Adding a humidifier to a heat pump?

[Ruby the Liberal]

The dry skin is going to make me insane if I don't end up with an infection from scratching first.

My installation is a 13 SEER Carrier heat pump/AC unit and I have a standalone room humidifier for overnight, but have had recommendations on this install (noting the cautions about mold and other airborne issues).

Any thoughts, suggestions, recommendations?

[jeff47]

1. It's a pretty straightforward situation

I'm not sure what sort of thoughts you're looking for. There really isn't anything tricky.

You'll just need to remember to turn it off during the summer.

[Ruby the Liberal]

2. My heat pump unit is in an upstairs closet

that was almost built around it.

Do they take up a lot of room? Is this something a handyman can do, or should an HVAC be called?

Also, if you know - how do they work? In googling I see references to humidifier controls (like temperature controls) to ensure that there isn't too much moisture as it can lead to mold issues and an increase in a potential dustmite problem. Is this something that can be combined with a thermostat, or do they have to fish the wires through the wall for a separate control?

Since I have you - are there options, and if so, what to look for/ask for, and more importantly - what corners shouldn't be cut for an ill thought cost-saving desire?

Just trying to understand this so I know who I should call and if what they are telling me gels with what people who understand this have advised. An elderly relative suggested this to me this week but couldn't speak to the particulars.

I don't want to pay $1,000 for something that can be accomplished for $500, but in the same token, I don't want to pay $500 for something that, done right, should cost $1,000. If that makes sense?

[jeff47]

3. Most units are roughly 12" by 16" by 4"

So it's usually possible to fit them into any HVAC space. The hard part is you need a supply of water - somebody's got to run a pipe to the humidifier. Some use small tubing, which is much easier than real plumbing. But there's some problems with that - tubing isn't as durable as pipe, so it's more likely to leak.

It is something a handyman can install, just read the directions first.

They way they work is they spray water into the air that is passing through the blower. That water evaporates and thus increases the humidity of the air.

As for the humidity controls, they're usually set to put a fixed rate of water into the air. Calculations in the instruction manual will give you a good starting point for that setting. You can tweak the rate based on how the house feels, or you could use a hand-held humidity meter.

It is possible to get a humidistat and put that out in the house similar to a thermostat. That tends to be overkill - if the temperature is off by 10 degrees, that's a big deal. If it's 40% humidity instead of 50% humidity, it's not a big deal.

As for options or corners not to cut, I'm not really aware of any that make an enormous difference. There's basically two kinds: ones that spray cold water, and ones that heat the water and spray steam. Both will get the job done. Some claim the steam ones are better since the water's already in gas form, but it really doesn't make a practical difference. The primary way people go wrong with them is solved by reading the instructions.

One option you may want to consider is a shower-mounted humidifier. Basically, you stick it just behind the shower head, and it sprays a mist of cold water into the air. While you're running it, turn the fan on for your heat pump so it circulates the air throughout your house (the fan can be run independently from the heating and cooling). That would be a pretty fast and cheap way to figure out if a whole-house humidifier is worth the cost and effort.

[Ruby the Liberal]

4. Ah! Interesting and very helpful.

I was curious about the water supply. As luck would have it, the AC/HP unit is on the opposite side of the house from any plumbing, so there is that.

Thanks for noting the shower option. I will follow up on this over the next week and hopefully have a plan.