Heat pump Dryers

[takyka]

We bought a Gorenje HP dryer recently. I took some measurements today with 5kg (11lbs) of wet clothes, spinned out on 1400rpm.
The dryer consumed 0,6kWh of energy, finished in 45min, max. power draw was 909W. The machine collected 1,2L(0,31gallon) water.

T.

[AC_Hacker]

Originally Posted by takyka

We bought a Gorenje HP dryer recently. I took some measurements today with 5kg (11lbs) of wet clothes, spinned out on 1400rpm.
The dryer consumed 0,6kWh of energy, finished in 45min, max. power draw was 909W. The machine collected 1,2L(0,31gallon) water.

T.

Thanks for this info.

The US is so far behind in energy conservation issues!

-AC

[Mikesolar]

I don't think the US would mandate (or ban) the things that Europe does. It goes against our individualist nature......bit it does force them to innovate. What is the saying...."one for all and all for .......never mind"

[jeff5may]

Originally Posted by AC_Hacker

Thanks for this info.

The US is so far behind in energy conservation issues!

-AC

The technology is here, there's just not enough demand for the major manufacturers to Mass produce enough to break even. The high end customers don't care enough about energy savings.

[AC_Hacker]

It is interesting to pause, while this thread is drifting, and to go back to the first post and look at the article that was linked to, part of which said:

Students from the University of Maryland won the Max Tech and Beyond Design Competition for their heat pump clothes dryer prototype, which achieved a 59 percent energy savings compared to standard U.S. electric dryers. (image via University of Maryland)

Every year, clothes dryers use about 71 terrawatt-hours of energy, making them one of the largest energy-consuming appliances found in the home. Unlike traditional electric clothes dryers, heat pump clothes dryers recycle warm air to reduce energy usage by 30 percent. These facts inspired the Maryland team to improve clothes drying technology. Led by Professor Yunho Hwang, the team of 17 students spent the past year designing, building and testing a heat pump clothes dryer prototype that is commercially viable. The end result is a prototype that achieved a 59 percent energy savings compared to standard U.S. electric dryers. The team estimates that if their technology is deployed to all American clothes dryers, it could save up to 25.8 terrawatt hours a year — or the amount of energy used to power about 2 million homes.

It is notable that a university class in Maryland gets an award for developing a prototype idea for a product that is already for sale in Hungary.

Am I the only one who thinks that there is something wrong with this picture?

But it is a hopeful sign that we have DIY people who are willing to try to build energy efficient appliances that are unavailable to them due to a failing government and unresponsive manufacturing sector.

I am super proud of those DIY people who are actually willing to get their hands dirty and try.

Best,

-AC

[GregRF]

Originally Posted by Zooomer

A dehumidifier is packaged better for this but they are all 110 units. This poses the problem of not enough BTU's/dehumidification and more complicated electronics to turn it on with the dryer's 220 coil.

Just an electrical note, in the US 220V is simply two 110V lines 180 degrees out of phase. So to run the 110V dehumidifier you would just use one of the hot lines from the heater relay (disconnect or cap the other line) and then tie the other 110V line to neutral. This is of course easier if you have a 4 wire plug already installed (line/line/neutral/ground) vs a 3 wire plug (no neutral).

[AC_Hacker]

Originally Posted by GregRF

...and then tie the other 110V line to neutral. This is of course easier if you have a 4 wire plug already installed (line/line/neutral/ground) vs a 3 wire plug (no neutral).

So, if I am understanding you correctly, if you had three wire, and you tied the unused line to neutral you would greatly lower the electrical resistance between the unused line and ground, right?

-AC

[GregRF]

Originally Posted by AC_Hacker

So, if I am understanding you correctly, if you had three wire, and you tied the unused line to neutral you would greatly lower the electrical resistance between the unused line and ground, right?

-AC

Three wire does not have neutral, just two hot wires (110V each, 180 degrees out of phase). So when connected across a load such as the resistance heater in the dryer, you get 220V (+110V to -110V). To be able to run a 110V appliance you need to have a neutral wire (to do it safely).

So with a 4-wire system you can run a 110V load from the relay controlling the 220V heater by using only one of the lines coming out of the relay, the other one would go unused. The 110V appliance has two wires (plus a possible ground) one of these wires connects to the hot wire from the relay, the other needs to connect to neutral.

So two hot wires = 220V
One hot wire, one neutral = 110V (same as every 110V outlet in your house)

If I understand your question, you are talking about tying the unused line (one of the 110V lines from the relay) directly to neutral? That would create a short circuit (lowest electrical resistance possible!) and draw a ton of amps till your circuit breaker blew.

Does that answer your question?

[jeff5may]

From the other thread:


At the upper right, the OP has added a "voltage selector" switch that allows the heating element to be run at 220 or 120 VAC. L1 and L2 are your split-phase power wires, N is the neutral. Ground is not shown in this schematic, although it is assumed the unit is properly grounded. Thus, it is a 4-wire rig.