Experience with Aprilaire 800 steam humidifier for radiant floor heating???

acustode

New construction in dry dry dry Colorado. Staple up hydronic radiant floor heating and engineered wood floors. We easily installed the Aprilaire 300 whole house humidifier in the crawl space and it does a good job of providing humidity BUT the vent where it releases the humidity is freezing cold and it seems like it’s cooling the rooms like a/c does and it’s competing with the warmth coming off the flooring. Would the Aprilaire 800 steam humidifier release warm/hot air into our home instead of the cooling effect of the Aprilaire 300? Thanks in advance.

mattmia2

The short answer is yes. The longer answer is that you have to add the latent heat of vaporization to the water to make it a gas. The steam humidifier does that by using a lot of electricity. The evaporative humidifier does that by taking it from the air that passes over it.

acustode

Thanks so much for your insightful reply Mattmia2. I will take the higher electrical costs into account. Do you think the steam which is vented out is actually warm or is it just not freezing cold? Also, from your experience is the fan of the 865 pretty quiet (they don’t list dB on their website for the 865 the way they do for the 300)? I’m pretty sound sensitive which is one of the reasons why we went with radiant heat in the first place. I was amazed at how much water is wasted with the Aprilaire 300 and I’m guessing this will be the same for the 865 as well?

mattmia2

i don't know but i can say the steam humidifier distribution box needs to move a lot less air than the evaporative humidifier because t is just moving it around, it doesn't need to keep the air at the plates dry enough to evaporate the water.

the instructions for the fan pack claim 50 db

https://s3.amazonaws.com/s3.supplyhouse.com/product_files/9f1a319925e5410cad851b9b04fa35ba7d34a9b4.pdf

looking at the manual, it looks like it only drains water when it feels it needs to flush the canister so it probably drains a lot less water than the flow through type pad humidifier, a lot more of the water goes i to the air.

my guess is the steam is steam hot but the fan pack dilutes it with room air and makes it cooler

HVACNUT

With the 800, if there's no HVAC ductwork to install the steam tube, its going to need a Fan Pack.

PFloro

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We have enjoyed the Aprilaire 800 in our gas forced air system for 10 years. It's the best thing since sliced bread. Even with Tucson's mild winters, it's always very dry in the house.

Our 800 is set to boil the lowest amount of water for the 2200 sq. ft. single level house. Yes..., it uses a decent amount of electricity and I estimate ~$20-30 / month in the winter. The provided comfort is worth every penny. The canister only fully drains if there hasn't been a call for humidity in 72 hours or if the 800 is shut off at the control panel. From time to time, some partial draining does occur. With our use (humidistat set to 35%), the canister lasts 2 seasons. I change it before the system forces a canister change. The old "heavy" canister is full of calcium & magnesium.

The insulated steam line gets hot and only steam is released into the ductwork (a bit above the evaporator coil). It should operate in a similiar fashion with the fan pack. With the fan pack, the 800 will run whenever there is a call for humidity. In our system, I keep the ECM furnace blower running at a low "air circulate" speed 24/7 (for air filtration). The 800 will run as needed without a call for heat. Even if I had the fan set to "auto", the 800 will command the furnace blower to start when there is a call for humidity.

After 8 years, the soleniod controlled drain valve did begin to leak. Over time, the hot draining water eroded the non-replaceable plastic seat. It was a $400 part, but not a difficult job to replace.

I can only say good things about the 800. IMO, it has first class design, engineering, and manufacturing.

Paul

mattmia2

i think there are different ways you can set up the control logic. for example here in michigan there are enough heat calls when it is cold enough to need humidification that you will get adequate humidification only running the humidifier during both a heat and humidity call.