Wednesday, July 25, 2018


INDEX to the series

I have added a small portable dehumidifier in the basement. So far, it makes lots of water and uses a ton of electricity.

After setting up the new freezer in the basement last week, I noticed that there was condensation - ice and water drops - more than a bit - in the area of the door seal and a coating of condensed liquid water mist on the front surface of the appliance.

This was not a surprise. The old freezer used to "sweat" in summer when the air humidity was high. Perched on 2x4s, the old freezer lived over a perpetual water pond. It's top lid was covered with condensation that ran down whenever it was opened. This water was constantly recycled within the basement, no possibility of escape.

I don't have air conditioning in the house. The freezer is much colder than anything in the basement so acts like a magnet for water in the air. I keep the basement door shut and the one window does not open so the basement is relatively shut off from the outside. Mine is an old house and there have been and perhaps still are water problems. Would I be able to dry out the basement at a reasonable energy cost? I had a dehumidifier but haven't used it. I decided to try running it to see the effect on the freezer external condensation.

The old Danby dehumidifier roared into action but unfortunately did not work. No water appeared in the unit after an hour. It made cycling noises and clicks and drew high power for a second and then nothing but the fan running. It was behaving as if the compressor wasn't starting. I took it to recycling and paid $35 to deal with the Freon.

So I bought a new mid size portable dehumidifier, a Danby DDR045BBCWDB 21L / 45 US pint rated for areas up to 2500 sq ft "depending on conditions". My home is approx 1250 sq feet by the real estate definition yet I am more concerned with the basement space which might be 1000 sq ft including the crawl spaces, none of which are included in the real estate definition. So I might be overpowered with the model I chose.

Danby shows the Energy Star logo on the product and packaging. Uses R410A refrigerant. Very slick appearance. Does not deserve to be on my basement floor.

Following are some reactions and observations based on a couple of days only.

I set it up first on the kitchen table the better to admire it and learn. This is really a nicely finished product. Made in China. Lighter than the 20 year old metal cased unit it replaces, this one is almost entirely plastic. Almost everything you see on the outside, the removable bucket and what you can see inside is made from plastic. There must be metal inside in the compressor and coils. I was tempted to lift the cover but I didn't.

The instructions warn that the unit may not start when you push the power switch the first time and mine did not. I feared that I may not be able to inhibit the running of the unit during peak pricing periods as I had hoped to do, using my preferred outlet switch/energy monitor Itead Sonoff S31. When power was applied to this dehumidifier, it justs sit there until the power button is pushed. Someone has to start it manually. It is smart. It has a computer inside! A line in the data sheet says "Auto Restart: unit automatically restarts after a power failure" so there is hope. I haven't tried yet to interrupt line power with the S31.

The purpose of the dehumidifier was accomplished. After about ten hours running continuously, the condensation on the new freezer reduced and in another ten hours or so, after a bucket or two of water was produced, the freezer shows NO condensation on the outside or around the door seals at all.

A LOT of water is produced. In just over a day and a half, I have removed three large buckets of water from the basement! That's a bucket every 12 hours or so. To get an almost full bucket, I empty the dehumidifier "bucket" into the larger bucket about three times.

There is no drain in my basement so carrying the large bucket once is preferable to carrying the internal bucket upstairs three times. The water goes into a toilet upstairs and hence out of the house. I have a "sump" in the basement floor but dumping the water there would be equivalent to pouring it on the floor. Water has to leave the basement and the house to be removed effectively from the air.

The unit will discharge some water when the internal bucket is removed so I don't want to go far with it. I am also finding removal/insertion of the unit's bucket a bit troublesome at ground level so I am thinking of raising it up somehow with a stand and tray for water spills.

So far I have used 12 kWh as I can see from the S31 to which it is connected. That is a lot of energy and makes my humidifier potentially a major appliance, at least in the summer.

It averages about 400 watts with the fan set to run FULL. I was surprised and I hope that sometime soon it reaches an equilibrium so that the unit does not run all the time. I think I have it set to 50% relative humidity.

When first started in the basement, the display was about 75 so I am guessing this is the RH that is measured? When I push the left right buttons, the display changes to the set point value and jumps 5% steps with each button push. Danby recommends 45-50% so I am starting with that and letting it run 24/7.

So here is a little calculation based on three buckets of water and 12 kWh used. I don't think it is quite right and it certainly is very approximate. Your feedback is welcome.

The Latent Heat of Vaporization - the input energy required to change the state from liquid/vapor at a constant temperature - for water 2260 KJ/kg

Using 12 kWh is equivalent to 43200 kilo-joules. Should be enough energy to evaporate or condense 43200/2260 = 19.12 kg of H2O

1 L of H2O = 1 kg

So 19 L of water is about 5 US Gallons

My 3 buckets each weighed about 9.1 kg. The empty bucket weight was 0.7 kg. Use 9.1 - 0.7 = 8.4 kg H2O per bucket

Total 3 x 8.4 L - 25.2 L

So I got more water than I should have, by about 25%?

One thing I know is not correct is that the Latent heat of Vaporization at 1 atmosphere should work at 100 degrees C and there is no way the Danby has heated the water to the boiling point. I need to learn more about humidifiers and how the Energy Star rating is applied. I did not receive an EnerGuide card in the box nor can I see one on the Danby website.

The temperature of the basement seems to be rising slightly, about 2-3 degrees C since I started running this dehumidifier test, probably because of dumping in excess of 12 kWh into the basement air?

Another benefit of lowered air humidity might be reduced ice buildup inside the freezer. Every time I open the lid, the freezer receives a blast of moist air from the basement. If the air is dryer, less ice will form inside on the walls.

Thanks for your interest.

George Plhak
Lions Head, Ontario, Canada

PS - the Itead ewelink S31 display for the dehumidifier only shows a couple of days and the total. I notice that the app now says kWh where before it showed the degree symbol. Progress is being made at Itead!

PPS - near drought conditions here so I am watering the garden plants with the recovered water rather than putting it down the toilet, even though it is distilled water and thereby lacking minerals. I am sure the plants won't mind.

INDEX to the series

Saturday, July 14, 2018

freezer 2

INDEX to the series

A new small chest freezer was delivered here and put into service yesterday.

Impressively quiet and efficient, my new Danby freezer might be half the weight of the old 1994 Wood freezer that it replaces although they are both the same capacity.

One large delivery guy carried the new boxed freezer from the truck on his shoulder and then slid it gently down the stairs by himself! It then took him and another with a dolly to haul the old Woods away.

Both new and old are the same capacity 7 cubic foot chest freezers separated in time by 25 years.

My freezer is plugged in through an Itead Sonoff S31 which gives me this kWh/day chart through my wifi and control of the outlet in various ways. The kWh/day chart is for June, the last full month of the Woods freezer so we'll have data to compare.

I had updated the Itead app for both iPhone and Android this morning and there are a couple of curiosities. I was surprised to see a degree symbol where I'm pretty sure it means kWh. I had installed the S31 at the freezer outlet on the last day of May so the 0.31 for May is only part of one day. I have not loaded a cost per kWh in the Itead app ewelink since I only need the kWh but the app could calculate the total cost.

So for June I used 26.85 kWh in total for my old freezer, about 0.9 kWh per day. Considering that my whole house used about 8 kWh per day in June, the old freezer was 11% of my usage. My "much newer used" 18 cubic foot refrigerator uses about 0.6 kWh per day. I monitor/control my refrigerator on another S31.

The peakiness of the bars is interesting. Each pair of taller bars shows a weekend when I let the freezer run all day since there is no Time of Use peak priced power on the weekends or holidays. For regular Monday to Friday I use the timer of the S31 to keep the freezer OFF during the peak periods. Currently my utility's peak period is 11am to 5pm so my freezer is OFF for 6 hours when electricity cost here is twice the non-peak rate.

I don't buy peak priced electricity for my freezer and I use less electricity, saving about 10-12% on each day I inhibit operation during the peak period. The freezer has to "catch up" for the time it has been off, but it does not use as much as if it had been ON the whole time.

I can also see that the freezer uses less electricity on Mondays! I guess it catches up on the weekend cheap power so takes a bit of a break?

One thing about my freezer and possibly most freezers is that I don't open the door very often, maybe once every couple of days. If the door got opened often and items loaded or removed, the kWh usage would be more scattered, less regular.

So what happens to the temperature in the freezer when the power is turned off for six hours? I knew you were going to ask.

[click pics to enlarge]

This is the temperature inside the Woods freezer last August one hot day. I am using an Elitech RC4 Temperature Data Logger. By the end of 6 hours the air in the top of the freezer has warmed but no higher than -4C. I am surprised that it did so well given the age and condition of the seals.

I am confident that the new Danby will do much better!

Thanks for your interest.

George Plhak
Lions Head, Ontario, Canada

PS - Here is the EnerGuide label for my new freezer (Canada version). We will measure how well it does here.

Update July 21 - I changed the freezer July 13. Here is the daily usage reported by the outlet which runs the freezer. The vertical axis is kWh/day, the horizontal is the day of the month. It looks like the usage will be reduced by half with the new freezer!

INDEX to the series

Sunday, July 08, 2018

bird strike preventer

About using an old CD, some string, and 3 hook eyes to keep birds from hitting my big windows.

Extensively tested for the past three years.

If you try this, please let me know how it works for you.

Thanks for your interest.

George Plhak
Lions Head, Ontario, Canada