Tywais Posted March 28, 2016 Share Posted March 28, 2016 Thought it might be of interest for some to see the dynamics of an air conditioner before and after cleaning. A couple of weeks ago when the temperature started going up my a/c at work was not up to it. Mornings just ok, afternoon uncomfortable. To show the a/c tech at the lab I slapped together a breadboard with a microcontroller, digital temperature/humidity sensor and a USB interface to my computer and put together some software to graph its history. This is in case he came early in the morning and says everything looks fine. When he opened the case the fan and fins were basically caked in grime with the fan not able to handle the load on it. This is the photo of my data monitoring system. This is the temperature plot over 2 days. The peak temperatures were around 2-3PM and the low points on the graph very early morning. The outside unit was running continuously but very little help in cooling. After cleaning showing temperature (top graph) humidity (bottom graph). The rise in temperature at the beginning of the graph is after shutting the a/c off and him opening the window for the pressure hose. After cleaning, closing window and turning on you can see the quick drop in both temperature and humidity. It was cool again. After it stabilized you can see the rise and fall of the temperature as the a/c cycles on and off (hysteresis) and the corresponding increase/decrease of the humidity reflecting the coils cooling and condensing the moisture. BTW, if using an inverter a/c, both those lines would be nearly flat as it maintains temperature and as such humidity in a linear fashion. The a/c unit is a Mitsubishi Heavy. Not sure if it is 9k or 12k, I lean toward it being 12k as the room is 20sqm and the moderately short cycle times of 16 minutes. Link to comment Share on other sites More sharing options...
BngkkB Posted March 28, 2016 Share Posted March 28, 2016 Very informative thank you. I just call the air conditioner cleaning guy. If the water in the bucket is dark after the first rinse I ask for a second rinse. He seems to understand that ok and does it. Link to comment Share on other sites More sharing options...
Tywais Posted March 28, 2016 Author Share Posted March 28, 2016 Very informative thank you. I just call the air conditioner cleaning guy. If the water in the bucket is dark after the first rinse I ask for a second rinse. He seems to understand that ok and does it. In my case the water was pretty much pitch black on the first round. The same thing happened less than a year ago with the same amount of gunk. Because I have two servers in that room on all the time I need to have the a/c on 24/7. Link to comment Share on other sites More sharing options...
BngkkB Posted March 28, 2016 Share Posted March 28, 2016 Sorry I was just having a bit of fun with you. No hard feelings. I keep my bedroom ac on 24/7 as well and 2-3 others on about 12 hours a day. I also have them cleaned every 4 months or so and it seems to keep the electric bill down after cleaning. Link to comment Share on other sites More sharing options...
likewise Posted March 28, 2016 Share Posted March 28, 2016 (edited) good post, informative. I'm far from technically sophisticated so I have them cleaned twice/year. Will be watching the water in the bucket next time. Edited March 28, 2016 by likewise Link to comment Share on other sites More sharing options...
lostinisaan Posted March 28, 2016 Share Posted March 28, 2016 good post, informative. I'm far from technically sophisticated so I have them cleaned twice/year. Will be watching the water in the bucket next time. Makes a good noodle soup and might be more hygienically than some others. Link to comment Share on other sites More sharing options...
paulinbkk111 Posted March 28, 2016 Share Posted March 28, 2016 How much is an air conditioner cleaning usually? Link to comment Share on other sites More sharing options...
Tywais Posted March 28, 2016 Author Share Posted March 28, 2016 How much is an air conditioner cleaning usually? In Chiang Mai it averages around 500 Baht for a full inside and outside unit cleaning. Link to comment Share on other sites More sharing options...
thrilled Posted March 28, 2016 Share Posted March 28, 2016 I clean them myself.Not sure about the rest of you but it seems that about 80% of the hotels I stay at the. Filters are dirty.I quit Notifying the hotel,I just clean it myself.You would figure the owners/managers of the hotel would have them cleaned on A regular Basis. Link to comment Share on other sites More sharing options...
Torrens54 Posted March 28, 2016 Share Posted March 28, 2016 Sorry I was just having a bit of fun with you. No hard feelings. I keep my bedroom ac on 24/7 as well and 2-3 others on about 12 hours a day. I also have them cleaned every 4 months or so and it seems to keep the electric bill down after cleaning. Does that send your electricity bill through the roof, or is it more efficient? Past few Summers, we've had a Bedroom AC on all night. One in the Computer Room several hours a day/night and the same in the lounge. Average Electricity has been between 5K Baht and 6K Baht PER MONTH. Link to comment Share on other sites More sharing options...
DogNo1 Posted March 28, 2016 Share Posted March 28, 2016 In the hotel, the maintenance guys have a little temperature gun that they aim at the AC. 14° or above - needs cleaning. Below 14° - still OK. Link to comment Share on other sites More sharing options...
BngkkB Posted March 28, 2016 Share Posted March 28, 2016 Sorry I was just having a bit of fun with you. No hard feelings. I keep my bedroom ac on 24/7 as well and 2-3 others on about 12 hours a day. I also have them cleaned every 4 months or so and it seems to keep the electric bill down after cleaning. Does that send your electricity bill through the roof, or is it more efficient? Past few Summers, we've had a Bedroom AC on all night. One in the Computer Room several hours a day/night and the same in the lounge. Average Electricity has been between 5K Baht and 6K Baht PER MONTH. Not to bad, I'm paying between 3-4K a month. May creep up to 5K during the hot hot season. I pay my bill directly to the power company so no apartment mark up per unit. Link to comment Share on other sites More sharing options...
mrsomchai Posted March 28, 2016 Share Posted March 28, 2016 I have a pretty decent air con guy and according to him air con should be cleaned every 3 months if in regular use and 6 months if occasional use. It should also be cleaned every 3 months if there are pets on the premises as pet hair blocks up the pipes. If air con is NOT in use on regular basis, it should be turned on for an hour every week to make sure gas does not dry up. In case of animals, it is wise to use high pressure gun to clean out all the pipes, as pet hair does create blockage which leads to overheating and leaks Link to comment Share on other sites More sharing options...
thairay Posted March 28, 2016 Share Posted March 28, 2016 very technical post with a conclusion that "i do not know what size it is 9000 or 12000".ps paint the ceiling mate Link to comment Share on other sites More sharing options...
weegee Posted March 29, 2016 Share Posted March 29, 2016 Sorry I was just having a bit of fun with you. No hard feelings. I keep my bedroom ac on 24/7 as well and 2-3 others on about 12 hours a day. I also have them cleaned every 4 months or so and it seems to keep the electric bill down after cleaning. Does that send your electricity bill through the roof, or is it more efficient? Past few Summers, we've had a Bedroom AC on all night. One in the Computer Room several hours a day/night and the same in the lounge. Average Electricity has been between 5K Baht and 6K Baht PER MONTH. Thats about the figure i get here also....so it may be the normal....If I use the welder a lot, it usually hangs either side of 6K...But i run a pool as well in that bill. Hope this helps. Link to comment Share on other sites More sharing options...
Naam Posted March 29, 2016 Share Posted March 29, 2016 I have a pretty decent air con guy and according to him air con should be cleaned every 3 months if in regular use and 6 months if occasional use. It should also be cleaned every 3 months if there are pets on the premises as pet hair blocks up the pipes. If air con is NOT in use on regular basis, it should be turned on for an hour every week to make sure gas does not dry up. In case of animals, it is wise to use high pressure gun to clean out all the pipes, as pet hair does create blockage which leads to overheating and leaks to make sure gas does not dry up ...which leads to overheating and leaks Link to comment Share on other sites More sharing options...
sipi Posted March 30, 2016 Share Posted March 30, 2016 I am more interested in the breadboard and usb interface. Could you post a schematic please? Link to comment Share on other sites More sharing options...
Tywais Posted March 30, 2016 Author Share Posted March 30, 2016 I am more interested in the breadboard and usb interface. Could you post a schematic please? Actually I just slapped it together without a schematic. I'll put together something for you. Because serial comm ports on PCs are becoming more scarce I designed a USB-Serial converter, the module you see at the bottom, and all new designs I do use this now. I sent the board out to a commercial PCB facility and had a bunch made. Then have a tech who populates it here. The parts for the breadboard: 1. PIC16F688 (any PIC or microcontroller will do) 2. A HopeRF HHT02D (SHT11 equiv) digital (2 wire) temperature/humidity sensor. This is an expensive item, $30USD at Futurlec but they had a similar version for $10 and I bought several of them. If only monitoring temperature a very simple solution is the LM35 sensor for about 72 baht at Elements. 3. 1 resistor Power for the system comes from the USB bus so no external supply needed. The USB-Serial converter uses one IC, FT232RL (about 100 baht IC) There are sensors shown on this Thai website - http://www.thaieasyelec.com/products/sensors/humidity-temperature.html And here - http://www.arduino.in.th/product/78/dht11-digital-temperature-and-humidity-sensor I bought several of those DHT11 sensors as they are cheap but haven't written the software for it yet. Link to comment Share on other sites More sharing options...
sipi Posted March 30, 2016 Share Posted March 30, 2016 I am more interested in the breadboard and usb interface. Could you post a schematic please? Actually I just slapped it together without a schematic. I'll put together something for you. Because serial comm ports on PCs are becoming more scarce I designed a USB-Serial converter, the module you see at the bottom, and all new designs I do use this now. I sent the board out to a commercial PCB facility and had a bunch made. Then have a tech who populates it here. The parts for the breadboard: 1. PIC16F688 (any PIC or microcontroller will do) 2. A HopeRF HHT02D (SHT11 equiv) digital (2 wire) temperature/humidity sensor. This is an expensive item, $30USD at Futurlec but they had a similar version for $10 and I bought several of them. If only monitoring temperature a very simple solution is the LM35 sensor for about 72 baht at Elements. 3. 1 resistor Power for the system comes from the USB bus so no external supply needed. The USB-Serial converter uses one IC, FT232RL (about 100 baht IC) There are sensors shown on this Thai website - http://www.thaieasyelec.com/products/sensors/humidity-temperature.html And here - http://www.arduino.in.th/product/78/dht11-digital-temperature-and-humidity-sensor I bought several of those DHT11 sensors as they are cheap but haven't written the software for it yet. Thanks very much. Currently in Oz but will check it out. Link to comment Share on other sites More sharing options...
Tywais Posted March 30, 2016 Author Share Posted March 30, 2016 May be just easier to buy a USB-TTL Serial cable for the communication as my board uses a high density surface mount IC and difficult to solder if you don't have SMD experience. https://www.sparkfun.com/products/12977 https://www.adafruit.com/products/954 Link to comment Share on other sites More sharing options...
TheCruncher Posted March 30, 2016 Share Posted March 30, 2016 I clean them myself.Not sure about the rest of you but it seems that about 80% of the hotels I stay at the. Filters are dirty.I quit Notifying the hotel,I just clean it myself.You would figure the owners/managers of the hotel would have them cleaned on A regular Basis. There is a bit more involved in cleaning an aircon than cleaning the filters. Link to comment Share on other sites More sharing options...
akampa Posted March 30, 2016 Share Posted March 30, 2016 TheCruncher, on 30 Mar 2016 - 11:42, said: thrilled, on 29 Mar 2016 - 00:53, said: I clean them myself.Not sure about the rest of you but it seems that about 80% of the hotels I stay at the. Filters are dirty.I quit Notifying the hotel,I just clean it myself.You would figure the owners/managers of the hotel would have them cleaned on A regular Basis. There is a bit more involved in cleaning an aircon than cleaning the filters. such as? Link to comment Share on other sites More sharing options...
Crossy Posted March 30, 2016 Share Posted March 30, 2016 TheCruncher, on 30 Mar 2016 - 11:42, said: thrilled, on 29 Mar 2016 - 00:53, said: I clean them myself.Not sure about the rest of you but it seems that about 80% of the hotels I stay at the. Filters are dirty.I quit Notifying the hotel,I just clean it myself.You would figure the owners/managers of the hotel would have them cleaned on A regular Basis. There is a bit more involved in cleaning an aircon than cleaning the filters. such as? Cleaning the fan and fins on the indoor unit, similar on the outdoor, unblocking the drain tube. The "pro's" have a pressure washer with a short lance to get in the indoor unit and a water catching arrangement to keep the carpet dry (ish). Link to comment Share on other sites More sharing options...
stoneyboy Posted March 30, 2016 Share Posted March 30, 2016 Pressure washing the compressor unit. Striping the inside unit totally. One can even spray nice smelly foam on the inside unit as well. Link to comment Share on other sites More sharing options...
IMHO Posted March 30, 2016 Share Posted March 30, 2016 TheCruncher, on 30 Mar 2016 - 11:42, said: thrilled, on 29 Mar 2016 - 00:53, said: I clean them myself.Not sure about the rest of you but it seems that about 80% of the hotels I stay at the. Filters are dirty.I quit Notifying the hotel,I just clean it myself.You would figure the owners/managers of the hotel would have them cleaned on A regular Basis. There is a bit more involved in cleaning an aircon than cleaning the filters. such as? Here's a service manual form Saijo Denki that shows what's involved: http://saijo-denki.co.th/download/technic/16clean.pdf Link to comment Share on other sites More sharing options...
Tywais Posted April 1, 2016 Author Share Posted April 1, 2016 I am more interested in the breadboard and usb interface. Could you post a schematic please? This is the bread board for the DHT11/DHT22 version. The schematics below that. As I mentioned, the hardware design is very trivial, it's the microcontroller code that is a pain. You could actually use an Arduino or Rasberry Pi to control the sensor if you have those. First schematic is for a SHT11 sensor the second for a DHT11/DHT22 sensor. The sensors are much cheaper on Amazon or ebay. Link to comment Share on other sites More sharing options...
Speedo1968 Posted April 1, 2016 Share Posted April 1, 2016 Some excellent replies and info thanks to all. Cleaning should certainly help reduce running costs. For me the important thing is getting rid of the mold and fungi. Anyone who has ridden in a mini-bus and looked at the blackened ceiling.......... Link to comment Share on other sites More sharing options...
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