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

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3
votes
4answers
3k views

Why would a furnace overheat with a standard density filter?

Some time ago I found my furnace (gas, forced air, downdraft) was getting stuck on, blowing cold air. I could reset it, but it would happen again after a while. After calling out a service man, I ...
7
votes
2answers
761 views

Is there any legitimate reason to have a direct vent between utility room and attic?

I've been doing some sealing and insulating in my attic, and discovered a purpose built vent directly from the utility room into the attic space. See most of these photos The house is in a ...
3
votes
3answers
16k views

Why is my furnace blowing cold air?

My HEIL 7000 natural gas furnace has stopped working what are the most likely causes, and how to verify faulty parts? Normal operation routine Thermostat sends "need heat" signal. Exhaust blower ...
6
votes
2answers
20k views

What are the pros and cons of two AC systems vs a dual zone system?

I have a Cape Cod with 1000 ft2 on the first floor and an apartment in the attic. In a few years I may get rid of the apartment and build up a second story + attic. Both the first floor and the ...
4
votes
1answer
989 views

What's wrong with my thermostat (fan / limit control)?

I previously asked about wiring the White-Rodgers fan/limit control on my wood stove. It's now wired and the wood stove is fired up. I ran the fan wires to the fan (hot) and I capped the limit ...
9
votes
4answers
12k views

Does lowering the blower speed of a forced-air furnace lower its efficiency?

My gas furnace has two options for the blower speed: MED, and MED-HI. It had been set on the higher speed, but that was too harsh, so I lowered it to the slower speed. Does that have any impact on the ...
5
votes
2answers
4k views

How do I install a wood stove as an auxiliary heat source?

I have a house with a forced air electric furnace. We've also got a wood-burning stove adjacent to the furnace. I didn't have it installed, and I want to understand if it's been done properly, and ...
3
votes
1answer
5k views

How should I wire this White-Rodgers fan and limit control? What about the thermostat?

I have a wood-burning stove, that is used as an auxiliary heat source in the house. There's a regular electric furnace, and adjacent to it is the stove. The warm air duct (out) from the stove ...
13
votes
3answers
50k views

What are the pros and cons of a whole house humidifier?

In the winter, my house (~2500 sqft) becomes unbearably dry. Last winter, my wife and I used a tiny humidifier for the master bedroom to keep us from completely drying out, but since then I have been ...
1
vote
1answer
8k views

Should I add a return air vent in a refinished basement?

We are refinishing our basement, and are nearing competition. The walls are drywalled, and the ceiling is dropped. There will be about 500 sq ft of finished space, including a full bathroom, and ...
1
vote
1answer
146 views

Fan between rooms?

I presently work at home, which means that I spend a lot of time in my office (ya think?). Unfortunately, this room is not a good one for air conditioning (or heating) in the house. I can often get 8 ...
2
votes
2answers
1k views

How do I clean an AC condensate pan?

I have a Ducane HVAC system that started leaking out of the evaporator coil housing. Mine looks like the EU1P. I read that i need to clean out the drip pan. II tried cleaning it by sucking out the ...
3
votes
1answer
207 views

Improve AC flow to secondary ducts

I have an AC which has 3 ducts coming out of it. Only one duct gets flow - I'm guessing the AC fan blows right into it. What can I do to improve the flow?
2
votes
2answers
754 views

How do I repair loose ductwork?

The ductwork in our 30 year old house has started coming loose where it comes up through the floor. It's nailed to the subfloor, but in several places, the nails have come loose, leaving gaps of an ...
4
votes
3answers
1k views

Is an interior laundry room without an HVAC vent a code violation?

Currently looking at a home which has a nice 2nd floor laundry. Vented dryer, nice rack for hanging clothes, etc. However, it's in the center of the home and does not contain an HVAC (central air) ...
1
vote
2answers
169 views

How do I choose a furnace airfilter?

I have a furnace/air-conditioner that can support filters of various thicknesses: 1", 2", or 4". Filters are available in various MERV ratings. How should I decide which filter to use?
3
votes
2answers
3k views

How do I install a jump duct?

Our master bedroom is considerably warmer than the living/dining/kitchen area of our house, and we've been setting the thermostat quite lower than we'd like in order for the bedroom to get cool enough ...
11
votes
5answers
6k views

How can I calculate how large an airconditioner my house needs?

I know there are a lot of possible factors that go into determining the size of the air-conditioning system a house needs. Is there a standard way of calculating what is needed, or do A/C companies ...
3
votes
3answers
115 views

Geothermal Resources

I am very interested in learning more about Geothermal solutions for my house. What are the best resources for learning about and planning a Geothermal systems for a residential house? Also, does ...
7
votes
5answers
9k 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 ...
4
votes
5answers
10k 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 ...
4
votes
7answers
5k views

Would putting a sprinkler on my roof help cool my home?

Anyone ever put a sprinkler on your roof to help out your A/C on unusually hot days? Just wondering if it helps.
1
vote
1answer
87 views

Weather stripping a door in an outside bldg

I have an office in the garage that is a standard room with insulation and an AC unit (8500 BTU AC in a 9' 3" tall room, 5" 4' wide). The room gets rather hot and I found the issue to be with the door ...
7
votes
6answers
8k views

Where should my furnace filter go in a Lennox G40UHX series furnace?

I have a Lennox G40UH(X) series furnace, which is installed in our attic (We have a single-story house on a slab). Because the furnace is installed in the attic, it is "laying down" on its side, and ...
6
votes
7answers
2k views

Should I apply car wax to the outside of my air conditioning unit?

Through different conversations with family members and friends, I have been told that it is good to apply a coat of car wax to the outside of the air conditioning unit frame. I assume that this is to ...
18
votes
1answer
7k views

Humidity Levels

What is a healthy and safe humidity level that I should try to keep my house at?
4
votes
1answer
716 views

two condensate drains?

we just had a new AC system installed in my florida house. the unit is in the garage, and the air handler is vertical with the evaporator on top. the unit he removed had 2 condensate lines: one that ...
12
votes
6answers
583 views

Is it worthwhile to have ductwork cleaned?

Was rearranging some ductwork in my basement, and noticed that the stuff I took down was pretty filthy inside (especially the return air ducts). Is it worthwhile to have ductwork cleaned out? What ...
8
votes
4answers
683 views

What type of regular maintenance should I be doing on my central air conditioning unit?

I have not done any maintenance on my central air conditioning system since I bought my house five years ago. Everything seems to be running fine but is there some sort of maintenance I should be ...
9
votes
9answers
10k views

Do thermostat-controlled, auto-adjust HVAC vents exist?

The residential forced-air HVAC systems I have seen are controlled by a single thermostat in one room. One has to manually adjust the vents in order to adjust the temperature in other rooms. Is ...