From: lking@chance.mitre.org (Linda B King)
Subject: Summary: Responses to Request for Central Air Info
Keywords: PVC, CPVC
Organization: The MITRE Corporation, McLean, VA
Distribution: usa
Date: Thu, 16 Apr 1992 19:59:22 GMT


As promised, I am posting the responses to my request for information
on central air conditioning.

I found out that I was given some incorrect information.  Rheem does 
NOT pro-rate their warranties, as I was originally told, and Carrier 
STOPPED using aluminum coils three years ago (they had supposedly 
decided that copper was better).  

Thanks to everyone for your responses.  BTW, we've decided to go with
a Trane 3 1/2 ton 12 S.E.E.R. unit.

************************ SUMMARIZED RESPONSES ******************

From: KALIHER@SKYLER.MAVD.HONEYWELL.COM
Subject: Central AC

We have been using our Carrier 3-1/2 ton for one year, with no complaints.
The noise has not been noticeable, but the compressor is on the back side
of the house.  The furnace is Carrier also, with Honeywell programmable
thermostat.  It's a new house, but the compressor was not connected for
the first year we were in it.  (It was purchased as part of the house, but
I had differences with the HVAC contractor.  The cooling coils were put
in at the time of furnace installation.  I don't know what the $$ was -
it's buried in the whole house cost.)
----------------------------------------------------

From: btree!hale@UCSD.EDU
Subject: Re: Central AC

We have a Lennox furnace and air conditioner system.  I have a couple of
complaints about it:

1. The fan is VERY noisy when on high speed (in FAN and AC mode it is
   on high speed).

2. Ours has an electrostatic dust filter.  The power to the filter is
   supposed to be controlled by sensing air flow through the system
   but the sensor switch that does that in ours doesn't work.  I looked
   over the design and didn't like it; it depends on having a partly
   clogged air filter to develop enough pressure differential to
   activate the switch.  I rewired the system to use power from the
   furnace which is switched on whenever the fan is on.

Several months ago someone posted a horror story about a Rheem furnace
and closed by saying "don't get reamed by Rheem."  I pass this on
without rendering judgement.

Hope this helps.

Bob Hale                                      
----------------------------------------------------

From: smb@ulysses.att.com
Subject: Re: Central AC

We had a Trane installed last year, and we've very happy with it.  It
is indeed quiet, and was spoken well of last year on the net.  (From
what I've heard, I would not get Carrier, btw.)  It helped that we
trusted the installers, through experience with the plumbing company.

----------------------------------------------------

From: isus!hoyt@asuvax.eas.asu.edu

I would think that (except in the case of RHEEM water cooled), that
a coil going bad is very unlikely.

The scroll compressor is touted as very efficient, and maybe it is, but
One contractor I know says they are not in practice, and thinking
about the thermodynamics, I don't see why they would be, as the
freon must be compressed to a higher pressure than the outlet side
pressure, as it's trapped in the scroll, unless the system is very
carefully engineered for a particular temperature difference-range
to match the two pressures (unlikely) (wow! what a long sentence).

Aluminum can be welded in the field using "sealcor" rod and others,
but I'd prefer copper.

If you can wait, a new type of unit from Albers technology, Tempe, AZ
will be coming on the marked (field tested in D.C.) which uses salt
to dessicate air in multiple stages of evaporative cooling.  It costs
much less to operate.


--
Hoyt A. Stearns jr.

----------------------------------------------------

From: smb@ulysses.att.com
Subject: Summary of Post from last year's discussion

Replied: Thu, 09 May 91 15:39:36 EDT
Replied: ACHEN@KELVIN.JPL.NASA.GOV (ARTHUR CHEN)
Return-Path: ulysses!KELVIN.JPL.NASA.GOV!ACHEN
Received: from nj/astro/inet.uucp by ulysses; Thu May  9 15:35:24 EDT 1991
Received: by inet.att.com; Thu May  9 15:35 EDT 1991
Date:    Thu, 9 May 1991 19:37:50 GMT+0000
From:    ACHEN@KELVIN.JPL.NASA.GOV (ARTHUR CHEN)
Message-Id: <910509193750.28000b46@KELVIN.JPL.NASA.GOV>
Subject: Re: AC recommendation - summary
To:      smb@ulysses.att.com
X-Vmsmail-To: SMTP%"smb@ulysses.att.com"

Here is goes (with updates)....

-------------------------------------------------------------------------

		pos	neg	io*
	YORK	 1
	Rheem		 2%
	ArcoAir	 1
	Carrier	 1		 1
	Lennox	 4		 2
	Trane	 2		 1
	Bryant+	 2

	(*) = information only, I take these as "at least the name-
	      recogination is there".
	(%) = no direct experience, but have heard of bad stories.
	(+) = probably made by Carrier OR Honeywell -gasp-


The detailed responses on AC recommendation follow:
==================================================
From: nash@ucselx.sdsu.edu (Ron Nash)

York.  I installed one 2 years ago and have been very happy with it.
Did most of the installation myself.  I have a 3 ton unit for a 1400
square foot house and it does a great job.  SEER is 10.  There are
some newer units with SEER as high as 15 but I don't know if the cost
is worth it at this time.

I have heard some bad things about Rheem.  A neigbor is a HVAC contractor
and is currently working on a project with about 500 Rheem units that
are not working properly.


From: smithd@software.org (Doug Smith)

I am looking at heat pumps.  The compressor technology seems
to be what the industry pushes.  A recent advance, "scroll"
compressors, only seem to be available in Lennox systems.  These
supposedly achieve SEER's of 12.0 or more.  The Trane systems
I am looking at range from 9.0-11.0 SEER.

The formula I am using to decide the best buy involves the
following stats (the dealers have promised to quote industry
statistics they have available):

    A.  Installed cost
    B.  Average life in years
    C.  Yearly maintenance cost over the average life
    D.  Yearly savings (usually from a worksheet) using:
            estimated heating
            estimated cooling
            electric rate structure

Every warranty I've seen leaves little real protection except
for massive failure (everyone covers that).  So I only consider
the warranty is all other cost are equal.  So the formula...

    Net Savings : B*D - (B*C +A)

Whoever gives me the best net savings (even if I have to buy
a new unit every year) wins.  This does not take into
account inflation.  If I find no clear winner, I plan to do
more detailed calculations.

I am waiting for my first quote, and have another dealer
coming tomorrow.  Let me know if you are interested in the
details, and we'll share further info.


From: miller@SCTC.COM (Steven M. Miller)

I posted a request like this a couple of weeks ago and got no 
answers.  I wonder if it ever made it out onto the net?

I shopped around a bit and am self installing an ArcoAire.  I've
heard a few good things about it and I can get a 11 SEER model
for under $600!   Of course that's because the local power company
gives big rebates to people who buy efficient major electrical 
applicances so they don't have to build more powerplants!

-Steve


From: eliot@dg-rtp.dg.com (Topher Eliot)

Carrier has been advertising a system that gets rid of heat by dumping it into
the domestic hot water supply instead of (or perhaps in addition to) dumping
it into the outside air.  It's worth investigation.


From: rod@com (Roderick Hartley)

Lennox is the best (IMHO).  I installed one last summer.  It is about 13
SEER and really works great.  It has something called a scroll compressor.
The air temperature coming out of the ducts is about 44 degrees.

My uncle-in-law owns an air conditioning business in CA and he told us to
get Lennox.


From: loul@ihlpm.att.com (Louis M Leciejewski)

I live in a Northwest Suburb of Chicago and had a TRANE Central Air
System installed back in 1975. It is a 3 -ton unit. I have not had
one problem yet with the system! Other people we know who had other
brands are on their second system already. Although initally more 
expensive, for 16 years of trouble free service I'd opt for TRANE.


From: maria@mcc.com (Maria Nasr)

It is my understanding that Trane is one of the best.  A friend just had his
central air replaced, and an independent dealer recommend it highly.  That is
also the brand we have in our house, and it is very efficient and quiet.


From: Kenneth L Shellberg <kls@magnus.acs.ohio-state.edu>

My neighbor spent a lot of time looking into this.  Claims Bryant is the
same as Carrier with different packaging, and was cheaper.  They had it
put it about a year or two ago.  Its quieter than my 15 year old Carrier,
but more importantly, they are happy with it.  Maybe this can be of use 
to you....


From: dsr@luke.mitre.org (Douglas S. Rand)

We have a Bryant system (I believe it is made by Honeywell) which
has worked well so far,  at a reasonable cost - about $80/month
during July last year for a 1500 sq ft ranch style house.


From: chaplin@keinstr.uucp (chaplin)
 
A friend of mine earns a living by installing air conditioning (among other
things).  He recommends based on ease of obtaining replacement parts.  He
says systems from the major manufacturers are all comparable in terms of
efficiency and reliability, so the important factor is being able to get it
fixed *when* it breaks down.


From: lstowell@pyrnova.pyramid.com (Lon Stowell)

You appear to be in California....so try the PG+E folks as well.
They offer rebates based on the efficiency of the
conditioner...the more efficient the bigger.  Our local office
has a pretty comprehensive list of makes and model #'s.


From: llf@research.att.com

Lenox.  Works nicely.

Make sure they size for your house correctly, though.
Too big is worse than too small.


From: urban@cps.msu.edu

We had a carrier installed about 3 years ago.  The installer was a Bozo,
but the AC works just great.  No problems.  I'm also impressed with
the effiency of the unit.  It doesn't cost nearly as much to run as I
had expected.

One word of advice on sizing.  We were told by our electric company not
to OVERSIZE the unit as it will cycle on, cool the house quickly, then
stay off without dehumidifying completely.  A reliable contractor should
be know that and avoid the tendency to sell you a larger unit than you 
need.


From: hale%btree%ucsd.edu@hellgate.utah.edu

Here's another vendor to add to your central A/C list: Lennox.
We have one of these; it works reasonably well, we have only had
one real problem with it (not Lennox's fault): a joint was soldered
with lead solder rather than silver solder, the joint cracked and
all the Freon leaked out.

I do have one major complaint: noise.  It is so noisy that I have
to turn up the TV about 10 DB to hear the TV over the air noise
in the air inlet.

I recall seeing a horror story about Rheem here a while back;
the poster concluded "don't get reamed by Rheem".


From: moody+@cs.cmu.edu (James Moody)
Subject: Lennox Air Conditioning Opinion
 
I'm considering having whole-house air conditioning installed, and I'm
leaning toward Lennox mainly because I am satisfied for the most part with
my Lennox pulse furnace, and very satisfied with the complany that installed
and service it.
 
I saw some discussion of AC brands in this newsgroup sometime in the past
two weeks, but I didn't notice any mention of Lennox.  Are any Lennox owners
out there satisfied/unsatisfied with their conditioners?  Are there any
other brands I shoudl be considering.
 
One consideration is that the unit will be installed between my neighbor's
house and my house so I'll need to have a very quiet system.  Lennox has
one model (Model HS 19) wich has the compressor in a sound-insulated
chamber, I'm just wondering how quiet it is.
 
Any comments would be appreciated.


From: rod@gli.com (Roderick Hartley)
 
I'm one.  We had a Lennox unit and coil installed and I am extremely
satisfied with it.  We opted for a higher end coil so the SEER rating
is almost 13.  My wife's uncle owns an air-conditioning business and he
recommended that we buy Lennox.
 
My unit doesn't have any special insulation but it is very quiet (especially
compared to the unit it replaced).

^L
From: achen@kelvin.jpl.nasa.gov (chen, arthur)

Thanks to all who responded to my posting on AC recommendation.  Here
is a summary of the replies:

		pos	neg	io*
	YORK	 1
	Rheem		 2%
	ArcoAir	 1
	Carrier	 1		 1
	Lennox	 3		 1
	Trane	 2		 1
	Bryant+	 2

	(*) = information only, I take these as "at least the name-
	      recogination is there".
	(%) = no direct experience, but have heard of bad stories.
	(+) = probably made by Carrier OR Honeywell -gasp-

One response suggested me calling up my electric company for recmmendation
which *I* have not thought of...  As to the quotes I got (In Los Angeles),
for a 3 ton unit, ~9 SEER with drain pump and permit, Rheem runs $2,800;
for Carrier add another $200 and Lennox goes for $3,200 total.  Lennox is
definitely the winner out of the survey, but it costs more --- what's new.

Email me if anyone wants the detailed information on all of the responses.

/arthur


From: akmbca@dante.lbl.gov (Alan K. Meier x4740 )
Subject: Re: installing central A/C in a home without air ducts

You might consider a "ductless" Japanese style air conditioning system.
Instead of air ducts, the air conditioners move refrigerant
through tiny (1" diam) pipes to evaporators located in 1 -3 rooms.
The evaporators -- about 3 ft long, 1 ft wide, and 6 " deep) hang 
on the walls.  They contain a tiny heat exchanger and fan.
An independent thermostat controls each room unit.

Most of the machinery (i.e. the compressor, cooling coils, fan) sits
on a small concrete pad outside the house.  The smallest units are
somewhat larger than a large suitcase.

The advantages of such a system are ease of installation  (a tiny supply
and return pipe for each room), very quite operation, individual
thermostat control for each room, and heating in the winter (via heat pump).
They have relatively high efficiency due to their variable speed
compressor (which also keeps the noise down). You can pay extra and
get wireless remote control thermostats, too.  (In Japan, I
always confused those wireless controls with the ones for VCRs because
I couldn't read the settings; this occasionally led to unintended
consequences.)

The disadvantages are high price and relatively low capacity.
Furthermore, your local contractor may be unfamiliar with
these units.  Almost all air conditioners installed in Japan
are of this design.  American manufacturers are at least five
years behind (sigh).

I'm looking at an ad in Home Energy magazine for Toshiba air 
conditioners.  They have an Illinois phone number (708) 541-9400 ext 345


From: jwc@Unify.Com (J. William Claypool)
Subject: Re: Central Air

In article <1991May15.170551.96@cbnewsm.att.com> cma@cbnewsm.att.com (christine.m.agonis) writes:
>
>What I found out so far about installing central air since
>I am now getting estimates for it:
>
>- don't use that "pressboard/fiber" ductwork, it leaves a yellowish
>  dust on everything since it flakes,
>  look for aluminum or copper tubing ductwork
>
>- look for an efficiency rating of 12 or higher, I think
>  13 is the highest, we found a 12.2 and a 12.8 so far

Actually, Trane makes an AC with varaible speed compressor which has
a SEER of 17-24.  17 when running at full speed, 24 at low speed.
It costs about twice as much as their SEER 12 model.
-- 
Bill Claypool					| Unify Corporation
jwc@Unify.Com		Voice: +1 916 928 6259 	| 3901 Lennane Drive
....!uunet!unify!jwc	  FAX: +1 916 928 6401	| Sacramento, CA 95834-1922


From: dougl@hpdmd48.boi.hp.com (Doug Leno)
Subject: Re: Central Air

in  hpdmd48:misc.consumers.house dougs@telxon.UUCP (Doug Saunders) writes:

>  Interesting, I am currently getting estimates to have central air added
>  to my house. Carrier, at least locally, is running a "No Payment 'till
>  Labor Day" program. I called 2 of the companies listed in the ad, and both
>  specfified the same 2 ton "TECH 2000" unit which has a SEER of about 8,
>  (and they wanted about $1600 for it). I too thought that sounded a little 
>  low, and inquired about higher SEER-rated units. The salesman said that the
>  one he quoted me for originally was the one that most people go with, but I
>  could get a 9 SEER model for about $400 more, and a 10 SEER unit for about
>  $2400! He said that payback for these units was too far out for most people,
>  (my electricity runs about 12.2 cents per KW/h). Annual operating costs were
>  estimated at about $200.

AT $200  total  cost per  season, it would  take  close to 20 years to
recover  the $400  additional  cost of the 9 SEER  unit.  You might be
interested  to know that (for  example)  the list price of the Amana 9
SEER equipment is only $180 less than the Amana 10 SEER equipment.

Anyway, I am currently  getting  estimates too, and am considering the
same issues.  Here are some of my considerations:

        There are only  three  makers of  compressors  from  which all
        major A/C and heat pump  manufacurers  (except  Trane) use.  I
        was  advised (by an A/C service  guy) to only  consider  units
        with  either   Copland  or  techumse  (sp?)  compressors.  The
        recommendation   I  got  was  to  stay   away   from   Bristol
        compressors.

        Trane units seem to be built  differently than others in a few
        areas.  They do make their own compressors (and are reportedly
        very  good).  To  boost  SEER,  Trane  has  a  rather   unique
        spine-fin design - this makes the condensing coils  impossible
        to repair if the fins get crushed, but they are protected well
        with the cabinet.  Another  area of  difference  is that Trane
        uses the  "Aeroquip"  quick  disconnect  connectors  for freon
        lines.  I've been  told that  they are  better  than  standard
        compression  fittings, but that  installation is very critical
        for a proper seal.  Another advantage is that pre-charged line
        sets can be installed  without the need to purge and recharge.
        perhaps that benifits the installer more than the consumer?

        A few  features  on the "low end" (8-10 SEER)  units that were
        recommended to me were:

                Crankcase  heater.  The least  expensive  8 SEER units
                generally do not have them.  Although rather manditory
                on heat  pumps, they do benifit (I was told) A/C units
                because the  compressor  spends  less time  running at
                less   than   operating   temperature.  Some  sort  of
                thermostatic  control  is  best,  so that  the  heater
                doesn't run all the time.  Heaters that do run all the
                time  apparently  don't  consume very much power - and
                the SEER rating includes this anyway, I'm told.

                Low  pressure  switch:  Cuts out the  compressor  when
                freon pressure goes below some point.  Seems like this
                would really be appropriate for units with compression
                or Aeroquip  fittings, due to the possible  failure of
                the connector.  Seems to me the brazed lines would not
                be as critical  an  application  for the low  pressure
                switch.

                Aluminum  coils.  All the major units  (except  Trane)
                have had  trouble  with Al coils.  Go for copper or go
                for Trane.

		Finally, units with service valves are easier to work
		on.

It  seems to me that if the  incremental  cost of a higher  SEER  unit
cannot  be  recovered  before  approaching  the  expected  life of the
equipment,  than it does not make sense to purchase the more expensive
unit.  One  might  also  want  to  factor  in  the  possibility  of  a
electricity rate increase.

A heat gain  calculation  should  always be done on your house  before
purchasing  an A/C  unit.  I was  told  that  oversizing  the  unit is
disastrous for efficiency.

To estimate operating costs, you can use the number of "cooling degree
days" per season for your area.  In Boise, a cooling degree day is one
day where the average  temperature is one degree over 80 F.  I got the
number  from the  local  power  commpany,  and then used the heat gain
calculation  (expressed  in BTU/HR for 20 degree drop) for my house to
estimate $$ per season cooling costs.

For my purchase, I am applying  the folowing  arbitrary  rule:  If the
increased cost of the higher SEER unit is recovered within 10 years at
the  current  electricity  rate + 30%, I  will  probably  buy  it.  Of
course, I plan on being in the house at least 10 years.

In  case  anyone  cares,  I'm   considering  an  Amana  unit.  Copland
compressor, 9.00 SEER, thermostat  controlled crankcase heater, brazed
lines, copper coils.  No factory Low pressure switch but can be added.

By the way, after  January,  1992 I  understand  it will be illegal to
produce  an A/C unit with SEER less  than 10.  So if an 8 or 9 SEER is
what you  want, get it now,  'cause  next year 10 SEER is all you will
find, unless someone has stocked some old models.

--
dougl%hpdmm04@hpdmd48.boi.hp.com          dougl@hpdmm04
relay!hpdmd48!hpdmm04!dougl              dougl%hpdmd48@relay.hp.com  
 


From: GA.MCL@forsythe.stanford.edu (Mark C. Lawrence)
Subject: Re: AC tonnage ratings: what do they mean?

In article <4458@uakari.primate.wisc.edu>,
bin@primate.wisc.edu (Brain in Neutral) writes:
>When one speaks of a "2.5 ton" or "3 ton" central AC unit, what does
>this refer to?  It's not the weight of the unit, I guess.  Amount of
>compression generated per some unit of time?

A ton of cooling is what you get by melting a ton of ice in 24 hours.
Figured like this:

Latent heat of fusion = 144 BTU/lb  (80 cal/gm)
2000 lbs. x 144 btu = 288,000 btu/ton ice
288,000/24 = 12,000 BTU/hr.

so, 12,000 BTU/hr. of cooling.

******************* END OF SUMMARIZED RESPONSES ****************
Newsgroups: misc.consumers.house
Subject: Re: hollow-core door questions