc. Obviously you can't have that much resistance in a residential system, so you have to change it whenever the entire system's ESP is pushing the maximum. I can see how there could be only .05 or .1 of "breathing room" on ESP with a fixed-speed motor - that doesn't seem to be the case for variable speed blowers though. Am I missing something here?

[dash]

Originally posted by perel

Originally posted by dash
.05 to .1,however you need to stay within the limits of total ESP that the fan can deliver the air flow required.

Where are you getting this from? Most medium efficiency media filters (which is what we're talking about here) are specified at a final static drop of 1.0"wc. Obviously you can't have that much resistance in a residential system, so you have to change it whenever the entire system's ESP is pushing the maximum. I can see how there could be only .05 or .1 of "breathing room" on ESP with a fixed-speed motor - that doesn't seem to be the case for variable speed blowers though. Am I missing something here?

My answer was in response to;

mfb
Member

Registered: Feb 2005
Posts: 35
How much static pressure change should be allowed before a media filter is replaced?


thanks


03-05-2005 08:51 AM IP:

so I was talking about the increase in static ,over what it was with the clean filter.I meant to say/type .05 to 1.0 in. w.c.sorry about that.

The OP(original poster) did stae that it was a Media Filter,so the static of it clean could be much more then 1.0 in wc.