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Passive solar design before you build On a new build, your very first stop is passive solar design. Strutting forward and designing a bad old stickhouse, and then bolting on solar as an afterthought, is wasteful. Passive solar design means engineering the building so it does not need active heating (except on rare occasion. The occasion is rare enough ...


17

Assuming that you are (a) on the regular electric utility grid and (b) are on the regular natural gas delivery system (i.e., don't require propane deliveries), as a general rule, natural gas heating will be most cost-effective in most parts of the US. If you are not on the regular (utility) natural gas system then electricity has some advantages. ...


17

I think some of the answers here are confusing because they don't really address that your furnace has two different air intake/outlets. One is for the combustion system. Air is pulled in from somewhere (usually outside, probably the metal duct on the right), mixed with natural gas, and burned. All of the outside air and combustion products go out of the ...


15

The answer is that it should have a fresh air source! This is an absolute for gas furnaces. Some systems use the “leaks throughout the house” to get the air. The filter in the furnace is for dust to keep that out of the heat exchanger it dose nothing with the gasses that a open combustion fire box generate. The most important thing you can do is to install ...


13

Your furnace controller board is very likely indicating a trouble situation and shutting itself down. This is the equivalent of a car turning on its check engine light and not wanting to move. Shutting the main power off clears the error code and allows it to work temporarily but doesn’t fix what’s actually at fault. First, change out your furnace filter. ...


12

If you design the solar thermal correctly, then given the annual solar insolation ( higher than my location in EU by about a factor of 2) then with good insulation you can avoid heating at all. But you will need to maximize the passive solar gain - allowing the sun's energy to enter the building in winter for example. Use underfloor heating driven from 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 ...


9

Bleeding radiators is quite simple, and can usually be done by homeowners. All that's required is a radiator key, a towel and/or bowl, and a bit of time. Why Bleed Radiators Even with closed systems, air can still find its way into the system. When it does, it will collect at the highest points available (the top of radiators). Trapped air can cause ...


9

Sometimes ductwork under pressure and heat can experience a sudden deformation commonly referred to as oil-canning. This is where large rectangular pieces of box ducts have stiffening ribs formed into them to prevent deflection under pressure. If a particular panel is installed in just the right (or wrong) way, it can temporarily flex when it warms up. It'...


9

Only if you have a humidifier installed, and in that case it would be a very small quantity. To determine whether your system has a humidifier, examine the primary ducts near the furnace unit. Look for a tray or housing with a water line and possibly a power cord. Here's an example. Notice the unit attached to the intake duct. It has a copper supply line ...


9

Very few HVAC systems aren't able to handle abrupt power loss. I've flipped the switches on dozens of systems hundreds of times to change filters and perform other service. The gas valve will close and the control boards have algorithms to recover. It may feel nicer to shut them down gently, but there's no good reason to worry about it. After all, power ...


8

WARNING: Furnaces are expensive, complex pieces of equipment. If you don't have the proper tools and/or knowledge, it's often best to let the professionals handle maintenance and repair. Gas Furnace Ignition Sequence: Thermostat calls for heat. Pilot gas valve opens. Ignition control starts (spark or glow). Pilot gas ignites. Flame sensor detects pilot ...


7

I'm dealing with the same problem in our "new" (1992 vintage) home. Long duct runs expand and contract with conditioning cycles. In places where the duct is held tightly against the home's framing or other objects, sudden slipping results in pops or squeaks. Solutions generally involve one or more of the following: securing the duct more ...


7

Your furnace probably exhausts more air than it intakes, creating negative pressure in the house which will draw air in. You can try to control is by "encouraging" the makeup air to come in through a route where it hits a filter ASAP. High efficiency furnaces have a (typically PVC) combustion air intake and exhaust and don't result in net air ...


6

I would start by turning the thermostat off, including the fan setting to "off" and not "auto". The HVAC breaker should be a 240v double pole breaker. Most homes have four of those. One for the water heater, range, dryer and the HVAC. Turn the breaker to the HVAC off. If you have a heat pump, there will be a shut off near it outside (probably mounted to the ...


5

I tend to think of questions like this about heating and cooling efficiency from a thermodynamic perspective, where its primarily a question of energy loss. The energy loss to the surrounding environment goes up when the temperature difference between the inside temp and the ambient temp goes up; the energy loss goes down when this temp difference goes down. ...


5

If partially closing a single supply vent caused your high limit to trip you probably have an restriction problem. I would recommend investigating a bypass damper with a return and supply temp. sensor. These devices are typically just a part of a whole house zoning system, but can be used to easily resolve supply air restrictions in situations where ...


5

Start with efficiency Harper's overall point about starting with an efficient envelope is dead-on; managing solar gains is going to be a huge part of it down in Texas, and you'll also need to be careful with how you apply insulation and air barriers to avoid trapping water vapor or moisture in wall or roof assemblies. The ultimate test of this is a blower ...


5

The zone board's gone bad Since upstairs is broken, yet downstairs is fine, and it's not a thermostat issue, I'd point the finger at the zone board having something wrong with it. Just to make sure, try pulling the upstairs thermostat and jumpering R to W on its base; if the heat doesn't come on, then something's dead with the W input for that zone.


4

This DOE reference indicates, with better double glazed windows and better insulation, that ducts should not be run in outside walls anymore. HVAC Ducts Shall Not Be Run within Exterior Walls In the past, it was common practice to run ducts inside a wall cavity of an exterior frame wall. It is sometimes done today. However, we have learned that ...


4

The room thermostat does not control the boiler directly. Instead, it controls a circulating pump that draws heat from the boiler and delivers it to the radiator(s) in the room. It is the removal of heat that subsequently causes the boiler to fire, when its thermostat indicates that its internal temperature has dropped because of the heat removal. It sounds ...


4

Central heating should not significantly increase your water usage. Though depending on what type of central heating you're talking about, it may consume some water. Forced Air Typically forced air heating will not consume any water. However, if it's a gas/oil forced air system, a humidifier may be required. The humidifier will consume water, though not a ...


4

Sure -- or at least, there's nothing about having round ducts in the attic that would make A/C installation more difficult. In fact, because cold air is more dense than warm air, ceiling vents are usually considered better for cooling. The cool air flows down from the ceiling, helping ensure your rooms are evenly cooled. That's why many houses in warm ...


4

Furnace installers and/or home owners will put a register in the duct work to provide some heat in the winter to that area. The number of these supply registers is determined by the typical use and desired temperature of this area. I recommend that all basements should have at least 2 supply registers and 1 return register in the basement/equipment area just ...


4

The furnace has the intake and exhaust of a sealed unit but the water heater is an old style open burner. The water heater requires the outside vent. The size of the vent is based on the BTU rating of the water heater. I would not close off the vent because this provides the fresh air for the water heater.


4

There may be some opinion on top of what I believe to be true. There are some large flex duct sizes but the ribs are horribly inefficient. Metal trunk is also better suited when going vertical it is easier to secure. Frame work is square to box-in a round trunk the box would be much larger. I have seen DIY main trunk in a home we were replacing the “mess” ...


3

Given that the return air vent in the storage room is the only one, I'm fairly confident that closing vents and doors to unused areas will reduce the cost to maintain the used areas at a comfortable temperature.


3

Despite scouring the Internet, I didn't find the solution - the gas man came today and after describing the symptoms to him he identified it immediately: Faulty zone valve contact switch Basically, the sequence is as follows: Timer turns on - sends current to thermostat Temperature is too low - thermostat relay sends current to zone valve Zone valve turns ...


3

This is the sound of metal pipes and radiator components expanding and contracting. As they do so, they rub against other fixed parts, like wood framing, brackets, etc. If they stick slightly, you'll hear a popping or clicking sound as they stick and unstick from the friction against this expansion and contraction. So the solution is to locate any points ...


3

You've bought a programmable thermostat so you can lower the temperature of the house at night, however by doing that you are making it much harder work for the boiler to bring the house back up to temperature. Before your house was at a constant temperature so you boiler would turn on for a bit, off for a bit, on a bit, off a bit over the whole day. Now it ...


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