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41

More than you've ever wanted to know about the C wire: Lets start by explaining what the C wire is, and why it's needed. Ye olde thermostat In the olden days thermostats were simple switch devices, that used Mercury Switches to complete the circuit and turn on the heat/AC. Mercury switches were commonly used in bimetal thermostats. The weight of the ...


25

I think you will just waste a lot of water compared to the cooling effect that you get. A better way to cool the roof is to change its color. A roof with a clean, smooth bright white surface can reflect about 85% of incident sunlight and emit thermal radiation with 90% efficiency. This surface will be only 9°F warmer than the outside air on a typical ...


19

I went though a similar debate last year and ended up getting a whole house humidifier. I never remember reading that you should be able to get the humidity level to normal levels though normal means (shower, cooking, etc). In a big house, that is most likely not possible. Do you have a humidistat now, or does your stand alone unit give you a reading? I ...


15

In the winter it is 30 to 40 percent in cold climates. During the summer, indoor humidity levels should be kept below about 65 percent to minimize the potential for mold growth and below about 50 percent to minimize dust mites. See this article for some more great information on humidity levels: Keep Your Home Healthy


14

I assume you are in a cold climate, like Minnesota (where I am). I will address your question in three parts; the first two have to do with the humidifier. The "winter" setting on the duct in your photo: It appears from the photo that the duct in question goes from your humidifier around to the return (intake) side of your furnace's ducting. This needs ...


12

Looking in 2011 National Electric Code Changes of Interest, they reference NFPA 90A-2009 : Section 4.3.4 of NFPA 90A-2009 states that “Wiring shall not be installed in air ducts” unless it is “directly associated with the air distribution system and does not exceed 1.22m (4 ft).” I don't have access to the full code, but just in the notes on the ...


12

The logic involved is much more complex. Right now the logic is simple: if AC Mode and it's too hot, turn on AC, else turn off AC if Furnace mode and its too cold turn on furnace, else turn off furnace But the determination of when to switch between heating and cooling modes is much more complex - otherwise the ac would kick on, and it would get too ...


10

The technology is relatively young, and not as well known to consumers as traditional heating and cooling methods. The upfront costs of a geothermal system are also higher, and there are fewer companies around with the knowledge and tools to install the systems. In the US most homes are not built by the home owners, they are built by development companies ...


10

They do make thermostat controlled vent covers, this particular one is ~$60. I'm not sure how difficult it is to install one of these (as I've never done it myself), but it sounds like this is exactly the type of thing you are looking for. This is not a recommendation for this product, simply an example to show that they do exist.


10

I wouldn't do it. The next poor sod (who may be you) trying to fix something (or perhaps changing the system!) is expecting to find properly colored #18 AWG wire. Instead they'll find #24 wire in all these weird (to them) colors. You're saving yourself some money now, and making someone else's life difficult down the line. And of course, if you or someone ...


10

Yes, placing registers (or other heat sources such as radiators) near exterior windows and doors is the usual practice. This is done in order to combat cold drafts and ensure a more even temperature throughout the room. Here's a Q&A on the subject from Ask This Old House: Window glass is the coldest part of a wall. When warm room air hits it, the ...


10

That pipe looks like an air intake. All "direct vent" style appliances (high efficiency on-demand water heater, gas fireplace, etc.) have an isolated air intake and it is common to have it suck in air from outside the building so as not to force air infiltration through doors, windows, etc. Indeed, that is ugly. Our fireplace and tankless water heater ...


10

It helps for sure. There have been a ton of studies done on this and I have read at least 10-11. At one point in time I was going into a partnership for a "greening" business. Your variance is somewhere between 1-15%. There are a ton of variables. Here is an OK study I read a few weeks ago from FSEC. I personally don't like this study because they ...


9

A thermostat basically just energizes the individual circuits (G (fan), W (heat), Y(cool) ) which in turn (via the furnace controller) powers a relay which provides line voltage to the actual units (like the fan or A/C. In the case of heat, it instructs your furnace to open the valve supplying gas). R (or Rh and Rc) provides the 24VAC power. To turn on ...


8

I live in south texas, last week we had a terrible heat wave, temperatures outside where in the 110F-115F range, I installed a wireless thermometer on the attic and it read 130F on the hottest days. Ac would not cut off when set at 77. Went to home depot, got a set of 3 sprinklers that you can connect in series, I had an extra 24v solenoid water valve around ...


8

A properly functioning and properly sized central air conditioning unit should be able to maintain the temperature of your house at any reasonable temperature you select. The amount of cooling available is related to the size of the system, insulation in the house, and finally outside air temperature. From your description I would guess either you don't ...


8

National Electrical Code 2008 300.22 Wiring in Ducts, Plenums, and Other Air-Handling Spaces. (B) Ducts or Plenums Used for Environmental Air. Only wiring methods consisting of Type MI cable, Type MC cable employing a smooth or corrugated impervious metal sheath without an overall nonmetallic covering, electrical metallic tubing, flexible ...


8

You may be looking at the problem backwards, the freezing lines could be a symptom of the problem not the cause. Start by looking for blockages in the system that would cause lower air flow / heat exchange. Dirty filters. Clogged ducts. Closed dampers. Closed/Blocked vent covers. Dirty coils. Basically if the system cannot exchange the heat/cold, it ...


8

Check your unit's warranty. The heat exchangers on some units are warranteed for 20 years or longer. You may be able to get at least some money from the manufacturer, or a credit toward a new unit of the same brand. They may also cover all or part of the installation labor. Find out whether there are any federal or state tax incentives that could help. A ...


8

Necessary? No. More efficient? Yes. When the HVAC is centrally located the warmer/cooler air has less overall distance to travel to cover the entire house, as it's radiating out from the center. If you have noticed that one side of your house is less comfortable than the other, it may be worth the relocation. If the house is generally comfortable year ...


8

For the ducts, the setting indicates where you should set the switch based on the season. If your house has separate air return ducts on different floors or even multiple ducts on the same floor, changing the setting changes which ducts pull air from the house, allowing lower ducts to suck cold air out in the winter and higher ducts to suck hot air out in ...


8

There are two types of tubing most people think of, when you say "flexible gas tubing". The first and more common, are flexible gas connectors. These guys are typically 3-6' long, and are used to connect appliances to the gas piping. They are only to be used as a short link between the fixed piping and the appliance, and so are considered a "connector" ...


7

There are various degrees of a "zoned" HVAC system. A simple zoned system will include motorized dampers in the ducts to direct air where it is needed. e.g. If one room is too cold, but the other ones are fine, the system will shut the dampers to the other rooms, and then fire up the heater so just the one room is heated. More sophisticated zoning systems ...


7

If the furnace and water heater are gas powered, it would be to provide adequate airflow for their combustion so that you don't get carbon monoxide forming in the utility room. Here's a link with some information. An excerpt: The heating appliances are fully isolated from the living space with partitions. Figure 1 provides two vents to the outside, ...


7

Carrier is one of the better brands. (However, most brands are pretty good these days.) If you plan to stay in the house for years, look at systems with a higher SEER rating, as those are more efficient. A more efficient system is generally more expensive, but it can pay for itself with lower power bills. Units with a >16 SEER rating are eligable for a ...


7

I can't think of any reason not to run the duct through any open path. If the duct goes into any uninsulated space, you'll need to have the duct itself insulated. And on a vertical run between floors, I like to have a fire block between the floors, but that may not be code in a single family dwelling. Be sure to block any drafts, run a vapor barrier, and ...


7

Try this on for size: Annual Oil Bill * Efficiency = Cost of Oil actually used for heating. (The rest is waste). So on an annual bill of $1000, you are currently paying $650 for heat, and $350 out the chimney. (i.e. $650 is as low as you can go with a 100% furnace) So, if you were to replace that with an 87.2% furnace, your annual cost would be $650/87.1% ...


7

Do the joints in adjustable duct elbows need to be taped as well once they're adjusted Yes, they do. or are they considered air-tight? No, they are not. Far from it, in fact. You want to tape every seam in your ductwork, using (as Shirlock pointed out) foil tape. Each exposed seam, whether it's at a connection or part of pre-formed metal like ...


7

Their insurance may lean that way. Rates are probably lower if they are not selling to end-users. They may also not have to deal with sales tax, if they are not selling to end-users. As for the (or more) economic incentive you (apparently) cannot see: They may also prefer dealing with competent licensed professionals, because they will have less time ...


6

Here are the EPA guidelines for duct cleaning and when it is necessary. http://www.epa.gov/iaq/pubs/airduct.html Keep in mind that the airflow ducts usually aren't as bad as commercials would have you believe, unless the system was run without an air filter. The filter usually sits in your air return, which makes sure any air flowing into your supply ...



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