Official Luthiers Forum!

Now that we/ve been in our new 2300 sq ft single story home for 7 mo I/ve noticed that the humidity is consistently high, especially this year. I use a spare bedroom to store our instruments. The garage will have to be dehumidified seperately . Checked amazon and they have an aprilaire dehumidfier for around $1050 listed as a whole house dehumidfier. 75% rh is the current humidity and drops down to 60% by late aft. What are you folks using for a whole house dehumidifier? and what would you recommend thank you

I own and use an Aprilaire 1850F. It works great, although the recent rainy season has been really taxing it. If you have the financial means to install the version that hooks into your central HVAC system, it would work even better than what I use, and what I use is awesome.

I will need to find someone to hook it up to our heat pump / ac unit. I don/t have the skills. But I was wondering if other luthiers were using one .
to get feedback We/ve had an unusually wet winter and spring. And summers here have high temps and humidity

Ernie--

The F designation on my model means it is the "freestanding" model. You don't need anyone to install the freestanding model (obviously), but you need to be able to direct the water to a drain via a hose and either gravity or a pump. That's very site specific. In my house, given where my floor drain is in my walk-out basement (where my shop is located), the location of the dehumidifier was clear. Depending on where your drain is, and where you want to put the dehumidifier, you might need a pump system.

An installed unit would be quieter, and probably a bit more efficient in terms of dehumidifying the whole house, but installation labor can be expensive. If you feel up for dealing with where to direct the water, the freestanding unit works just fine, and requires no installation cost.

Thanks don . there is no place to drain water into but the sink in our new 1 story home . Am testing our 3 yr old fridgedaire dehumidifier in the garage work area . The house is way too humid, 70% avg so we need to find a way to bring it to 50%. Thanks for your input . Is aprilaire the only whole house dehumidfier or are there others that are reliable as well ?

There are other brands, like Ultra Air and Santa Fe. I don’t have any experience with the others; just Aprilaire.

Never mind. Found my answer. Thanks for the tip on the Aprilaire

James—

I am not using any duct work at all. It sucks in air at the front and spits it out the back. The unit sits on casters close to a wall, and my floor drain is on the other side of that wall. I just drilled a hole in the baseboard of that wall and ran the condensate tubing straight to the floor drain through the wall.

Noise: it is like the white noise of a window air conditioner. If you are within 10 feet, it is prominent, but I have my desk within 6 feet, and I only have to increase the volume on any audio I am listening to a bit in order to hear over the white noise. Further away than 10 feet and it is not a huge factor in what I hear. In any other part of that floor of the house, you can hardly notice it.

I don’t think you can put it outside, but you can certainly house it with the rest of the HVAC system if you run ductwork for it, and/or tie it in with the HVAC system. I think integral installation is quieter and more efficient for the whole house, but more expensive. And space can be an issue in some houses. My mechanical closet would probably need to be expanded if I went with an installed unit.

I hope that helps.

Thanks for the info. You must have read my post before I deleted it. I did some reading and came to basically the same conclusions.

Great video, Clay. Thanks.

Ernie, one thing you mention is that you don't have a basement so does that mean you have a home built on a cement slab or is it a wood structure floor system over a crawl space? If it's cement slab, it could be challenging to get the RH under control if the cement is allowing moisture to wick up through the floor. If it's a crawl space then you might want to investigate what is going on in there.

_________________
jw ( o)===:::

Thanks Joe .Was just talking to the local hvac guy who works on all the new homes in our subdivision,It is a 2375 sq ft home built on a concrete slab on a hillside e of guthrie ok. We have a 3 car garage. The hvac is a lennoxheat/air unit no bsmt no crawl space . we do have an attic for storage. The problem is an unusually large amt of gulf air this past winter. and spring . It/s supposed to dry out . But looks like a wet june, HOt and sticky supposedly dry july and august. The house is almost all brick with some PB wood trim . inside is trowelled stucco wallboard. We like the home but humidity avg is 75% in the am and 65-70% in the aft and pm. The floors have carpet and tile. We moved in nov27 2018.

Gotcha' Ernie. Since you know it's a slab home another detail worth looking into is how the slab site was prepared. Is it cement over dirt, clay or other and another very important detail to look into is whether they insulated under the slab. You also mention that the home is new or that you might be the first owner? If so, another thing to consider is that stick buit on site homes can often get thoroughly soaked while under construction and it can take quite a while to get the home dried out. Add the unusually wet spring that you are describing and you have the perfect storm of internal and external RH to try and tame. You might consider contacting professional home restoration services in your area that deal with flooded or fire damaged homes and they may be able to install temporary commercial dehumidifiers that are able to quickly get the RH under control while you research the best option for permanent RH control.

_________________
jw ( o)===:::

That elevated of a relative humidity inside the home is really unusual. Joe may be onto something. My slab foundation home in Houston usually ranges from 40% to a high of 55% during the year. Right now it is 46% but that is because we are in a dry front. Outside it is currently 53% which is quite low for this area. Normal outside humidity at this time of year is 70%. Your air conditioner SHOULD keep your house at least 20% lower than outside conditions or something is wrong.

Yes it is stick built from june to nov / 18 .We will definietly have to look into this. Probably a whole house dehumdification system

talked to builder . no insulation under slab but 14in sand over clay soil. yes . some moisture during construction, current outside temps 77 f and 41% humidity , not so inside . my old radio shack hygrometer reads the same outside but 68 % inside . I will be ordering a large dehumidifier that will work with with heat/ac split. Tnx everyone way too much moisture !

Your hygrometer may be way off. Have it calibrated lately?

Ernie, I'm in the process of selling our old home that had a basement that would reach 65 to 70%RH easily but as far as actual water, it was dry as could be. The consumer grade dehumidifiers sold at most home improvement centers would do very little to bring it down so after researching better options available we ended up getting a Sante Fe Classic sold online through Sylvane. We used it as a stand alone unit in our basement and I ran it on a timer that kept it off from 11:00 PM to 7:00 AM to have quiet sleeping hours. There are many options on the Sylvane site as well as a lot of good info on RH monitoring and control.

_________________
jw ( o)===:::

It has been a wet spring here in Maryland. The run down bungalow I use for a work shop has a crawl space over a dirt substrate. It is located in the woods above a stream. At this time it is neither heated nor cooled. I have two hygrometers - one is reading 85% and the other is reading 90%. I'm waiting for it to start raining inside the shop!
On another note, the "baby" vultures look like large featherless black skinned turkeys, and sound like a herd of elephants as they roll around in the attic. And of course they make the place smell like road kill.

Clay , thanks for the updated info, on your shop . Sounds like their is a lot of work to be done to get it into a useable luthiery shop LOL

Hi Ernie,
At this point I'm just making cigar box instruments and trying to reorganize things to fit in a larger project in the shop and do some building maintenance elsewhere.
When I get back to instrument making I will use a dehumidifier in a plastic lined closet as I have done in the past. That keeps the wood where it needs to be humidity wise. To try to dehumidify that leaky old building would be like dehumidifying the great outdoors.
One thing I didn't realize was that black vultures take 3 months to fledge, so I will have to deal with them for awhile yet.

Joe and clay thank you . Yes I did check sylvane, they have some good prices on large home dehumidfiers. But we would need an hvac guy to put it into the attic and run a line down to the garage water heater outlet drain, The local contractors here use an hvac co , They use a lennox whole house dehumidifier system, pricey . but has better warranty than sylvane, apriaire, and a few others listed on amazon. We are going to check around for the best option , shop and garage are still not organized

Most basement moisture comes through a slab - up to 18 gal/day for 1000/ft2 without looking wet. But a considerable amount also comes in through air leaks, so sealing leaks is a big deal. The worst leak is a return duct in an attic because it is outside wet (or dry in winter) air directly into the unit with a high-powered fan running to increase the amount of air through the "leak" and evenly distribute it throughout your house. Check both returns and supplies in an attic for leaks at corners and seams, but especially for ends of return runs that might be made of a piece of unsealed plywood or even drywall - these are huge, more so if they are missing which happens all the time. You can't seal enough and you can buy a material called "duct mastic" at Home Cheapo and Blowes. You put it on with a rubber glove and smear it into the cracks and holes.

https://www.lowes.com/pd/design-polymerics-64-fl-oz-gray-duct-sealant/3736193?cm_mmc=shp-_-c-_-prd-_-rpe-_-google-_-lia-_-171-_-ductworkandventing-_-3736193-_-0&kpid&store_code=2589&k_clickID=go_1793722707_69617671672_346785529575_pla-323061816227_c_9007971&gclid=EAIaIQobChMIuuqxgtrr4gIVggOGCh1hMAD-EAQYAiABEgJK9vD_BwE

The rule on humidity is that wet goes to dry, so if you dry one area of an open basement, then the whole basement stabilizes at the same RH over a short time, less than an hour. Once you have closed doors, or multiple floors, then things need help. Modern thermostats have a "circ" setting that runs the fan, say, 10 minutes on 20 minutes off even when heat or A/C is not called for. This mixes the air in the house, RH included, so that more moisture can hit the coild of the dehumidifier until everything evens out.

This works best with a modern High Efficiency (90+) fossil fuel heater, or a higher-efficiency (above 15 SEER usually) heat pump because they have an Electronically Commuted Motor (ECM) that costs about $40 a year to run continually, whereas a standard efficiency unit might cost $25 a month = $300 a year, not so good.

As for portable dehumidifiers, the larger the capacity the more efficient they run, so even if you don't "need" the capacity, it is best to buy oversize, 72 pint rating not too much. And since most of the central units are 100 pints per day or even less, one or two of the larger portable units would have the same or more capacity.

If the only place in the house needing dehumidification is the basement (or garage), a portable (drained into a sump) unit would be the least expensive option, but if the problem is not too bad upstairs and you have the right HVAC equipment, the portable might do for the whole house also.

More than you wanted to know

Ed

PS - This Old House's description of how a dehumidifier works is condensed for the TV watcher. They are exactly the same as an A/C unit. However, on an A/C unit, the heat taken out of the interior air is pushed outside through the outdoor unit, but on a dehumidifier it is put back into the cold (now dry) air so the temperature of the air coming out is very close to the temperature of the air going in, less water.

I have a 55 year old house with 3/4 basement/ crawl space. I have plastic down on exposed dirt. Moisture got high and mold showed up in several places several years ago. HVAC friend had me turn basement gas space heater on low which warmed the basement a little and the rest of the house stayed at 74. Humidity went down and mold disappeared. I cry when I pay the electric bill.