How Much Power does a dehumidifer USE

MadHacker · 08-22-2003, 02:26 AM

I was thinking of using a dehumidifier as a water chiller and was wondering what it would do to my hydro bill.
It would be nice to cool below ambient temperature but at what cost. If it is going to cost me $100 a month then I'll pass.

bigben2k · 08-22-2003, 11:11 AM

I dunno!

This mod is on my list too. Check out the unit that Sears has on-line: you ought to be able to find power consumption.

MadHacker · 08-22-2003, 11:26 AM

thanks for the idea

the cheepest one i looked at at sears uses 650 Watts...
that is quite a bit of power to run 24/7.
For me that runs me about $60 a month in hydro...
Looks like a water chiller won't be in my system

Note: edited Dead URL

redleader · 08-22-2003, 01:58 PM

Its less then that. Much less. 650w is probably the power pumped, not consumed.

At 650w a a compressor could condense quite a few gallons of water per hour from the air. Clearly its not that powerful.

MadHacker · 08-22-2003, 04:03 PM

Quote:

Originally posted by redleader
Its less then that. Much less. 650w is probably the power pumped, not consumed.

At 650w a a compressor could condense quite a few gallons of water per hour from the air. Clearly its not that powerful.

I don't think so.
It is rated at 5.8 amps, 115 volts
total of 667 watts. (volts x amps)
and this is the cheeper on of the 2 they had listed in sears.

#Rotor · 08-22-2003, 04:51 PM

also remember that you should not run the thing constantly 24/7.... it should cycle.... basically the same as what a fridge does.... I had mine with a thermostat and a time delay cct, so it will sense the liquid temp, and when it reaches a certain temp, the compressor will be switched on for a settable length of time, then shut down.... and so forth..... worked real good, actually...

MadHacker · 08-22-2003, 05:07 PM

but if it ran 24/7 it would get the water colder..
kooling the system that much more...

what is the on time/off time interval of your waterchiller #Rotor?

Heavy_Equipment · 08-22-2003, 07:49 PM

I have a Ranco commercial temp. sensor/relay wired into mine.

The temp. probe is submersed in the dehumidifier res., and the controller is spliced right into the power cord going to the wall.

I have been running it this way for almost a year now, with the water at 16 C., and a 3 C range to combat condensation. (Turns on at 19C) It cycles every 15 minutes roughly, and runs for 30 seconds. This is cooling a 1700+@ 2.2 GHz.

Due to the energy crisis of sorts up here lately, I have been running with my water at 24C. Less cycling- every 20 mins.

Prior to this setup, I did run 24/7 for about 3 months, maintaining -10C. This dehumidifier is well over 10 years old to begin with (R12), so I was pushing my luck abusing it that bad, the compressor was damn hot, with no breaks, and surely would have failed before too long.

As for energy consumption, I'd be afraid to guess what this old thing is using, the lights dim for a second when it kicks on... luckily the power is included in my rent.

hydrogen18 · 08-22-2003, 07:54 PM

Quote:

Originally posted by MadHacker
I was thinking of using a dehumidifier as a water chiller and was wondering what it would do to my hydro bill.
It would be nice to cool below ambient temperature but at what cost. If it is going to cost me $100 a month then I'll pass.

umm....maybe this is slang I dont get, but why would it effect your water bill?

Heavy_Equipment · 08-22-2003, 07:59 PM

Regional dialect 101:

Hydro = Hydro Electricty.

Around here, everyone calls the power company the "hydro".

Yes we have more nuclear, coal and gas generation than hydro generation these days...but it's like the whole tissue/Kleenex thing.

hydrogen18 · 08-23-2003, 10:33 AM

oh.....

#Rotor · 08-23-2003, 09:39 PM

depending on your water-body volume, and the Delta-T between ambient and your coldest spot in your system, not to forget the actual heat load your rig puts on the cooling system, it's going to vary..... Mine was set to a 3 minute on time, and that gave me a 5º drop in liquid temp, which lasted my rig about 25 minutes, before it got triggered for the next stint.

My thermostat was a custom job, It not only gave me the ability to change the trigger temperature, but I could also change the length of the power-up cycle. It was configured such that if the liquid temp was constantly higher than the trigger temp, the compressor would stay on, all the time, the timer only starter ticking, when the liquid temp dropped below the trigger temp. This insured that the compressor would not get shut down in High load conditions....

hey Heavy_Equipment How are you doing.... LTNS....

Heavy_Equipment · 09-05-2003, 05:28 PM

Hello #Rotor.

Waterblock order coming your way...

myv65 · 09-05-2003, 08:25 PM

The power listed is likely the start-up power requirements. One thing to bear in mind regarding phase-change systems is that the cooling power produced is much higher than the energy consumed by the compressor. A lot of the cooling energy comes from the radiator in the circuit.

Refrigerators typically have what is called a "coefficient of performance" or similar. It is a measure of the cooling power produced vs the power input to the system. Depending on the refrigerant, delta-T from ambient air to expanded gas, and compressor efficiency, this number may be higher than ten.

What all this means is that to cool 100 watts in a continuous fashion, the electrical power to the compressor would be ~10 watts. The remaining 90 watts gets handled by ambient air blowing over the radiator. Now compressors take way more than 10 watts, but that's why the "on" time is so short in the examples listed above. If you averaged out the compressor power to an equivalent continuous usage, it would be much less than the power input from the CPU.

I have no idea how efficient dehumidifier compressors are, but would expect a minimum of 5:1 cooling:compressor electricity. Fans blowing on radiators add to the electric bill, too, but aren't so bad.

All that said, the best bet is to find out what compressor sits inside that thing. Good chance it's a Copeland, for which you can get data direct from the manufacturer.

MadHacker · 09-05-2003, 11:11 PM

I have been looking for a used dehumidifier...
but no luck so far...

don't get out to many garage sales...
I'm not going to buy one new:shrug:

Heavy_Equipment · 09-06-2003, 12:13 AM

Classified ads.

MadHacker · 09-06-2003, 11:11 AM

Quote:

Originally posted by Heavy_Equipment
Classified ads.

have been looking but nothing so far...

08-22-2003, 02:26 AM	#1
MadHacker Cooling Savant Join Date: May 2003 Location: Okotoks, A.B. Canada Posts: 726	How Much Power does a dehumidifer USE I was thinking of using a dehumidifier as a water chiller and was wondering what it would do to my hydro bill. It would be nice to cool below ambient temperature but at what cost. If it is going to cost me $100 a month then I'll pass. __________________ "Great spirits have always encountered violent opposition from mediocre minds" - (Einstein)

08-22-2003, 11:11 AM	#2
bigben2k Responsible for 2% of all the posts here. Join Date: May 2002 Location: Texas, U.S.A. Posts: 8,302	I dunno! This mod is on my list too. Check out the unit that Sears has on-line: you ought to be able to find power consumption. __________________ WBTA (Water Block Testing Alliance) Nordic Hardware WC 101

08-22-2003, 11:26 AM	#3
MadHacker Cooling Savant Join Date: May 2003 Location: Okotoks, A.B. Canada Posts: 726	thanks for the idea the cheepest one i looked at at sears uses 650 Watts... that is quite a bit of power to run 24/7. For me that runs me about $60 a month in hydro... Looks like a water chiller won't be in my system Note: edited Dead URL __________________ "Great spirits have always encountered violent opposition from mediocre minds" - (Einstein) Last edited by MadHacker; 08-22-2003 at 04:04 PM.

08-22-2003, 04:51 PM	#6
#Rotor Cooling Savant Join Date: Feb 2002 Location: Dione, sector 4s1256 Posts: 852	also remember that you should not run the thing constantly 24/7.... it should cycle.... basically the same as what a fridge does.... I had mine with a thermostat and a time delay cct, so it will sense the liquid temp, and when it reaches a certain temp, the compressor will be switched on for a settable length of time, then shut down.... and so forth..... worked real good, actually... __________________ There is no Spoon....

08-22-2003, 05:07 PM	#7
MadHacker Cooling Savant Join Date: May 2003 Location: Okotoks, A.B. Canada Posts: 726	but if it ran 24/7 it would get the water colder.. kooling the system that much more... what is the on time/off time interval of your waterchiller #Rotor? __________________ "Great spirits have always encountered violent opposition from mediocre minds" - (Einstein)

08-22-2003, 01:58 PM	#4
redleader Thermophile Join Date: Jun 2001 Location: The deserts of Tucson, Az Posts: 1,264	Its less then that. Much less. 650w is probably the power pumped, not consumed. At 650w a a compressor could condense quite a few gallons of water per hour from the air. Clearly its not that powerful.

08-22-2003, 07:49 PM	#8
Heavy_Equipment Cooling Savant Join Date: Mar 2002 Location: Newmarket, Ontario, Canada Posts: 282	I have a Ranco commercial temp. sensor/relay wired into mine. The temp. probe is submersed in the dehumidifier res., and the controller is spliced right into the power cord going to the wall. I have been running it this way for almost a year now, with the water at 16 C., and a 3 C range to combat condensation. (Turns on at 19C) It cycles every 15 minutes roughly, and runs for 30 seconds. This is cooling a 1700+@ 2.2 GHz. Due to the energy crisis of sorts up here lately, I have been running with my water at 24C. Less cycling- every 20 mins. Prior to this setup, I did run 24/7 for about 3 months, maintaining -10C. This dehumidifier is well over 10 years old to begin with (R12), so I was pushing my luck abusing it that bad, the compressor was damn hot, with no breaks, and surely would have failed before too long. As for energy consumption, I'd be afraid to guess what this old thing is using, the lights dim for a second when it kicks on... luckily the power is included in my rent.

08-22-2003, 07:59 PM	#10
Heavy_Equipment Cooling Savant Join Date: Mar 2002 Location: Newmarket, Ontario, Canada Posts: 282	Regional dialect 101: Hydro = Hydro Electricty. Around here, everyone calls the power company the "hydro". Yes we have more nuclear, coal and gas generation than hydro generation these days...but it's like the whole tissue/Kleenex thing.

08-23-2003, 10:33 AM	#11
hydrogen18 Cooling Savant Join Date: Feb 2003 Location: USA Posts: 248	oh.....

08-23-2003, 09:39 PM	#12
#Rotor Cooling Savant Join Date: Feb 2002 Location: Dione, sector 4s1256 Posts: 852	depending on your water-body volume, and the Delta-T between ambient and your coldest spot in your system, not to forget the actual heat load your rig puts on the cooling system, it's going to vary..... Mine was set to a 3 minute on time, and that gave me a 5º drop in liquid temp, which lasted my rig about 25 minutes, before it got triggered for the next stint. My thermostat was a custom job, It not only gave me the ability to change the trigger temperature, but I could also change the length of the power-up cycle. It was configured such that if the liquid temp was constantly higher than the trigger temp, the compressor would stay on, all the time, the timer only starter ticking, when the liquid temp dropped below the trigger temp. This insured that the compressor would not get shut down in High load conditions.... hey Heavy_Equipment How are you doing.... LTNS.... __________________ There is no Spoon....

09-05-2003, 05:28 PM	#13
Heavy_Equipment Cooling Savant Join Date: Mar 2002 Location: Newmarket, Ontario, Canada Posts: 282	Hello #Rotor. Waterblock order coming your way...

09-05-2003, 08:25 PM	#14
myv65 Cooling Savant Join Date: May 2002 Location: home Posts: 365	The power listed is likely the start-up power requirements. One thing to bear in mind regarding phase-change systems is that the cooling power produced is much higher than the energy consumed by the compressor. A lot of the cooling energy comes from the radiator in the circuit. Refrigerators typically have what is called a "coefficient of performance" or similar. It is a measure of the cooling power produced vs the power input to the system. Depending on the refrigerant, delta-T from ambient air to expanded gas, and compressor efficiency, this number may be higher than ten. What all this means is that to cool 100 watts in a continuous fashion, the electrical power to the compressor would be ~10 watts. The remaining 90 watts gets handled by ambient air blowing over the radiator. Now compressors take way more than 10 watts, but that's why the "on" time is so short in the examples listed above. If you averaged out the compressor power to an equivalent continuous usage, it would be much less than the power input from the CPU. I have no idea how efficient dehumidifier compressors are, but would expect a minimum of 5:1 cooling:compressor electricity. Fans blowing on radiators add to the electric bill, too, but aren't so bad. All that said, the best bet is to find out what compressor sits inside that thing. Good chance it's a Copeland, for which you can get data direct from the manufacturer.

09-05-2003, 11:11 PM	#15
MadHacker Cooling Savant Join Date: May 2003 Location: Okotoks, A.B. Canada Posts: 726	I have been looking for a used dehumidifier... but no luck so far... don't get out to many garage sales... I'm not going to buy one new:shrug: __________________ "Great spirits have always encountered violent opposition from mediocre minds" - (Einstein)

09-06-2003, 12:13 AM	#16
Heavy_Equipment Cooling Savant Join Date: Mar 2002 Location: Newmarket, Ontario, Canada Posts: 282	Classified ads.

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