I live in a 2023-build house in north Houston / Spring with spray foam insulation. I'm trying to get the relative humidity down. We sit around or just over 60%. Our AC units run almost continuously this time of year, so I'm exploring adding whole-home dehumidifiers to help. Can anyone recommend an HVAC contractor they trust?

Also, any brands of dehumidifier that I should seek or stay away from?

We're in the same boat and I'm interested in doing the same thing.

El_duderino said:

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You want Santa Fe brand. Has your installer/technician lowered the cfm's to help with dehumidification?

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If the AC units are currently struggling to maintain temp, would lowering CFM exacerbate that issue?

AggieInHouston said:

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El_duderino said:

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You want Santa Fe brand. Has your installer/technician lowered the cfm's to help with dehumidification?

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If the AC units are currently struggling to maintain temp, would lowering CFM exacerbate that issue?

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Maybe. Lower cfm will allow better cooling and better humidity removal but it also might ice over your coil . I prefer slightly undersized units to oversized ones. The problem is most ac techs are lazy and don't want to get call backs because people can't get their AC below 78 when it's 110 outside so they oversized the units to make those people happy which makes the ac hit the set point but have high humidity.

When it's 104 on my porch, I generally cannot hit a 78 set point. But she will run all day long trying and the humidity will be in the 40's. When I had my system installed I ran the calcs and set the design temp. If hadn't they would have put in a 5 ton unit for A 2200 sq foot zone.

Multi stage units are superior for this and a dehumidifier generally wouldn't be required.

I also live in Spring (2020 build w/ spray foam insulation) & recommend KAC Express for HVAC stuff. Your 60% humidity is very high and is at-risk for mold. I had a similar problem of the A/C running all day even though I had a dehumifier -- turned out my coils were leaking. I decided to replace my whole A/C+ coils since it was old & the industry switched to R-454 refrigerant last year. They quoted me a 4-ton Trane "Choice 16" for $7600 installed (they have veteran discounts). My humidity went down from 55% to 45%. The A/C can easily cool to 74 degrees now with little effort during this summer.

IMHO
New Trane variable HVAC sized by experts, then add a bit if lots of parties or open-close fenestration SOP
Seal ducts, even if Aeroseal is required, then insulate about them
Trane thermo/humistat
You'll be pampered
We finally are .... Aggieland humidity and loads of R-1 glass

Thanks everyone!

Thanks Dr. Nefario!