electrostatic filters

[fat eddy]

Earlier in this post CondenserDave said :

"Don't start this fruit on duct design, please."

Although I do beleive he was referring to me,I'm going to let it go until I find out for sure .Then he will get the duct design lesson of his life,and he will get it for free. And thats the same low price

I charged him for the other lessons he has received during my tenure here. eg; many


[Edited by fat eddy on 03-02-2005 at 02:08 PM]

[docholiday]

Originally posted by dash
Why wouldn't a home owner want his A/C system to "clean" the air?

Thats not what I said now is it.... I said clean their homes. As in they think its some sort of vaccuum cleaner or something.

[stef]

How about this dirt trapping system.

We treat the water say like the chiller does. Spray the water and let our return air pass through it. Pretent the air is like a car passing through the car wash. The air will be cold and the dirst will be trapped in the water. This way we don't have to have evaporator coil in the system.

What you guys think ?

Have fun

[dash]

Originally posted by docholiday

Originally posted by dash
Why wouldn't a home owner want his A/C system to "clean" the air?

Thats not what I said now is it.... I said clean their homes. As in they think its some sort of vaccuum cleaner or something.

Sorry Doc,but I didn't say you said it ,but I admit I thought you were saying what Robo said earlier.Basicaly use a HEPA to clean (purify) your air.

I think EAC's and media can do a great job,and home owners seem to agree,but the duct Must be sized to allow "better " filtration.

[muck]

Okay....I have a Honeywell filter. Not the electrostatic one or anything hooked up to any power source.
It's the thick job (5" or so) and cost about $25 at Home Depot.
When I have a new gas furnace put in soon, should I just go with the regular sized filter media? It sounds like I'm really restricting the air flow by using the thick one.
I also have a UV light/filter bypass unit connected to the furnace as well as a HRV.
I should get stock in the filter company!

[pstu]

Has anyone ever checked the pressure in your return, or the External Static Pressure? I would be highly skeptical of anyone who tells you an answer without knowing the health of your particular system. Without measuring, I don't see how any answer could be other than a stab in the dark.

I'm no expert but if your system has reasonable ESP using your 5-inch filter, then I would continue using it. If the ESP is too high and changing to a 1-inch filter solves that problem, then you might do that. The acceptable ESP varies with the type of air handler, with my old system it was 0.5 inch water column and with the new one apparently it is OK up to 0.9 inch w.c.

Best of luck -- P.Student

[RoBoTeq]

Originally posted by dash

Originally posted by docholiday

Originally posted by dash
Why wouldn't a home owner want his A/C system to "clean" the air?

Thats not what I said now is it.... I said clean their homes. As in they think its some sort of vaccuum cleaner or something.

Sorry Doc,but I didn't say you said it ,but I admit I thought you were saying what Robo said earlier.Basicaly use a HEPA to clean (purify) your air.

I think EAC's and media can do a great job,and home owners seem to agree,but the duct Must be sized to allow "better " filtration.

I agree. As long as the filter surface area is large enough and the ducting is properly sized for lower static even the most restrictive filter can be useful.

For those who have allergy is best to go with the HEPA system along with properly located UV lights. If you don't have respiratory issues, just use a tight fitting filter that is not restrictive and change it regularly. If you have respiratory issues, go for a system that will do the best for your home air quality.

[maxair]

Hepa filter is the best no dought.We just installed a
carrier aqua snap chiller.State requires 40 percent outdoor
air minimum for the operating room.We installed a series
of cartridge hepa filters and they are very expensive,1 inch pressure drop got to pay for a larger blower and
electricity to run it.Had an indoor air quality test for
the state and another for the insurance company.They rated
the air 100 percent sterile. They last 6 months at time.

[fat eddy]

Is it graduated , does it start wiyh a lower efficeincy like a 40 then a 75,then a 95 then a HEPA ? or just straight HEPA's ?

[maxair]

Straight hepas.Made to order from the filter company.It only
does the 4 surgery rooms.It is pre filtered with 4 inch
pleated filters.Got a toshiba freq drive motor, carrier
premier link ccn network.Air quality is great,however when
it rains that 40 percent outside air makes it hard to
keep humidity in check.

[fat eddy]

No reheat ? they are usually constant volume with hot water reheat coil or electric. Just curious, I'm wondering how other places do it.

I got called out to a med college last night for a reheat coil not working on the same type of setup.

[trane]

I just thought I would add some thoughts to this subject. It has been mentioned that the pressure drop should be checked when changing to a more restrictive filter and I agree but it is seldom ever done. The problem is these filters load up very fast and almost need checked every few days to see how long they can go if you are close to the allowed static on your system. Its hard enough to get people to change filters and when they start putting pleated filters in and forget to change them the problems are worse than with the throw away filters. There has to be some margin on the static to allow for the filter loading up in the time frame they are wanting to change the filters.

[fat eddy]

There use to be a device that would whistle when the filter got clogged but I can't find them anymore

[trane]

Originally posted by fat eddy
There use to be a device that would whistle when the filter got clogged but I can't find them anymore

I install General AC-1 filters and they come with a gauge that mounts on the return that is supposed to tell you when to change the filter. (They like selling filters)

[docholiday]

Hook one of those differetial pressure switches to one of those anti-bark dog collars and tell the homeowner that he will indeed know when the filter gets dirty if he would just wear this around his neck.

[fat eddy]

LOL