# Dehumidifiers

• 06-18-2008, 01:15 AM
DanW13
Dehumidifiers
I realize dehumidifers are rated by how many pints of moisture they remove/hr, but how is that determine ? Is it determined by the number of fin's on the condenser or the size of the compressor or something else....
• 06-18-2008, 08:52 AM
mchild
They are rated based on energy used vs. water removed = Pints/kWh. The link is a listing of Energy Star rated units. Check out how much more Teddy Bear's Therma-stor units extract.

http://www.energystar.gov/ia/product..._prod_list.pdf
• 06-18-2008, 09:26 AM
DanW13
I understand that but it still doesn't answer my question as to how they come up with how much the dehunidifer will remove. Is it the size of the comressor or the condenser that makes one remove more water then the other ??? How do they get one to remove 30 pints and another to remove 50 pints is what I want to know.
• 06-18-2008, 09:33 AM
paul42
The size of the compressor is the primary driver. However, there also has to be enough 'fins' to match the compressor size. So, the size of everything goes up to increase capacity.
• 06-18-2008, 09:41 AM
firecontrol
It takes X amount of energy to condense X amount of water at a specific temperature and humidity in the space the dehumidifier is located in.
The energy/capacity is going to be directly tied to the capacity of the compressor to convert electrical energy into the required temperature on the condensing/evap coil so it's surface will maintain a temperature below dew point.
So yes, it's dependant on both.

http://www.aham.org/ht/a/GetDocumentAction/i/8187
• 06-18-2008, 09:45 AM
beenthere
Its by how cold their coil gets, at what the air flow over the evap coil is, at x &#176; room air temp.
• 06-18-2008, 11:07 AM
teddy bear
I did not appreciate how simple dehumidifier design was until I read the preceding posts.
AHAM (an association of appliance mfg.) decided to rate dehumidifiers at 80^F, 60%RH. In reality, the dehumidifiers typically operate at 65-75^F, 45%-55%RH and cycle on/off. The dehus are rated on pints/day and liters/KW, The combination of componets determine the capacity and efficiency. The range of residential dehu available is 5-75 liters or 10-150 pints per day. The range of moisture per KW is 1-4 liters per kw or 2-8 pints per KW. Some of the lesser dehus will not operate well at colder temperatures. The difference is more sizing components. The majority of dehus use a compressor, coils, and a fan/blower. The most efficient dehus use opitmum components plus they utilize the cold dry air to increase the moisture condensing ability of dehu. There is also a variation of reliability in the components in the dehus. The high efficiency units are designed for 10 year life. All dehus are not created equal or even similarly. People do not appreciate the energy consumption of the lowly dehu. A common 50 pints pint/day dehu operating in a large cool basement can consume @\$.10 per KW \$75/month and be borderline on keeping a cool basement dry. Using a 90 pint/day top of the line dehu in the same basement will maintain <50%RH on highest load day and operate for \$40/month. The investment in the better system maybe 3-5 times more. Basements with a better dehu can be the nicest space in a home when kept <50%RH. Regards TB