For general questions regarding cooling your home.

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1answer
15 views

How do I connect a 24v air purifier to hvac?

I have a MicroPure MX4 that the previous homeowner left behind new in the box. This is a 24v unit and needs to be hardwired. My question is can I connect the two wires to the terminal where the ...
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1answer
50 views

Is this HVAC capacitor dead?

HVAC system stopped blowing cold air today. Last time it did this, we gave it a 2-3 hour break, in case it was over-heated, and it came back. Today, same deal, but no cold air after a few hours. I ...
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1answer
35 views

How can I install a window air condition and still allow the window to be opened?

I want to install a window based air conditioner but still allow for the ability to open the window when needed. I was thinking of using a piece of wood screwed into the window frame to support the ...
4
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2answers
104 views

90% Humididty @ 23 Celsius direct from Air Conditioning Outlet

I have a mold problem in my apartment, in certain areas there is condensation. I believe I have traced this to the air conditioning, in the apartment the humidity will vary from 60% to 85% RH at a ...
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2answers
27 views

Combine evaporative cooling with ventilation to increase efficiency of temperature equalization?

We live in San Francisco, which is not known for high temperatures. But our apartment is on the third floor and we get a ton of direct sunlight through our 5'x8' windows. We open the windows enough to ...
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1answer
22 views

AC Blower Relay

I have a question? How much current does it typically take to close the blower relay on a air handler. I recently got a new thermostat which requires an external transformer and it doesn't appear to ...
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0answers
31 views

Keep finding thermostat on heat

On multiple occasions now, I have noticed odd things going on with my HVAC system, only to go to the thermostat and find that it has been set to heat! This happened once in the middle of summer, when ...
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1answer
1k views

How often should “self clean” and “allergen clean” functions be used in an air conditioner?

Some air conditioners, for example Mitsubishi heavy industries SRK20ZJ-S have "self clean" and "allergen clean" functions. First takes 2 hours to complete, latter 1.5 hours. How often should they be ...
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1answer
71 views

Is this mold on my AC vent?

I went to close the AC vent in the apartment we're renting and saw this. Is this mold or just many years of dust buildup? If it is mold, can I safely just remove the vent and wash it?
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2answers
93 views

Why do the evaporator and suction lines freeze when there is low refrigerant?

In an AC, why does a low refrigerant condition cause the evaporator, and/or suction line, to freeze up?
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0answers
29 views

Lint when running AC

There seems to be a lot of lint when I run my AC unit. I have recently replaced the filter and made sure that the filter is put in correctly. What could be the issue?
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2answers
6k views

Why does my Central A/C Keeps Blowing its Fuse?

For years, my A/C condensing unit has blown a fuse once, maybe twice a year. It's 27 years old now and blew a few fuses last spring. Now it blows a fuse every few days. So, I replaced a bad running ...
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1answer
27 views

Should my A/C compressor come on when I turn only the fan on?

I have a bog standard HVAC system with a Nest thermostat. When I tell the theromostat to turn the fan on for 15 minutes the A/C compressor also kicks on. Is this normal?
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1answer
209 views

Can I replace this Airwell thermostat?

I am in market to replace my simple A/C control unit with one that integrates with home my z-wave based home automation system. However, before I make the splash and buy a compatible thermostat, I ...
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2answers
84k views

What's the most common cause of A/C refrigerant lines freezing?

I noticed my house wasn't getting under 75°F this weekend when I had the thermostat set for 70°F. Since I'd done a lot of drywall sanding inside recently, my first idea was to replace the filthy air ...
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4answers
8k views

What could be causing an A/C blower motor to turn off randomly?

The Blower motor on my AC unit turns off at random times while the outside unit continues to run which is causing the coil to freeze up. The blower won't come on for 30-45 minutes after the AC has ...
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0answers
63 views

Furnace not working properly with digital thermostat

I have been attempting to use several different types of digital thermostats to replace my old mercury thermostat, however none of them are able to control the furnace properly. All of them are able ...
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1answer
66 views

New condenser fan motor burned out

AC technician replaced my condenser fan (through a home warranty service). The new fan worked for 5 min and stopped working after that. the fan motor was extremely hot (180F or more) The old fan motor ...
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3answers
14k views

How can I install a window air conditioner in a metal window frame?

I'm trying to install a window unit air conditioner, but most of the installation instructions don't seem to work with this window configuration. A little bit about the setup: The apartment is the ...
2
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1answer
897 views

What can cause an A/C to freeze up

Our A/C evaporator coil freeze up last year, so I called out a technician. He said that it was charged with the proper amount of Freon, and my problem [paraphrased] "something had narrowed the inside ...
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1answer
25 views

How to install a 4-wire a/c & fan thermostat with only 3 wires

My home currently has a central a/c unit which is controlled from an 3-wire old mercury switch thermostat. I want to replace it with a newer Honeywell that requires 4 wires. The existing thermostat ...
0
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1answer
105 views

Single phase vs three phase commercial air-conditioning

I have a building in which I am going to replace 9 3ton units. There is 3 phase in now but my tech suggests single phase. My clients pay for their own electricity. These machines have been in service ...
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5answers
11k views

How much cooling can I expect from a central air conditioner?

Yesterday's high was 106.0F, low of 79.2F, full sun all day. AC set at 78F, indoor temperature reached about 85F. Today's high was 105.4F, low of 81.1F, full sun all day, now about 102 at 7pm. AC ...
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2answers
72 views

Can I stack my boxed air conditioning units for storage?

I pulled out the AC units from the windows and have put them back in the original boxes that they came in. Can I stack them one on top of another for storage? I know not to stack the units normally, ...
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2answers
58 views

thermostat batteries replaced, AC unit won't start

Came home from work to find no AC. I checked the thermostat and the display was blank. After replacing the batteries and resetting the program, my AC unit never started up. I checked: - The AC unit ...
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1answer
106 views

Air handler condensation draining problem

For the life of me, I cannot figure this out. My air handler and heat pump were installed in 2006 and work great. For the first summer since I've owned the home, condensation started to not drain ...
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1answer
73 views

Furnace filter inserted backwards, will this cause permanent damage?

Just found out that my wife changed the last furnace filter and inserted it backwards. This was noticed after the ac was not cooling the house very well. I went outside and noticed that the coil ...
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3answers
1k views

How do outdoor mist-cooling A\C units fare in real-world usage?

I live in Phoenix where summer outdoor temperatures regularly exceed 110°F and humidity around 15% or lower is not uncommon. In this environment a mist system can easily pull the temperature down ...
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1answer
67 views

A/C Unit Has Leaking, Has Ice Buildup

Came home yesterday to find that the house was burning up and the thermostat had automatically switched itself to heat... in the summer! We didn't know what was going on, and assumed some sort of ...
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3answers
82 views

A/c makes the lights turn on and off! No Joke!

The lights on the first floor, upstairs bathroom and upstairs Laundry room won't work. The breakers did NOT pop The air conditioning was running this morning but is not working now. When the ...
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1answer
41 views

Why does my air conditioner say not to shut it off and restart within 3 minutes?

My air conditioner says not to turn it off and then back on within 3 minutes. Why is that, and what will happen if I do?
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0answers
54 views

What could cause a condensing units fan to stop working?

My AC unit fan stopped working suddenly. I tested the 3 pole condenser (capacitor) and the it looks OK ( 45 uf , 5 uf is what is mentioned in the spec of capacitor). I tested the resistance in the the ...
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3answers
15k views

How much less power does a three-phase A\C unit use as apposed to a 220v unit?

I'm planning to install a 5 ton central AC. I'm deciding between a condensing unit that runs on 220V and a costlier unit that runs on 207Y three-phase. My understanding is that three-phase motors use ...
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6answers
13k views

How often should I run a bleach and water solution through condensate lines?

How often do you need to run a bleach and water solution through the condensate drain lines (of a heat pump) to keep the bacteria away? What are the recommended parts (e.g. 1 part bleach, 10 part ...
0
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1answer
30 views

Air conditioner that keeps turning off

My air conditioner unit outside keeps on turning off and the fan in the house keeps on running. When I switch the circuit breaker off, then on the outside unit works again. Do you know what might ...
0
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1answer
56 views

How do I connect original to new wiring when repairing an electrical fault in an AC unit?

The AC failed at a neighbor's house and the problem was quickly diagnosed as electrical. I saw that a few of the wires had corroded and one had actually burnt through. The unit is only 5-6 years ...
0
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1answer
71 views

Window unit AC installation in narrow window

My apartment has double hung windows, but they are quite narrow (~19.5 inches at the screen, 22 inches at the opening). I'm currently using a portable air conditioner, but I'd really like to use a ...
0
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1answer
59 views

Inverter air-conditioning units or non-inverter air-conditioning units?

I want to purchase new 8-9 units of air-conditioning for my new house. For the hall, kitchen and all the bedrooms. Some people say inverter air-conditioning is only suitable if you are using more ...
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2answers
90 views

Can I redirect airflow from AC to under the house?

I have a small 950 sq ft single floor house, with a crawl space and force air heating. I have a portable Air Conditioner that has a large Intake and Exhuast tube. The issue is that none of the ...
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0answers
50 views

Covering Up A Large Gap In A Wall

I was looking for advice on how could i create a partition between my two rooms which have a huge frame in between them. The place was originally covered by curtains but putting up curtains on the ...
0
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2answers
67 views

Acceptable to install whole-house evaporative cooler with only a single supply vent?

My new house has a 20+ year old evaporative cooler on top of the roof. The cooler is ancient and rusted, difficult to service due to the location, and the forced air heating ductwork it feeds into is ...
0
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1answer
156 views

Air Conditioner woes: water pooling in basement, condensation on ducts, frost on outdoor copper pipe

Can someone help diagnose what's wrong with my air conditioner? The symptoms are: the air that it is blowing is not very cold It's colder than the ambient air, but not cold enough to cool the ...
0
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1answer
37 views

Is this pipe layout acceptable?

We recently had our heater and air conditioner replaced, and now the drainage pipe is installed on the floor of the basement. It's quite annoying and it wasn't like that before (it was on the walls ...
0
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1answer
93 views

Increase airflow central air

I have central air in my home and the majority of the house gets really cold with no problem. However, my master bedroom has a washer/dryer & I typically use my laptop for leisure. With that ...
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2answers
51 views

What are the external airflow requirements for portable and window AC units?

I have a window well in a basement where I'd like to setup a portable AC unit (~10000 BTUs). There is a cover that I need to keep in place to avoid water collecting in the window well, but I could ...
3
votes
2answers
492 views

How can I calculate the Btus needed for a single room A/C unit?

How many Btus is recommended for a room about 35 square meters? I have 2 units with 13,000 Btus each. I'm thinking it should be enough, but the room is just so-so cool. I can never say it's COLD in ...
4
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1answer
1k views

How does low freon cause the compressor suction line to freeze up

There are many questions about air conditioner issues with the most common being that it isn't cooling properly. Among the typical answers are low Freon and the standard diagnosis for low Freon is ...
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5answers
306 views

Solution for A/C Condensate Drain Line that doesn't require emptying a bucket of water every day?

I have a split A/C system in a room that runs on low 24 hours a day during Summer that unfortunately cannot be connected to any drain or pipe and which therefore requires a bucket to be used to ...
0
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1answer
68 views

AC unit (turned on year round) leaves so much ice in the blower causing no cooling (pic included)

My mother has asthma and tells me she needs the AC on almost year round. The AC unit is outside the condo we own, and it connects to the coils in the heater/ventilation system. We are experiencing ...
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1answer
55 views

How to repair leaking blower / air exchanger in attic?

Earlier this summer I went up into my attic to retrieve something, and was surprised to feel a cool draft. I discovered that a gap had developed between two portions of the big metal box that ...