Which Humidifier to install for heat pump system

[ebanks]

I have a heatpump/air handler system (Richmond. KY) and would like to install a whole house humidifier. I do not want to consume a tremendous amount of water and do not want to double my electric bill. I do not have a floor drain , only condensation pump on air handler. Which humidifier do you recommend???

I have seen many different opinions about the honeywell, aprilaire, and desertspring.

What would you reccomend for DIY and which for pro install?

:confused:

[t527ed]

for diy a nice tabletop should do the trick...;)


for pro install either a powered humidifier or steam are the only ones that will work right with a heat pump.

where does condensate pump to?

[BaldLoonie]

Or you could tighten the home so you don't need a humidifier. Works wonders on the heating & cooling bills too!

[beachtech]

usually don't need a humidifier on a HP system :)

i would seek loonie's advice :)

[bmathews]

usually don't need a humidifier on a HP system :)

i would seek loonie's advice :)

You don't need a humidifier with a heat pump unless you're going dual fuel. It's a waste of money otherwise and I don't think I want water anywhere near the strip heaters.

[BamaCool]

I have never personally seen a humidifier on a heat pump. Maybe just my location, but I've never heard of that.

[ebanks]

Yes I have a heat pumpthat works pretty good in the winter but as usual does not work too good below 20 degrees. When the strips turn on in the air handler you can feel the moisture being sucked out of the air. The small portable units are OK but I would rather install a whole house unit on the air handler. My son has eczema and it flares up in winter when it gets dry.
Would making the house air tight help under these conditions? How?

What would you recommend?

[beachtech]

You don't need a humidifier with a heat pump unless you're going dual fuel. It's a waste of money otherwise and I don't think I want water anywhere near the strip heaters.

lol humidifier is far away from strip heat its not a big deal lol

and he said HP not dual fuel :)

[beachtech]

Yes I have a heat pumpthat works pretty good in the winter but as usual does not work too good below 20 degrees. When the strips turn on in the air handler you can feel the moisture being sucked out of the air. The small portable units are OK but I would rather install a whole house unit on the air handler. My son has eczema and it flares up in winter when it gets dry.
Would making the house air tight help under these conditions? How?

What would you recommend?

tighter house will allow less of your humid air to escape to the drier air outdoors :)

there used to be a humidifier kit that was available for heat pumps the misted the indoor coil :) lose some efficiency by doing so.

there are plenty of humidifier products available that should help you with your indoor conditions and your sons health :) have you located a local contractor to help with this? do you record your indoor temp and humidity conditios throughout the year? you can record whether or not your indoor air is dry or not. it is standard for the indoor air to be between 30 and 50% RH. if you are above 50%RH then you have other problems :)

[ebanks]

Over the past couple of years we have monitored the RH to be around 20 to 25 in the dead of winter. Our skin gets very dry.

Is there a name brand that I should eb looking for?

Is there a style that I should be looking for? pads, wheels, steam, etc.

[bmathews]

lol humidifier is far away from strip heat its not a big deal lol

and he said HP not dual fuel :)

I don't know where you install them. If you install them in an air handler it would be a few feet away from the suppy side of the air handler which is where MOST strip heats are. So maybe 1-2 feet. A bit close for a water source that is as fallible as anything in an hvac system. That is why we install drain pans from plenum to plenum, water is your enemy.

[beachtech]

Over the past couple of years we have monitored the RH to be around 20 to 25 in the dead of winter. Our skin gets very dry.

Is there a name brand that I should eb looking for?

Is there a style that I should be looking for? pads, wheels, steam, etc.

i would use a blow through pad style that many manu's make. what brand of equipment do you own. i am sure they have thier own humidifier. if not i have used many aprilaire without any problems :)

[beenthere]

On a heat pump, if you use a flow through, it will work better if you hook it to the hot water line.


And it doen't matter if you use a heat pump or gas furnace. Its the air infiltration(leaky house) that causes low humidity.

I don't care if the discharge air temp is 80 or 180°, it doesn't matter.
Its your house that needs sealed better.

The reason you take notice to the lower humidity when he aux is coming on. Is because, the humidity in the colder fresh air coming into your house is lower.

[beachtech]

I don't know where you install them. If you install them in an air handler it would be a few feet away from the suppy side of the air handler which is where MOST strip heats are. So maybe 1-2 feet. A bit close for a water source that is as fallible as anything in an hvac system. That is why we install drain pans from plenum to plenum, water is your enemy.

that's funny. your electric heat strip in a AH unit for a HP is in the AH, not the duct.

and a properly installed humidifier will not effect the heat strips or hinder thier operation :)

if they blow through as i recommended is used, then supply air is forced through the humidifier and then the added moisture to the air is retuerned back into the system :) no ill effects to the strip heat at all :)

[zoneitewc]

Pad type units rely on temp in side the duct and run time of the unit to evaporate water. With the low temp of a HP, 95 degrees, these units will not put out much water, even hooked up with hot water.

For that reason, a steam humidifier is the only way to go. They mount inside or under the duct. If the heat is not running and the humidistat is calling, the steamer will turn on its heating elements, heat the water and then turn the fan on to distribute the humidity. They have a auto flush mode that can pipe into a condenstate pump. And best of all, they put out 16 gals for the 120v model and 22 gals for the 240v model.

Todd

[ebanks]

I am now very interested in the steam option. This sounds better for a heat pump unit. Sounds like it would use less water. Not sure about electricity. I have a tempstar system.

I will look at possible drafts around my house, but where are some common areas where people loose moisture out of their home??


Who makes some steam humidifiers? I know about honeywell. Who else makes steam humidifiers?

Which would you recommend?

[beenthere]

zoneit was giving you the steam rates for EWC Autoflo steamers.

[beenthere]

Worn door seals, around windows, switches and receps on outside walls.
Fireplace dampers that don't close proper.

[beachtech]

zoneit was giving you the steam rates for EWC Autoflo steamers.

BT does know EWC :p

[Focko]

Speaking from high desert experience (central Oregon):

The air here is almost always very dry. In Winter it can get to below zero (F) occasionally, and is usually below freezing.

Cold dry air heated to "room temperature" gets extremely dry, which can affect the wood in the building as it shrinks and expands. Here, if you have a lot of wood, especially expensive wood, you want humidification in the heating months.

I service a lot of humidifiers. The steam ones are good, but can cause a disaster if there is any airflow problem (think water dripping off a ceiling). Another consideration for all humidifiers is, what if they leak? If they're installed above stuff that can be damaged expensively, such as a furnace or zone control board, leaks can be a major deal.

April Aire's humidifiers, at least the ones I work on, are the most reliable in my experience. Steam ones are harder to service and can cause a lot more problems if there is an airflow issue. They push humidity into the air whether the airflow is good or not, and that can be a problem, big time. Think condensation dripping off a ceiling.

In a place like here, I recommend the "water panel" type rather than the steam type. If the airflow has issues, less water will be evaporated and that's almost a fail-safe way to prevent condensation problems in the living space.

If you are in a part of the country that's not so dry and/or cold, and you don't have expensive wood such as fancy flooring or whatever, you might not benefit much from a humidifier.

[zoneitewc]

Yes I was quoting the EWC steam cap. And focko is right, if you don't have airflow you will get condensation in the duct. There are different manuf. of steam units and each has addressed the issues that steam humidifiers had 15 years ago.

Now, steam units are made out of SS and they have overflow drains. They also have logic built into the unit that looks at how long it takes to fill. If the unit see's the fill valve open to long, it will shut it down. It also flushes the water every 8 hours of the day and does not fill back up untill it see's another call for humidity. So most of the time, unless there is a need, the unit is dry. The steamers also do not have a float on the fill side anymore. The unit wires directly to the fan, so on a call for humidity it will bring on the fan to distribute the moisture. They also have provisions for an airflow switch, so no airflow means no humidity. Service is required once a year, and the average increase in elect. is about $40 per month As you can see, all of the concerns of the past have been addressed.

Steam units are the most expensive way to put water in the air. But, they rely only on themselves to put out the water, so you are guaranteed the RH you want.
You also want to make sure you have the right size unit, there are models that put out 6 gals a day to models that put out 30 gals per day. But remember, humidity seeks it's own level, so even if you can only duct the humidifier to the first floor, it will travel at about 7 feet per sec. trying to equalize throughout the entire house. We figure 22 gals per day does about 3800 sq ft.

As far as the need for humidity. Anytime you heat the air, weather it's with a HP, hydronic, gas, or geo you increase the air's ability to hold water, so the RH decreases. Also, the more RH the warmer the air feels, so a house with a 40% RH @ 68 degrees feels alot warmer than the same house @ 72 degrees and a 20% RH.

The different manuf. are Honeywell, EWC, Aprilaire, General, Nortec, and skuttle.

Todd

[beenthere]

Zoneit.

Edit out your prices.
They are not allowed here.
Not even ball park prices.
Please read the rules, Thank you.

[zoneitewc]

Beenthere,

Thanks, didn't see that one.

Todd

[Focko]

zoneitewc, good info, TYVM:D

I'm a service tech and almost all of the systems I see in my area are either old steamers or newer water panel types. I'm glad to see that past problems are being corrected.

[gary_g]

I'm a service tech and almost all of the systems I see in my area are either old steamers or newer water panel types.

Question on terminology: Is a bypass humidifier a water-panel type, flow thru type, etc?

Thanx.

[zoneitewc]

Gary g,

The different types of humidifiers are; Steam - they boil water and introduce it into the duct. Flow thu/bypass - they have a water panel the water drips onto, hot air from the furnance pass over the wet panel to evaporate water and introduce it into the duct. Drum - uses a wheel with a sponge material that rotates in standing water to make the warm air water contact. Nozzel trype - they spray atomized raw water into the duct. Self contained Room style - the type you buy at a hardware store.

Each has advantages/disadvantages.

Hope that helps

[gary_g]

Gary g,

The different types of humidifiers are; Steam - they boil water and introduce it into the duct. Flow thu/bypass - they have a water panel the water drips onto, hot air from the furnance pass over the wet panel to evaporate water and introduce it into the duct. Drum - uses a wheel with a sponge material that rotates in standing water to make the warm air water contact. Nozzel trype - they spray atomized raw water into the duct. Self contained Room style - the type you buy at a hardware store.

Each has advantages/disadvantages.

Hope that helps


Outstanding - thank you.

I will be installing a bypass humdifier for my heat pump air handler in the very near future.

I suppliment the heat pump with a masonry wood burning fireplace w/insert. I get a lot of dry air due to the number of air exchanges caused by the fireplace.

Take care.

[beenthere]

A flow thru, is not always a by pass.

The Aprilaire 700 is a flow thru, but it is not a bypass, its powered humidifier.
The Aprialaire 600, is both a flow thru and a by pass.
The Aprilaire 400, is a bypass, it is not a flow thru.
All three use pads.

[dgbehrends]

On a heat pump, if you use a flow through, it will work better if you hook it to the hot water line.


And it doen't matter if you use a heat pump or gas furnace. Its the air infiltration(leaky house) that causes low humidity.

I don't care if the discharge air temp is 80 or 180°, it doesn't matter.
Its your house that needs sealed better.

The reason you take notice to the lower humidity when he aux is coming on. Is because, the humidity in the colder fresh air coming into your house is lower.

First of all I think this is an outstanding thread, and I thank the knowledgeable members for their informative posts.

Beenthere states above that air infiltration causes the low humidity. Most definitely true. I'd like to consider another potential source of air infiltration. Today's houses are generally built very tight. So tight that air exchangers (ERV/HRV'S) are installed to replace stale air during months of harsh weather when windows can't be opened to ventilate the home. It seems to me that this ventilation requirement potentially creates a problem of low RH%.

If we assume there is a limited amount of air infiltration, can the ventilation typically be scaled back such that it provides sufficient air exchanges without leaving the house in need of a humidifier?

Or is a humidifier required to meet both basic ventilation (home dependent) and humidity (30-50RH) requirements ?

My opinion thus far was that a steam humidifier can better handle this situation, mainly because the furnace does not need to run(just the fan) to distribute moisture. I know that it is possible to do this with a bypass humidifier but without the warm air the bypass is not very effective even when hooked to warm water. (please correct me if this is not true) My research thus far leads me to believe that the steam approach will be more costly to install and maintain then a bypass. I think there will be significant increase in the electric bill, what I don't know is whether there will be a savings in the gas bill to partially offset this.

[Artworksmetal]

I too have been researching humidifiers. I have a very tight 4,000sf home. HP with a Propane furnace that kicks in at 30F.

The Honeywell TrueSteam looked good, but 1500 watts is a big draw. $40 a month, as Zoneit suggested? That's as much as my hot tub.

Flow thru models obviously waste water - that just seems wrong this day and age. But how much actually goes down the drain on a given day?

I had a Desert Spring in my old house. It was a unique design that worked well, but that house was half the size.

Anyone have experience with the Triton 707 centrifugal? I like the idea of it's simplicity in design and installation.

"The Aprilaire 700 is a flow thru, but it is not a bypass, its powered humidifier.
The Aprialaire 600, is both a flow thru and a by pass.
The Aprilaire 400, is a bypass, it is not a flow thru."

Is there one that's powered but not a flow thru?

Thanks for letting me participate in this discussion.

[dgbehrends]

I too have been researching humidifiers. I have a very tight 4,000sf home. HP with a Propane furnace that kicks in at 30F.

The Honeywell TrueSteam looked good, but 1500 watts is a big draw. $40 a month, as Zoneit suggested? That's as much as my hot tub.

Flow thru models obviously waste water - that just seems wrong this day and age. But how much actually goes down the drain on a given day?

I had a Desert Spring in my old house. It was a unique design that worked well, but that house was half the size.

Anyone have experience with the Triton 707 centrifugal? I like the idea of it's simplicity in design and installation.

"The Aprilaire 700 is a flow thru, but it is not a bypass, its powered humidifier.
The Aprialaire 600, is both a flow thru and a by pass.
The Aprilaire 400, is a bypass, it is not a flow thru."

Is there one that's powered but not a flow thru?

Thanks for letting me participate in this discussion.

As I have learned from beenthere, not all bypass humidifiers waste water. The 400A is a bypass humidifier but water does not flow through it, and therefore it does not have a drain. I looked into this type but decided that the extra filter changes and the potential for gunk build up was not for me. Just my opinion here, but the 400A is well suited for setups where a drain is not present or difficult to get to.

Edit: I forgot to mention that the truesteam also requires a yearly in-line filter change to make the 5 year warranty valid. I can't list the price for it per forum rules, but I can say it's a little more than a bypass filter would cost.

[Artworksmetal]

I just looked at my furnace. The return doesn't have much flat vertical surface area. One spot is real close to some joists - might work if I never want to finish that area. The other is at floor level, just before it hangs a left into the furnace.

What would Joe the HVAC expert do?;)

[beenthere]

1500 watts, is, and isn't a lot.
Thats 1500 watts in an hour of run time.

If it has to run for an hour at any outdoor temp, then either your house isn't as tight as you thing.
Or its too small for your house.

1500 watts can add better then ½ a gallon of moisture to a home an hour.

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.

[Artworksmetal]

1500 watts, is, and isn't a lot.
...
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.

OK, that's interesting. Say it does that 2x a day, that's about $5.00 a month at $0.12 a KWH. I could live with that. Would that be a reasonable expectation ?
Yes, my house is very tight. Although it's not Energy Star Certified, my building inspector showed me all of the ESC things they did (such as caulking between double studs at door jambs).
Still - how much water goes down the drain with a flow thru?

[beenthere]

Depends on which orfice it has, what the discharge air temp is, and how high the humidity is in the house.

An Aprilaire 600, ranges from 3 to 6 gallons an hour.

Flow throughs rely on constant water flow to keep them clean for the year(minerals).

[dgbehrends]

Yep, the decision is made. Based on the comments of many knowledgeable members here and my own calculations for air exchanges based on my energy report I have decided to go with the Truesteam. I got a few bids on installing a Truesteam vs the 600A and the 600A was about half. I think the cost will be more to operate the Truesteam unfortunately. The yearly in-line filter change will cost more than the yearly bypass filter change. I don't know how the utility bills would come out with the Truesteam or the Bypass but if I had to guess I think the bypass would probably be a little less expensive after natural gas, electric, and water are considered. The main reason I went with the Truesteam is because once I get my HRV under control, infiltration in my 4000sq/ft home will be limited and the on demand nature (meaning the furnace doesn't need to run) of the Truesteam should be able to complement my HRV.

So the net is, I'll have to pay more, install and maintenance, but I'll be able to control my humidity better with my IAQ zone panel and stats.

[BestSax]

Okay, let me get this right... The big issues are if the thing really works or not in the size of the home you have and if it is not leaking and how much water is being wasted.

Well, it seems to me that if your home is < or = to 3000 sf then the Desert Spring is effective and more efficient compared to steam.

I am sure the steam will get the job done better, but it seems to me that it is a bit over kill.

Has anyone used the barrel version of Desert Spring? It claims to be 100% energy efficient, not filter to EVER change and no extra electricity.

Am I reading everything correctly?

[Artworksmetal]

I like the Desert Spring. Depending on how hard you water is, you take the barrel out and soak it in vinegar or other mild acid solution every month to once a season. Uses basically a clock motor to turn it, so almost no electricity. I highly recommend installing an automatic drain that empties the pan once every 2 - 3 days, to keep the scuz out.
That being said, the output is not quite (or just barely) adequate for my 4,000 sq ft house. At my old house (2400 sq ft), it was perfect.

[dgbehrends]

I thought I would post my thoughts on my Truesteam after 2 days of usage. So far I am pleased with it. I am monitoring the number of flushes it does to determine how long it is running. (I have one of those KillaWatt devices and will plug that into it tomorrow). It flushes every 10 hours and in the first 2 days it ran a total of 5 hours per day. I have a 4000sq/ft house that is fairly tight. I keep the indoor temp between 68 and 70. The outdoor temp has ranged between 5 and 15 the last couple of days. And my indoor RH setting is 30. The first hour after I had it installed, I let it run continuously and it raised my indoor RH from 30 to 34. I verified this 15mins/1%RH the next day when I monitored it bringing the RH up from 29 to 30. Just for the record, my air exchanger is what keeps my RH down and not infiltration. When I don't run my air exchanger the house gets stale fast and you can smell last nights dinner in the morning and I can usually maintain humidity

I pay about 10.5 cents per kilowatt. The Truesteam takes 12 amps so 12Amps*120Volts = 1440Watts * 5 hours = 7.2Kw * 10.5cents = 75.6 cents/per day * 30 days = $22.58 per month. I didn't consider the water used because I think it is very minimal.

Figuring out how much a bypass would cost is a little harder. I'll take a guess since I don't know how much my water costs or how much my Natural gas costs off the top of my head. Lets assume its hooked to the warm water side of things to increase its efficiency. Most contractors I have talked to in my area suggest that be done. So here is my guess, I'd probably pay 5 to 10 bucks more in water usage since water is pretty cheap even if a lot is wasted. Natural gas to run the water heater more would probably cost 5 to 10 bucks a month more to. I'm not sure if the furnace blower fan would run more with a true steam or not so I'll just say that one is a wash. The install cost for the truesteam is roughly double that of a large bypass. The truesteam has an inline water filter that Honeywell recommends changing every year. I priced it out at around 20 bucks. Bypass humidifiers also have a filter that should be changed once a year too. I think they range from 15 to 20 bucks. The truesteam has a lot more parts to go bad then a bypass, so maintenance might be more in the long run.

All in all I like the performance of my truesteam, however I think it will cost me a little more in the long run to operate it.

My recommendation would be if you have a loose house and/or your furnace runs a lot then go with a bypass because it will take advantage of the furnace running. However if you have a tight house and/or your furnace doesn't run much (possibly oversized) then the Truesteam might be a better solution.

I pondered my humidifier selection for a long time, partly because the Truesteams weren't ready for last years heating season. Would I have been happy with a bypass model, hard to say for sure, but my guess is probably yes. I chose the Truesteam because I felt it had the best chance of meeting my humidification needs, and so far it has done that.

[Indy]

Speaking from high desert experience (central Oregon):

The air here is almost always very dry. In Winter it can get to below zero (F) occasionally, and is usually below freezing.

Cold dry air heated to "room temperature" gets extremely dry, which can affect the wood in the building as it shrinks and expands. Here, if you have a lot of wood, especially expensive wood, you want humidification in the heating months.

I service a lot of humidifiers. The steam ones are good, but can cause a disaster if there is any airflow problem (think water dripping off a ceiling). Another consideration for all humidifiers is, what if they leak? If they're installed above stuff that can be damaged expensively, such as a furnace or zone control board, leaks can be a major deal.

April Aire's humidifiers, at least the ones I work on, are the most reliable in my experience. Steam ones are harder to service and can cause a lot more problems if there is an airflow issue. They push humidity into the air whether the airflow is good or not, and that can be a problem, big time. Think condensation dripping off a ceiling.

In a place like here, I recommend the "water panel" type rather than the steam type. If the airflow has issues, less water will be evaporated and that's almost a fail-safe way to prevent condensation problems in the living space.

If you are in a part of the country that's not so dry and/or cold, and you don't have expensive wood such as fancy flooring or whatever, you might not benefit much from a humidifier.

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.

[dgbehrends]

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.

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.

[Indy]

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.

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.

[sbe]

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.

[sbe]

I get it now. That was 40 minutes out of every hour, yes?

[beenthere]

Yes, that was 40 minutes per hour.

[sbe]

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.

[motoguy128]

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.

[beenthere]

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.

[sbe]

motoguy,

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.

[skizot]

motoguy,

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.

[cecilt]

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.


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

[beenthere]

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.

[cecilt]

Beenthere, question for you. The new HP I am putting in will be 3.5 ton with a VS 4 ton air handler. This heats/cools upper and lower level of a contemporary ranch with about 2700 sq feet. I want to add a humidifier to this unit.

I also have a separate HP (not VS) that heats and cools about 1800 sq feet. This is an addition that ties to the existing house on both upper and lower levels.

Would you recommned a humidifier on both units or just on the new HP I'm installing? I was thinking doing the 600a on the new unit but thought that 2 500a's would be better. But then it will be a lot more hot water consumption which will add up. Thanks. Both HP are electric backup.

[beenthere]

Probably better off with a 600 on the new system, and a 500 on the addition.

[cecilt]

Probably better off with a 600 on the new system, and a 500 on the addition.

Contractor just visited and he recommended 2 flow through Skuttle humidifiers. I think they were 55 series. How does these sound?

[beenthere]

Thats the under duct mount series.
If your duct work is slightly under sized.
They can interfer with air flow.

[cecilt]

Beenthere. Yes, they are the under duct mount. His first recommendation was the Honeywell steam but I did not want to spend that much nor pay the associated monthly cost to run it. We discussed bypass humidifiers and his opinion was they were okay but you would loose humidifier efficiency with a bypass and they are not as good with HP's. That brought us to the flow through which I had an 8" deep duct and the skuttled needed about 7 5/8" to mount. Said this would be more efficient than a bypass. Do you agree as well or should I push him on a bypass model. They seem to prefer skuttle since the local distributor sells these and they get great service from them. Thanks

[beenthere]

Both bypass, and powered work ok on heat pumps, if they are connected to the hot water line.

I have a low opinion of under duct humidifiers. Anything in the air flow path is a restriction.

[cecilt]

Both bypass, and powered work ok on heat pumps, if they are connected to the hot water line.

I have a low opinion of under duct humidifiers. Anything in the air flow path is a restriction.

Thanks Beenthere. My contractor does not seem to keen on the bypass but its not his money to spend. Anyone else have an opinion before I make a decison on bypass/powered/flow through on a HP? Thanks

[sbe]

Trion makes a model 707-U that looks kind of interesting. Has anyone had any experience with it? It's a centrifugal atomizing humidifier which I'd never heard of before.

One of the problems I have in the job I'm working on now is that the heat is radiant so keeping the air handlers going all winter just for humidification doesn't make a lot of sense. If I could run on low, say 300 cfm it wouldn't be that bad because the blowers all have ECM motors which don't use much power at low speed. Unfortunately the spec's on the humidifiers want 100 fpm minimum to avoid condensation which means running the fan on high.

What I like about the Trion is that it can be mounted someplace like the crawl and ducted into the house independent of the air conditioning. Since the water vapor should migrate pretty well on its own that means I don't have to run the blowers at all. Plus it uses significantly less power than a steam humidifier. The only problem is I can't find anyone who has used one so I don't know how well they work.

One other question. Anybody every heard of a whole house ultrasonic humidifier? Something like the Trion but using ultrasonics instead of a spinning disk.