For general questions regarding cooling your home.

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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 ...
2
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1answer
169 views

How do I properly size an air conditioner for a very sunny room?

I'm trying to size a window air conditioner for a room, but having trouble deciding if the usual guidelines are a good fit. The room in question is about 230 sq. feet, and does not have full 8 foot ...
2
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1answer
1k views

How can I prevent heat loss through heater/air conditioner wall units?

HVAC experts out there... I live in Wisconsin and it gets mighty cold here! I have a condo with 2 wall units that are used for both air conditioning and heat. My heat bill in the cold winter months ...
2
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2answers
128 views

Is a combined AC/Dehumidifer unit more efficient than separate units?

I've just moved into a "basement-ish" apartment; the actual ground level is about at my waist. It's a bit mustier than I'd hoped, and not as cool as I'd like during these closing days of Summer. I'm ...
2
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3answers
860 views

Vented vs unvented crawl space

I've asked this question before: Vented vs unvented crawl space However, now that I'm going to get air conditioning the question comes back again and again people seem to have different opinions. ...
2
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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?
2
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1answer
901 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 ...
2
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1answer
294 views

How do I convert an A/C window unit from thermostat to humidistat control?

I've managed to get my hands on a really nice window unit AC that can cool my entire living space (about 900 sq ft), but the downside of it being so powerful is that I either have to leave it ...
2
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1answer
647 views

Is it possible to control the speed of the fan on my central A/C unit?

I have one of those medium sized AC-units (don't know the model name at the moment) and a very basic Honeywell thermostat that the installers put in when the house was built. However, there doesn't ...
2
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1answer
36 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 ...
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6answers
2k views

How do I keep my house cool especially my terrace during summer?

I live in Bangalore in an apartment on the top floor and during summer, my terrace (built of concrete) absorbs a lot of heat. When I come home and switch on the fan, it ends warming my room and it is ...
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1answer
96 views

Is my Heat pump and gas furnace installation incorrect?

I moved into a house about 2.5 years ago, and the previous owners had a heat pump installed, together with a gas furnace. Recently I had my furnace repaired (faulty igniter) and the HVAC technician ...
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0answers
208 views

How can I insulate and elevate an A/C line set on a flat rubber roof?

The Scenario An apartment building with a flat black rubber roof. The A/C condenser is on a platform on the roof with an air handler inside the unit. The line set runs across the roof for about 20 ...
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2answers
884 views

Is there a filter-reminder thermostat that uses run-time instead of total time?

My HVAC filter is in my crawlspace and is a hassle to change. I don't want to change it more than needed. "Change it every month" is bogus advice because in some months (like May) we don't have to run ...
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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
1k views

Is it possible to use my window A/C unit without actually installing it in the wall?

So, here's the dilemma. I want to install a window unit in my garage. I know how to do this, but my wife isn't supportive of the idea because we are trying to sell the house currently. Anyways, ...
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2answers
2k views

Is my window air conditioner cooling properly?

I am renting a place where the only air conditioner is a window unit mounted in the wall in the main living area. The space in that main room is about 325 sq ft, and it has a 9 ft ceiling on average. ...
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1answer
4k views

AC Unit Blow Warm Air Indoor But Colder Air Outdoor

I have two AC Units. One for upstairs and one for downstairs. The upstairs one works just fine but not the downstairs. So, i did a test by turning both units on and went outside to compare the two ...
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2answers
252 views

Is a little ice on the cooling coils ok?

This is our first summer in a new house which has central air. It was a bit hotter today than normal so the AC was running for a long time. After awhile we noticed the airflow stopped because the ...
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1answer
603 views

A/C Condensation from duct getting into drywall

My A/C unit has ducts that run to the second floor, into the attic, to feed some ceiling vents. Today, after several days of brutal humidity, I noticed paint blistering, and in one spot bursting, ...
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2answers
477 views

Is a Heat pump / AC unit considered more or less effecient in hot states?

Just learned a house we purchased has a heat pump vs a traditional heater. The heat pump / AC unit configuration outside, blower inside. We live in the phoenix AZ area, and an efficient AC unit is ...
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1answer
534 views

What to do about a gas leak on my air conditioner?

I have an air conditioner that displays an error of gas leakage on the board. What should I do? Shall I turn it off? It is dangerous?
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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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2answers
29 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
107 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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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 ...
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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 ...
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2answers
358 views

What to do about different rooms in the house being a completely different temperature?

I moved into a 30 year old home last December. There is a problem with the HVAC. I have included a very crude drawing of the floor plan The problem is that I can't maintain a comfortable ...
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4answers
1k views

How can I calculate the power consumption of an A/C unit?

I have an AC unit with the following specs: Cooling Capacity: 1260 kcal/h, 1.47kW, 5000 Btu/h Fan Motor Power: 0.034 kW Current: 0.155 A My question is how much power does this unit actually ...
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2answers
5k views

How do I replace a condenser fan motor in a central air unit?

The condenser fan motor on my central air unit has seized up (tried like crazy to turn it it, but no go). I'm not sure how old the motor is but I'm guessing it's original, so about 12 years old. I ...
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1answer
436 views

How should I evaluate my central A/C to see if it's working properly?

I was once told by a service tech that they evaluate how well the system is performing based on temperature difference between the the return and supply sides. On our first really warm day (80F+), I ...
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2answers
263 views

Why do air conditioners have thermostats, not humidistats?

I've noticed it over the years in various living quarters: an inside A/C temperature setting that's appropriate and comfortable for a given outside temperature is quite unbearable when the outside ...
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1answer
598 views

How to efficiently circulate air to keep room cool?

I live in Indonesia and I have an apartment with a 6.7 x 5m room, which contains a dining table and a couch. In this room are two 1.5PK (13,000 BTU) AC units on the same side of room nearer to the ...
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1answer
154 views

Water falling on top of central AC

So I have an AC unit outside my room onto which a whole bunch of water falls from straight from the gutter. Will this ruin the unit? Also, it makes A LOT of noise. What would be the best way to dampen ...
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2answers
2k views

Confused on what AC Unit to purchase and install?

I am replacing a 30 year old AC unit and I have had 4 estimates. 2 of the 4 people did not even take any measurements and the other two took a lot of measurements. I am leaning towards the ones that ...
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1answer
1k views

Central air conditioner electrical disconnect amperage

My HVAC guy is telling me I need a 25 amp breaker and a 25 amp disconnect for my soon-to-be-installed central air compressor. I've asked him for more details but he's less than forthcoming. My ...
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3answers
371 views

Assuming you can go either way, is it better to install a Multi-split or multiple Split Air Conditioners?

For 2 bedrooms and 1 living room, and assuming you have the flexibility for both options and the total output is the same, is it better to install a Multi-Split 3x1 Air Con System (3 interior units / ...
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1answer
301 views

What would cause a hardwired smoke alarm to give one short beep when appliances are turned on?

I have hard wired smoke detectors. I've noticed that when I plug my tablet into a power strip connected to an outlet in my living room it caused the upstairs detector to emit a quick beep. I now ...
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1answer
400 views

What could be causing my air conditioner to make a humming sound?

I have an air conditioner that has an in-floor intake. When the heat pump turns on, there is a fairly loud humming that comes from the intake. If I step in certain places around the intake the ...
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2answers
2k views

What could be causing this leaky evaporator problem?

My apologizes if I do not know the correct terminology for some of the parts. I will try my best though. We have a Trane A/C system that is causing us a headache. It is causing water damage in our ...
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1answer
631 views

How to get rid of a few mosquitoes/gnats that constantly sneak in?

I live in an older house, a duplex. I constantly see a few mosquitoes or gnats sneaking in and biting me at night. It's really annoying. It is mainly on the bottom floor, where the A/C vents go to the ...
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1answer
161 views

HVAC unit won't come on

This morning I noticed that my main floor wasn't cooling. I found the condensation pump full ( little giant model VCMA-15ULS ). I disconnected the hose from the unit to the pump, drained it, dumped ...
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1answer
1k views

Why is my outdoor air conditioner unit making a screeching/squeeling sound?

During the winter time when I have my heat on, my outdoor air conditioner unit randomly makes this awful-sounding squealing/screeching sound. It lasts for about 15-30 seconds at a time, stops, and ...
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2answers
1k views

What should be cleaned or examined after an air conditioner drain pipe leak?

The other day, we found some water on the floor in our utility room. After some research and investigation, we discovered that the drain pipe from the central air unit was blocked. We were able to use ...
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1answer
463 views

Furnace Airflow

I have central air. When the furnace comes on, we can feel air coming out of the registers for a few minutes, then the airflow stops. If we turn it off for a few hours, we can turn it on again and get ...
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1answer
17 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
68 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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1answer
27 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 ...
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2answers
59 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
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 ...