Conference 7.286::home_work

  1 I am under the impression that the electro-static air cleaners would
    go into the return air duct just before entering the furnace.  This
    would help to lengthen the life of the blower as well, keeping it
    cleaner.
    
  2 I would check out the prices from Grangers Wholsale distributers
    before going to Sears for the unit.  Grnagers would have the same
    unit at half the price of sears, and it would be a better unit made
    by a real company.                                
                                                      
    Graingers in MASS                                 
                                                      
   	Norwood		762-7375                      
   	Woburn		935-8808                      
   	Worcester	853-7300                      
   	Springfield	781-7525                      
                                                      
    New Hampshire                                     
                                                      
   	Manchester	668-7161                      
                                                      
    						.dave.   
    

    
    Starter hole and tin snips will get thru the ductwork. If you don't
    have the snips handy, a metal-cutting blade in a jigsaw will work,
    but that's noisier than a dog pound.

>   What will we get into cutting sheet metal? I understand that there
>   is an attachment for the drill that will work?
 
    For cutting into the center of an existing duct, Weiss makes a pair
    of sheet metal shears for just that purpose.  It has a sharp point
    on the end with which you "punch" a hole into the duct and them
    cut the duct much like tin snips except that these cut out a piece
    of metal about 1/4" wide (kinda' looks like the strip from a canned
    ham).  Only problem is, is that they are very expensive for one
    job (I have a pair 'cause I do a lot of tin work on pipe organs)
    and were worth the for the amount of greif they've saved.

    When working with sheet metal, WEAR GLOVES!  You'll be surprised
    how easily (and quickly) you can cut yourself even if you've done
    a lot of 'tin' work.
    
    Attachmets for a drill (as I recall) make basically the same type
    of cut, but have no experience with them. 
            
>   What about having the ductwork cleaned? House is only 9 yrs old
>   but was filthy, had 3 floors of carpet replaced last month &  I
>   still can't breathe!  Some say with forced air, duct cleaning not
>   necessary, but others say since rel. humidity is down, all the gunk
>   in the ducts is drying out & blowing up into the house.  Opinions??
 
    I have FHA heat and have checked the ducts.  Both the heat ducts and
    cold air return had a layer of dust and misc. crud in them (return duct
    was MUCH worse). I cleaned them the best I could (as far as I could
    reach), but have never had them cleaned. If you can, remove a register
    and look inside (use a mirror as necessary) and see what they look
    like. 
    
    -Bob
    

    I put two Sears Electrostatic filters inside my Lennox furnace.
    They fit inside the air blower plenum, replacing the original air
    basket type air filter. The installation included cutting a hole
    for the high voltage power cord and air pressure sense tubes to
    pass to the outside the of the furnace. I purchased the two 26X20
    units at the cost of $109 each when they were on sale. Check it
    out next time you're at Sears. These filters claim a 85% efficiency
    factor for smoke particles.
    
    If you're looking at the 4" thick unit, there'd be some sheet metal
    cutting to install it. That's why we opted for the other route.
     
    BTW, think about modifying the furnace with a motor speed control
    connected to the slowest speed of the blower fan. The advantage
    is that the house is constantly being circulated through the filter
    at the low speed. If you have a hudmidifier in the furnace, it will
    help with that also.
    
    You will have to run the filter for several weeks to notice the
    benefits. Sears have excellent instructions for washing the filters
    after the first few weeks of operation. After that, you will note
    a definite lower dust level on your furniture. A good indicator
    of the filter getting loaded up is the static crackle of the dust
    particles getting zapped.
    
    I used my soapy carwash water jet to wash the filters and the wet/dry
    vacuum to help the drying process.
    
    Call me at DTN 522-2585/2525 if you have questions.
    
    /calvin hoe

    I've installed many of these air cleaners, I can't remember any
    that I didn't have to go back to the shop and make some new pieces
    of ductwork to make it all come out right. This is stuff you normally
    just can't buy anywhere, it is all custom made. It requires a fair
    amount of equipment and experience to fabricate it correctly.
    
    You might want to find your best price on the unit and then locate a
    local sheet metal shop that will do the duct modifications and
    installation, leaving the wiring job for you to do.
    
    Many of the units have the filter elements in two pieces and will
    fit into many dishwashers. We had to service some units used in
    some very severe industrial applications (oily smoke) and would
    immerse the elements in a solution of dishwasher detergent and hot
    water. The high pressure spray at the carwash works well also if
    you happen to just have them with you when you take your car to
    be washed. Its funny how our van always needed to be washed when
    ever we had to service those filters.
    
    Nick 

    re .4
    
|    BTW, think about modifying the furnace with a motor speed control
|    connected to the slowest speed of the blower fan. The advantage
|    is that the house is constantly being circulated through the filter
|    at the low speed. If you have a hudmidifier in the furnace, it will
|    help with that also.
    
    One should assume that such a modification would leave the blower
    running at lowest speed when the furnace is shut off, and at normal
    operating speed when the furnace is on.
    
    Blowers are variable speed so that the temperature at the outlet side
    of the heat exchanger can be adjusted to within certain limits.
    Slowing the blower down while the furnace is on will increase this
    temperature, decrease efficiency of the heat exchanger, and lead
    to possible overtemp shutdowns and resulting frequent on/off thrashing
    (same effect can be accomplished by using a filthy filter).
    
    Furnace blowers can perform a multitude of functions when the furnace
    is off; when it is on, the blower should always be set to mantain
    the proper heat exchanger outlet temperature.

    (RE: .2)
    
    	Just last weekend I installed the larger SEARS electronic air
    cleaner on my FHA furnace. First let me say that the Granger unit
    (made by Emerson) is the IDENTICAL unit that SEARS sells. Although
    the regular Granger prices are better, SEARS has their larger model
    on sale (in their current sales catalog for catalog customers) for
    199.99, you're not gonna beat that price at Grangers (as a matter
    of fact the Granger price is $100 more). I also investigated the
    cheaper models of electronic air cleaners that replace your current
    furnace filter. These units (alittle more than half the price of
    the larger units just mentioned) are btter than your typical furnace
    filter, but don't even come close to the efficiency of the larger
    duct-mounted units. But they are a hell of alot easier to install.
    
    Now for installation of the larger units. Yes they take some doing
    to install. I've done plenty of sheet metal work and it still took
    me a full day to install the unit. I would recommend that you have
    an adapter made to specification by a sheet metal worker, it'll
    save you some time and might cost you the same as the route I went.
    To install mine I purchased standard rectangular duct pieces from
    a heating supplier (D.H. Adams in Worcestor) that is, a 24" X 8"
    and 3' long and capped both ends and then mounted the air cleaner
    to one side and my cold air return (which is alot smaller than the
    air cleaner to the other side). These air cleaners are sized so that
    they fit standard cold air return furnace openings, so one side
    of the cleaner mounts directly against your furnace. Just off the
    top of my head the medium unit has an opening of approx 14" X 24"
    and the larger unit's opening is approx. 18" X 24". 
    
    As for wiring, the unit is not wire into the furnace. It is just
    wired directly to 120v. The unit has a built-in air flow indicator
    that turns on the unit automatically when the furnace blower comes
    on. And as previously mentioned you can wire a timer switch to your
    furnace blower to operate the unit for several hours at a time or
    continuously. Most multi-speed furnace blowers have several taps
    that allow you to turn on the blower at different speeds for different
    applications (i.e. heating vs. AC). This way you can have one speed
    as previously set for your regular furnace operation and another
    for the air cleaner or both the same. 
    
    I should also add that the unit can be mounted in any position and
    can be easily converted to handle air flow in either direction.
    
    Lastly, these units ARC! You can hear them zap occaisonaily when
    large dust particles go thru the filters....you get used to it though.
    
    						/Glenn Tremblay
    
    P.S. If any one is SERIOUSLY interested in installing one of these,
    	 I will send you a copy of the SEARS owners manual via inter-office
    	 mail if you contact me.   VINO::TREMBLAY
    

    I forgot to mention....I believe it was this months "Practical
    Homeowner" that had a article on air cleaners and what they remove
    from the air.
    							/Glenn
    

    Thanks for all the response and encouragement/discouragement! 
    
    Yes, the Sears model is on sale in Ohio for $239 & my Sears card
    is one I haven't yet thrown out! 
    
    Had a suggestion from other sources that we add a switch that would
    keep the blower going on low, then kick into high when the heat
    or A/C came on - seems worth considering while we're at it!  Any
    input on how this would interact with an automatic set back thermostat?
    Is any of this wiring intricate enough that it would need to be
    inspected?
    
    The November issue of Home Mechanics has an article on them - will
    check out Practical Homeowner, too.

    Terry

    Re: .6 & .9
    
    The individual speed winding will not have an interactive mode.
    In the slow mode, air is moving through the air ducts at a very
    little low volume; when the furnace cuts in, it runs at the higher
    volume (I'll call it medium). When the airconditioning is running,
    the blower is going at FULL speed. Our furnace is controlled by
    a SEARS Weekender set back thermostat. Each of it's seperate function
    was not affected by the low volume air flow.
    
    Re: .9
    
    We found that Sears charges 21% finance charges but Discovery card
    hawked by Sears financial services charges only 19.2% nation wide.
    Throw out the Sears card!
    
    /John Ryan III

    RE:.9 
    		Correction: I had stated the article was in Practical
    Homeowner, but I believe .9 was correct in stating it was Home
    Mechanics magazine. Sorry for misleading anyone. 
    
    Multiple blower speeds: I'm not sure if some multi-speed blower
    motors might be damaged by applying power to more than one speed
    tap at a time. Check it out thoroughly before you do so.
    
    Sears unit: I paid 199.99 for the large model, on sale in the sale
    catalog until mid January '87. I'll look up the catalog number
    and post it later.
    						/Glenn
    

    Just incase, here is the catalog number incase someone was considering
    ordering a Sears electronic air cleaner...this is the larger model.
    
    Cat "FA":   42FA84921C  Was 349.99 sale price 199.99 (shipping weight
    								43 lbs.)
    
    On sale until Jan 20, 1987.
    
    /GAT
    

    How effective are the small stand alone Electro-static air cleaners.
    Anyone out there tried any of these models? any reccommendations?

I tried a standalone a few years ago in our 600sq ft apt., and then in 
the 10 x 12 bedroom with the door closed.

				useless

					/j

    I installed one of the Sears electrostatic "slide-ins" last night.
    It was a little harder than it would otherwise be, cause my furnace
    didn't have a formal filter slot.  The filter was propped up against
    the return air opening with a rock and a piece of wood!  I created
    a couple of holders from some aluminum bar stock and screwed them
    in place.
    
    It may not be as efficient as the heavy duty units, but the difference
    is amazing!  We used to get a real strong basement smell when the
    furnace kicked in in the morning (sort of a dusty, musty thing)
    that made us sneeze and hack.  This morning, nothing but warm odorless
    air.
    
    Don't know if I got an improved model, but the blurb in the store
    said 90 to 95% efficient.  Anyway, if you want better filtration
    with easy installation, it's not bad.
    
    /Dave

    OK, what about us poor fools who are stuck with electric heat?
    Any sort of air cleaner for us?
    
    Dick
    

    Do you mean heaters that are part of the baseboard and act like
    space heaters?  When I was first starting to look into this, I went
    to the library and found quite a bit of information about tabletop
    and room size air cleaners.  Mostly Consumer Reports.  They compared
    efficiency vs. noise factor and cost.
    
    BTW - have had ours in since the weekend before Thanksgiving and
    the difference is just short of miraculous!  Have already cut down
    asthma medication!  Now just waiting to see if we have enough other
    deductions to claim it on taxes!

    RE: .16
    		Several companies make stand alone electronic air cleaners
    along the efficiency of the larger furnace mount types. These units
    cost around $200 - $400 and are the size of large free standing
    humidifiers. (Lechmere had some models on sale several weeks ago
    by Teledyne).
    
    As for tabletop models, I had one made by Pollenex and I didn't
    like it. It made too much noise and there was no real noticable
    difference after many months of use. It was a waste of $65. It 
    would be sufficient though if you ran it in your bedroom for instance
    all day while at work, ofcourse with your bedroom doors closed.
    But don't try and clean the air in your whole house with it.
    
    Follow-up: I just wanted to post here that I am extremely happy
    		with my furnace mounted electronic air cleaner. It has
    		exceeded all my expectations! My house air smells so
    		sweet now and a hell of alot cleaner in everyway. I
    		installed a timer switch so I could run it (without
    		the furnace) several hours during the day, but to my
    		surprise I haven't needed too. A definite recommendation
    		for anyone with a force hot air system.
    
    /Glenn
    

    FYI - in case anyone is still considering this but concerned w/cost
    - we have had ours running constantly since Thanksgiving week, and
    currently it is wired to the highest speed tap.  Our electric bill
    went up only $20, and this was for the first month that we also
    had the furnace running for any amount of time.  Since at this point
    our priority is clean air/fewer asthma attacks and with Christmas
    & all, we have yet to look into adding the switch that will allow
    it to run on low when furnace is off, and on high when it kicks
    in, but plan to.  Another thing that we have to finish up is the
    return air duct - luckily our return duct came down from the ceiling,
    and in two parts, so no cutting was necessary.  Where it comes apart
    is about 2 feet above the top of the cleaner unit, so until we get
    the transition fabricated, we figured the air would fall down into
    the cleaner.  Whole contraption is located in a tiny laundry room
    that is pretty enclosed.  
    
    Planning to wash it for the first time tomorrow - any hints on that?
    Any other way to cut down drying time besides wet/dry vac? Don't
    have one! Can you set the pieces in front of a floor fan, or maybe
    use a hair dryer aimed at it?  How delicate are the ionizing wires?
    The instructions talked about how to replace them - how frequently
    might this be necessary? If you put them in the dishwasher, do you
    use the same amount/type of detergent for dishes? Could you use
    the drying cycle on the dishwasher, or would this be too hot?
    
    Thanks,
    
    Terry

    Washing recommendations on residential units are usually once a
    year. Maybe your unit is different but you may be pushing it a bit.
    
    The ionizing wires should not be of any concern, I have a 10 year
    old unit with 6" wide elements that are in perfect condition.
    
    If you clean them in a dishwasher use a standard cycle and the same
    amount of detergent that you use for dishes. The whole idea is that
    you want to use a non-sudsing detergent and dishwasher detergent
    is just the right stuff. I probably wouldn't use the drying cycle,
    just let them drain off the excess water and put them back in the
    furnace with the air cleaner shut off. The normal flow of air through
    the furnace with dry them off in a few hours then you can turn the
    air cleaner back on. You may hear a few snapping noises after you
    turn it back on, don't be too alarmed, it should quite down in a
    little while.
    
    Nick

    Re: Monthly/yearly cleaning - the destructions that came with it
    (Sears) said every other month or so, but more often if you have
    new carpet installed, which we did, at the same time.  That, plus
    the dog is inside (not my choice!) makes me think that it might
    be time for the first cleaning.  Plus, I am just curious! I was
    asking about the drying cycle because I thought it might be faster
    than just letting it air dry, and I'm not sure what having the dog
    inside without the cleaner going would do.
    
    Guess I oculd just let the ol' man do it Friday & I'll hit the after
    Christmas sales for a couple hours!
    
    Yours is 10 years old? I just heard of these things recently, but
    I guess I can understand why my allergist wanted to keep me on the
    shot routine instead of telling me about these!
    
    Thanks for the info!
    

    I just tossed my Sears unit in the dishwasher for cleaning and
    it came out fine.  I used the drying cycle, as stated in my set
    of instructions, but still needed to let it stand propped up on
    a corner to drain the last water out.  Took maybe 3-4 hours to
    wash and dry.
    
    If you have a set-back 'stat, you could pull it in the morning after
    the furnace turns down, run it through the washer, and toss it back
    in when you get home from work.  Good thing I decided not to throw
    out my last old-style filter.  I'll keep that around to insert when
    I'm cleaning the electrostatic unit.
    
    /Dave
    

    Problem solution!
    
    Problem: How to keep electrostatic air filters working when you
    don't run the furnace in the summer.
    
    Solution: Add a fan motor speed control to the slowest winding to
    furnace blower (I have a four winding furnace blower motor). The
    two leads from the speed control is connected to the furnace power
    L1 (usually black) and the slow speed winding lead (usually red).
    The control should be mounted outside the furnace in a single wiring
    box (like the type you use for outlets or switches).
    
    Set the motor speed about half range and you have it. Ours can hardly
    be heard but I can feel a slow, positive air flow from the air register 
    in the bath room.              
    
    cheers,
    
    cal hoe

What do you do when your electrostatic air cleaner makes the air smell WORSE??!!

I've got a Gen. Elec. FHA (electric heat pump) furnace with an electrostatic
air cleaner that's about 10 years old.  The furnace/heat pump were serviced
last winter.  I had the heating ducts professionally cleaned last month.  I
clean the electrostatic elements in my dishwasher about every month during
heating season. 

But the air coming out of my heat registers still really stinks of
dust/mustiness.  When I turn off the electrostatic, the smell seems to go
away.

Anybody have any idea what's up? 

/Brian

    I read somewhere that electrostatic air cleaners are _not_ reccomended
    for asthmatics, as the ozone produced can make your asthma worse
    instead of better.  Anyone know anything about this?
    
    Also, I'm very allergic to cats, and just on the off chance that we buy
    a pre-owned house with FHA (most of the ones we've seen have cats,
    grumble grumble) what does it cost to have the ductwork cleaned out? 
    Ballpark numbers are OK, has anyone had this done?
    
    Willie

    My cube mate just had his house FHA ductwork cleaned.  I believe he
    payed about $350 for the entire house.

    re .24
    
    My last house had the instructions for an E-static air cleaner, and
    it suggested 2 ways to reduce the ozone ... 
    
    1) engineering mod to reverse teh polarity of the attraction grid in
    the cleaner ... this made the cleaner less efficient but was supposed
    to significantly reduce ozone.
    
    2) carbon granule post filters ... these filters go in the air path
    after the e/s filter and only go in about 50% of the air path. 
    
    Stuart

    RE: .24
    
    Does anyone have any references on how much ozone a typical
    electrostatic air cleaner produces? And how much is harmful?
    
    -Paul

  Re last couple, Sears currently offers carbon-granule filters for use
  with their two largest furnace-mount air cleaners. These are the same
  size as the pre-filter screens, and appear to get inserted downstream
  of the electrostatic cells (the pre-filters are upstream). In addition
  to reducing ozone, these would probably put the finishing touch on
  smoke and odor filtering.

  Now for my question:

  I'm in the process of installing one of these, and from the looks of
  it, the blower fan only has one speed. There are no taps (just a
  two-wire connection), and I've never noticed any variation in blower
  speed. Naturally, I don't want to run the fan all the time, and seem
  to recall some discussion of a timer which could be set to run it,
  say, for 5 or 10 minutes of every hour. Anyone know what this sort of
  timer would be called, and what sort of store would carry it?
  Recommendations in the Greater Maynard area would be greatly
  appreciated.

  Thanks very much.

    
    Time to revive this topic for some opinions and answers...
    
    Current situation:
    FHA heat.  No central A/C.  Too much dust.
    
    Desired situation:
    FHA heat.  Simulated central A/C.  Less dust.
    
    Proposed plan(s):
    
    Plan A
    I'd was thinking of installing an electrostatic air cleaner to the
    furnace.  I've checked out the slide in types ($109 at Home Depot). 
    They claim to remove 95% of the dust, pollen, etc.  Seems pretty good.
    Installation not too difficult.  Just have to add an outlet near the
    furnace.  Will have to make a few modifications where the filter slides
    in because the current space won't accomodate either of the sizes
    available.  But this is a big deal.  No actual ductwork rework.
    
    The larger Sears model is $199 right now.  It appears to have
    the same efficiency as the slide in except it is better at removing
    smoke.  Since I don't smoke, I don't think this is a real issue.  The
    Sears unit would require ductwork changes as well as electrical power.
    
    Then last night I saw a filter at HQ made by Purolator that claimed to
    be as efficient as the electrostatic.  It cost about $3.50.  It
    definitely seemed at lot better than the normal air filter.
    
    Questions:
    
    1. Has anybody used any of the above electrostatic air cleaners?  I was 
       all set to go for the slide-in electrostatic filter but if the same 
       results can be gotten with a normal slide-in, seems like a quicker way 
       to the ultimate goal of less dust.
    
    2. Does anybody out there use the Purolator filters?  Have you
       noticed an improvement since using them?
    
    
    Plan B
    I'd also like to be able to turn on the furnace blower to circulate the
    air in the house in the summer.  I was also going to install a large wall
    mounted A/C unit.  
    
    
    Questions:
    
    1. Do you think the furnace blower would adequately circulate the cold 
       air throughout the house?  The blower on my furnace runs at one speed.  
       Is there any way to vary the speed?
    
    2. I was thinking of replacing the current thermostat (regular round
       Honeywell) with a programmable heating/cooling thermostat.  The
       cooling part would turn the blower on and filter the air
       periodically.  Has anybody done this type of thing before?  Will
       this work or am I crazy?
    
    Any comments, ideas, suggestions, warnings?
    

    RE: .29

    I haven't used the Purolator filter, but am currently using a 3M one
    that cost $16.99 and is suppose to last three months.  It's very
    similar to the Purolator (if that was the other brand at Builder's
    Square), will filter down to .3 microns but does not have activated
    charcoal. It CERTAINLY removes a lot more dust and dirt than a regular
    air filter.  However, I think you will never be free of dust.  I've had
    it in for a little over two months now and have not really seen a
    reduction in dust.  Since one of the major components of dust is
    suppose to be skin cells, you'll never really be free of dust unless
    you get rid of people. :-)

    One of the many catalogs I get listed a similar type filter, but was
    washable. It costs somewhere in the $110 range for the size I need. It
    is suppose to have a permanent static charge that is enhanced by air
    passing through it.  Needs no electricity.  I am considering one
    instead of putting out $17 every three months.

    -Bob
            

I think someone mentioned this before -- how about using a regular cheap-o
filter followed by one of the .3 micron filters.  Why clog up an expensive
filter with big particles?

The only negative consideration I can see is reduced air flow caused by two
filters in series.  Any comments?

								-- Chuck Newman

    
    2. Does anybody out there use the Purolator filters?  Have you
       noticed an improvement since using them?

	    Yes, I use the purolator.  No, I haven't noticed any significant
	improvement.  I think you would have to clean the ductwork out to
	notice any drastic improvement.  I figure you have umpty number of
	years of dust build up lining the duct walls.  It would take a long
	time and a lot of good filtering to blow all of this out.  
    
    
    1. Do you think the furnace blower would adequately circulate the cold 
       air throughout the house?  The blower on my furnace runs at one speed.  
       Is there any way to vary the speed?

	   I would think that a big air conditioner in a small house would
	cool the whole house... if you ran the air conditioner all of the
	time.  It sure doesn't sound nearly as efficient as installing A/C
	directly to your FHA system, though.  The room with the air con-
	ditioner would always be colder than the other rooms in the house
	and the operating costs would be high.
	    If you look at your blower motor, you may find a small schema-
	tic diagram on it for different speeds.  If it's configured this
	way, there will be a neutral wire, a low, a medium and a high speed 
	wire.  Your motor is probably hard wired for medium speed operation.
	You may consider installing a 3 position switch if you want to be 
	able to switch between speeds.
	    If you don't know anything about electricity, I wouldn't suggest
	you do any wiring without some kind of guidance.  If you're not
	going to install A/C to you FHA system, I don't see any benefits
	to buying a programmable thermostat.  The blower would be running
	so much, you could hard wire an on/off switch (or a wind up timer
	switch) to the blower and save yourself a lot of money.

					Tim 	    

	re .31  There may be some restriction but I don't think it would
	be significant.  The expensive filters are pleated so as to allow
	more surface area for the air to flow through (low restriction?).
	You can see right through the cheapo filters, so I don't see them
	as being much of a consideration.  Now if you let your filters
	get dirty (ie. clogged)...

					Tim

My last house had a Honeywell electrostatic air cleaner.  Very expensive, but
VERY effective at removing ANYparticulate matter from the air that was being
circulated.  The only problem was that it also produced a relatively high
level of ozone, which I did not appreciate.  I made an optional wiring change
to the transformer to lower the voltage.... still smelled like ozone to me.
I shut the unit off and lived with the dust.

I now have one of those "permanently charged, washable, no electricity"
electro-static filters in my central A/C system.  Cost about $90.  Is
nowhere near as efficient as the Honeywell but, then again, doesn't produce
any ozone.

Trade-offs, I guess....

Peter

    re: .32

>	       . . .  I think you would have to clean the ductwork out to
>	notice any drastic improvement.  I figure you have umpty number of
>	years of dust build up lining the duct walls.  It would take a long
>	time and a lot of good filtering to blow all of this out.  

    After having a new furnace installed, I opened up my duct work to see
    how dirty it was (I expected a lot of dust and other dirt) I was
    surprised to find that the heating duct was very clean.  The return air
    duct on the other hand was full of dirt. Thinking about this it makes
    sense.  The warm air duct air is drawn through a filter (even if not at
    a .3 micron size, it still gets out the big stuff) and is blown with
    enough force to keep them relatively clean, whereas the cold air return
    is drawing heavier air back at floor level with all the dust and dirt
    it can drawn in.

    I think a good example of how poorly a regular filter filters is to
    look at any blown joint that is not really tight.  There will always be
    a built up of dirt around the joint where it leaks (after a number of
    years that is). The higher the pressure, the more dirt, which is
    especially evident in pipe organs, which has absolutely nothing to do
    with this discussion. :-)

    -Bob                                                   

	re -.1  Maybe I'm making ground but just haven't noticed any improve-
	ments yet.  When we bought our house, it was apparent that the filter
	hadn't been changed in many months... perhaps years!  It would seem
	that I'm in the process of making up for lack of routine maintenance.
	    I've heard of filters you can install on all of your return vents.
	I've looked around a little but I haven't found any such animal.  Has
	anyone out there used them?  Do they seem to work?  Should this be
	in another note?

					Tim
				

    
    RE: .30
    
>    One of the many catalogs I get listed a similar type filter, but was
>    washable. It costs somewhere in the $110 range for the size I need. It
>    is suppose to have a permanent static charge that is enhanced by air
>    passing through it.  Needs no electricity.  I am considering one
>    instead of putting out $17 every three months.
            
    Could you please list the source for these?  I've never seen them in
    any of the stores I've checked.
    
    
    RE: .31
    
>I think someone mentioned this before -- how about using a regular cheap-o
>filter followed by one of the .3 micron filters.  Why clog up an expensive
>filter with big particles?
>The only negative consideration I can see is reduced air flow caused by two
>filters in series.  Any comments?
    
    This would require a minor alteration of the opening of the ductwork to
    get it in.  But considering the low efficiency of these filters, even
    two of them may not be that good.
    
    
    RE: .32

>	    Yes, I use the purolator.  No, I haven't noticed any significant
>	improvement.  I think you would have to clean the ductwork out to
>	notice any drastic improvement.  I figure you have umpty number of
>	years of dust build up lining the duct walls.  It would take a long
>	time and a lot of good filtering to blow all of this out.  
    
    I was adding a new piece of ductwork last Friday to extend an existing
    run and the old (38 years?) ductwork wasn't that dirty.  Certainly
    nothing very loose which is to be expected I guess.    
    
>	   I would think that a big air conditioner in a small house would
>	cool the whole house... if you ran the air conditioner all of the
>	time.  It sure doesn't sound nearly as efficient as installing A/C
>	directly to your FHA system, though.  The room with the air con-
>	ditioner would always be colder than the other rooms in the house
>	and the operating costs would be high.
    
    The problem is circulating the cool air throughout the house.  There is
    a return in the room where the AC would be.  Installing central AC is
    not an option.  
    
>	    If you look at your blower motor, you may find a small schema-
>	tic diagram on it for different speeds.  If it's configured this
>	way, there will be a neutral wire, a low, a medium and a high speed 
>	wire.  Your motor is probably hard wired for medium speed operation.
>	You may consider installing a 3 position switch if you want to be 
>	able to switch between speeds.
    
    No blower schematic that I can see.  But then I didn't crawl into the
    blower compartment on my back. 8-)
    
    I have checked out the wiring going to the blower.  There are 4 wires
    coming from the motor.  Only 2 are used I believe (maybe 3).
    
>	    If you don't know anything about electricity, I wouldn't suggest
>	you do any wiring without some kind of guidance.  If you're not
>	going to install A/C to you FHA system, I don't see any benefits
>	to buying a programmable thermostat.  The blower would be running
>	so much, you could hard wire an on/off switch (or a wind up timer
>	switch) to the blower and save yourself a lot of money.

    	I've done my share of wiring but furnace wiring is new to me.  I
    like the idea about the windup timer.  Maybe I'll go with a setback
    heating thermostat and a windup timer next to it.
    
>    After having a new furnace installed, I opened up my duct work to see
>    how dirty it was (I expected a lot of dust and other dirt) I was
>    surprised to find that the heating duct was very clean.  The return air
>    duct on the other hand was full of dirt. Thinking about this it makes
>    sense.  The warm air duct air is drawn through a filter (even if not at
>    a .3 micron size, it still gets out the big stuff) and is blown with
>    enough force to keep them relatively clean, whereas the cold air return
>    is drawing heavier air back at floor level with all the dust and dirt
>    it can drawn in.
    
    I agree.  The inside of mine weren't that bad for the number of years
    of operation.  I do remember vacuuming out quite a bit of stuff from
    one of the cold air returns last time I took the cover off.


    RE: .36
    
>	re -.1  Maybe I'm making ground but just haven't noticed any improve-
>	ments yet.  When we bought our house, it was apparent that the filter
>	hadn't been changed in many months... perhaps years!  It would seem
>	that I'm in the process of making up for lack of routine maintenance.
>	    I've heard of filters you can install on all of your return vents.
>	I've looked around a little but I haven't found any such animal.  Has
>	anyone out there used them?  Do they seem to work?  Should this be
>	in another note?
    
    Hmmm....  Never thought of this.  Sounds like a good idea.  Maybe one
    of those filters that goes on the front of a window A/C unit could be
    cut to fit.  I have seen these in a number of places and they are
    pretty cheap.  I think I will give this a try and see how much I catch.
    
    
    Well, I bought a Purolator filter for $3.97 and will give it a whirl. 
    I think I'll also try placing a few filters on the returns.  If this
    experiment doesn't produce noticeable results, then I'll consider the
    electrostatic slide in filters.
    
    Thanks for all the input!
    
    Stay tuned...
    

    Do filters for FHA vents exist?  Do you need special ones for the
    return vents vs. the heating vents?  Do they significantly cut down on
    the dust or is FHA inherently dusty since it is constantly circulating
    the air?
    
    Thank...Rhonda

re: .38

      I suggest that a single filter located in the return air duct just
      before the return air reaches the furnace does as good  a  job  as
      filters  at  each outlet/return -- and for a lot less effort.  The
      exception to this would be if your furnace itself is  puting  dust
      into the heated air.  If it is, it needs to be fixed, IMHO.
      
      As  to  FHA being "inherently dusty"... Well, some will agree that
      it is, beccause, as you say, "it  is  constantly  circulating  the
      air".   Others  will  say  that  it  is  less  dusty becuase it is
      constantly filtering the air.  I tend toward  the  later  opinion,
      assuming  that  you  have  a  good  central  filter  and vacuum it
      regularly durring the heating seasn (and cooling season, iff...).
      
      Bottom  line  is  that a good heating and/or coolign system of any
      type should not be "dusty".

	    I've heard of filters you can mount on the FHA returns but 
	haven't actually seen any.  I've opted for the high efficiency, 
	pleated filters.  They trap "95%" of the dust, pollen, etc. that
	passes through them.  Standard filters don't do a very good job
	of filtering. 
	    I think the level of dust in my house has decreased with the
	better filter.  It takes a while to notice any improvement.

					Tim

    RE:  .40
    
    We had such a filter on a FHA furnace when we lived in St. Louis.  It
    was, indeed, very efficient.  It was especially useful for our
    asthmatic son who had tremendous problems with dust, etc.  Don't
    remember the cost, but it was a minor add-on when we had the furnace
    installed.  I'm sure doing it after-the-fact would make it far more
    expensive.
    
    A very nice feature was that the filters could be removed and run
    through the dishwasher.  We did that about once a month just to make
    sure everything was clean.
    
    Only one annoying downside:  Occasionally, we would get a fairly large
    piece of dust or lint which would "bridge the gap" between two of the
    charged elements in the filter.  When this happened, we would get a
    "snapping" or "crackling" sound, not unlike the sound a bug-zapper
    makes.  These would sometimes fix themselves when the blower went
    on/off.  However, at other times, I had to take the filter out and
    remove the offending stuff.  This didn't happen often.  
    
    On the whole, we were extremely pleased with the unit.  We would have
    one now except it's hard to install one on a FHW system!
    
    Chet

    Where does this filter go ... on the furnace or on the cold air return? 
    Where would you get one in this area (I live in Townsend)?  Is it just
    a filter or is it a unit that has to be installed on your furnace? 
    Would you have to have it professionally installed? 
    
    I also have a son with allergies and asthma ... anything that would reduce
    the dust level I'm sure would help his breathing.
    
    Thanks.
    
    Joyce
    

    In my case, the electrostatic filter was installed in the cold air
    return just before the air entered the furnace.  In other words, the
    same place most "standard" filters are installed.
    
    Chet

Ditto.

We got ours from Sears. It's Sears' largest furnace-mount model, and is
no longer stocked in the stores. You have to order it (but can have it
shipped to a store where you can pick it up). This model is made by
Honeywell (which I found by pricing a Honeywell unit installation by a
local plumber). It's everything we hoped it would be, and we're very pleased.

By the way, I did the installation myself, and it took about 6 hours
(including the time to remove the existing ductwork). But I will tell
you it is not a job for people who haven't done sheet-metal work: I had
new ductwork custom fabricated by a local sheet-metal shop, and it was
still no picnic. Total cost was about $500, including ductwork and new
electrical supplies -- exactly half the quote I got from two different
plumbers.

    just a comment FWIW...
    
    - The Honeywell Electrostatic furnace filter is mentioned in the recent
    Consumer's Report article on filters.  I remember that they weren't too
    hot on it.
    
    - I have a Lenox furnace with an Electrostatic filter on it 
    (may be a Honeywell OEM .. I don't know)   Seems to work fine, but...
    (this is a house I bought earlier this year.. 6 years old)
    
    The control module was dead in one (I have two furnaces, etc)
    I talked to the HVAC company about it when arranging the replacement,
    and they said that my model tended to blow after several years.
    Cost about $150 to replace, and they keep the labor down as a sort
    of gesture. They don't recommend them any more, purely on this basis.
    Well when the guy replaced the control module, he couldn't get one
    of the preciptators to stop sparking, so he swapped into the other
    filter.  Guess, what... that one doesn't seem to work now.
    Sigh,... I going to try to get them to eat the cost of fixing it.
    
    	Dave.

    Beckett Medical (they used to be in Worcester) makes (made) an air 
filter that was supposedly much better than the electrostatic variety.

    I'll look for the brochure.

    -Phil

    
     Any recommendations for free-standing (room = 12x10) air cleaners?
     In particular, any non-electrostatic variety as this is for a child
     with allergies as well as asthma.
    
     Thanks,
     jc