"The Humidex unit takes air from the first floor, that is considered conditioned."
And that is what I said.
But you are completely ignoring the next step.
HOW IS THIS AIR THAT IS REMOVED FROM THE FIRST FLOOR REPLACED? WHERE DOES IT COME FROM.
You will have to register to read the whole thread, but I am copying and pasting this one message.
From: experienced Jun-13 12:02 am
To: DonNH (4 of 5)
74934.4 in reply to 74934.3
I know the inventer of the Humidex. When I lived in New Brunswick, he lived about 20 miles from me. We were both early in the HRV industry about 1980-1.....he with a manufacturer and I as an vendor/installer. The Humidex was invented as a "dehumidifier" for damp summer basements to replace standard units and run at lower costs.
He had an idea based on the fact that due to cool summer basements (especially if uninsulated) he would see condensation/dampness in the low corners and at the floor/wall intersection. From this he determined that moisture "fell" to the lower levels of the home and basement. Confirming RH's by psychrometer but by neglecting another variable in RH measurement- temperature- he missed the temp stratification of the basement air from higher temps at the ceilings to lower temps at the floor. Thus he found higher RH's at the floor, lower RH's at the ceiling.... and this proved his theory....albeit wrongly.
So he built the humidex protypes to clean up his summer basement moisture. He found that in some "weather", he needed a fan that would exhaust 200 cfm to do the job. From there he popularized the product locally and it took off.
How does it work .... and not work!!
It works not by dehumidifying (no compressor, evaporator, etc) but by exhausting the lower, cooler basement air with higher RH's and replacing it with warmer air from upstairs and outside. With enough air exchange the basement would begin to warm up slowly and the average RH would be lowered not by having lower absolute moisture content in the air but by having a warmer basement through free heat, a lower RH and a low fan electric bill.
It does not work well or at all in very hot humid weather. You're now bringing in air at 75-95 deg F and 65-80% RH that just needs to be cooled a few degfrees before it will condense on even a slightly cool surafce. The last two summers in our area have been the most humid of my 13 years in this locale. The Humidexs are not working as in past summers. People go to the storage room, bring out the old dehumidifier, fire it up and set the two systems working against each other!!! The dehumidifier actually dries the basement air by refrigeration while the Humidex sucks it out to be replaced by more humid air for the dehumidifier to dry and be exhausted. IGet the idea??? have had a few calls from frustrated homeowners that have two machines running that never shut off and the Rh is not going down- in one monitored case it had gone up!!!
The Humidex "dehumidifier" is like the foil faced foams claiming outrageous R values for 1" like 27- more "smoke and mirrors".
Ture storey: I used to be the provincial energy analyst (wrote the energy regulations) and 1 of 4 public residential energy advisors. As part of the job, we put on public energy conservation seminars around the province. One evening a gent came to ask specifically about why the Humidex was not working in his home.
His basement was a partial basement with a big piece of the local granite bedrock (not much soil cover in some areas here due to past glaciers) forming one corner of the basement. In addition there was a high water table under his slab about 8 inches down. He put his dehumidifier away, started up the Humidex and nothing happed. Since he was so well connected to the cooling effect of the bedrock + high water table, the temp in the basement would not rise much if at all.
He called the manufacturer about his situation. They said to heat the basement to boost the temperature so the unit could then maintain it at a high enough level for the system to work. So in July he fires up his basment wood stove for 2 days!! (free firewood from his own lot = cheapest energy form) Neighbours thought he had lost it. After 2 days all was sufficintly warmed so that the system worked for a few days but eventually lost the higher temps leading to basement RH rise. His money was refunded by the vendor and now he still uses the original dehumidifier.
Now it is possible that the Humidex can work in some conditions and climates. But even in those cases it can probably be done better by other means.
But he is in mid-atlantic area. So I choice Baltimore.
For the month of July the highest dew point has been 75 and the average 67.
You DON'T WANT TO BE BRING THAT MUCH MOISTURE INTO YOUR HOUSE, EITHER THROUGH VENTS OR FROM DEPRESSURIZING THE HOUSE WITH A HUMIDEX.
Not to mention that it will also draw in more pollen and mold spores.