dehumidifier questions

[brewyourown]

Ok, so I have learned that I have some humidity problems in my home (1,100 square foot ranch) in southern New York State. Winter time is fine and summertime is fine. where I have issues is on cooler days or mornings where the dew point is high. For example, last night when I went to bed, the RH was 50%, the ac had been on from the late afternoon through the evening. It seems to do a great job at removing the humidity even though it is a bit oversized.

However, last night the temp dropped to 62 outside and the RH this morning OUtside is 85%. I had slept with some windows open b/c my AC just would not have run overnight with temps that low.

The RH in the house this morning is 70%. That has me nervous about mold,etc...


I do run a dehumidifier in the basement which works great at keeping the entire basement at 50%, I have the drain go directly to my sump, so it runs auto pretty much.

I have seen some posts about whole house dehumidifiers and the possiblilty of hooking them up to the main return? of the house.

Are these types of dehumidifiers, sante fe, etc.., that hook up to the duct work easy to find and also are they the type of thing that a homeowner installs?

I installed the one in the basement, but it was easy, just put it there and hook up a garden hose to it. Not so sure about hooking up to the ductwork though.

[Senior Tech]

Not a diy project...


http://www.aprilaire.com/index.php?znfAction=ProductsCat&category=dehumid

[brewyourown]

Not a diy project...


http://www.aprilaire.com/index.php?znfAction=ProductsCat&category=dehumid

Good stuff in there, I have only read some of it at this point. Further question though:

My central AC when it runs removes humidity fine, so it is only when the AC is NOT running that I need dehumidification. Do the units that you linked to specialize in that type of application or are they more suited to run in conjunction with AC?

I would want the unit to remove humidity in my living space but also remove humidity in the basement. If this is hooked up to the house return vent, how would it remove humidity in the basement?

[MB1211]

Your problem doesn't really have a yes or no answer or even a 2 page response. A pro really needs to see your home and evaluate what you have and what needs to be done to fix your problem. Without a proper evaluation you can throw a lot of money at a problem and never fix it.

[brewyourown]

Your problem doesn't really have a yes or no answer or even a 2 page response. A pro really needs to see your home and evaluate what you have and what needs to be done to fix your problem. Without a proper evaluation you can throw a lot of money at a problem and never fix it.

I don't know a good pro and I had a bad experience witht the installation of my AC 5 years ago. I know there are good HVAC contractors out there, but I have to find one in southern NY.

[MB1211]

I don't know a good pro and I had a bad experience witht the installation of my AC 5 years ago. I know there are good HVAC contractors out there, but I have to find one in southern NY.

I can understand your pain. Sorry I can't help there. I guess the best advice I can give there is too keep looking. You really need a proper evaluation. Maybe someone on here can suggest someone.

[comfortableguy]

Regardless of system, regardless of S.E.E.R., regardless of situation. Look up an Aprilaire 1750. Most of the time, if you do not have enough heat load on your house due to trees or weather or what not or some "genius" ovesized your system so it does not have enough run time. An Aprilaire 1750 hooked into the ducts will fix most problems. Down here in Ga. people are just now "catching on" that the Higher the S.E.E.R., the less it dehumidifies. And yes, lets all say it "Bigger is not better!". No I do not work for Aprilaire, Aprilaire works for me! I have a 1850 square foot home on a slab surrounded by trees. I tried a 3 ton then a 2.5 ton. Then i got smart and installed a 1750-NIGHT AND DAY!-Boz
P.S. To answer the basement question, you can run ducts off of the 1750 to the basement as well. But I would try it on the system first. Remmember the #1 rule in humidity, "HUMIDITY GOES WHERE HUMIDITY IS NOT."


Good stuff in there, I have only read some of it at this point. Further question though:

My central AC when it runs removes humidity fine, so it is only when the AC is NOT running that I need dehumidification. Do the units that you linked to specialize in that type of application or are they more suited to run in conjunction with AC?

I would want the unit to remove humidity in my living space but also remove humidity in the basement. If this is hooked up to the house return vent, how would it remove humidity in the basement?

[teddy bear]

Good stuff in there, I have only read some of it at this point. Further question though:

My central AC when it runs removes humidity fine, so it is only when the AC is NOT running that I need dehumidification. Do the units that you linked to specialize in that type of application or are they more suited to run in conjunction with AC?

I would want the unit to remove humidity in my living space but also remove humidity in the basement. If this is hooked up to the house return vent, how would it remove humidity in the basement?

The ducted Ultra-Aire or Santa fe only operate when the %RH exceeds the %RH setting that you select. If the a/c keeps the %RH below the setting- no dehu. These unit have a strong fan that can blow into or suck from the a/c ducts while the a/c operates. The attached web site shows a possible method of dehumidifying the home and basement. The fresh aire is optional. Many northern climate homes do not get enough fresh during the summer because of the lack the winter stack effect. The Santa Fe can be connected similar to the UA. As you see there are several brands and sizes of dehu available. Our dehus have been refined for this application for 18 years. They are the most reliable and efficient dehus manufactured. Combining the dehu with your a/c will provide 50%RH throughout your home. Regards TB


http://new.thermastor.com/Ultra-Aire-65/UA-65_sheet.pdf

[brewyourown]

The ducted Ultra-Aire or Santa fe only operate when the %RH exceeds the %RH setting that you select. If the a/c keeps the %RH below the setting- no dehu. These unit have a strong fan that can blow into or suck from the a/c ducts while the a/c operates. The attached web site shows a possible method of dehumidifying the home and basement. The fresh aire is optional. Many northern climate homes do not get enough fresh during the summer because of the lack the winter stack effect. The Santa Fe can be connected similar to the UA. As you see there are several brands and sizes of dehu available. Our dehus have been refined for this application for 18 years. They are the most reliable and efficient dehus manufactured. Combining the dehu with your a/c will provide 50%RH throughout your home. Regards TB


http://new.thermastor.com/Ultra-Aire-65/UA-65_sheet.pdf

So who installs these things? Any HVAC contractor? If you were me and didn't know an HVAC contractor, how would you go about choosing?

[brewyourown]

I have an idea, maybe :)

How about this. I have a pretty large vent in my basement attached to the main trunk line of the AC/Heating Ducts. The vent faces down and I use it in winter for a little heat to the basement.

What if I open that vent up and allow ac to go into the basement as well as the upstairs. In essence I would end up reducing the CFM of the air to the upstairs and thereby making the AC run longer.

sure, this will cost more and the basement would probably be a little on the cold side, but the AC would run longer and I might get better humidity control?

What do you think?

I would have to balance out the air flow a bit upstairs with the downstairs vent open, but if it helped to solve the problem, man would it be worth it.

Good idea? Bad idea?

[brewyourown]

Also,

What is cheaper, getting a smaller AC or adding in the whole house dehumidifier?

[hangfirew8]

What if I open that vent up and allow ac to go into the basement as well as the upstairs. In essence I would end up reducing the CFM of the air to the upstairs and thereby making the AC run longer.

sure, this will cost more and the basement would probably be a little on the cold side, but the AC would run longer and I might get better humidity control?

I do that. It knocked a couple percent off the basement humidity, but it was still too high, so I bought another dehumidifier to replace the one that bit the dust last Fall. I still do it now, though, because the dehumidifier raises the basement air temperature two degrees, and we use the basement as a cool play room in Summertime.

The main problem with humidity in the rest house is that this Spring was cool and rainy, and the A/C just didn't run enough. Even now that Summer is here and it runs plenty, the house is OK but the basement still needs a little help. (Like, I dump a gallon every 24 to 36 hours).

If you were to go all the way to a whole-house dehumidifier, I would use that opportunity to introduce fresh air venting through it. Oh yeah, that dehumidifier might be Energy Star but it will still cost a little more, and a little more than opening the basement vent.

-HF

[brewyourown]

well I opened up the basement vent and this afternoon since doing it, I have been getting 40 minute run times with 5 minute off times. I have stat set to 73 degrees and it is 79 degrees outside.

I think I solved my problem. Humidity was brought down to 50%. We'll see over the next few days if humidity remains at that level though. But I have to believe if I am getting 40 minute run times holding 73 that when the temp outside gets up to lower 90s, it'll basically be sized correctly.

[teddy bear]

So who installs these things? Any HVAC contractor? If you were me and didn't know an HVAC contractor, how would you go about choosing?
Every region has a couple good a/c contractors that deliver value. Referrals from friends and nieghbors are good reference. The competitive bidding process is an opportunity to meet the contractors. I prefer doing bussiness with the contractor that installed your current system if possible. These dehus are simple systems that are reasonable to install.

I read your later post. In the final analysis, you will need many hours of dehumidification without any cooling. Blowing away a lot cooling for short term humidity control is not very practical. As a last resort, operating a free standing Santa Fe in your basement with a single duct connect to you cold air return is short term fix for this problen. The graphs I have posted using the Santa Fe no duct connects. I keep the finished basement at 48%RH. I operate the fan "on" mode. this blends the dry air throughout the home. Chech the uniform temps and %RH. Santa Fe Compact is less than a thousand dollars. It is capable of removing 5 gals. or 50 lbs. of moisture a day. The amount of electricity is comparable to the residential dehus. You could do this yourself. This idea is better than blowing a large of cold air into the basement. Regards TB

[brewyourown]

Every region has a couple good a/c contractors that deliver value. Referrals from friends and nieghbors are good reference. The competitive bidding process is an opportunity to meet the contractors. I prefer doing bussiness with the contractor that installed your current system if possible. These dehus are simple systems that are reasonable to install.

I read your later post. In the final analysis, you will need many hours of dehumidification without any cooling. Blowing away a lot cooling for short term humidity control is not very practical. As a last resort, operating a free standing Santa Fe in your basement with a single duct connect to you cold air return is short term fix for this problen. The graphs I have posted using the Santa Fe no duct connects. I keep the finished basement at 48%RH. I operate the fan "on" mode. this blends the dry air throughout the home. Chech the uniform temps and %RH. Santa Fe Compact is less than a thousand dollars. It is capable of removing 5 gals. or 50 lbs. of moisture a day. The amount of electricity is comparable to the residential dehus. You could do this yourself. This idea is better than blowing a large of cold air into the basement. Regards TB



Thanks, I went to Aprilair's website and looked up some local contractors. There was a company called Encon out of Connecticut that looked pretty good, at least they had a good website design and said all the right things on the website. Says they do load calculations, taylor's systems to client needs, has a senior staff of career HVAC techs, etc...

Has anyone heard of them? I may give them a call and ask their opinion.

[plarian]

I know there are good HVAC contractors out there, but I have to find one in southern NY.
Where do you live exactly? I live in Ithaca NY. I don't know the HVAC contractors here but I'm likely to be hiring one soon.
Laura

[comfortableguy]

Laura,
I am in Ga. so I am "a neutral party". I am a liscensed contractor here and not a salesperson for Aprilaire. I have used the Santa Fe products in the past and liked them but the new Aprilaire 1750 dehu can be wired to control your furnace fan as well as its own. What I would recomend is to go on the aprilaire website at www.aprilaire.com and look at the "dealer locator". Insert your zip code and they will give you a few dealers to choose from. I recently pu a 1750 in my own home and it works great! We have a little humidity in Georgia-lol! Good luck-David

Where do you live exactly? I live in Ithaca NY. I don't know the HVAC contractors here but I'm likely to be hiring one soon.
Laura

[teddy bear]

Laura,
I am in Ga. so I am "a neutral party". I am a liscensed contractor here and not a salesperson for Aprilaire. I have used the Santa Fe products in the past and liked them but the new Aprilaire 1750 dehu can be wired to control your furnace fan as well as its own. What I would recomend is to go on the aprilaire website at www.aprilaire.com and look at the "dealer locator". Insert your zip code and they will give you a few dealers to choose from. I recently pu a 1750 in my own home and it works great! We have a little humidity in Georgia-lol! Good luck-David

Aprilaire ok but do not operate your furnace fan when you dehumidify. Furnace fan operation rapidly evaporates the 2-3 lbs. of moisture on the cooling coil. Also a 65 pint whole house dehu is big enough for your home. Ultra-Aire dehus have been developed over the last 15 years. This is fourth generation of the design. It makes a difference in reliability, efficiency, and function. Regards TB

[pstu]

As a customer, I see a couple of trade-offs between the brands (I own a Thermastor Santa Fe RX and two small Soleus dehus, all have been good purchases). If you intend to connect to the central air system in any possible way, the Aprilaire models have stronger fans that will allow the more difficult setups. For example, pulling air from the central return plenum and pushing it into the supply plenum means when the AC is running, the dehu blower must push against the entire static pressure of your central duct system at that airflow. How much back pressure would that be? It all depends on your house but static pressures of 0.8 are not uncommon (Units are inches of water in a manometer. Mine was measured at 0.7 before some duct work helped that). Myself I would look for ways to avoid the dehu blower doing that much work, but you will need to consult with your professional to decide how to install.

On the other hand, if you look at the wattage of models with similar capacities, the Thermastor models generally have an energy efficiency advantage. I have a larger house and am seeing a 150 pint/day unit available that draws only 6.9 amps (828 watts), of course that would not fit your house but it shows what kind of efficiency can be in that 4th generation of product. This replaces an earler generation of the same size that drew 12 amps, and compares with the Aprilaire counterpart that draws 14 amps.

It would be entirely reasonable for a person to estimate the running cost of a dehu and conclude there's not much payoff for energy efficiency, especially if the initial install costs more. A 5.0 amp unit, if it ran 100% of the time at that load would result in 440 KWH monthly on your bill -- but it will surely run a lesser fraction and under part load so I think 100-150 KWH would be more realistic. If your electricity costs 12 cents/kwh that would be $12-18 per month. You *can* expect to be more comfortable, and you *might* raise your thermostat setting enough to offset that cost.

Another smart poster has posed the question of energy usage at part loads. All the Thermastor ratings I have seen have been at the standard of 80F degrees, 60% RH. Most but not all manufacturers rate their products according to this standard. I am told Aprilaire publishes more detailed info, using different temperature and humidity levels too. I have not seen that but would like to. The hypothesis here is perhaps Aprilaire is less of an energy user than standard conditions ratings would suggest -- it is a rational hypothesis but my opinion is it will probably be disproved if we can obtain detailed info for the Thermastor products.

I just am a nut for efficiency, like a Prius owner who is so proud of getting 60 mpg, so my emotions favor the Thermastor line. But I have tried to present the argument objectively for not worrying about that.

Hope this helps -- Pstu

[teddy bear]

As a customer,
, the Aprilaire models have stronger fans that will allow the more difficult setups. For example, pulling air from the central return plenum and pushing it into the supply plenum means when the AC is running, the dehu blower must push against the entire static pressure of your central duct system at that airflow. How much back pressure would that be? It all depends on your house but static pressures of 0.8 are not uncommon (Units are inches of water in a manometer. Mine was measured at 0.7 before some duct work helped that). Myself I would look for ways to avoid the dehu blower doing that much work, but you will need to consult with your professional to decide how to install.

Another smart poster has posed the question of energy usage at part loads. All the Thermastor ratings I have seen have been at the standard of 80F degrees, 60% RH. Most but not all manufacturers rate their products according to this standard. I am told Aprilaire publishes more detailed info, using different temperature and humidity levels too. I have not seen that but would like to. The hypothesis here is perhaps Aprilaire is less of an energy user than standard conditions ratings would suggest -- it is a rational hypothesis but my opinion is it will probably be disproved if we can obtain detailed info for the Thermastor products.

I just am a nut for efficiency, like a Prius owner who is so proud of getting 60 mpg, so my emotions favor the Thermastor line. But I have tried to present the argument objectively for not worrying about that.

Hope this helps -- Pstu

All of the newer Therma-Stor ducted dehus have fans that handle +.5" WG duct pressure. The Ultra-Aire XT150 handles +.7" WG. Regarding operation is lower temps/%RHs, the SF/UA are stronger than most. All dehus use less energy at lower temps/%RHs but remove much less moisture. Regards TB

[Gotto]

Well, if you were actually reviewing the latest ThermaStor brochures on their latest product line, all of the units are rated at 0.0"WC, and their performance drops off greater than that, which testing, and an insider from ThermaStor, has confirmed...it is validated by their recommended installation instructions, which also tells you to duct a separate return for the all the units...kind of defeats the "whole-home" dehumidification statement, unless you are a firm believer in a migration strategy inside the home, and have an open, single-level floorplan...

as far as power consumption, it is correct that the ThermaStor units do draw less power - which is only possible via their core, it was verified by other posts that the power consumption difference adds up to about $10-$15 max per month...what I don't see people commenting about is that if you try to take the unit appart, you ruin the seal around that core...which over time, will lead to moisture buildup inside the core and some nasty black mold buildup...I have seen some actual pictures from installations of this, none myself...

What I found out is that the new Aprilaire unit, like the 1750 mentioned earlier, is designed to extreme durability & reliability standards, far superior to anything else out there at the moment, probably why they have a 5 year warranty and are touting a 15 year service life with the new improvements...

Also, because I do see a lot of misunderstandings of ducting, the Aprilaire unit can be zoned, nobody elses does...it can be zoned to do a basement or separate living space as well as run in whole home mode...the only way you can possible do it with another system is a more complicated installation of relays to trick dampers into zoning...

The biggest difference is that the Aprilaire unit has a patented ventilation control. First, because the Aprilaire ducted units have an internal humidity control, it can dehumidify the ventilation air at the point it enters the home...from what I understand, and things may have changed, competitive units would not dehumidify the air until the living space control registers the added load...loading the whole home first before dehumidification...again, controls may have changed since my last update...

Second, and more importantly, the Aprilaire vent control system in their dehumid is smart in that it, when wired to the HVAC equipment, can track HVAC run time, vent when the HVAC is running, and make up the ventilation requirement difference, if needed, at the end of the set period...just for example, if you need 30 minutes of ventilation in one hour, and the HVAC runs for 20 minutes during that hour, the Aprilaire dehumid will run the ventilation during those 20 minutes, dehumidifying that air if necessary...if at the end of that hour, the last 10 minutes required doesn't come from another cooling call, it makes up the last 10 minutes...

That's why the HVAC tied to the dehumid is a great option in some installations, especially in tighter, foam-seal, icynene homes.

Running the dehumid & HVAC at the same time is not an issue in most cases...however I have seen issues in running the HVAC fan when the HVAC is NG or LP powered...the coil is on the supply side. In some instances I have seen the blower re-evap some of that HVAC coil moisture...in those cases you simply disconnect the HVAC-Dehumid connection

However, anytime you run the dehumid separate from the HVAC, you have to be careful of the distribution of warmer, dry air to "the path of least resistance"

At the end of the day, it comes down to brand preference...if you like the ThermaStor, they make good units...if you like the Aprilaire units, they make good ones as well...the question is more about what features you value...the only one I have seen in favor of the ThermaStor is the power consumption...the Aprilaire is more bang from the buck...If you were to read the Honeywell comparison brochure, you need to realize they spent a lot of time and money on a separate marketing piece that doesn't have the facts straight...maybe they should spend more time designing their own than re-labeling a ThermaStor unit and calling it magically better somehow...

I've got to go, this is getting to be too much and I think some of you may have already gone to sleep reading this...good luck...

oh yeah, before I forget, remember that the new ThermaStor manuals & brochures tell you that the units are not suppose to be run above ambients above 100F, which elimates the south for the most part...at least if you actually spend time with contractors in the south...100F in an attic is an every day occurence...I guess the units would work in the midwest for most of the year, and and the north...

MG

[comfortableguy]

:)As I said before in a previous post, I am in Ga. So down here we may not be as hot as nevada but we get our fair share of 90+ degree days and 90% humidity days. Building codes are somewhat of a joke. Therefore, humidity is a big issue down here. Buit Attic ventalation is one as well. We Have NONE! This is why I push power attic ventalators and Aprilaire 1750's. They handle "warm" attics with no problem. Also, as far as consumption of power, they are on a 15 amp 120v circuit-is this really a concern? I have seen dorm refrigerators pull more amps. Yes they may pull more than the Honeywell, but you just read in a previous post-they also have stronger motors. Can't have both unless they start putting ECM motors in there(Then watch the cost spike!). I have an 1850 sq. ft. single story ranch style home with a 1750 and can pull the humidity down below 20% any time I want-I don't but can regardless of outdoor ambient conditions(in ga. remmeber) so up north should never be a problem. I am orig. from chicago so I can speak for both sides. I also have a customer I put one in a 2 story garage with no ducts and it handles both floors due to the open floorplan and the "migration theory"-which does work. If you want to pay for a name, buy honeywell. if you want a product that has been thought out and properly designed for ANY SITUATION-buy aprilaire. No I am not a salesman for Aprilaire but I sell alot of it in my company. Boz


Well, if you were actually reviewing the latest ThermaStor brochures on their latest product line, all of the units are rated at 0.0"WC, and their performance drops off greater than that, which testing, and an insider from ThermaStor, has confirmed...it is validated by their recommended installation instructions, which also tells you to duct a separate return for the all the units...kind of defeats the "whole-home" dehumidification statement, unless you are a firm believer in a migration strategy inside the home, and have an open, single-level floorplan...

as far as power consumption, it is correct that the ThermaStor units do draw less power - which is only possible via their core, it was verified by other posts that the power consumption difference adds up to about $10-$15 max per month...what I don't see people commenting about is that if you try to take the unit appart, you ruin the seal around that core...which over time, will lead to moisture buildup inside the core and some nasty black mold buildup...I have seen some actual pictures from installations of this, none myself...

What I found out is that the new Aprilaire unit, like the 1750 mentioned earlier, is designed to extreme durability & reliability standards, far superior to anything else out there at the moment, probably why they have a 5 year warranty and are touting a 15 year service life with the new improvements...

Also, because I do see a lot of misunderstandings of ducting, the Aprilaire unit can be zoned, nobody elses does...it can be zoned to do a basement or separate living space as well as run in whole home mode...the only way you can possible do it with another system is a more complicated installation of relays to trick dampers into zoning...

The biggest difference is that the Aprilaire unit has a patented ventilation control. First, because the Aprilaire ducted units have an internal humidity control, it can dehumidify the ventilation air at the point it enters the home...from what I understand, and things may have changed, competitive units would not dehumidify the air until the living space control registers the added load...loading the whole home first before dehumidification...again, controls may have changed since my last update...

Second, and more importantly, the Aprilaire vent control system in their dehumid is smart in that it, when wired to the HVAC equipment, can track HVAC run time, vent when the HVAC is running, and make up the ventilation requirement difference, if needed, at the end of the set period...just for example, if you need 30 minutes of ventilation in one hour, and the HVAC runs for 20 minutes during that hour, the Aprilaire dehumid will run the ventilation during those 20 minutes, dehumidifying that air if necessary...if at the end of that hour, the last 10 minutes required doesn't come from another cooling call, it makes up the last 10 minutes...

That's why the HVAC tied to the dehumid is a great option in some installations, especially in tighter, foam-seal, icynene homes.

Running the dehumid & HVAC at the same time is not an issue in most cases...however I have seen issues in running the HVAC fan when the HVAC is NG or LP powered...the coil is on the supply side. In some instances I have seen the blower re-evap some of that HVAC coil moisture...in those cases you simply disconnect the HVAC-Dehumid connection

However, anytime you run the dehumid separate from the HVAC, you have to be careful of the distribution of warmer, dry air to "the path of least resistance"

At the end of the day, it comes down to brand preference...if you like the ThermaStor, they make good units...if you like the Aprilaire units, they make good ones as well...the question is more about what features you value...the only one I have seen in favor of the ThermaStor is the power consumption...the Aprilaire is more bang from the buck...If you were to read the Honeywell comparison brochure, you need to realize they spent a lot of time and money on a separate marketing piece that doesn't have the facts straight...maybe they should spend more time designing their own than re-labeling a ThermaStor unit and calling it magically better somehow...

I've got to go, this is getting to be too much and I think some of you may have already gone to sleep reading this...good luck...

oh yeah, before I forget, remember that the new ThermaStor manuals & brochures tell you that the units are not suppose to be run above ambients above 100F, which elimates the south for the most part...at least if you actually spend time with contractors in the south...100F in an attic is an every day occurence...I guess the units would work in the midwest for most of the year, and and the north...

MG

[teddy bear]

Well, if you were actually reviewing the latest ThermaStor brochures on their latest product line, all of the units are rated at 0.0"WC, and their performance drops off greater than that, which testing, and an insider from ThermaStor, has confirmed...it is south..

.100F in an attic is an every day occurence...I guess the units would work in the midwest for most of the year, and and the north...

MG
Welcome to our forum. Your posting will lead to some lively discussion. Probably the best since Aprilaire invented whole house dehumidification a couple years ago. I will be glad to address your points during next week. I have tried to focus on the benefits of whole house humidity control vs trying to control with the a/c. As opposed to attacking the competitors and mis-information from specs/literature. More to follow next week. Regards TB

[pstu]

ThermaStor... recommended installation instructions, which also tells you to duct a separate return for the all the units...kind of defeats the "whole-home" dehumidification statement, unless you ... have an open, single-level floorplan...

...the Aprilaire vent control system in their dehumid is smart in that it, when wired to the HVAC equipment, can track HVAC run time, vent when the HVAC is running, and make up the ventilation requirement difference, if needed, at the end of the set period...just for example, if you need 30 minutes of ventilation in one hour, and the HVAC runs for 20 minutes during that hour, the Aprilaire dehumid will run the ventilation during those 20 minutes, dehumidifying that air if necessary...if at the end of that hour, the last 10 minutes required doesn't come from another cooling call, it makes up the last 10 minutes...

...However, anytime you run the dehumid separate from the HVAC, you have to be careful of the distribution of warmer, dry air to "the path of least resistance"
...

MG
With one single post to your name, I have to wonder if you are willing to post any answers to my questions, but here goes:

>>the Aprilaire vent control system in their dehumid is smart in that it, when wired to the HVAC equipment, can track HVAC run time, vent when the HVAC is running, and make up the ventilation requirement difference...

As I read your sentence, it sounds like the dehu is going to ventilate the entire time the AC runs, and then some more is optional if the desired time is not reached. Is there any ability to stop ventilation while the AC is running? Because the longest runtimes could be over an hour non-stop and that seems to me just when you want all the sensible capacity available. In other words over-ventilating in such a period is undesirable. Do I understand right?

I'll just say this once and then let it drop: when the Aprilaire was new, its marketing material did claim Aprilaire was soooo brilliant because it had just made something to DEhumidiy. They said that as if nobody had heard the idea before. As a customer I found that very off-putting. But I realize that was a marketing guy and it would be unfair to be too harsh on Aprilaire for that.


Regards -- Pstu

[teddy bear]

Well, if you were actually reviewing the latest ThermaStor brochures on their latest product line, all of the units are rated at 0.0"WC, and their performance drops off greater than that, which testing, and an insider from ThermaStor, has confirmed...it is validated by their recommended installation instructions, which also tells you to duct a separate return for the all the units...kind of defeats the "whole-home" dehumidification statement, unless you are a firm believer in a migration strategy inside the home, and have an open, single-level floorplan...

MG

Yes we rate our units at 0 in. of WG. Many people use them at that condition. There is a minimal decline in capacity as the duct pressure increases. Is the inference that Aprilaire's preformance not decline as presures and conditions decline. Your early literature stated that your dehu removed the same amount of moisture regardless of temperature and %RH. I can not find that literature any more. But be my guest with your claims.
Yes, duct the dehu in the best method possible to maximise preformance and extend the life of the equipment. You can duct your unit anyway you want but please ducts ours as recommended if possible. I am a firm believer in our basic recommendation for the circulation of air and moisture control throughout the home. More to follow later. Regards TB

[pstu]

Is there anything about the Aprilaire that makes it more able to handle zoning? I admired the pictures in the Aprilaire literature but always figured those creative ideas could be applied to any dehu.. with the exception of the bypass configuration (hope I am using the terminology right).

Best wishes -- Pstu

[comfortableguy]

You might look at that title and wonder what I mean? I have noticed in HVAC, you can be "brand-stupid". What I mean by that is it is alright to be dedicated to a certain brand, to a point. Personally, I like Aprialire for filtration(2400 or 5000),dehumidification(1750) and humidification(600 or 700). Air-Purification I like Abatement Technologies (500UVP) and for zoneing I like Honeywell. If you need lights to tell you if a damper is opened or closed or you need a powered-open damper, we need to chat. I personnaly do not care who "made it first" I just care about who makes sense. I do not mean to insult anyone or degrade any brand, it is just what I have seen that is dependable,reliable and "customer friendly". If there is anyone in the field who has not "played" with the Honeywell YTH9421C1002-Check it out, it is worth a look! Boz

Is there anything about the Aprilaire that makes it
more able to handle zoning? I admired the pictures in the Aprilaire literature but always figured those creative ideas could be applied to any dehu.. with the exception of the bypass configuration (hope I am using the terminology right).

Best wishes -- Pstu

[Carnak]

The aprilaire blowers can handle some static pstu as we have discussed, and yes I have seen them zoned.

One installation method they show is the Bypass Method and I have found that to be problematic down here as it requires the air handler fan to run when the dehu runs. So this elevates RH as it re-evaporates mositure on the air handler cooling coil. It is better to let them have their own dedicated intake grille and then let it blow into the supply ducts and this installation is also shown in their manuals.

I think you do see a lot of hype in the forums though, but I will give aprilaire credit, they publish a wide range of mositure removal against various entering air conditions and not just the standard 80F 60% rating.

Aprilaire has a fan cycler control as well, but I think on another thread if you want to set your thermostat up high during the day, you are better off just shutting it off so it cannot run as there is a potential for the self sustaining scenario I was describing in the $900 thread.

[pstu]

Is there something about the Aprilaire that is special that allows zoning? Is the stronger fan a factor? Is the controller equipped with different capabilities?

Agreed, Aprilaire publishes ratings under a range of conditions and Thermastor uses just the standard. Agreed, Aprilaire has a stronger fan. And the big Aprilaire weighs only 100 lbs while the Thermastor weighs 150 lbs. That's the real reason isn't it, less physical labor for the professionals<g>?

Best wishes -- Pstu

[Carnak]

If you are zoning it, it is probable that you have more duct work involved and you need some fan power.

If it just has to move air free air in a musty basement it does not need any fan power.

[teddy bear]

Is there something about the Aprilaire that is special that allows zoning? Is the stronger fan a factor? Is the controller equipped with different capabilities?

Agreed, Aprilaire publishes ratings under a range of conditions and Thermastor uses just the standard. Agreed, Aprilaire has a stronger fan. And the big Aprilaire weighs only 100 lbs while the Thermastor weighs 150 lbs. That's the real reason isn't it, less physical labor for the professionals<g>?

Best wishes -- Pstu

The UA xt150H can survive 1" WG of duct pressure. This is twice of the Aprilaire. The UA uses half of the energy to remove 150 pints of water per day verses the Aprilaire. Yes it weighs more,so. If you want a little lite unit, check out the UA Compact for tight installs. The above info is bogus. Where do you guys get all this info? Regards TB

[teddy bear]

Well, if you were
as far as power consumption, it is correct that the ThermaStor units do draw less power - which is only possible via their core, it was verified by other posts that the power consumption difference adds up to about $10-$15 max per month...what I don't see people commenting about is that if you try to take the unit appart, you ruin the seal around that core...which over time, will lead to moisture buildup inside the core and some nasty black mold buildup...I have seen some actual pictures from installations of this, none myself...

MG

Regarding cost of operation, we have a full spectrum of dehumidifiers. Some are similar to AA while our most efficient units remove almost twice as much moisture per kw as AA. Facing upto $.17 per KW could mean upto $2.00 per day in operating cost. In heavy load conditions this is $60 per month.
Any cooling device dehu or a/c allowed to set around for days with a wet cooling coil causes mold to grow on the damp surrounding surfaces like insulation or other interior surfaces. Over a period of years the mold will be visible to the eye. Any surface that is washed by condensate is clean enough to not grow mold. Both spores and organic dust are washed down the drain. The aprilaires(AA) will grow mold on the surrounding surfaces inside the cabinet if the coil is keeped damp for extended periods of time. After the AA have been out long enough, you will find mold growing in the right situtuations. In all a/c accessories including all dehus, you need an air drying cycle to throughly dry the equipment every couple days. The safest way to avoid mold in all these ducted devices with cooling coils is operate the fan enough to dry the coils after using.

Another day, we will answer the other issues raised by gotto
Regards TB

[comfortableguy]

What? One minute those on here are worried about amp draw on a 15 amp/120v circuit and now we are concerned about physical weight? NO DISRESPECT BUT MAN! HVAC must have gotten ALOT easier up north than when I lived there if those are the 2 main concerns. By the way, if you have that many static pressure problems on your zone system, a dehumidifier is the LEAST of your worries! Anybody ever hear of a "dump zone powered damper or barametric damper" when zoneing? Like I said, no disrespect but if I did not know any better I would swear I was watching salesman chatting and not techs! Aprilaire is hands down the most reliable and can but put in multiple situations-what else do you need? Specs are nice but those are in a controlled enviorment-Georgia homes are ANYTHING but a controlled enviorment. I like teddy bear, he has his specs.



The UA xt150H can survive 1" WG of duct
pressure. This is twice of the Aprilaire. The UA uses half of the energy to remove 150 pints of water per day verses the Aprilaire. Yes it weighs more,so. If you want a little lite unit, check out the UA Compact for tight installs. The above info is bogus. Where do you guys get all this info? Regards TB

[Carnak]

The UA xt150H can survive 1" WG of duct pressure. This is twice of the Aprilaire. The UA uses half of the energy to remove 150 pints of water per day verses the Aprilaire. Yes it weighs more,so. If you want a little lite unit, check out the UA Compact for tight installs. The above info is bogus. Where do you guys get all this info? Regards TB

http://www.thermastor.com/Ultra-Aire-XT150H/

probably removes twice the water of the other thermstors, maybe you should just sell these

[teddy bear]

This is the state of the art in dehumidifiers. 7.9 pints per KW is highest we make. We will work in these improvements in our other units. Glad you noticed. and thanks for the advice. Unfortunately, using a 150 pint per day unit on 75 pint per day job is expensive and some of the efficiency is lost. Fortunately, we have many sizes and styles to best fit the application. Regards TB

[teddy bear]

Well,
What I found out is that the new Aprilaire unit, like the 1750 mentioned earlier, is designed to extreme durability & reliability standards, far superior to anything else out there at the moment, probably why they have a 5 year warranty and are touting a 15 year service life with the new improvements...

Also, because I do see a lot of misunderstandings of ducting, the Aprilaire unit can be zoned, nobody elses does...it can be zoned to do a basement or separate living space as well as run in whole home mode...the only way you can possible do it with another system is a more complicated installation of relays to trick dampers into zoning...
MG

This sounds like the AA dehu intro where they discovered dehumidification. "Extreme durability & reliability" I guess the rest of us do not know what we are doing. This type of boosts are best proved by performance rather than marketing statements. The original model did not do that well. I never mentioned any of the problems. As all of us design, apply, and wear out equipment, we learn lessons, myself included.
AA made another discovery by able to duct to different spaces. There is an attitude about all this that puts me off, sorry. Just goes to show that you can work hard at something for 18 years and come up short. There are a few of those 18 year old units operating yet and many are not. Miracles. Regards TB

[teddy bear]

Well,
The biggest difference is that the Aprilaire unit has a patented ventilation control. First, because the Aprilaire ducted units have an internal humidity control, it can dehumidify the ventilation air at the point it enters the home...from what I understand, and things may have changed, competitive units would not dehumidify the air until the living space control registers the added load...loading the whole home first before dehumidification...again, controls may have changed since my last update...
MG
Another invented here deal and the rest of us are dumb smucks. Imagine this. It’s hot outside and the a/c is operating full bore. The ventilation timer is calling for fresh air even though the people are not home. The humid fresh air is being brought in through the dehumidifier. With the moisture sensor in the dehumidifier is activated. Brilliant? Not! The a/c has enough cooling load to handle the moisture in the fresh air. Operating the dehumidifier at this time adds additional heat uses a lot of extra electricity. These are the kind of things that lead to excessive energy cost. During peak a/c times, an additional $100 per month of electricity could be used with this control strategy.
Like I stated previously, there is arrogance about AA claims & this analysis that says they are better than the rest of us smucks.


Well,
That's why the HVAC tied to the dehumid is a great option in some installations, especially in tighter, foam-seal, icynene homes. Finally something I agree with.


I've got to go, this is getting to be too much and I think some of you may have already gone to sleep reading this...good luck...

oh yeah, before I forget, remember that the new ThermaStor manuals & brochures tell you that the units are not suppose to be run above ambients above 100F, which elimates the south for the most part...at least if you actually spend time with contractors in the south...100F in an attic is an every day occurence...I guess the units would work in the midwest for most of the year, and and the north...

MG

There is no statement about ducted dehumidifiers in hot attics that limits our dehus to <100^F. Ducted dehus can be located in 140^F attics. The proformance of the dehu is determined by air in the space not in the attic. More mistatements. There is statement about operating non ducted dehu in high temperatures recommending limiting the dehu to <100^F. At 100^F, a 80^F dew point is 50%RH. Like I said before, there is an arrogance that about all of this... Let the market place settle these issues. Save these mis-statements for the salesman when they call on the contractors. At least, I will not have to hear them. MG, let's do this again, it was real productive. Regards TB

[Carnak]

Another invented here deal and the rest of us are dumb smucks. Imagine this. It’s hot outside and the a/c is operating full bore. The ventilation timer is calling for fresh air even though the people are not home. The humid fresh air is being brought in through the dehumidifier. With the moisture sensor in the dehumidifier is activated. Brilliant? Not! The a/c has enough cooling load to handle the moisture in the fresh air. Operating the dehumidifier at this time adds additional heat uses a lot of extra electricity. These are the kind of things that lead to excessive energy cost. During peak a/c times, an additional $100 per month of electricity could be used with this control strategy.
Like I stated previously, there is arrogance about AA claims & this analysis that says they are better than the rest of us smucks.


Thermastor has the greatest hype in this forum, probably triggering the flames from someone other than me.

On that $900 thread, I agree that it could very well be the ventilation control that is driving up the RH. The problem is an owner in a well insulated home sets up the thermostat so high that it would never come on, on its own until it is time to recover for the "Return Period"

So the vent system gets tricked to think it is a shoulder season and needs to cycle on to get some fresh air in there.

Commerical programmable stats have dry contacts for occupied and un-occupied modes, maybe time for residential stats to have this can open contacts during the "Leave" or "Away" program setting.




There is no statement about ducted dehumidifiers in hot attics that limits our dehus to <100^F. Ducted dehus can be located in 140^F attics. The proformance of the dehu is determined by air in the space not in the attic. More mistatements. There is statement about operating non ducted dehu in high temperatures recommending limiting the dehu to <100^F. At 100^F, a 80^F dew point is 50%RH. Like I said before, there is an arrogance that about all of this... Let the market place settle these issues. Save these mis-statements for the salesman when they call on the contractors. At least, I will not have to hear them. MG, let's do this again, it was real productive. Regards TB

maybe he is confused with some note that says do not draw in air hotter than 100F, as in straight outside air in Dallas