The TrueSteam allows as an option to install an airflow switch which will shut the steamer down and turns on the service light if airflow is not detected. For the reasons that you have already stated I like this feature. I have added an airflow switch to every TrueSteam that I have installed.
Originally Posted by Focko
If my truesteam is connected to my environzone board panel, do I need to worry about adding an airflow switch? I'll contact the contractor that installed my Truesteam about this, but if you have any more info it is appreciated.
Originally Posted by Indy
-D in MN
I can't answer that. If your Envirozone system is using the static pressure controller then it is possible that the switch is hooked up to work with the TrueSteam. Contacting your contractor is the way to get the right answer.
Originally Posted by dgbehrends
Question on run time
Beenthere would you walk me through the calculation you did for run time? I just want to understand how one calculates this.
On a 4000 sq ft home, with a .34 an hour air exchange, it would take about 40 minutes of run time for a 1500 watt steamer to add enough moisture to replace what is lost at an outdoor temp of 30° at 40% outdoor RH. To maintain an indoor 70° 40 % RH.
Also, if the run times are generally only a few hours it looks to me like the EWC is way oversizing. The S2000 can do 16 gallons a day, yet they say it only is good up to about a 2,400 sf home. How can that be when you are coming up with only a couple of hours run time for a 4,000 sf house? They must be assuming one leaky house.
I'm not one to undersize equipment but there doesn't seem to be any good reason to put something in that is so big it only runs a couple of hours a day. Why not down size and let it run longer?
The OP asked about which humidifier for use with a heat pump. I've got more or less the same problem, radiant heat, ERV's and full ducting (for AC) that I plan use intermittently to move the air around (the ERV's are independent of the ductwork).
It would be great to find something that is more energy efficient that heating the water that would work with unheated air. If steam is really better, well then so be it, but is it really better, or enough better than the alternative to warrant the cost of the energy to run it?
Thanks for the help.
I get it now. That was 40 minutes out of every hour, yes?
Yes, that was 40 minutes per hour.
So 16 hours a day, 1.6 kw/hr, that's 25 kwhrs/day at about $0.10/kwh or about $77/month. Not cheap.
Is there something cheaper than steam that works well with a heat pump or radiant? I see that Skuttle is still making a spray humidifier the 592-9 that they say works with heat pumps and Aprilaire say the same for their model 400 although it's derated 40%.
Would you be willing to comment on these or any other alternatives to steam? It sure would be nice to find something more energy efficient.
BTW another great reason to do the best job you can sealing the house. At .10 ACH that electricity bill would be only a third as much.
The spray humidifiers won't work with water with high mineral content. You'd have to add an inline water filter in most installations and change it regularly. I would be concerned about mold growth for water that does not completely evaporate and you could run the risk to reaching the dewpoint in cooler ducts downstream and having water condense inside hte duct. Depending on the air temp or downstream ductwork temp, there's a maximum amount of moisture you can add at a certain CFM.
At 0.1 ACH, normal household activities should provide enough humidification on their own. You would need ventilation for sure and may need to use the ventilation to dehumidify on some days. Perhaps I understood you incorrectly.
Spray units tend to have more troubles then they are worth.
Aprilaire 600s and 700s connected to the hot water line of the water heater work pretty god with heat pumps.
Thanks for the suggestions.
One comment however. Although I see it all the time I don't think its really possible to say much of anything about whether or not a structure is going to need fresh air with only the ACH number alone. People need a certain level of absolute air quality, but 0.1 ACH on a 1200 sf home with 6 people living there is going to yield a completely different result that 0.1 ACH on a 5000 sf home with 4 people.
Since the house I'm working on is the latter my assumption is that I won't need much fresh air except when there is cooking or showering going on or a bunch of people visiting. On the other hand it isn't clear to me that the normal household activities are going to provide enough humidity.
I should know more once we get the infiltration number and a lot more once the owners move in.
Thanks for the help.
That's an excellent point that the ASHRAE standard fails to address. It basically says anything less than 0.35 ACH requires mechanical fresh air ventilation. There are calculations that can be done to determine the amount of fresh air required for X number of people/animals and Y square feet. That's what builders should be using when building tight homes.
Originally Posted by sbe
Originally Posted by beenthere
Would you mount the 600 or 700 to the return or supply? I have very little room on my supply and would have to mount something upside down which I assume could not be done with these units. Thanks
The 600 can be mounted on the return, its a bypass, (so it doesn't matter where its mounted) and give better results then the 700 mounted on the return.