If you look in your phone book's business section (i.e., the Yellow Pages in the USA), you will probably find companies that offer mold and mildew mitigating services. They will have the equipment needed to gather air samples inside your home and then to analyze the samples so as to determine the fungi (mould) count. I must warn you that it will probably be very expensive.
As for other sources of odor, there are quite literally hundreds of odorous gases. It would be even much more expensive to attempt sampling and completely analyzing them for odorous gases if you don't have any idea what gases you are looking for.
If you have gas burning appliances in your home (kitchen range and oven, water heater, space heating system, etc.), you must understand that natural gas or bottled gas (Propane or LPG) are deliberately odorized with very small amounts of gaseous mercaptans which smell exactly like flatulence (also known as farts) so that people will be alerted to gas leaks. (If you have ever been squirted upon by a skunk, that was mercaptans.)
If that is what you are smelling, open your windows immediately and don't light any matches or any of the burners in any of your appliances. If it is a very strong smell of flatulence or skunk squirts, evacuate your home immediately and call your fire department!!
Dear Milton,
Thanks for your response.
I am thinking the odor may be coming from some form of humidity, but I am not sure.
Do you have any idea what sampling air might cost in the Northeast?
Appreciate your input.
This gentleman sells various affordable systems you can install, which claim to remove your mold odors and any surface mold from your home. Unfortunately, if it is behind the walls, you will have to treat the studs or block with bleach and remove any paper products effected, such as wall-board.
I would recommend spraying with KILLS to seal the area from further moisture or deep rooted re-growth.
Unfortunately, there are also serious chemicals used in modern trim and wafer-board used in new home construction. Formaldehydes, isocyanate adhesives will often cause difficult odors.
Organic offenders such as bees, rodents and birds will nest in eves, soffits and chimneys as well. Dead bees are bad news.
Here is a link for the various systems I would buy. (I intend on purchasing one myself, soon.)
Best would be to remove the cause of the smell instead of trying to neutralize it. If you suspect mold or mildew then it has to be moisture. I would remove the source of moisture (e.g. water leak from the roof or from bad plumbing) first. Once the area is dry, treat the area with chlorox and dry it again. The chlorine smell will neutralize the mold/mildew smell. In areas where the humidity is high it will be necessary to set the thermostat at a lower temperature for the AC to keep the air in the house dry.
Rather than running your AC until your lips and fingertips turn blue (not to mention your power bill giving you an aneurism), get a de-humidifier.
Unless your roof or plumbing is leaking, odds are that you have what is the most common reason for humidity/moisture/mustiness/mold, which is a damp basement. If the odor is most obvious in the basement, look for damp walls & floor where the concrete is exposed. The solutions then would be to excavate around and waterproof the outer foundation walls (below grade), install proper drainage tile, and insure there is proper slope of the soil (grade) away from the house. A de-humidifier might still be necessary.
__________________
You can have it good, fast or cheap. Pick two.
As to using bleach, the more recent school of thought is that the cure is worse than the disease (chlorine gas is toxic and corrosive). Only certain types of mold are toxic, and you and/or your family would probably be having symptoms if they were present. Bottom line is, if you permanently remove the moisture source, mold goes dormant, and is no longer a health issue (or a smell issue).
__________________
You can have it good, fast or cheap. Pick two.
It is not the intention to run the AC at a lower temperature permanently. Running the AC at a lower temperature e.g. 70 F instead of 74 F for a week would remove a great deal of the moisture and would reduce the odor significantly if moisture is really the problem. This is a cheaper test instead of buying a dehumidifier.
With regard to the use of chlorox, I forgot to mention that you only need to spray a 5 % chlorox solution. This works well for killing mold/mildew on sheetrock or wood and in a well ventilated room you almost won't smell the chlorine vapor. One gallon of chlorox cost at the most $ 2.- and in most cases you won't need the whole gallon.
Consider collecting the water from the dehumidifier and having someone analyze it for molds, etc. Likely some of the mold (?) particles would show up in the water.
__________________
"Consensus Science got us into this mess, then why can't it get us out?" : Rephrase of Will Rogers Comment
I buy and clean dirty houses. My favorite product for odors is www.OdorXit.com. It must wet or touch the item to be cleaned. First cost looks very expensive, but it chemically works and I consider it my best cleaning aid. It is not perfume.
Thank you all for your input.
I will be looking closely at the possible sources of odor.
We are going to install an electronic air cleaner by Aprilair model 5000.
In addition we will be putting in an automatic basement dehumidifier.
We have a dehumidifier now but it is small and has to be emptied at least once a day.
Ron
You are wasting your time and money with the Aprilair unit.
Didn't you read the link I sent you?
Air purifiers are scams. Ionization does nothing. It's like when the water test people use fresh water from the tap to sell you a $5,000.00 water purifier for your home.
No one tells you the chlorine GAS ratio drops to nothing within a half hour of doing nothing more than sitting on the counter. But people are scared of Chlorine!
So they shell out their kids college funds for peace of mind. It's hogwash.
The ozone machine link I sent you is the real deal built by a scientist who works for Martin and Raytheon, not home economics marketing or proctor. Are you an engineer or scientists?
The black soot the advertised machines remove is common residual from the electrolytic reaction from the machine, not pollution.
Go to "Consumer Reports", don't take my word for it,...
and look at the facts. Your going to laugh. It's snake oil!
You will be amazed that ALMOST EVERY single consumer grade air purifier; EXCEPT the one I sent you, built by a physicist, are junk. Total rip off!
Time shares, Air machines, water purifiers and deer whistles are the most laughable devices ever perpetrated on the American public, IMHO.
Please do not ask for advice and then succumb to fraudulent science.
Diluted bleach is perfectly safe for cleaning. Without it your drinking water would ruin your day, every day. The entire cleaning chemicals industry has made a multi-billion dollar business out of re-formulating BLEACH with a different smell.
Just don't use full strength bleach ever! Especially around your hot water heater or any open flame!
Read the link, and stop believing TV commercials selling PROGRAMMING.
I'll sell you the parts for the Aprilair machine for $17.65 and triple my money!. It still won't outperform a $10.00 air filter! It has the scam built in, so you "see the dirt". Any halogen lamp will create the same soot from ionization. That would mean your lighting is already cleaning your air, right? Answer me this, why hasn't the cost of Aprilair gone up in 20 years? Answer: because the parts to make it are so cheap it's not funny.
Here's a link from 1957 popular electronics, showing the Meller Smeller, using High Voltage:
http://www.copperwood.com/carlandjerry.htm
Notice the caption: "It fails miserably". How many volts are you using in your ductwork? 10,000? Unless you are building a particle separator, in front of a sub-micron filter, like they use for helicopter turbines, your good old $20.00 #1700 3M filter, from your local lumber store, is the best your going to get.
Remediation is not rocket science. If the rug smells, get rid of it. If there's a dead cat under the house, time to crawl under the house. Roof leaks? Shower stall has a science project behind the wall? Cigarette smoke in the duct insulation? Mold in the evaporator coil? Combination of all of these? Guess what?
Do diligence overcomes impulsive thought. There are no short-cuts, just wasted time figuring it out how to avoid the truth or hard work. It's what humans do best.
I'll bet you won't even consider sending me $450.00 for saving your time and money though, will you?
There is an instrument called a gas chromatograph that may be able to identify it, but I don't know how you could get a hold of one. Check your sink traps to see if any one is leaking. If so, you may be smelling sewer gas.
S
__________________
“I would rather have questions that can't be answered than answers that can't be questioned.” - Richard Feynman
(Ironically, my parts estimate was about 50% of what this guy states he can make a profit on, selling you an ion thingy. I will have to raise my price!)