Conference 7.286::home_work

When I lived in California, we had a Lennox heat pump (converted from propane),
and it was great on fuel bills, etc.  This was air source.  The only problem
I had was that the fan, the evaporator/condensor, and the air cleaner were in
the attic, and that made it pretty noisy when it was running.  Also, the 
compressor was too noisy.  The compressor sat outside on a slab right next to
the house, and the vibration ran right up the wall of our bedroom.  If I were
to put in a heat pump now, I would shock mount everything, and put it all in
the basement on thick slabs.  Most of the noise problems are conductive, not
through the air.  

The ground source thing really seems to make a lot of sense in this (NE) 
climate, and it should not be that expensive if it were done as part of the 
initial construction of the house.  I would think that if it were more 
common, it would be a lot cheaper, just due to economy of scale.  An 
interesting question I have is do all heat pumps work only in a forced air
type system, or it is feasible to get high enough temperatures (200+) to work
in a FHW system?  I prefer FHW because of its relative silence.  Of course I
realize that you can't pump the other way (Air conditioning) with this method,
but it is an interesting question.

    Heat pumps are feasible in Massachusetts, though I would recommend
    doing some research before approaching dealers.
    
    THIS OLD HOUSE installed a heat pump in its Energy 2000 house down
    in Brookline in '84/'85 (Boston 'burb).
    
    Dwight

    RE: .0
    
    The efficiency of the heat pump is lower in winter but it dosen't
    mean that it doesn't work. You need a secondary heat source (usually
    electric coils). My father-in-law has a system in their central
    Utah home. His overall energy savings in the past 5 years has paid
    off the heat pump. They get the western slope winters with temperatures
    averaging in the teens in January and February.
    
    /cal hoe

    From reading that I've done, apparently the point at which
    "supplementary heat" [electric heating elements] is required
    is about 30-32 degrees. Above this point you are operating
    with a COP [coefficient of performance] of greater than 1.
    This probably varies from unit to unit.
    
    Less than 30 degrees renders a COP of less than 1. In other words
    for every one unit of energy input, you are getting something less
    than one unit out. This, of course, is conventional operation. The
    beauty of the heat pump lies in the ability to achieve greater
    than 1 coefficients of performances above 30 degrees, or for every
    one unit of energy input, you get greater than one unit out.
    
    Yes, but isn't this perpetual motion or snake oil or something?
    
    Not really, because we aren't *CONVERTING* energy from one form
    to another, just using energy to move other energy from one place
    to another. BTW, one Popular Science article had one interesting
    application by using a simple solar panel on the input to the
    heat pump and boosted the COP to a whopping 8!
    
    Charlie 

    With a greater initial cost, the heat pumps that extract heat from
    the ground in some fashion rather than the air would seem less prone
    to needing the electric heating elements, provided they can get deep
    enough, where the ground stays temperate year round. The version
    that was installed in the All New This Old House some years back
    operated on a brine solution (?) pumped down into the ground
    quite deep. Since its source of heat was not dependent upon the
    ambient air temperature, I assumed it was immune from the need
    for supplemental heat. Anybody have concrete details?

    I would recommend you folks refer to note 62. I placed some info
    there about a year ago regarding my ground water heat source system.
    
    All I can say is it works great....
    
    Merle

	Extracted from the Springfield, (MA) newspaper..

	Question: My water heater is going fast...
		  I have heard of an electric water heater that can help
		  to air-condition and dehumidify, is it energy efficient?

	Answer:	  Referring to an electric heat pump water heater.
		  It is basically an air-conditioner-type of system built
		  around a water heater tank.  Instead of the heat being
		  blown outdoors as with an air-conditioner, it is transferred
		  to the water in the tank.

		  Heat pump water heaters are very energy efficient, using
		  less than half the electricity of a standard electric water
		  heater.  That can mean a savings of hundreds of dollars
		  a year for a large family.

		  Often, they can compete favorably with the cost of operating
		  a standard gas water heater.  Although their initial cost is
		  substantially higher, the savings can easily pay back the
		  additional cost, and you get the free air-conditioning too.

		  A high efficiency heat pump water heater has a coefficient
		  of performance, COP, of 3 or more.  That means you get the
		  equivalent of 3 kilowatt-hours of electric heat for each
		  one you buy from your electric company.  There is also a
		  backup electric heating element in the water tank.

		  This type of water heater works by drawing heat out of the
		  surrounding air.  If the air is damp, more the 60% RH, then
		  some of the heat comes from dehumidifying the air.  The rest
		  of the heat comes from cooling the air, thus air-conditioning
		  the area - a plus in the summer.

		  Especially in colder climates, you should locate the heat 
		  pump water heater near your furnace if possible.

		  In the winter, it then draws its energy for heating the 
		  water from the furnace's waste heat that would normally
		  be lost anyway.  This is often in a basement or crawl
		  space where dehumidification is also needed.

    

    I know that this isn't quite the season for doing this, but here
    goes.  My heating system is forced air with a heat pump and an electric
    furnace backup.  The electric furnace is turned on via a switch
    on the thermostat labelled 'emergency heat'. 
   	I know that theoretically, a heat pump should be able to extract
    heat from the outside air and transfer it to the inside air down
    int sub-zero temperatures.  However, there is a point at which it
    makes more sense economically to simply switch to the electric furnace
    and use resistance heating.
    	I have two questions:
    
    1.	Is there a 'rule of thumb' for determining the temperature at
    	which one should switch heat sources.
    2.	Is there a thermostat that will sense outside temperature and
    	switch heat sources automatically?  If so, how much $$.
   
    					Thanks,
    					Larry

    Never dealt with those rigs, so this is off the wall, but why not
    attach the electric furnace to a seperate thermostat set somewhat
    below the setting of the heat pump thermostat?  (It should be in
    the same location to make sure it measures the same temp as the
    main 'stat.)  The furnace would then come on only if the pump couldn't
    maintain heat.
    
    /Dave

    RE .1
    
    It has never gotten so cold that the heat pump could not maintain
    the temperature in the house.  The place is pretty well insulated.
    I don't know the R values, but in the attic, there's about a foot
    of fiberglass batts.  The place was built in 1978, so it's not too
    old...it was built in the days of high energy costs.  I want to
    switch over to resistance heat at the financial break-even point,
    not at the point where the heat pump can't maintain temperature,
    which would be considerably below the financial break-even point...
    Also, an objection to .1 is that a seperate thermostat set lower
    than the main one would cause the electric furnace to cycle on and
    off but the heat pump would run all the time, since the house would
    never get warm enough to cause the heat pump thermostat to turn
    off....
    					Larry
    
    

    Larry
    
    My late wife's folks live in central Utah and have run a heat pump
    since 1978. The unit has a fixed thermostat that kicks in the
    electric coils when the air from the heat exchanger drops below
    52�F. He uses a back up Kerosun heater from the adjoining hot house
    that's part of his air preheat system. Here's a man who grows tomatoes
    in the middle of January and keeps his heating bills to less than
    70$ per month through the coldest months of January and February.
    
    /cal hoe

re .0
    
>        1.	Is there a 'rule of thumb' for determining the temperature at
>       	which one should switch heat sources.
    
    I was browsing through Sears Cooling Catalog and noticed
    that their heat pumps turn on the electric heating  element
    at 45 F.
    
    It is also interesting that their efficiencies ranged from
    280 to 300 % (even natural gas costs more) with an outside
    temp of 47 F.  Too bad, for us folks up north, that he have
    a lot of weather below 45 F.
    
    - gerry

re Note 821.1 by CADSYS::BURDICK:

> interesting question I have is do all heat pumps work only in a forced air
> type system, or it is feasible to get high enough temperatures (200+) to work
> in a FHW system?  

I'm interested in the answer to this question, because I have to replace a FHW
boiler and oil burner, and I'd love to get away from storing and using a fuel
in my basement.

Bob

    I suspect the answer is "yes". My system heats my hot water, in
    addition to the FHA. 
    
    As I recall when the system was originally installed they indicated
    I could have the system either way. I will give them a call and
    verify this statement and file the info here.
    
    Merle

re Note 821.7 by COLORS::FLEISCHER and Note 821.1 by CADSYS::BURDICK:

In particular, I would like any recommendations of contractors who install heat
pumps.  My 9-year-old oil-fired boiler has burned a hole though its side, and
winter's coming!

Bob

    Mine was installed by Aqua Systems Inc in NH.. 
    
    Call 603-778-8796  Ask for Ernie Cherry.
    
    Merle

    
    	A couple of basic heat pump questions...
    
    	1)  Can it be connected to my existing FHA system?
    
    	2)  How many $$$$$s to get into the game?
    
    	3)  What is the cost to run it and how many BTUs are obtained?
    
    	I realize that all three of these questions will have answers
    that vary from model to model, but I'm just looking for some
    generalities to see if I should look into this deeper...  Thanks!
    
    							-craig

    First question = Can you use on a FHW system ? Answer: Yes
    
     I spoke to Ernie and he stated the heat pump will work but the
    high range for the water is 130 to 140 degrees. This means you have
    to size the amount of baseboard radiators to meet your heat demand.
    Determine the heat (BTUs) for your area and then determine how much
    baseboard you need (specs on baseboard will tell you the BTUs/foot
    dependent on water temp). 
    
    Next question(s)
    
        1)  Can it be connected to my existing FHA system?
        
    		Yes.
    
    	2)  How many $$$$$s to get into the game?
    
    		Difficult to answer without knowing size of unit needed,
    		whether you are going to use for hot water, A/C, etc.
    
    		Call Ernie and provide details.
    
    	3)  What is the cost to run it and how many BTUs are obtained?
    
    		Same as 2. Depends on size of unit. 
    
    		Call Ernie. 
    
    	Aqua Systems Inc - 603-778-8796
    
    	I will state that my system is working very effectively and
        am quite satisfied with the operation.
    
    	You will have to speak with the technical wizard and determine
        what your costs would be. Ernie would be happy to discuss with
    	you and I am not about to speak for him or their company (except
    	to say I am very satisfied with their product).
    
    Merle
      
     

My basement has been tested as having a moderate Radon problem, and I am
interested in air-to-air heat exchangers as one way of ventilating the basement
and perhaps the entire house.

I don't know anything about air-to-air heat exchangers, and I don't know
anybody who has one.  Does anybody reading this have some experience with them? 
Can anybody recommend a contractor and/or dealer in the Nashua or Lowell area
that deals with them?  How do they work?  How much do they cost?

Thanks,
Bob

    
    Bob, they (air to air heat exchangers) are a fairly common component
    in industrial HVAC systems, so getting the device should be no problem.
    I can think of a couple of places to get them -- Chet Kelly Sheet
    metal located in Lowell is a large HVAC contractor, and there are
    several other suppliers listed and recommended in several of the
    notes pointed to by the keyword -- HEATING_FHA.
    
    You might also consider contacting one of the state agencies dealing
    in this problem, as well as the University of New Hampshire at Durham
    (they do a lot of testing and publish materials dealing with corrective
    measures, so they might be a good source.
    
    Good luck.
    
    /Dave

    I have a NUTONE air exchanger that I installed into my home last
    year... very happy with it, and the cost (approx. $375+ducts). I
    installed mine for the main house because I found that I had built
    the house too tight..... It operates between 75-95% efficientcy
    depending upon direction of moisure transfer and inside to outside
    temp differential..... Can be bought with all the fixin's at MASS
    GAS and ELECTRIC in Boston.... They have them in stock I believe..
    
    
    							Dave Hartwell
    

    Another place that has these is Solar Component Corp.  121 Valley St.
Manchester, NH, 603-625-9677.  Last I knew, they had a catalog, too.

There are two basic kinds of exchangers.  I have the rotary kind, made
by Bernier.  The rotary kind is resistant to internal frost buildup. It
works with a rotating drum with corrugated passageways. Stale indoor
air deposits heat and moisture on the drum, and exits the house. The drum
turning is timed, so that the same passagway then takes outside fresh air
and transfers the heat and moisture to it, returning to your inside air.

    And now, for a question.  I had my electric hot water heater wrapped
    last October, but just got around to insulating the hot water pipes
    this weekend.
    
    The heater and pipes are in an unfinished basement of a split-ranch.
    The basement is occasionally heated by the wood stove (about 40%
    of the time).  The basement ceiling (the main floor) is well insulated
    with 6" pink fiberglass.
    
    Two sections of pipe (about 2' each) are partially covered by the
    pink insulation, and partially exposed.  Should I put the foam tube
    insulation around these as well?
    
    I'm asking because I'd have to buy another package, but I'd rather
    not if I don't need to.
    
    Thanks.
    
    Elaine

    We've been having problems with our heat pump and were wondering
    if anyone could solve our problem.
    
    The heat pump is a rather old unit (probably as old as the house which
    was built in either '71 or '72).  The problem is that the compressor
    often will turn itself off, leaving the fan running until the interior
    temperature gets low enough (in the winter) to turn on the second stage
    resistive heating coils.  This means that the system blows *cold* air
    for 3-5 degrees of thermostat range!  Of course, the problem is
    reversed in the summer, where the system blows hot air _all_ the time!
    To rectify this problem, I've got to go outside, remove the cover
    on the unit, and reset the system.  Ain't no fun when it's 35 and
    raining!
    
    This problem has been around for a long time.  My father-in-law
    (who had the house before us) had the unit "repaired" many times
    - I think just about everything has been replaced in it!  I've just
    about given up on someone else fixing it and am ready to either
    fix it myself or get a new one (gag!)
    
    My first guess is that it may be dirty AC coming down the line,
    causing some protection relay to trip.  Am I off the wall?  Is there
    an easy way for me to determine this?  The AC *seems* to be relatively
    clean while we're home, but what may be clean as viewed by a light
    bulb may be filthy when seen by some overly-sensitive circuitry!
    
    The unit is a Westinghouse HE036S1A, with a 35000 BTU heating and a
    26000 BTU cooling capacity.
    
    Additionally, I was wondering about simple ways to make the unit
    more efficient.  I've seen some suggestions about covering the unit
    in the summertime to keep it cooler, and was wondering about a simple
    method to direct solar energy onto the coils to help heat them in
    the winter.  Anyone have any ideas?
    
    Thanks for any help in advance,
    
    Aaron

    Okay, since noone would answer my question, I decided to do a little
    leg work and answer it myself.  I went down to the local library
    and got an excellent book on heating and refrigeration systems
    troubleshooting, which went into significant detail on exactly what
    my problem could be.
    
    I am experimenting with one possible solution right now.  I've
    increased the airflow over the inside loop coils to aid in the
    cooling/heating of them.  Said another way, I replaced the air filter
    with a clean one and opened all the vents! 8^)  It seems that a dirty
    filter on an overworked heatpump is sufficient to cause overheating
    of the indoor part of the loop, enough so to trip the protection
    circuitry, taking the compressor out of action.  Same thing happens
    in the summer when it overcools.  Additionally, we'd closed off
    several of our vents in unused rooms; we've now opened them back
    up to aid the air flow.
    
    I'll report back whether or not this is successful.

    Aaron

    Now we all know a little more.

    It's been working fairly well since I last reported.  Haven't had
    to replace the air filter yet, but that will probably happen soon,
    now that pollen season (Aachoooo!) is upon us!
    
    But, I've also got an interesting story to relate.  My wife was
    laid up at home for a week with back problems.  During that week,
    she saw power fluctuations occur at least once daily!  Not complete
    blackouts, sometimes not even significant brownouts, and occasionally,
    spikes.  Sometimes it would throw off our clocks, other times, not.
    But it would usually throw off the heat pump!  Seems that TVA doesn't
    know how to make 'clean' power!
    
    Now, if I can get a Power Conditioning System + through the Employee
    Purchase Plan at a 50% discount, I'll be broke, but will be able
    to live through the worst of the thunderstorms!
    
    Anybody know where I could get a transient suppressor for a 220v line?
    
    Regards,
    
    Aaron  :^)

Speaking of heat pumps and power ...

does anyone know whether it's recommended to shut off the power to a heat
pump during the summer?  (I don't use it to air condition.)

I don't know if it draws much current ($$) just sitting there all summer,
but would it be easier on the motors, etc. to cut the power when I don't
need it?  Conversely, what harm could shutting it down do?

Thanks,

Brian

When we built our house three years ago, we purchased a heat exchanger and
installed some ducting for it, and but never got around to installing it.  Now
we're looking at installing it, but I'm not sure if it's really necessary. 
We've never noticed the house being particularly stuffy in the winter.  Our
woodstove draws perfectly fine, including when it's just starting.  And the
humidity in the house stays fairly low, all of which are indications that we
are getting sufficient air exchange.  We are going to be doing some additional
sealing of the basement and solarium, but I don't think that will eliminate
enough air exchange to make a significant difference.  Are there any sorts of
air quality tests or air exchange tests that can be done to tell whether we
need the thing?  We'd probably have to spend another $100 on ducts, and install
them in a fairly convoluted fashion, so if I don't need it, I'd rather sell the
thing for $300 or so and be done with it. 

Paul 

    Mr. Moderator: I have read all of the heat pump notes and replies
    and have not found any that answer my question. If I missed one
    please direct me to it.
    
    This question is in anticipation of the upcoming heat season. I
    have lived in a condo for the last two years which has heat pumps.
    It has two pumps, one for the first floor and one for the second.
    I have not been satisfied with the heating of the condo when the
    temperature falls below 20 degrees. It is my understanding that
    the back-up heat source (electric coils) should kick in when the
    heat pump can't keep up with the demand for heat. There are settings
    on the pump so that you can adjust the kick in temperature for the
    back-up heat. I have them set at 20 degrees. What happens when the
    temperature falls below 20 degree is that the heat pumps will run
    constantly and the temperature set on the thermostat never is 
    reached. I have had the temperature set for 70 degrees. The condo
    has 6" outside walls and it well insulated. Only two of the walls
    are outside walls. The other two abut other units. I assume if the
    units never turn off then the set temperature is never reached.
    I can manually turn on the back-up heat, which I have done on several
    occasions, to help raise the temperature.
    
    Does anyone have any ideas as to where the problem is? Is it the
    thermostat or the heat pumps? Can help would be appreciated.
    
    

    Normally the onset of backup resistance heating is controlled by
    the thermostat.  The thermostat has two sets of heating contacts,
    one a couple of degreees lower than the other.
    
    Make sure there aren't any tripped breakers; the resistance heating
    is often on a separate breaker, even though it is in the same unit.
    
    ...tom

    This is at a condo in Chelmsford, Massachusetts.  
    
    PROBLEM (?): This heat pump system includes two major components;
    an indoors "box" that moves and filters air and contains backup
    electric elements, and an outdoors "box" that extracts heat from
    the air.  Our problem, if we indeed have one, is that the outdoors
    box (about the size of a dishwasher) has some pretty heavy frost
    building up on its internal coils and external louvers.
    
    BACKGROUND:  When we moved here in November we did a few things
    in preparation for winter.  In addition to plastic on the windows
    and changing the heat pump air filter, I noticed that the foam
    conduit insulation on the 1/2" copper pipe running between the
    building and the outside box had completely deteriorated....so,
    replaced it.
    
    RESULT:  The heat pump seems to be running more efficiently now
    than before the winter prep -- in spite of the frosting.  Here,
    more efficient means that we do not need the electric back up
    as much as before.  
    	     I called the resident manager and he says frosting is
    normal.  I have trouble believing him.  First, no other unit in
    the twenty or so that I can see has any frost build-up whatsoever.
    Second, I'd guess the coils and the louvers are there for a purpose
    and suspect that the frost could be reducing efficiency.
    
    Does anyone have experience in this area?
    
    Thanks, RC

    Hi,
    
    	Heat pumps usually have a reverse cycle built into the via the
    controls, that cycle some of the heat from inside the house(without
    the inside fan operating)for a few minutes every so often to reduce
    the frost buildup on the outside coil. Check the maint. manual for
    the unit, there should be a simple wiring diagram in it that will
    show the defrost timer, if there is one and whatever other controls
    are associated with it. Then you can probably determine if your
    unit is equiped for defrost and if it is working correctly.
    
    Paul L.

.5 you have a classic problem with older heat pumps.  .6 is correct.
Call in a maintenance person.  In the mean time, if the frost build
up gets too far out of hand, turn the airconditioning on this will
force the reverse cycle and, by pushing hot air out to the unit,
full defrost the heat pump.  Our condo days saw us doing this a
few times each winter!  Not a big expense!

Douglas

    The repair person came yesterday while we were out.  He/she didn't
    leave a note but the ice was thoroughly removed from the unit and
    it is working fine.  We are renting this condo so I doubt we'll
    ever hear what was done but I'll keep an eye out for the automatic
    reverse cycle mentioned in .6 and .7.  And will watch for frost
    buildup and will run the AC if needed.  
    
    Thanks!  /Rick

    I'd appreciate some advice on the pros and cons of electric 
    heating.  Specifically, I'm considering buying a house (in 
    Massachusetts) which has electric forced hot air with twin heat 
    pumps.  From the look of it, the heat source is air; there are
    some hefty fans outside the house.  I imagine the secondary
    heat source must be resistive heating, since there's no other
    fuel in the house.
    
    The idea of electric heating sounds like bad news, but I have
    no experience in these matters, so I'd welcome any comments
    you might have.  Other discussions in this file about electric
    heat focus on baseboard and radiant heating, and the heat pump
    discussions are useful but don't directly answer my questions.
    
    The house is located in Littleton, MA.  Power is provided 
    by Littleton Power & Light, which has a reputation for being
    pretty cheap compared to other electric utilities.
    
    The electricity bill for the house (heat, hot water, the lot)
    was $2100 in 1989.  I don't have any way of knowing "how much"
    they used the heat; i.e. was the house kept warm all day every
    day, or did they turn it off except for the evenings when they
    were at home;  so I'm not sure this figure really tells me 
    much.  The building is a 2300 sq.ft. Garrison Colonial, by
    the way.
    
    Since the overpriced Seabrook came on-line last week, will I see 
    my rates rise or is that only a problem for New Hampshire residents?
    I don't understand the politics of energy here, I'm an import 
    from a country that until recently had a nationalized electricity 
    industry.
    
    Even if this heating system is reasonable, what effect might
    it have on resale ability?  (Of course, I'll press for a
    price reduction to me on the same grounds!).
    

    My wife used to live in an apartment built in the last 3 years and
    approved as "Energy wise" by the local utility companies which
    indicates it has superior insulation, double pane insulated windows,
    etc.  It also had FHA using an electric heat pump.  
    
    She was unhappy with it.  The way it heats is it draws heat from some
    other source (surrounding air, water etc.) and then heats the air
    moving thru the system by confection.  This ususally heats the air in
    the system 1 or 2 degrees.  It blows this "warmer" air into the living
    space.  Draws out the "cooler" air in the living space and warms it 1
    or 2 degrees and puts it back in the living space.  
    
    The problem is if your interior temp is 65 and you want to raise the
    heat of a 2000 sq ft house by 3 degrees, you have to exchange all the
    air in the whole house at least twice assuming no lose of heat due to
    people coming and going.  The air coming out of the registars "feels"
    cool to the touch because it is only 66 degress.  Your body temp is 98
    degrees.  Significant difference.  
    
    Set back thermostats only worsen the problem.  When using FHA with
    electric heat pumps, pick a temp. and stay at it.  If the source used
    to heat the air it not sufficent for the demand, electric heater coils
    are used to heat the air.  You are now creating heat using electricity,
    not natural occuring heat sources.  $$$
    
    I lived with her for a while and hated always feeling cold and having
    "cold" air blowing on me.  Yeah I know that the air is 1 degree warmer
    than the air I am sitting in but still not the temp I want to feel
    blowing over me.  
    
    FHA with gas will typically blow air of about 85-100 degrees out a
    registar.  You can feel the room warm up in about 10 minutes.   I
    personally would never have a house with FHA and and electric heat
    pump.  Particularly in the North.
    
    

    
    
    	Ditto on the previous note, except I would like to add that
    with heat-pumps once you get down to 35 deg F, or close to that,
    the heat-pumps are not capable of extracting enough heat from the
    cold outside air. To overcome this the manufacturer has a thermal
    switch installed in the outside section that cuts the compressor
    off and turns on the electric resistance heat on if the temp. outside
    is below a predetermined level. So basically what happens here in
    the Northeast is the furnace runs as a very inefficient electric
    heater for most of the winter. Now, my experiece is based on the
    units that were manufactured from  1975 to somwhere around 1983.
    if you have a newer model they may have gotten more efficient in
    extracting heat in the pump mode.
                                     
    	I recently converted my own house from baseboard electric to
    gas FHA because of the heating costs here in So. NH. Electric
    heat looked like a great idea when I was building, cheap to install,
    easy to maintain, no fuel storage. But I'll admit it, I should have
    gone with the more costly version the first time around.
    
    	I would not recomend electric heat or  heat-pump that used the
    outside air as a heat source here in New England. They would probably
    be great in, lets say, Virginia etc.
    
    	Just my opinion.
    
    PL

    
      I live in Littleton, heat and hot water are FHW by oil, then
    there's the electric.  My annual cost is about $1500-1600 for
    this combination in a smaller home than you describe.
    
      Littleton is one of the few towns that did not get in on
    Seabrook, thus the low rates, in fact in November for the past
    2 years, residential customers received free (that's right no bill)
    electricity.  Overall, the town's water and power companies seem
    to be well managed.
    
                          Mark

    Our house is tight enough that we're considering adding a way to
    bring in some outside air to get rid of the stuffiness. Also, my wife
    objects to the odor (ozone?) given off by the electrostatic air cleaner
    on our FHA heating system. So we're looking at air-air heat exchangers.
    
    Does anyone have any experience with a RecoupAerator air exchanger?
    
    I'm looking at model SW-115 which is a 20x20x9 unit that can be
    mounted in a window or through the wall (RecoupAerator is made by
    Stirling Technology of Athens, OH). Specs say it replaces air at 65-90
    CFM, uses 90-100 watts, recovers 90% of the intake heat, and retails
    for about $450.
    
    Any info will be appreciated!
    
    -Paul

    Builder's Square has a Ventex VT-80 window/through wall unit on
    sale for $199 (normally $249).  According to the manufacturer,
    it will handle a room size of 1000-1700 square feet (assuming a
    standrd 8 foot ceiling).
    
    The manufacturer has a toll-free number for information; (800)
    243-5114.
    
    No experience with it, just noticed it when I was wondering if
    I would need one for a basement recreation room conversion.

    
    heat pumps are chip to operate, But It feels cold in the house. I just
    bought a new house and, It has a heat pump, I think It uses the air as
    a heat source. When the air comes out, It feels cool, eventhough the
    termostate is set to 70, and the temp stays around 68, somehow it feels
    cold. I used to have a oil heat in my old house, and I kept the temp.
    around 68, The house was confortable. I know you guys going to say ,hey
    it shows 68 in the house, how come you feel cool, I think Its that air
    draft from the heat pump makes you feel cool then it realy is..I think.
    Is is the way heat pump works? 

    Is the blower fan on all the time ?  Moving air always feels cooler
    than still air of the same temperature.  This is a known problem
    with heat pumps.
    
    The other difference may be calibration of the thermometer and
    thermostats.  It sounds like your thermostat and it's associated
    thermometer have a different idea as to what the room temp. is.
    And then 68 in your old home may not be the same as the new one.
    
    You may well find to be comfortable in your new hoem you'd have
    to increase the temperature by a degree or so for the same comfort
    level.
    
    Stuart

    The temperature of the air coming out of the vent with a heat pump
    system is lower than that coming out with a gas/oil FHA system. So, 
    although the overall room temp is OK, the flow of air feels "drafty".
    Its just part of the nature of the beast.
    
    Eric

>    The temperature of the air coming out of the vent with a heat pump
>    system is lower than that coming out with a gas/oil FHA system. So, 
>    although the overall room temp is OK, the flow of air feels "drafty".

      Yes,  it  can  feel "drafty", but the problem is NOT with the heat
      pump.  What you need is to avoid having heated air blow forcefully
      from  vents.  There are several ways to do this:  (1) Install more
      vents so that less air blows from each of them.  (2)  Install  the
      vents in an area where you won't feel the "draft".  (3) Use grills
      on the vents that are designed to spread the air flow in  a  wide,
      even  patter,  rather  than concentrated "drafts".  (4) Use larger
      vent  openings.   In  most  cases  a  combination  of   these   is
      appropriate.
      
      BTW  these  techniques  will  make ANY forced hot air system, heat
      pump or not, more comfortable to live with.

I have had an exchanger for a number of years, and now that I'm
doing some ceiling work in the basement, I plan on moving it closer
to the furnace. At the same time, I'm thinking of reconfiguring the
inlets/outlets as I am not totally happy with the current setup.

Currently, I have:

                <<<<<<<<<<<<<<<<<<<<<return air duct
hot air         vv               v
to house        vv               >>>>>>>v        <<<<<<<< outside air
     <<<<^      vv                      v        v
         ^      vv<<<<<<<<<^            =========
	===========	   ^		||     ||
	||	 ||	   ^		||     ||air-to-air exchanger
	|| 	 ||	   ^		=========
	===========	   ^		v	v
	hot air furnace    ^<<<<<<<<<<<<<       >>>>>>>> exhaust to outside

The problem with the above is that I suspect there may be a closed loop
formed with air-to-air exch air within the return duct. In addition,
when the furnace is off, any use of the heat exchanger would be
useless, as there most certainly would be a closed loop formed.

The only thing I've come up with so far to improve, if not fix the
situation is the following:

                <<<<<<<<<<<<<<<<<<<<<return air duct
hot air         vv               v
to house        vv               >>>>>>>v        <<<<<<<< outside air
   <<<<<<^      vv                      v        v
     ^   ^      vv                      =========
     ^	===========	    		||     ||
     ^	||	 ||	   		||     ||air-to-air exchanger
     ^	|| 	 ||	   		=========
     ^	===========	   		v	v
     ^<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<       >>>>>>>> exhaust to outside

Naturally, with this method, any air supplied by the heat exchanger
is not heated by the furnace, and also bypasses the furnace filter.
But on the other hand, having more distance and obstructions between
the inlet/outlet lessens the possibility of a closed-loop flow.

Do you think the plan I have will work? If not, any improvements or
better ideas?

thanks!

dave l
                                                            

    This runs the risk of not working either because by feeding the outlet
    of the heat exchanger into the hot air side of the furnace, you are
    the pressure of the furncae fan may well push the air backwards
    through the exchanger (the furnace fan outmuscling the exchanger
    fan).
    
    As it is now, when the furnace is running, there should be no problem,
    the suction of the furnace will prevent the exchanger short-circuiting.
    But with the furnace fan off, the exchanger will definitely short
    circuit.
    
    The real answer is to have the furnace fan operating (albeit slowly)
    when the exchanger is running and leave the ducts set up as is.
    
    Stuart

Why is there any value in having a fan run in the heat exchanger when 
the furnace is off?  Why not just hook up the heat exchanger fan to
only come on when the furnace fan is on?

	Larry

    Well, the heat exchanger fan is supposed to move sufficient air in and
    out of the house to perform the required ventilation ... and they
    are normally set up with separate duct networks ...
    
    But in this case they have attempted to integrate the two duct
    networks.
    
    There are a number of possibilities here ...
    
    1.  have the furnace fan on low when the exchanger fan is on ...
    
    2.  install a baffle into the cold air return duct to direct the
        outlet air from the exchanger into the duct towards the furnace,
    	but not such a big baffle as would seriously impede the flow of
    	air when furnace fan is on full.
    
    3.  probably the best solution is to run a separate intake
    	air duct into the exchanger from a couple of strategic points in
    	the house if feasible.  (I have a bungalow, so it would be
    	comparatively easy.)  And not take the intake air from the
    	cold air return duct at all.
    
    Stuart

I recently moved into a newly-built home that uses a TempStar multi-stage 
heat pump (sorry, I don't have btu info with me at the moment) which uses 
the outside-air as it's heat source.  This is the first house I have had 
that was heated/cooled by a heat pump -- all other experience (with 
exception of heating oil in W.Germany) has been natural gas, forced air 
heating -- and, quite frankly, I am not pleased with this thing.

I am having a difficult time having the system maintain a constant inside
temperature during the evening and throughout the night.  If I set the 
(analog) thermostat to approx. 71(F), sometime during the night it 
undoubtedly gets down to approx. 66(F)-67(F) and is constantly running.
Last evening, as an attempt to maintain the approx. 70(F) temperature, 
I set the thermostat to approx. 74(F) -- it's hard to tell because it's
analog -- and it seemed to maintain 70(F).  However, it would appear it 
is relying on the heat-strips to maintain this temperature which, in
my mind, may constitute a problem.  The outside temperature is not what
I believe to be *terribly* cold -- this morning was in the mid-20s.

. Am I expecting too much from this system?  Should I be able to set
  an inside temperature via my thermostat and expect it to maintain 
  that temperature?  It doesn't seem very efficient to have it run 
  constantly throughout the night in order to try (unsuccessfully) 
  to maintain that inside temperature.

. At what point should the heat strips come on?  I would assume, under
  normal circumstances (ie. not bumping up the thermostat) they would
  come on only under conditions which limited the amount of heat that
  could be drawn from its heat-source (outside air).  Is 25(F) too 
  extreme?

I would appreciate any comments regarding these issues.

-Andy

If it is unusual to have 20 degree temeratures, then I wouldn't think 
this is a problem.  (Is a 20 degree low common near Atlanta?)  It sounds
like the heat pump has a setback temperature:  the heat strips only
come on if the temperature drops a certain number of degrees below
the requested temperature, e.g. 3 or 4 degrees below.  It also sounds
like 20 degrees outside temperature isn't enough for it to heat your
house to 70 degrees.  That doesn't seem surprizing -- the heat pump
has to compress 20 degree air enough to make it enough hotter than
then inside air to radiate heat into your nearly 70 degree house.
There's bound to be a sharp dropoff in efficiency below a certain
temperature.  But so long as the heat strips don't come on very often
over the course of the year, it should still be cost effective to use
the heat pump, if that's your question.  If the problem is how slowly
the system heats up your house when it is cold out, well, I beleive
that's an inherent feature of heat pumps.

	Luck,
	Larry

PS -- Here in central New England, it was once between 10 degrees and
20 below for a solid week.  My oil fired furnace ran constantly and
couldn't keep the house at 67 degrees!  I think heat pumps are designed
to run continuously, but I don't think my furnace is.  I've now got a 
long range plan to add more insulation...  LS

  This looks like as good a place as any to put this in....


  A friend of mine was telling me about a heat exchanger that recovers the
heat from the exhaust vent of a furnace.  He said that you 'just' splice it
into the flu pipe and when the furnace is running a small fan will turn on
to move air through the heat exchanger.  Other than the cost of the unit (and a
small amount of electricity to run the fan), this could be considered 'free' 
heat.

  Does anyone have any info on these units?  Do I need to be concerned about
back pressure?  Where can I get one of these?


  The reason I'm interested in it is the fact that I can't afford to heat my
basement right now (install a second zone on my furnace), and it gets a bit
chilly down there (average temp is about 44F with the low being 38F this winter)


  Any input is appreciated!


                  Jim

See note 4050.  They're also sold in the Northern Hydraulics catalog.

  Thanks!

Are they stupid or clever?  Does the fan run continually or only when there's
heat going up the flue?

    Actually, clever. Fan goes on when element in the stack gets hot
    enough. No idea on current pricing - I paid about $25 ten years ago.

There are also motorized vent dampers which close when the furnace shuts
off; they are claimed to save fuel, but some are expensive.

			Steve

    My father had/has a air to air exchanger on the exhaust of his oil
    burner. It heated the basement, during the winter, to a comfortable
    temp. The thing worked real well. Simple design too.
    
    Get one.
    
    Marc H.

  After reading 4050.*, I've decided to get one of these units.  A 
friend of mine saw the Magic Heat brand at Spags a couple of weeks 
ago for $75.  I'll update this note or 4050 after I get some experience
with the unit.


                   Jim

  Well before I went out and spent the money on the heat exchanger I talked
to my oil burner service man.  He said that I should *not* use one on my furnace
because the flu temp on mine is pretty low (somewhere around 350F).  My burner 
is only 9 months old and has a high efficiency rating.  Just as a sanity check
I *carefully* touched the flu pipe while the furnace was running last night.  
Even though I couldn't leave my hand on it for more than moment, I could still 
touch it.  So to avoid potential problems with my burner, I've decided that
I'll forget about the heat exchanger (at least until I can find out much more
about them).

BTW - My He said that they work fine with older furnaces that do have higher
flu temps.


              Jim

    
    
    Hummmmm.....i'll have to get a different temp gage.  I placed
    the gage that I have for the wood stove on the oil flue pipe.  I 
    dont think the temp went over 300'F.  Look like i'll have to
    take a my melt sticks home and try it.
    
    JD
    

    re: .21
    Could be your thermometer is off - I doubt that those magnetic 
    stick-on flue thermometers (I assume that's what you have)
    are high-precision.  Or it could just be that the outside of the
    flue pipe is not a particularly accurate way to measure the
    temperature of the flue gases inside.  

>    Could be your thermometer is off - I doubt that those magnetic 
>    stick-on flue thermometers (I assume that's what you have)
>    are high-precision.  Or it could just be that the outside of the
>    flue pipe is not a particularly accurate way to measure the
>    temperature of the flue gases inside.  

	    The mag. thermometer I have is guaranteed to be accurate.
	calibration is only $1.00 but you have to pay for the shipping 
	(Not really worth it).
	    The surface temperature on a black pipe is supposed to be 
	~50% of the temperature at the center of the pipe.  On a steel 
	pipe, the surface temperature will be slightly lower.
	    I have the Magic Heat blower on my wood stove.  If the
	catalytic combuster is running over 400�F (~800� center temp.),
	the air coming out of the blower is fairly warm.  Unless the
	pipe you want to connect one of these to gets much too hot to
	touch, I don't think it will do you much good.
	    BTW, I thought I saw them for $90.00 at Spags.

    Heat recovery is attractive but be carefull. High efficiency gas
    boilers/furnaces are requried to use PVC for the exhaust. The reason
    is that if the temperature of the flue gas is too low, it will
    condensate and form sulphuric acid inside the flue. Goodby chimney--
    
    Joe

    
    I'm looking at installing a unit called a "heatpump helper". Actually
    the more I learn about it the name is a bit missleading in that you're
    actually replacing the heatpump in the heating cycle and only using it
    for summer A/C use.
    
    What they do is install an oil-fired boiler that will both supply hot
    water (to replace the electric water heater) and provide hot water to a
    heat exchanger placed in the blower unit. The register temp is raised
    to over 100 and, hopefully, heating costs are reduced.
    
    My question is twofold; one, does anyone have any experience with this
    type of installation and two, does anyone have any experience with the
    Energy Kinetics EK-1 oil burner?
    
    Thanks,
    Ray
    

    I have a heat pump also that is approximately 10 years old (the old GE 
    variety) and I live here in NH. so I would really be interested in 
    hearing more about this also if anyone has any info at all about it.
    
    Barry 
    

Our water tank and heating system are due for a complete replacement. Our oil
service company recommend a solution called the System 2000, from Energy
Kinetics in Lebanon NJ., "since 1979", that is quite expensive but claims to
be much more energy efficient, as well as quieter, and high-capacity.

I am interested in any experience anyone has with the brands or technologies
involved, as well as opinions about the plausibility of their claims.
Generally they provide a lot of glossy tech data and a hi-tech sell. 

DESIGN:
They use a Beckett AFG burner. A "patented chamber and [wet-base] boiler
design so stable that it is installed without a draft regulator". They use a
small boiler: 160 lb steel, 2.5 gallons (cf.  600 lb cast iron, 8 gal
allegedly typical). Heavy boiler insulation: 2" glass wool outside and 3"
ceramic board on the front and back. 10' coiled flue, circulates cold water
inward and exhaust gases outward to capture more heat. The boiler produces 120
gal/hr; it can supposedly drive a dishwasher, a washing machine, and several
showers at the same time. HW is indirect: the water that goes through the
boiler is a closed loop, to a heat exchanger mounted externally on the HW
tank.

"Purge Cycle": after the burner shuts down, a controller keeps circulating
water for a while to drain remaining heat from the boiler into the HW storage
tank or a heating zone.

"Limited Lifetime Warranty" on the boiler vessel with "extended limited
warranties of 3 years on the burner and System Manager" [controller]. I can't
tell yet if this warranty covers me if actual heating coil cruds up or rusts
out. Is that "vessel"?

Price:  $3800 was bid last year for all except new tank; stainless steel
storage tank is about  $700 more. How much more expensive is this than it
ought to be? 

WHAT THEY CLAIM:
The Gov't specified AFUE (Annual Fuel Utilization Efficiency) rating "only
measures some chimney related losses" and doesn't take into account: 
(A) Jacket losses, "heat lost from a boiler with minimal insulation or a
dry-base boiler", 
(B)  Room Air Loss, "draft regulator losses which occur when the unit operates
with a real chimney" using the draft regulator to mix (previously heated) room
air with exhaust gases to keep the draft right. 
(C) Standby losses, "from maintaining temperature for a tankless coil, which
keeps the chimney warm and the draft regulator pumping heated home air into
the chimney". 
They give the following table. Col 1 is for "Boiler with tankless coil", Col 2
for "Demand fired system with tank" and Col 3 for System 2000. All figures
except percentages are in gallons of fuel oil/year.

	497	497	497	Annual Fuel Usage for Space and Hot Water.
	123	118	17	Chimney Losses.
	86%	 86%	87%	AFUE rating (combustion efficiency).
	44	42	12	Jacket losses
	131	112	6	Standby losses
	85	75	6	Room Air loss
	880	844	599	Annual Fuel Use
	56%	59%	83%	Real Efficiency

So comments please: how plausible are these figures, and the whole argument
about AFUE vs. real efficiency? 

The low boiler mass is the base of their argument. After heat-up, conventional
boilers have 12,500 BTU's in them, which they lose up the flue or through the
jacket; System 2000 has only 4000, nearly all of which is recaptured by the
purge cycle. Also, they don't have to standby warm: they go from 55F to 140F
where it can start delivering heat in 1.5 minutes. "It can take a conventional
boiler as long as 18 minutes to go from a cold start to 180F and satisfy a
call for heat or hot water. During that time System 2000 can go from a cold
start to 180F, cool back down to 105F [end of purge cycle], and recycle all
its stored heat via the purging cycle."

"In the winter it will probably start [next heat cycle] soon after the end of
the [purge] cycle and may not cool below 105F. [Other seasons] it may cool
further to 90F or 70F." They calculate the heat lost due to cooling below
105F, i.e. not recaptured by purge cycle, and get 9.5 gal/year, all in the
non-winter months.

The external heat exchanger on the HW tank is good because you could get at it
and service it. You can backflush it to clean it out, and if that isn't enough
you can pump vinegar through it, and if ultimately necessary, that you can
ship it back to the mfr who will clean it. (Wonder how long that takes.) The
circuit between the heat exchanger on the HW Tank and the boiler is closed, so
it is not supposed to corrode and crud up. Do I understand right that in
typical tankless coil systems, by contrast, the domestic HW that comes out of
my shower head has passed through the heating coil inside the boiler at some
point? We have hard, acidic water - no wonder the tankless coil has
thrombosis.

They can use different HW storage tanks. We were adviced to buy a stainless
steel tank ($700, 10 year warranty) instead of a conventional glass-lined
steel tank ($500, 5 year warranty). This tank is by SuperStor. The steel is
"#316L", some grade of stainless steel I guess. It has 2" foam insulation,
losing 0.5 degree F/hour, "best in the industry".  (Izzatso?) A 10 year
warranty on the storage tank, insulation and outer jacket, 1 year on the rest.
It isn't clear to me whether it is also lined with glass or plastic, and just
uses stainless steel in fittings, or if the entire vessel is stainless steel -
is that even plausible for only about $150 more? I thought stainless was a lot
more expensive than that.

It is claimed to be very quiet. But it uses the Beckett AFG "flame-retention"
burner. Another oil man I talked to said that all flame-retention burners are
inherently noisy.


Thanks

/Malin

    Sounds like a gold-plated system to me - one that puts lots of
    gold in the service company's wallet and takes it out of yours.
    
    Consider - my Weil-McClain HE boiler keeps less than a gallon of
    water inside it at any time; this means that the boiler isn't
    spending a lot of energy reheating and letting cool a large
    amount of water.  The boiler itself is $900 or so (with burner).
    For hot water I've got an Amtrol BoilerMate storage tank (plastic
    lined - lifetime guarantee) run as a separate circuit.  It normally
    doesn't need flushing, but the instructions tell how to do it if
    you need to (including optional flush with phosphoric acid).
    
    My heat doesn't take any 18 minutes to come up - the radiators are
    hot within 2-3 minutes of the boiler coming on.
    
    Even if the claims for this super-duper system are valid (and I'm
    not sure they are), it's likely you'd never recoup the extra costs.
    There's also the consideration that a "non-standard" boiler may be
    difficult to get serviced in the future.
    
    					Steve

See notes 2442 and 3093 for information on various hi-tech heating systems.

    
    There was an info sheet in my last gas bill that touted a "new"
    kind of heat pump.  The cutuway drawing showed what looked like a
    small gas engine connected to a compressor and heat exchanger.
    No mention of a radiant heat fallback, only of waste heat recovered
    from the compressor engine.
    
    Is this design intended to work better at lower temperatures?
    
    C

I would like to revive this topic and hope that someone out there with heating &
air (or, specifically, heat pump) experience may jump in.

Not unlike the previous noter, I am having a problem with excess ice/frost
buildup on the outside compressor unit.  Though the unit is suppose to go into a
reverse cycle (I've seen this before so I know it's suppose to do it), it no
longer does.

Actually, I first noticed the problem last winter but did nothing over the warm
season to correct it (in other words, I procrastinated).  So now the cold season
is close upon us again and I feel I should probably have this addressed.

Any ideas what could cause this?  I'd really like to see if it's something I
could handle myself before having to pay $$$ for someone to come out.

Thanks to all responders!

-Andy

    Depending upon the brand and age of the heat pump there could be
    several different things contributing to your problem.  Some of the
    newer/fancier units have more elaborate controls for the defrost cycle
    in which, as you surmise, the unit basically operates in reverse: kind
    of like a/c in the winter ;^)> although the inside unit doesn't
    participate so you don't cool the house.  I doubt if you could or would
    want to do it yourself.  I would strongly recommend getting it checked
    out ASAP, even in your (relatively) warm climate (compared to up here
    in MA).  Too much ice buildup can lead to compressor failure and then
    you are talking big, big bucks.  I've got the bills to prove it (and my
    compressor was still under warranty)!  Hopefully you haven't already
    done too much damage to the unit.  
    
    One other thing: don't try to defrost the ice buildup yourself --
    according to my repairman, anyway, there are different kinds of ice and
    by using the wrong technique you can actually cause the problem to get
    much, much worse.
    
    Good luck,
    	/jeff

    I have an old heat pump unit in the Mid-Atlantic.  We have recently had
    several days of 90+ degree heat with lots of humidity.  The coils on
    the INSIDE unit have froze over with frost and ice - to the point that
    there was no noticeable air flow from the registers.  So when the house
    temp was 85 last night and I sensed no air flow, I pulled the sides off
    the inside unit and found about an inch of ice on both sides of the
    condenser (is that the right term?).
    
    We used a blow dryer to thaw it out completely, closed the sides up and
    it ran most of the night, but this morning it had begun to freeze up
    again.  So we are thawing it out once more.  A storm has moved thru
    dropping the outside temp, but the humidity is real high.  
    
    Isn't there supposed to be some sort of "reverse cycle" where some heat
    periodically runs thru the inside unit to keep the frosting problem in
    check?  What broke and what should I be looking for - is it time to
    call in a service tech (and get in a long queue) or is this something a
    reasonable handyman (like me) could fix?
    
    Thanks for any advice.  Rick

    What's the temp of the basement (I assume the heat bump is down there).
    If it has anything like the coils of a dehumidifier, it cannot operate
    in temps less than 55 degrees or so. 
    
    My guess is that there's nothing wrong with it. It's just too cool to
    operate at the moment.. Open the windows/doors of your basement to
    raise the temp.  Of course, I'm not an expert, but I've just had the
    same experience with a dehumidifier...
    
    -Gary

	I once had a similar problem and it had something to do
	with the requested temperature setting on the thermostat.
        There's a delta to current temperature that cannot be exceeded.
	I forget what it was in my case.   I think the workaround was
        to only set the thermostat to small increments of cooling.

	Something like don't ask for more than 5 (or 10 or n?) degrees 
        cooler than current inside temperature.

	

	
	

    Well, it appeared to be working fine on Sunday - which was about 90
    degrees outside and about 70 inside.  The basement is always about 5
    degrees cooler than the first level (where the thermostat is), and
    and another 5 degrees or so warmer on the second level (3 level
    townhouse).  
    
    Monday was in the mid-90's, and I didn't notice anything wrong,
    although it could have been partially frosted.  
    
    Tuesday was in mid-90's and humid - followed by thunderstorms in the
    afternoon.  Tuesday evening is when I noticed the themostat set on 70
    and the themometer reading 85 - and no air movement at the registers.
    
    My wife and kids  have on occasion  moved the settings in WILD swings 
    (i.e. set to 80 when they leave, reset to 70 when they return).
    I will have to check and see if they did that.  
    
    I will also try to lower the temp 1 degree at a time to see if 
    it prevents the ice build-up.  But I still think it should not be
    acting this way.  Does the outside unit periodically send warm
    refrigerant (with no fan movement) to the inside unit to defrost it?
    I know this is how it works in reverse in the winter to keep the
    outside coils from icing over.   Still pondering a cure....
    
    

    
    Well the fact that it iced up shows the compressor and refrigerant
    are working.  I'd look at anything that might reduce airflow (clogged
    filters, weak blower, dust/dirt/hair in exchanger...) or whether you
    just tried to dehumidify too fast.
    
    
    	DanF

    Any recent recommendations for Ground Source Heat Pumps in the
    Southern NH area (or New England).   Interested in combined
    heat/AC systems with domestic hot water pre-heat. 
    
    Recommendations on suppliers and installers needed ASAP!
    
    Thanks,
    Patsy