(Heating, Ventilating, and Air Conditioning) For questions about installing, repairing, and troubleshooting HVAC systems.

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3
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0answers
88 views

Adding vents to duct?

My house has forced air HVAC. When I finished the basement, I used a closed cell foam insulation that worked very well. The basement will get only 8 degrees cooler than the first floor during a time ...
2
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0answers
79 views

Dust reduction and removal?

I have a room with west facing windows (I dont think the direction bears any importance to this question), but for some reason this room seems to accumulate dust on surfaces a lot faster than other ...
2
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0answers
261 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 ...
2
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0answers
90 views

Should I install the jumper on my new limit control?

I needed to replace fan and limit control (White-Rodgers, model 5D51-35), because the fan switch was broken (fan would constantly run) and heat would not stay on. I took a picture of the control, ...
2
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0answers
583 views

What are good Relative Humidity and Temperature settings on an MHRV and are the settings related?

I need to configure the threshold Relative Humidity and Temperature settings on an whole house MHRV system. The way the system works is that if the RH threshold is exceeded the system increases the ...
1
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0answers
22 views

Where does the C wire connect in a dual transformer system?

When wiring a common ground (C wire) for a dual transformer system, does it matter which transformer you connect the ground too? I'd assume that the ground on either transformer would serve as a ...
1
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0answers
29 views

Can I remove HVAC pipes after exposing the ceiling?

I recently removed the drywall ceiling from my basement and have two related questions about removing the HVAC ducts/pipes. Pictures attached here: http://imgur.com/a/qep4w 1. Is it OK to remove the ...
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0answers
21 views

How to Change Chinese HVAC Thermostat

I am looking to put Nest thermostats in the house, I have now found out my entire house (one in each room, 6 of them) has been wired with HVAC Chinese U12A UNIVERSAL A/C CONTROL SYSTEM urrgh – they ...
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0answers
52 views

How can I use a portable A/C unit to cool my clean room?

So, I have built a room inside my shop, a clean room for finish and airbrushing. I want to cool this room as I spend more time in it than the rest of my shop (garage) So, I get a portable unit. ...
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0answers
151 views

Can't find the circuit board of my HVAC system

I'm trying to install a wireless thermostat for my church building's HVAC system. Currently there is no C wire, so I tried to see where the circuit board was so I could install one. I couldn't find ...
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0answers
44 views

Does polarity matter when wiring a humidifier solenoid?

The 56 was receiving 24vac whenever the furnace was on via a red wire and a white wire. 24vac was supplied to the solenoid when humidity was called for via a pair of junction terminals. The 4655 is a ...
1
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0answers
40 views

Should I look into getting an active or passive whole-house humidifier?

My wife and I moved into our place a few months ago. Now that is is winter, the humidity levels dropped down to 20% throughout the house. We want to install a whole-house humidifier to raise it up ...
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0answers
37 views

How to clean carbon build-up on Honeywell whole house air purifier made of aluminum?

Bought a house recently that has a Honeywell F300 whole electric house air purifier/cleaner. The cell's aluminum fins have a black baked-on dust that I expect is preventing the unit from working as ...
1
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0answers
45 views

Testing the exhaust of a natural gas furnace?

I recently had maintenance performed on my natural gas forced-air furnace. During this maintenance, the technician went outside and used an electronic handheld device with a wire-attached probe to ...
1
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0answers
73 views

Can ultrasonic humidifiers be used in a bypass setup for a whole house humidifier?

My home is about 3000sqft, with lots of high ceilings. I'm having trouble keeping the relative humidity up in the winter. When it gets down to 10F outside, the RH drops down as low as 25%. This is ...
1
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0answers
27 views

Why is my hydro kinetics system blowing out cold air?

I have a hydro kinetics system that is blowing out cool air when set to heat. Thermostat was replaced when I bought the house a year ago so I don't think that's the issue. Toggle switch is set to ...
1
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0answers
30 views

How can I reduce the noise from an HE boiler vent?

I have a HE boiler that is direct vented out the side of my house on the neighbors side, they find the 'roar' of the exhaust to be very annoying. Have anyone tried troubleshooting these to ...
1
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0answers
137 views

How can I install a furnace register in a kitchen-cabinet toe kick?

I'm planning to install new kitchen cabinets. I'll be covering up the kitchen's existing sidewall diffuser with new cabinets, so I'd like to relocate it to a new register in the toe kick of the sink ...
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0answers
892 views

How can I tell if my bathroom ceiling vent is working properly?

Seems to take the vent forever to clear shower vapor from room. I purchased a vent that had a good rating. It is vented to the outside. How do I know if it is working properly and actually venting to ...
1
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0answers
947 views

Reducing air conditioner compressor vibration noise

I have a two year old Carrier air conditioner with an outdoor condenser. The condenser sits on a plastic pad on the side of my house, and I have two--one for downstairs and one for upstairs. ...
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0answers
85 views

How do I troubleshoot my central A/C?

It's 79 outside right now. It's been running for hours and it's remaining 79 inside. I'm in a brand new 2 story home in Monroe, OH. It has rained a lot recently but I just feel like it should be ...
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0answers
89 views

Why doesn't my A/C get power when using the alternate C-wire thermostat hook-up method?

I changed my old Honeywell thermostat for a new Honeywell WiFi thermostat. I installed it just as the directions stated. I used the alternate C-wire method as the old unit did not have one. ...
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0answers
2k views

How do I size a wall sleeve for a through-the-wall air conditioner?

We are shopping for a through-the-wall air conditioner. We do not currently have a hole in the wall with a sleeve in it. We are trying to figure out what sleeve to buy. The air conditioner we like ...
1
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0answers
1k views

What's causing my draft inducer to stay on?

I have a new, 3-year old, high-efficiency, gas furnace in my home. I recently realized that my draft inducer, which normally kicks on before the burners and before the main blower, is not stopping. ...
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0answers
812 views

How can I properly drain heatpump condensate?

I have a heat pump in the attic That drains to the ground outside two floors below. I naively added a hose fitting so I could redirect the water where I wanted it, slightly up hill. This created a ...
0
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0answers
12 views

How much refrigerant in an average 12 cu. feet freezer?

How much refrigerant goes into a 12 cu.ft chest freezer? On the nameplate it says ______POUNDS ___16___OZ (nothing written in front of pounds) is there really only 16 ounces of refrigerant in those ...
0
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0answers
19 views

Help AC question

We purchased a home last year, at one time it was zoned with separate AC units upstairs and down. Well a past owner took out the upstairs unit but left the blower in the attic, there is duct work ...
0
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0answers
13 views

A/C still blows when unit is off.

Our A/C is turned off but we still get cold air coming out of the vent diffusers. This is from our downstairs unit. Is that a problem?
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0answers
19 views

HVAC 3A fuse shorting on cool

I recently came back from a trip, and the thermostat was still working. On turning the AC on, the wall-powered thermostat decided to die. Upon investigating in the attic, I noticed the 3A fuse had ...
0
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0answers
11 views

Can I add another heat run to my furnace?

I'm looking to add a bedroom to the basement and would like to add a heat run to the new room (return air will occur through an opening between the ceiling joists). This seems easy enough, but I ...
0
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0answers
11 views

How to fix uneven central heating and air?

My central heating and air conditioning system does not heat my home evenly. Half of the house gets significantly warmer / cooler than the other half. I have tried adjusting the registers, but to no ...
0
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0answers
12 views

Will a Carrier heat pump generate hot air in the heat mode if the compressor is bad?

The heat pump works ok in putting out heat, but puts out hot air in ac mode as well. Had an hvac tech look at it. He replaced the capacitor and said the compressor was bad. Can the heat pump put ...
0
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0answers
21 views

Adding dual zone capability to an existing HVAC system in a house with existing 2 zone manual ducting

I have a house that has existing dual zone ductwork in place (separate ductwork for the upstairs and downstairs) that has manual dampers. I recently replaced the HVAC system with a new geothermal unit ...
0
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0answers
20 views

Troubleshooting pressure error code for Trane XV80

I have a ~7 year old Trane XV80. Recently, it started throwing up the pressure error code (3 flashes). Inducer fan would start, but the burners wouldn't light. Being lazy, I would basically power ...
0
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0answers
53 views

heat pump/air conditioning wiring to thermostat

We decided to change the thermostat of our heat pump/air conditionnning unit. First 3 images are the old unit. The first 3 wires(1 and 2 picture) yellow red orange were not connected to anything, just ...
0
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0answers
47 views

Why would my AC turn on and off randomly?

My AC unit turns on and off randomly regardless of whether the thermostat is set on or off. I've even tried removing the batteries. Does anyone know why this might happen?
0
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0answers
68 views

Would increasing the size of the A/C duct for my kitchen improve cooling?

As part of an ongoing kitchen project, I'd like to relocate the existing a/c register in the ceiling (which is located next to an interior wall) to the center of the room and upsize the duct (and ...
0
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0answers
30 views

What to look for in central air installation?

I'm having an HVAC company install a York central air unit in my house today, and I'm wondering what things I should be looking for in the quality of the installation? Existing York central heating ...
0
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0answers
25 views

Why does the A/C come on downstairs when heat is on?

I just moved in to a 2-story house. It is zoned upstairs and downstairs. If I turn the downstairs thermostat to OFF and the upstairs to COOL, the HVAC in the attic comes on, the outside compressor ...
0
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0answers
18 views

What could be causing my goodman furnance to not work?

My furnace starts, than the blower motor runs constantly, but trips out on roll out limit switch. The air inlet and outlet lines appear to be unobstructed, but when it shuts down there seems to be ...
0
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0answers
46 views

Baseboard heat not keeping up

This is my first winter in my house which was built in 1991. A Navien CH-240 that provides both hydronic baseboard heat and hot water was already installed. We have two zones, upstairs and downstairs. ...
0
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0answers
52 views

Furnace blower intermittently stops working

The blower on my furnace is set to be on constantly. The last two nights in a row I have woken up in the middle of the night to hear that the blower is not running and that the temperature is dropping ...
0
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0answers
14 views

What could cause my Trane furnace to not light?

after I set my thermostat for heat the combustion fan motor comes on but the burners does not fire, and after like two minutes everything turns off and the LED flashes two times, which means SYSTEM ...
0
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0answers
19 views

baseboard heat problems it makes loud noises and does not heat 2 zones at the same time

The baseboard heat will heat the main floor and not the upstairs and vice a versa. What could be the problem, it also makes loud noises.
0
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0answers
75 views

Is it normal for this PVC pipe to be dripping from under the eaves?

I have a 2 story house, 14 yrs old. There is a PVC pipe under the eaves over a window on the 2nd story, that has been dripping more than normal the past couple of days. Our AC unit is located in the ...
0
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0answers
19 views

What type of control systems are available for a home with multiple HVAC systems?

Our new (used) home has two HVAC systems, one for upstairs and one for down. There is a thermostat in the dining room, which is directly affected by sun. And one in our bedroom, that clicks all ...
0
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0answers
10 views

old furnace and thermostat upgrade

In a furnace that has no circuit board, can the C wire be connected between the C terminal on the thermostat and to one of the contact leads on the 24V transformer and operate safely?
0
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0answers
25 views

How do I measure the size of a duct that runs through a finished wall (the register end is accessible)?

I am trying to redo a Manual D for my house (heating mainly). I can pretty much determine the length of each run but I can't figure out the exact size of the ducts that are already installed The ...
0
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0answers
36 views

What size exhaust fan do I need for a pool house?

What size exhaust fan ( how many CFM ) do I need for my pool house . The pool is 36 feet x 18 feet x 8 ft deep, and is kept at 32 C. The building is 42 x 28 feet, 10 feet high ceiling, all insulated, ...
0
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0answers
39 views

What could be the reason why all my registers at foundation slab level have weak air flow?

In the picture below all the ducts that have a long leg going toward foundation have weak air flow. Read the details on the picture Could anybody tell me what is the problem with these guys? The ...