Dehumidifier for basement - Reciprocating or Rotary compressor?

[Kevin O']

Hi All,

We need to dry out the basement a bit, it's anew new home, w/ full unfinished basement, located in NE - we've noticed it's damper than we'd like down there (no leaks or flooding, just damp)... the temp in summer never gets above 68 even when 90's outdoors

I've noticed that Sears sell several models of dehumidifier, and they are delineated by 2 factors:

Compressor type - Reciprocating or Rotary - any thoughts on benefits of either? Energy Star compliance - obviously a plus when considering ROI

I'm not concerned about the dehumidifiers tank capacity as I will install a small pump to empty the reservoir whenever it needs it (did this w/ an earlier house, used a fishtank pump, worked great - pumped the water through a small hose out a window into the garden), never had to worry about it going off due to full tank.

I'm more concerned with the reliability of the compressor, hence the request - any thoughts?

Also, I've got about 40' of un-insulated cold water pipe running along ceiling - sweats a lot in humid weather (leaves tell-tale wet line on concrete floor - no real puddle though) - will insulating this have much of an effect either way?

Thanks,

Kevin O'

[mark Ransley]

I dont know about reliability , maybe sears repair dept would tell you what they have more problems with, an energy star model would be my preference, insulating your pipes with the black foam pipe insulation will stop condensation and help to lower humidity,be sure to use the type with glue on the seams

[Edwin Pawlowski]

No it won't.

Condensation is the same humidity in the air just in a different form. Insulation will stop the condensation, but the humidity will still be there, just not visible. Ed

[mark Ransley]

Insulation WILL lower the humidity in the basement because the water he says is dripping on the floor will have ceased. And will not be evaporating in the basement, I said "help lower" maybe 5% .maybe 10%, maybe more. maybe less, Go in your dry basement look at your humidistat , spray water on the floor in 1 hr it will be up 10 % Evaporation

[Stormin Mormon]

1) I don't like the whole Sears system. 2) In the AC field, rotary comps are more dependable. And less energy usage. 3) I don't like much about Sears 4) Insullating the pipe will help keep the humidity in the air, instead of on the pipe 5) I never did like Sears very much. They usually have off-spec parts in their devices. The sizes are just different enough that if you want to fix a Sears product, you can't get parts anywhere else but Sears.

[Stormin Mormon]

To lower the humidity, you remove moisture from the air.

Water condensing on the pipes removes moisture from the air (and drips it on the floor). So, the uninsulated pipes.... lower the humidity.

Different point of view, here. Unless you mean that the black wrap keeps the moisture in the air so it can get to the dehum?

[Edwin Pawlowski]

But the water is already evaporated in the basement. If it forms drops and can be drained away, that would work. that is essentailly how a dehumidifier works, taking the moisture in the air, condensing it, then putting it into a bucket to be tossed. The pipes are also doing that if it is collected. Insulation will stop it from condensing, but it remains ithe air otherwise.

Think about the ocean, how it give up water in the form of vapor, thenit rains some place, runs into a river, then back to the ocean.

Yes, Spraying water is bringing in water from another source and when it evaporates, it is added to the present humidity. If the air is trapped, it will not change at all. It will remain the same humidity level forever. Ed [e-mail]

[Kevin O']

Hi guy's,

Thanks for al the feedback - but I should have been clearer, here's the big question:

Is there a difference between a dehumidifier with a reciprocating compressor and a dehumidifier with a rotary compressor?

Thanks!

Kevin O'

[mark Ransley]

Hi folks, He said it is dripping onto his unfinished concrete floor,, and not puddeling, of course, it wont puddle as drips , it is being absorbed into the concrete and evaporating , thus raising the humidity level because it evaporates. He said he has 40 ft of dripping pipe , alot of pipe..in My view. I had uninsulated pipes maybe 20 ft, dripping with condensation when it was humid and hot out, and insulating the pipes helped alot by stopping condensation, hence dripping, hence evaporation, hence humidity. My basement was so bad at one point it looked, "foggy" one day, and I had a Minor drip leak ...to... I had no humidistat or dehumidifier then to varify results . But honestly folks , it makes a difference. Are there studies as to water evacuation due to humidity on pipes ? Im sure there are ! Its a tough issue for specifics are all unique . C.B. ...... I disagree with you here........ althought you are the most Knowledgable and learned HVAC person Ive run across. I have learned from my experiance personaly, I have seen a reduction in humidity levels which lead me to an overall elec , cost reduction. in operating costs. but in the idea of paying more juice to the juice co to remove humidity , i have found obscure options to more than pay for themselves in lowering my elec bill Ex for my 1800 sq ft house I pay 600 for heat and elec for a year ,before it was 2400 + and here we go to -20 to to 100+ . less water entered = less money paid to remove .. mark

[CBHvac]

If anything, the humidity is lower for a time..LOL

[mark Ransley]

FINE, the CB ,,, Tech ,, aside from it all, I got a 110 yr house , that nipsco checks and re checks , and im the most EFFICENT IN THE STATE .......L ittle things add up ..... ..............CB...........wake up.....

[mark Ransley]

now, withought any outside expense, or B.S. just common sense. I have one of the most eficient houses in the USA

[mark Ransley]

CB cut the BS its true

[mark Ransley]

you have to be registered some how ? my utility bills prove it, fact is its true,, r110 atic r35 walls r 30 to 40 basement r7.5 under conc floor , triple and double pane , tankless water heater , lenox 94% furnace , who do I contact for cert..... Kent Heating my co did , but salesman is N. I.

[Stormin Mormon]

My experience is that rotary comps are quieter, and use less energy.

[Brad]

Please just give up on him. He's a lost cause. I guess he thinks the pipes are somehow creating moisture where it didn't previously exist.

[Drummer of The Vibe]

Of course you're forgetting that the water dripping from the pipe was in the air to begin with, once it hits the floor it will re evaporate and go right back into the air. No gain, no loss closed system.

Now, if you wanted to be ultra slick, you could form a sheet metal trough 1" underneath the cold pipe and have it slope towards a collection basin that pumps the water out of the house. Now THAT would act as a dehumidifier and lower your humidity by .02% or something like that. I guess it depends on how cold the pipe is and how humid the air is to begin with. You would never gain enough to feel a difference, but it's pretty cool to make use of physics that are already occuring as a result of other systems. I'd liken it to heating your car with engine heat.

Bobby

[Dan O.]

Phil wrote

There are a couple of models which are suppose to work at slightly lower temperatures than normal ones do you can see them at the following link:

You can also read some additional alternatives to the frosting problem at this link:

Dan O.

- Appliance411.com

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[Ella]

I don't get all the talk about the insulated pipe -- the poor guy wanted to know relative advantages / disadvantages of rotary vs reciprocating compressors in dehumidifiers. Geez folks, get focused! I'm wondering the same thing. Talk all that other talk to the coffee shop with your coffee and gossip.