household dust is an odd combination of things- and having a dog certainly increases the 'dead skin' component of it. increasing the humidity in the room is the easiest way to cut down on airborne dust- it might also cure your cough (though if you're having any other breathing symptoms, or any swelling anywhere- get yourself checked for allergies. I'm an adult-onset dander, never USED to be allergic- but now the cat's not allowed in the bedrooms any more) the ionic and HEPA filter air cleaners WILL take out airborne dust- one of my clients has the 'smarter' ones in his house that needed cleaning EVERY DAY for the first few months he had it, and then it started catching up with itself, and now they get cleaned once a week, and even the plants look healthier.

Hey guys, I got a similar issue. I live in Arlington, VA. I have a split heat pump system. In my air handler we have found some, what looks like, mold/dust around the insulation of the cylinder shaped element that drives the blower. I have had some people come in to look at it, and these are their respective comments: -replace the whole heat pump system (quote 6,000-7,000 for 2 ton trane/ge air split heat pump system) as clean up (removal of insulation around the "driver") of the air handler will be so expensive that it's not worthwhile. Also, as the outside unit is 15yrs old and the inside unit (air handler/furnace) is 20yrs old you might as well replace the whole thing - someone quoted me to clean up the airhandler for $600 - had the insurance agent come over who told me that it's not even mold - did myself a check with bleach and mold/dust did not change the dark colour We have tenants in the house now, and have lived for some time in the house. The house is in generally good shape and there is no smell of mold in the air handler or the house. If this is clear to anyone, any ideas what I need to do?

Some of these comments are reiterated again and again. I am a retired HVAC/R professional with over 40 years experience. There is no cut and dried answer to most of these questions. Most of the answers are mostly correct in that you need to seal your ductwork, insulate it if it is in non-conditioned space (attic/crawl space), and the ductwork needs to be laid out correctly to supply AND return the correct amount of cfm to each room. After that, NO air conditioning technician in the world can correctly diagnose an air conditioner's problem unless several criteria are met. First and foremost, BOTH the condenser coil and the evaporator must be clean and the furnace (air handler) filter must be clean and not restricting flow. If you call a company out to your house and the technician comes up to your house with his gauges and refrigerant tank FIRST THING and immediately hooks the gauges up and starts putting refrigerant in, my advice is not to call that particular company back again. The coils MUST be clean before you can even begin to decide that the system is under or overcharged. Next you must make sure that you are moving the correct amount of cfm for the size air conditioner you have. 400 cfm/ton is the nominal amount for air conditioning. NOT ONE person has mentioned how important this is. On MANY occasions, I have seen brand new equipment installed and no one can figure out why it won't work! With brand new equipment, we know the coils are clean so that is not the problem. Let's say we have a house that is 2400 square feet and a new furnace and air conditioner are installed. It's a 105,000 btu furnace and a 3 ton unit. The homeowner complains that their old furnace and a/c (same size) worked fine until they had to have it replaced. Technician after technician comes out.....they hook up their gauges and add and remove refrigerant and can't figure out what the problem is. The a/c runs almost all the time and the pressures are correct but the relative humidity in the house is REALLY high and they can't figure it out. Some technicians recommend a whole house dehumidifier as a fix. C'mon people, let's not put a bandaid on this problem. What most technicians tend to forget with an installation of new equipment is that the new furnace doesn't KNOW what size air conditioner it is being mated with! The new furnace can typically be mated with (and has the blower assembly to work with) anywhere from a 3 ton to a 5 ton unit. These furnaces will have as many as 6 different speeds for the drive motor. A 5 speed motor is more typical but the factory sends these furnaces out USUALLY with the lowest speed set up for heat and the highest speed set up for cool. This means with the 3 ton unit (which needs 1200 cfm delivered), on the highest motor tap speed from the factory, the furnace is delivering 2000 cfm or more! Moving 2000 or more cfm through a 3 ton evaporator will result in a "delta T" of 10 degrees or less which explains the unit running almost continuously and the high relative humidity in the house. These technicians need to remember that they need to look in the installation manual to find the right motor tap speed to utilize with the size a/c being mated to the furnace. With the advent of the 95+ % furnaces, we are seeing ECM motors being deployed in the furnaces. These have no speed taps, but instead have a motor that is in essense a variable speed motor. The technician still needs to consult the installation manual as the motherboard in the furnace will have dip switches to set the motor drive unit to supply the desired cfm. Now, some "rules of thumb." IF your coils are clean, IF your furnace filter is not clogged up with dirt and providing a restriction, IF you are moving the correct amount of cfm for your size a/c, IF the superheat is correct and IF the subcooling is also correct, you should get a delta T of between 17-22 degrees and your supply temperature should be between 51-55 after the unit has run for 10 minutes or longer.

one other question ... when i set my Fan on AUTO ... the fan runs for about 1 to 2 minutes after the compressor shuts off ... just long enough to increase the RH in my ducts to a humid 75% before shutting off the airflow ... Is there a way to tweak the electronics so that the fan actually completely shuts down exactly when the compressor shuts off? That would keep the air in my ductwork a dry and mold inhibiting RH of 45% Thanks for any ideas