Whole House Humidifier in AC System Only

[speziak]

We have an old house with hot water heat. About 3 years ago, we retrofitted the house with central air. Now we want a whole house humidifier and our AC company is saying they can install a humidifier in the attic with our AC unit and it would work because we run our fan 24/7 in the winter.

They said, it might mean we need to clean the vents more frequently, say every 3 years, they also said we'd need to insulate the unit in the attic to avoid freezing.

Does this seem feasible? We really need a whole house unit as the kids just hack in the dry heat during the winter.

Thanks!

Speziak

[comfortdoc]

Yes it is feasible. Depending on attic construction it may need to be insulated and the water line and drain heat traced. I recomend a steam type humidifier. I find them to operate better when the air is not heated.

One option to have your contractor look into is the new Honeywell Tru-Steam humidifier. It has an option to be remote mounted and the steam can be injected into the ductwork up to (I think) 20' away. As of 3 wks ago delivery dates are still up in the air, but I'm sure it would be available to be installed before next heating season.

[speziak]

Thanks very much for your reply. So there are no worries about condensation in the vents since there will be no heat in those vents? The attic is not insulated, except for the floor. Could we insulate the pipes?

Thanks!

Speziak

[jgm74]

Like comfort doc said, the honeywell that can be remote mounted would probably be your best bet. Steam is definatley the way to go.

[beenthere]

Check the temp of the air coming out of those vents before you put install a stream humidifier.

The remote mount is ok. But, you still could have moisture condensing in the ducts if the ducts are losing too much heat to the attic.
If it condenses in the ductwork, you will end up with mold issues.

[drcustom]

Condensation will form not due to heat, but because of the lack thereof in the ducts. Cooler air holds less water, thus if the air which is currently blowing out of your registers in the winter (that's why beenthere suggests recording this temp) suffers enough heat loss in it path through your attic ducts and thereby drops below the dew point, the steam will condense in part before terminating into your conditioned space. You can check the delta by measuring the air temp at the return and at the furthest supply outlet to see the heat loss incurred with your own eyes. The better the attic ducts themselves are insulated/sealed, the lower the heat loss and the lower the chance of condensation being a problem.

Why not a stand alone unit like the Aprilaire 350 or 360 series set up and ducted from your basement or elsewhere in a more conditioned environment? Just needs a short 7'' duct run to the living area. Unless you super insulate (and seal) the A/C ducts, you will probably have steam condensing within them in the cold winter-y attic. Sure, most of the water quantity will reach the living space but IMHO it's a bit risky: You have to imagine the cumulative effect of condensing water over the course of years. Disaster immediately?--no, not if installed conscientiously. But down the line, who's to say?

[Shophound]

We have an old house with hot water heat. About 3 years ago, we retrofitted the house with central air. Now we want a whole house humidifier and our AC company is saying they can install a humidifier in the attic with our AC unit and it would work because we run our fan 24/7 in the winter.

We really need a whole house unit as the kids just hack in the dry heat during the winter.



Running your indoor blower 24/7 with ductwork in the attic is likely contributing to your low indoor humidity levels. Low interior humidity levels are typically caused by too much outdoor air getting into the house, overwhelming what amount of natural interior humidity generation is available (cooking, showering, laundry, etc.) with cold, dry, outdoor air.

If ducts in an attic are leaky, and they most often are, by running the blower around the clock you are pushing air in your house up into the attic. You cannot lose air to the outside of your house (an attic space is considered, in a sense, "outdoors", since you do not heat or cool it) without needing to make it up somewhere else. Leaky windows, doors, and other gaps in construction are the usual culprits for cold, dry outdoor air sneaking in to make up for what you lost to the attic.

What is the reason you run your blower 24/7? For more even room to room temperatures?

[speziak]

Hi,

A few questions about the tru steam. Which specific model number would it be? Would it need to be mounted in the attic and would it potentially freeze in ultra cold temps?

Is there a puddle of stagnant water when the unit is not in use?

Thanks!

Jon

[NCambient]

Just curious, have you measured the humidity in the home with a good quality gauge?
I am not talking about the wall-mart brand humidity indicator.

Are you sure the hacking is not being caused by allergies?

I have seen some folks screaming about the low humidity in their home only to find it was an issue with the way it was measured (incorrectly) with a cheap gauge.

Then they began addressing the dust and allergy issues for relief from their symptoms.

Running the blower upstairs can be a bad thing. Cost you money, causes more infiltration of outdoor air which can bring dust and air with lower humidity into the home.

[speziak]

Yes, we have tested the humidity and I wish I could remember exactly what it said, but in the two gauges we had (they each came with humidifiers) the humidity was well out of the 'comfortable' or 'acceptable' range.
We run the fan all the time because it has a HEPA filter in it, that's okay, no? I thought that was advised.

As for allergies, etc. we don't really have those sort of problems, but we all get that awful dry mouth from these cast iron radiators in all of our rooms! :)

I'm certain it is a humidity issue. It's more discomfort than anything else but why put up with that? :)

Also, our local AC person has said that the price of operating the Honeywell True Steam would be quite high. He also mentioned that there would be stagnant water in the pan when not used. He felt that there were other options that would work just as well that would not cost anything additional in electrical and would have no pan.

Does that make sense? :)

Thanks!

Jon

[beenthere]

Infiltration is causing your low humidity. If you address infitration, you'll help minimize the humidity problem.

Any humidifier you install in an attic, is at risk of freezing.
Steamers will show a rise in your electric bill, but they will increase the humidity.
They can add moisture to the air, even when the stat isn't calling for heat.


The True Steam, purges itself. The purge time can be adjusted.
Doubtfull the water will sit in it long enough to become stagnet.

[speziak]

I called our AC person and he is recommending an Aprilaire 400. He claims for our needs this is the way to go. I told him about steam, we discussed the freezing issue and he seemed to think it would most likely not happen except under extreme circumstances. He said, "I can get anything" I just think it's going to cost you a fortune to run.

Now I am TOTALLY confused :)

Thanks for your time.

Speziak

[NCambient]

I wish you the best with the humidifier.
I cannot advise you as to which brand would work best for your application.
Our company does not install humidifiers in attics. We have other options.

As far as running the fan, you need to be very sure that your duct is well sealed and not leaking. There may be a secondary drain connection coming off the indoor unit. Check this and be sure it is not left open (or plugged for that matter).
If left open it will cause you to loose air. We install float controls on all our secondary connections to stop leaks and stop the unit in the event of a main drain blockage.

Im not saying it is a bad thing but why are you using a HEPA filter if you do not have allergies? Just curious I have to ask. Dust? Just feels like the right thing?

[speziak]

Thanks for your info! We have cats, they have hair, dog fur, old house, dust. I'm amazed at the difference it has made on the molding, it moves the air around and I think we're all benefitting from it. Are we nut cases? :)

[beenthere]

Bad idea on the 400. It has a pan, so the stagnet water concern is there the same as a steamer.(steamers have auto flush) The 400 should have its pad changed twice a year. The 400 needs a heat sourse to work. Hooking it up to the hot water line won't always work. And Aprilaire does not recomend it on the 400.
Freeze up is a Big concern.

The 400's performance is rated with 120*F air temp to get its .7 gallon an hour(16.8 gal per day) rating.
You won't get enough, if any moisture into the air to make a difference, installed in the attic, on a cooling only system.

The 400 is a complete waste of money for your application.

A console unit set close to your return grille will do better then a 400, or any flow through that is not hooked to the hot water.

If your installer insist that it will work. Have him put it in writing, that if it doesn't, he will remove it, and refund all of your money.

[speziak]

Thanks very much, I think I"ll need to then push for the Honeywell unit as you all seem to agree on this! :)

He said, "Hey, I'll do whatever you want" so, . . .

There ya go! :)

Thank you very much for all your time.

Speziak

[amd]

Infiltration is causing your low humidity. If you address infitration, you'll help minimize the humidity problem.

I concur.

Draftproofing costs less than installing and operating a humidifier, and doing so reduces utility bills year round.

Given the risk of freezing, installing a humidifier in the attic should only be a last resort.

[speziak]

Thank you for the info! "infiltration," means we have air coming in but I'm not sure where to look. We have all new Marvin replacements in the house now and they cut the drafts from tons to nothing. Our attic is insulated so the upstairs, where all of these problems occur, is sealed fairly tight in my opinion. It's the typical winter stuff where there's tons of static electricity due to the heat, hair is flying, etc. This is from heat, no?
Sorry to be questioning so much but I am confused.

[beenthere]

Your duct system in the attic could be your highest sourse of infitration.
Your ceiling grilles/ register boxes if not sealed are also a big infiltration item.
Pecepticle and switch boxes on outside walls can also contribute.
Is your garage attached. If so, then consider that an outside wall, and figure you have infiltration there also. Plus the door to the garage if its an attached garage.
next, your basement. That boiler is getting combustion air from somewhere. If its pulling it from the basement, then the basement is getting replacement air from either outside, or pulling it from the house, which in turn pulls it from the outside.

[speziak]

So, what would be the gallons per hour at 70 degrees on the Aprilaire 400? And how does one know how much water we're actually going to need in our air? He has followed up with the possibility of a 700.

He feels the Honeywell True Steam is brand new and untested so he is concerned about its reliability and service record. Thoughts?

Thanks,

Speziak

[flange]

The Truesteam is anew product offered by Honeywell for residential use. It isnt even widely available yet, so your contractor may be thinking about a commercial type steamer. Most contractors received literature on the new honeywell, and a link to trianing for it on their website. There is even a link to it on this forum. Your local guy probably is not aware of it yet. check for the link here and see for yourself.

[speziak]

Thanks for the info. I have been to their site and watched the video too :) So, he feels that the cost is prohibitive for NY electricity. Also says the Aprilaire has no pan.

Hmm, so confusing! I really appreciate your help.

Speziak

[beenthere]

Didn't see ratings at 70*F air temp for it.
The 700 won't do any better at 70*F air temp. Its rating at 120*F air temp is .75 gal per hour, not much bette then the 400 at the same air temp.
You can hook the 700 to hot water which will allow it to add moisture to the air.
Which will in turn increase the bill for the water heater, and your water bill. with no guarranty that it can raise the RH high enough.

Yes the Honeywell True Steam is new.
Steam himidifiers have been around a long time though.

Is your installer still waiting to to upgrade to Windows 95.

The question is, do you want to buy something that will add moisture to your home.
Or do you want to buy a bill of goods.

[speziak]

Thanks for the info. I do not think he has upgraded to Win 95 yet, he has an Atari 800! :)

Ugh, I've asked him to join this forum but he doesn't seem to be a computer person. He seems to have a counter for everything I read to him. His main concerns with the Honeywell Tru Steam are cost of running, says it'll be just a pricey as running the central air in the summer, and it's unproven track record.

Are these typical concerns of those in your industry or do you feel the Honeywell would be cost effective over the long term?

Thanks,

Speziak

[flange]

Just curious, is "he' the only hvac contractor located in your area? second opinion would possibly help

[speziak]

Yep, he's the only one! :) They've done such a good job for us, retrofitting our 100 year old house with a great Lennox system. They've proven their worth (except in this instance) :)

[beenthere]

Cost of operation of all space conditioning appliances is of concern.
The trade off is, what good does saving money do, if the cheap way doesn't work.

Since he has a counter for everything. What did he say about guarranting the Aprilaire to work, or he removes it, and gives you all your money back?

If I want my house to have proper humidity, and a steamer is the only unit that will do it.
Then I'd tell him, I want the steamer, put it in.

But its your, a sreamer that humidifies your house.
Or an Aprilaire flow through, that turns out to be a conversation piece.
Its your house, its your money.

[speziak]

We're going to insist on the Honeywell. He'll do it, it'll also cost us considerably more because I guess it's not something he has. I really appreciate your help. He definitely will not guarantee the Honeywell but Honeywell doesn't make crap! :)

Thanks again.

Speziak

[beenthere]

Your welcome.