Aprilaire 800 best option for me?
I have a 5500 sq ft house with cielings that prob ave. 12 ft. Half of that sw footage is unfinished basement. I was told that the 800 model was about the only thing that would be able to humidify such a large space, but would like to know what you guys think. Also, in terms of operational cost and effectiveness, I definitely dont want something that will raise my power bill significantly ($0.10 p/kwh) and arid climate.
How much moisture you need to add depands on a lot of vairables. Maintly the air leakage rate of your home. How much dry outside air is comming in. SOme newer homes are built so tight that they actually need ot ventilate the home to REMOVE moisture in winter. Natural moisture sources frmo cooking and bathing are enough to humidify the house. Actually too much.
2nd is how humid you want to keep it. This will depend on the level of insulation in your home and the quality of the windows.
THe basement shouldn't be considered, Moisture naturally wicks in through the concrete even if you have a vapor barrier.
FYI - $0.10 isn't too bad. Its' about average for most of the country. It's 20% lower than my winter rate. Besides, electrical consumption is minimal on a humidifier, even a fan powered one. It's teh water use that you need to pay attention to.
Let get some info on you current environemnt wihtout a humidifier. What is the indoor temperature and humidity level and what is the outdoor temeprature and humidity level right now? Where do you live? When was the house built?
For my house, I have a unit similar to a Aprilaire 700 equivalent. It can deliver supposedly up to 18gpd and it's heat source is the gas furnace and gas hot water heater (hooked up ot hot water), so its' costs 1/2 what a steam unit does to operate even when I factor in the wasted water and installed it's about 1/3 - 1/4 the price once you factor in electrical service and such.. It's also very, very simple. It supplies plenty of humidity for my 3200 sqft 86 year old home. Just jsut my opinion. Keep it simple.
the 800 was designed with a company that are true pros, Dri Steam, this can be run on diffrent voltages and the canister which is the tank and element gets changed out yearly, we have had great success with these, and for the large customs we do, it was the definitive answer for humidification, jmo
The house was built in 2007, I live in salt lake area. I keep my house around 70. 5500 is considerable larger than a 3500. We arent using the basement, but my end up with a room or two down there later.
Originally Posted by motoguy128
P.S. What is the true annual cost of running these?
That will depend on the leakage rate of your home, how high you keep your RH level, how much door traffic you have, and the leakage rate of your duct system if it isn't inside the conditioned envelope.
Originally Posted by hippypink
5,500 sqft of space should have a minimum of an air change in 5 hours to pruge indoor pollutants and renew oxygen. During cold windy weather, most home will naturally ventilate enough. The natural ventilation could be +150 cfm. During mild calm weather, most homes need supplemental fresh air ventilation to be healthy.
During near zero temps, the outdoor air has a <0^F dew point. At 70^F indoor temps, 40%RH, 45^F dew point, 100 cfm requires 2.5 lbs. of moisture per hour humidification. People and activities add .5 lbs. per hour per person while in the home. A typical home your size needs +6 occupants full time to maintain 40%RH.
A lb. of moisture takes 1,050 btus of heat to vaporize at 100% efficiency. A KWH provides 3,414 btus of heat to vaporize water to steam, minus the heat losses to space.
Figure out the KWH per day to use steam.
Natural gas space heat provides 90,000 btus of heat per therm.
Using steam uses a large amount of electicity. The problem with using heat in air from a furnace is getting enough air flow through your humidifier. A fix is to attach a 6" duct fan to a standard evap pad flow through humidifier drawing air from the home and blowing the humidified air back into the heating ducts. At +200 cfm of air flow, a 10^F rise in dew point will add 3 lbs. of moisture per hour. This is more than enough to humidify when added to the moisture from the occupants.
I did this a house with small flow through humidifier/6" duct fan and had the windows sweating in one day.
Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
Use +Merv 10 air filter. -Don't forget the "Golden Rule"
Personally I'd get a high capacity conventional unit. General 1099LHS for example.
The GeneralAire site says its for up to 3,000 sq ft .
Originally Posted by BaldLoonie
Well, I can see its about 3x cheaper to buy the hardware. Are operational costs also a lot less?
I found on amazon "GeneralAire Model 5015 1099 LHS Legacy Series Humidifier" that it sells for about $ on various sites.
They do have "flow through" models as well. not sure what these are.
Last edited by beenthere; 12-31-2011 at 07:50 PM.
How about a general range?
Originally Posted by beenthere
Considering the house was built 2007, will keep at normal humidity (guessing 30 - 40%), 6 people in the house (mostly kids, so lots of foot traffic), and the ducting is mainly in the unfinished basement.
I read somewhere that I can lower the house temp a bit too (because moist air feels warmer), which should save me some money. I only plan to use in winter when our skin is falling off.
What is your current indoor RH? And what is your current outdoor RH at what temp.