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by LazyMans·4y ago·view on hn ↗
Where do you live? I'm just curious because I can't imagine living at 78F anymore.
6 comments
I'm not OP but I live in Washington DC, where our summers are definitely hot and humid. I keep my apartment around 78F to 80F. I use a dehumidifier to keep relative humidity around 50-55%, which corresponds to a dew point of ~60F which is low enough to still feel comfortable instead of "sticky".

On especially hot days, I will raise the setpoint higher, and use a small fan to circulate air around where I am spending time, which is very effective when humidity is not too high.

A dehumidifier is essentially an air conditioner that dumps heat back into your living space.

What you are doing sounds inefficient.

The dehumidifier does use power and produce heat which must be removed from my apartment by the air conditioner.

Because it's less humid, I can maintain a higher indoor temperature and still be comfortable, meaning the air conditioner needs to run less.

Do I use net less energy? In my case, yes, but your mileage may vary depending on your equipment, insulation, etc.

He's saying that you have two air conditioners: one that vents heat inside your house and one that vents heat outside your house.

Your dehumidifier and your air conditioner are mechanically identical. The only difference between the two is where the waste heat goes. The exact same device is called a 'dehumidifier' if the waste heat is vented indoors and an 'air conditioner' if the waste heat is vented outside.

There's not really any efficiency gains from running a dehumidifier to reduce air conditioner use. They both use the same power and have the same effect on the absolute humidity, so you might as well just run the air conditioner (unless you want it to be warmer).

There's also dessicant dehumidifiers that don't use a refrigeration cycle. They do also warm the air a bit but may be more efficient per mass of water removed from the air, depending on the temperature and humidity range.
I ended up buying a dehumidifier to complement my AC, which is ancient and can't seem to keep up with the humidity in the summer.

Before the dehumidifier I could get the room cool, but it still felt sticky. With both I'm able to keep the humidity at bay and cool the room as well.

Yep. They're adding heat to the inside of their home. They need to use an AC unit to remove the moisture and pump the heat outside.
I do have an air conditioner (well, an air-source heat pump), but it doesn't adequately remove enough moisture before the indoors gets too cold. It's possible this is not properly sized, but I cannot change it because I rent.

In my case I did some tests, and the additional power usage of the dehumidifier is way more than offset by the power savings I realize by running the air conditioner less frequently. This only works because the dehumidifier enables me to be comfortable at a higher indoor temperature.

78-80 doesn't feel to bad in a dry climate imo
I live in Austin, TX. It has been 105-ish every day this week, but the humidity is 30% during the hot part of the day. My office has a ceiling fan which is on low most of the time. Some people will not believe this, but I have the minisplit set at 80F and when the sun sets I turn off the fan because I start to get cold. When I leave my office (which is attached to the garage) and walk the 40 feet into my house through the 98F evening air I often feel: ah, that warmth feels good.

To summarize: it is one part adaptation to the heat, one part low humidity, and one part air circulation.

I live in a fairly humid area, but the AC helps to drain the moisture out of the air so it's still livable. Ceiling fans on a low setting can also help you feel comfortable, especially if you don't have the sun shining on you.
Yeah we live in the foothills in Colorado at 7700 feet elevation. Typical summer day is 85 degrees and 20% humidity and we don’t have AC.

It gets warm but fans are enough and I have a portable swamp cooler for when it gets really hot.

In Wisconsin we set the AC to 78 in the summer. We tried doing that when we moved to Florida. Couldn't do it. Had to go down to 72, 74 max, because of the humidity. There's just too much moisture in the air and we have to set the thermostat that low to make sure it gets removed from the air.
Is it too high or low? I am interesting about condition settings of foreign!
78 at my thermostat means some rooms in the upper floor might be 84+!
Same. I keep mine at 74 during the day and cool it to 71 closer to bedtime.

That, plus blocking the vent closest to the thermostat in summer, tends to get the upstairs to within 3-4 degrees of the thermostat setting.

Seems pretty normal to me. Maybe not as refreshing if you come in out of working in the heat, but fine for being a desk jockey.

Temperature Comfort is largely a learned behavior in my humble opinion