What Is a Heat Recovery Ventilator?

Heat-recovery ventilators, or HRVs, are made to address the problems of tightly-built houses—stale air, lingering odors, and high humidity—without ruining the energy efficiency of the structures. Opening a window can “work,” but that allows a home’s heat to go outside unabated. It can also let humidity in. Heat-recovery ventilators, on the other hand, are made especially to let the stale air out while keeping the heat in. While they don’t bring the incoming air all the way up to the ambient temperature, they can save about 70% of the heat which would otherwise go straight to the outdoors.

Despite their name, heat-recovery ventilators can also be used to help keep air cool in the summer as they provide ventilation. During hot weather, the incoming hot air is cooled by the outgoing indoor air.

Unlike an open window, heat-recovery ventilators give continuously-controlled ventilation with a motorized system. They use the heat from the outgoing, stale air to warm up cooler (or cold) incoming fresh air. The two streams of air are never mixed. Instead, they go through a closely intertwined chamber setup. This allows the two air streams to get close enough to exchange heat from one to the other, without allowing the actual air to commingle.

Most heat-recovery ventilators are designed as whole-house solutions. They usually have between 4 and 8 supply-and-return ducts. In this way they are similar to typical built-in heating or air conditioning systems.

The ideal configuration of a heat-recovery ventilator will take air out from the most moisture-laden rooms like the bathroom, kitchen, and laundry room. Incoming fresh air, which is still slightly cooler than the old air, will go into lesser-used areas like hallways, closets, and other less-trafficked areas where air movement will not be uncomfortable.

Due to the size of a full installation job, whole-house heat recovery ventilators are usually installed by professional services.

Single-room heat-recovery ventilators also exist. These are good if there are one or two “problem” rooms which you need to address, without the expense or work required for a whole-house solution. Like room air conditioners, these ventilators install in a window or through a wall. Some models include filters, which is another thing they have in common with air conditioners.

For the most effective placement of a single-room heat-recovery ventilator, choose a location which will be high on an outside wall yet isn’t right up to the inside ceiling. Keep it away from thermostats to avoid skewing the temperature readings. Also keep it away from seating areas if the air movement would be a bother. Remember that there is fan noise associated with a one-room heat-recovery ventilator, and plan accordingly when it comes to placement. A noise which is quiet enough in a living room may sound like a plane taking off when it’s in an otherwise-silent bedroom.

All in all, heat-recovery ventilators seem to be a great way to get rid of stale air, odors, and overly-high humidity. They allow the fresh air in without bringing the cold, rain, or humidity in with it. To get an estimate on a whole-house heat-recovery ventilator, check with your local heating and air conditioning contractors. Or, if you are a handy type who doesn’t mind the bigger-than-average product, you can buy a whole-house heat recovery unit online, and install it yourself!

November 15, 2010
Posted in Home — Knowledge Buff @ 3:56 PM

How To Install an Electrical Outlet in the Floor

If you have a large space to furnish, you may find yourself with the problem of bringing electricity to a lamp or other item far from the wall. Installing a floor outlet is the professional way to avoid having to string an electrical cord across the room. This is the way it’s done in large, higher-class hotel lobbies, and there’s no reason not to do it in a large room in a home.

Installing a floor outlet means keeping some special considerations in mind. In the United States, most local electrical codes require a special box and receptacle, a gasket seal, and a strong, moisture-proof cover plate. This is because floors are subject to both foot traffic and at least occasional wet cleaning, and the floor outlet has to be able to handle this.

You will need: A drill, keyhole saw or hacksaw, a stiff wire, floor outlet hardware, wire connectors, and a power cable, cable clamp, and cable staple. If you’re installing the floor outlet into a carpeted floor, a carpet knife will be needed as well.

To avoid hassle, it’s best to install the floor outlet in a location that’s close to a nearby circuit. This will make it easier to do the wiring.

General steps for installing the floor outlet include:
• Positioning the floor outlet: Position the outlet between the joists. Once you’ve decided on the position, drill through the floor with a long bit. Drop a long coathanger wire though the hole, so you can see it from the level below. Bend the top of the wire and tape it so it doesn’t fall through the hole. Go downstairs and make sure that the area you intend to place the floor outlet will indeed be suitable—no pipes, existing wiring, or joists in the way.

• Using the outlet box as a template, draw an outline on the floor. Cut a hole for the floor outlet, using a keyhole saw or a jigsaw. If the floor is carpeted, cut a hole through the carpet and pad, drill marker holes at the corners, and then cut a hole through the substrate from underneath.

• From below, attach a cable clamp to your power cable (which is still not attached to the power at this point), and then snap the clamp into the floor outlet box. This will keep the weight of the power line from pulling downward from the box. Secure the cable to a joist within a foot of the box. Use a cable staple for this.

• Assemble the floor outlet: Go back upstairs and fasten the box into the floor. Attach the wires to the receptacle(s). First, connect the ground wire to the ground screw and then to the receptacles. Position the receptacle(s) into the box and secure them.

• Turn off the power to an existing circuit in a box which has a constant hot feed (this is one which is not operated by a switch). Then find the incoming hot wire. Using wire connectors, connect the new wires to the hot feed. The floor outlet is now able to get power.

• Turn on the power. You should now have a working floor outlet. Test it by plugging in a lamp.

That’s it! Now your floor outlet is installed, and you can have lamps which “mysteriously” get power even though they’re way in the middle of the floor, just like in fancy hotels! With creative placement of the lamp’s cord and other furniture, visitors won’t even be able to see where the floor outlet is unless they blatantly look for it. The overall effect is very professional.

Posted in Home — Knowledge Buff @ 3:44 PM

How To Install an Anti-Scald Valve In a Shower

Have you ever been standing in the shower, only to get blasted with super-hot (or super-cold) water when someone elsewhere in the house flushes the toilet or runs the water? Installing an anti-scald valve in the shower will put an end to these jarring and dangerous surprises.

Anti-scald valves, also known as pressure-balance valves, compensate for sudden pressure changes in both hot and cold water lines. This prevents the temperature from changing in response to other water draws. Since sudden temperature changes can cause a showering person to jump or otherwise lose their balance, keeping the temperature even can prevent slips and falls. It can also prevent scalding injuries—hence the name, “anti-scald valve.”

To install an anti-scald valve, the first step is to turn off the water supply to the shower you’ll be working on.

Then remove the current handle and escutcheon plate (that metal plate that goes behind some water handles in the shower). Measure the setback from the outside of the tile to the center of the pipes in the wall. This is one time you don’t want to buy the new part first. That’s because you need an anti-scald valve which has a similar setback, for easier installation.

The next step in installing your new anti-scald valve is to get behind the valve, from the other side of the wall. If there isn’t already an access hole, you’ll need to cut one in. Once you have access, remove the tub spout and shower arm. Cut the supply lines where the shutoff valves will be located. Remove the old faucet valve and old piping above where you made the cut.

Use the old valve and pipes as a template for determining the size of the new anti-scald valve assembly. Solder connections, using a fireproof cloth to keep from lighting the work area on fire. While soldering, open the shutoff valves and remove the valve cartridge. Secure the valve and pipes with support blocks and pipe straps.

Go back to the shower side (front). Now install the new escutcheon plate, set the anti-scald limiter, and install the new handle. Install the tub spout and the shower arm. Test the anti-scald valve and the connections.

To adjust the anti-scald valve, look for a gear-like rotational stop behind the handle. This stop controls how hot the water can be turned. All you have to do to get at this part is remove the handle—no need to cut back into the wall. This makes it fairly easy to re-adjust if you find you aren’t satisfied with the way it’s initially set up.

Once these steps are complete, you have finished installing the anti-scald valve. You can now enjoy taking a shower, knowing that you won’t be blasted in extremely hot or cold water whenever someone runs water somewhere else in the house!

Posted in Home — Knowledge Buff @ 3:14 PM

What’s So Great About Ground-Source Heat Pumps

You may have heard of using the warmth from the Earth to heat your home. But how? Ground-source heat pumps are one way to extract the heat from the ground (“geothermal heat”) and turn it into indoor heat.

Ground-source heat pumps have many advantages, but the fact that they produce heat without burning fuel is their major plus. While the best natural gas furnaces can run at 92% efficiency, a ground-source heat pump whomps on that with an efficiency rating of an eye-popping 300%! This is because of the lack of fuel burning. They are using heat that is already there, and just transferring it to where you want it.

A ground-source heat pump has 3 main components. There is a “ground loop” which collects the heat, a heat pump (or exchanger) to condense that heat, and a duct system to distribute the heat throughout the house.

There are two kinds of ground loops in a ground-source heat pump system. A closed-loop system circulates anti-freeze through buried polyethylene pipe. This pipe is buried at least 6 ft. under the ground, where temperatures are at about 55 degrees F all year round. Open-loop systems, on the other hand, use a water supply to transfer the heat. This water is run through the heat pump to extract the warmth, and then discharged to another location (usually a pond).

The underground piping for a ground-source heat exchanger can be installed in many configurations. It can be buried in trenches, underneath ponds, or run in a series of vertical well holes. It can be installed in straight lengths or heavily coiled. This versatility allows it to be installed in many locations, regardless of the terrain.

Inside the heat pump, the ground-source heat is absorbed by a refrigerant. This refrigerant is compressed and heated until it reaches 160 degrees F. Air is then passed over the hot coils, where it picks up the heat. The hot air then goes through the house’s duct system to heat the house.

For areas with mild winters, a ground-source heat pump is usually all it takes to heat a house. The extraction of heat from the ground can overtake the opposing cooling forces of the wind and outside air temperature in these areas. People in cold places like Michigan, on the other hand, often find that they need to use old-fashioned natural gas during the deepest months of the winter. Even there, though, a ground-source heat pump can cut heating bills tremendously, and possibly eliminate them during the milder seasons of spring and fall.

November 13, 2010
Posted in Home — Knowledge Buff @ 4:04 PM

About Drywall Joint Compounds

When installing drywall, you will soon run into the question of what to do with the joints between the panels. There are several kinds of joint compounds. But which one should you use? Here is a brief description of the most common types of drywall joint compounds.

There are two main categories of joint compound: Setting compounds and drying compounds. Setting compounds contain plaster of Paris and harden through a chemical reaction. Drying compounds, on the other hand, harden through drying (evaporation) of their moisture.

Setting compounds are joint compounds which can take various times to dry. The fastest-drying only take about 10 minutes, while slower-to-dry versions can take 3 ½ hours. Watch out—these times estimate how long the compound will remain workable after you mix it, not after you apply it! So only get the 10-minute kind if you can mix AND apply the joint compound that fast. If you’re not a super-efficient professional, you will probably want one that takes a bit longer to become hard.

Setting compounds are good for filling large gaps in a wall, fixing holes, or for cutouts around electrical boxes which turned out to be too big. This type of joint compound is also good if you’re installing paper-covered metal bead. These compounds stick wonderfully, shrinks very little, and dries extremely hard. The downside is that their hardness also makes them hard to sand. Therefore, you need to be careful not to overapply them.

Easier-to-sand setting compounds are a lot like premixed joint compounds, but they dry fast. For this reason, you can only mix small batches of them, or they will harden up on you before you can finish using them.

Drying compounds, also known as “drywall mud,” are the most common type of joint compound. They are so named because their hardness comes from them drying out, rather than through a chemical reaction. These joint compounds come in both powder and premixed forms. Premixed joint compounds often need to be thinned before use. How much thinning they need depends on what you’re going to use them for—thin less if you’ll be using a knife to work with them; more if you’ll be using a spray-on texture.

All-purpose drying compounds can be used with all kinds of topcoats, even textured surfaces. This is a versatile type of joint compound, but specialized applications may be done better with a different type of compound.

Topping compounds are thin joint compounds. They are soupy and don’t have as much adhesive as the all-purpose variety. The upside is that they’re easier to feather and sand, and therefore they are ideal for the final coat.

Now that you know a bit about each of the kinds of joint compounds, you should be better able to choose the proper one to use on your drywall. With the proper compound and technique, you should be able to make a seamless wall which will look like a completely unbroken expanse.

Posted in Home — Knowledge Buff @ 4:00 PM

How To Avoid Ice Dams

Ice dams happen when ice on the roof melts, only to refreeze when it gets to the roof’s edges. The ice at the roof’s edge then dams up the liquid water behind it, forcing it to find another exit—often through the roof’s shingles. Therefore it is essential to avoid ice dams if you want to keep the roof in good condition.

There are several ways to avoid ice dams. You may need to use one or more of these methods for complete success.

The first way to avoid ice dams is to keep the roof cold. Insulate the attic, and seal every ceiling penetration. This helps keep heat intended for the living area down where it belongs, instead of allowing it to rise to the roof. When insulating the attic, make sure to keep vents to the outside clear. If insulation blocks the soffit vent, it will actually keep the attic and roof warmer—the exact opposite of the desired effect. There needs to be proper ventilation to keep the attic cold.

A properly-built roof will help avoid ice dams, as well as helping to prevent damage from those that do form. When reshingling (or even completely redoing a roof), install an ice-and-water membrane. These are 3-ft. wide waterproof membranes. They’re self-sealing, so you don’t have to worry about nail holes. They need to go from the roof’s edge up 2-3 ft. higher than the exterior wall.

The most labor-intensive way to avoid ice dams is to manually remove the snow from the roof. You can use a snow rake to pull the snow down from the roof, but with this method, you have to watch out not to hit any power lines. You will also have to then clear the snow from the ground, if having mounds of it below the roofline is a bother. There is some controversy to this method of avoiding ice dams. The Reader’s Digest Complete Do-It-Yourself Manual lists it as a viable method. State Farm Insurance, on the other hand, says that the routine scraping-off of snow is likely to cause shingle damage.

Another way to avoid ice dams is to use heating cable to heat the edge of the roof, the rain gutters, and the gutters’ downspout. There is cable made especially for this purpose. This is a surefire method, since it actively prevents water from being able to freeze in the affected area. Follow the manufacturer’s directions for installing the heating cable.

Since the last two methods involve hard, ongoing work, I prefer the second method of avoiding ice dams—the ice-and-water membrane. Since I have no attic in the house, there is no space up there to insulate. There are a lot less icicles out there since an ice-and-water membrane is installed, so it has made an improvement.

Posted in Home — Knowledge Buff @ 3:38 PM

Why You Should Get a Power Planer

When it comes to woodworking tools, a power planer is one you might not think you need. After all, it’s not a lot of work to use a manual one. Or is it? After having to plane down something like a large door, a power planer may begin to make a lot of sense.

The power planer, like a manual one, rides on a shoe or sole plate. But a power planer’s shoe is broken into two sections: A stationary rear shoe, and a movable front shoe. The front shoe’s height can be adjusted by a knob, and the resulting offset from the rear plate controls its cutting depth.

The main benefit of a power planer is speed. It takes a lot less work to remove a lot of material. This makes it good for large jobs. It’s also great for jobs where you have to hold the tool in an awkward position, or where you’d have a hard time getting enough leverage with a standard plane.

One such job is leveling uneven joists in unfinished ceilings. This may need to be done if you want to install ceiling materials or some kinds of overhead storage units. Of course, they’re also good for evening out floor joists so you can put new flooring down. The power planer will be able to take off wood from areas which would laugh at a manual planer.

Scribing is another use for a power planer. Even though it can’t follow curved contours, it can allow you to trim excess material to let a cabinet frame fit nicely against a wall.

Power planers have an adjustable fence. This lets you plane beveled edges without hassle. One common use for this is on entry doors. There needs to be enough clearance for the door to close against the jamb. Planing it down is usually the way this clearance is provided.

Since it is a power tool, a power planer requires more precautions than a manual one. It can eject material with more force than would otherwise be present, so it’s best to wear protective goggles. Ear protection and a dust mask are also good ideas. Also, some practice on a piece of scrap wood is good, so you will be familiar with the tool when you start working on something that counts.

If you have big or awkwardly-located projects to do, or if you just want to have the most cool woodworking tools, add a power planer to your arsenal. When you realize how much time you’re saving when planing a big piece of wood, you just may find you really do need that, after all.

Posted in DIY — Knowledge Buff @ 3:36 PM

Types of Electric Sanders

There are many, many types of electric sanders. Most of these are specialized to make certain types of projects easier. They come in many shapes and all sorts of sizes. Here are some of the most common types and what sets them apart from each other:

Handheld electric sanders:
Belt sanders: These electric sanders are almost ubiquitous in wood shops. They are good for rough sanding jobs which would ordinarily take ages. Flattening large panels, taking large amounts off of stock, and leveling glue joints are some of the things they are good for. However, belt sanders are so powerful that it’s easy to dig a gouge into the wood, so you need to be careful with them. They work by running a belt around two or more spindles, so as to provide a constant, unidirectional sanding motion.

Finishing sanders: These machines use either a circular or back-and-forth motion to do their sanding. The stock removal is slower and more controllable. Finishing sanders also make less cross-grain scratches. Usually they take a quarter or half sheet of sandpaper. Electric sanders of this type are especially good for preparing veneered wood like hardwood plywood for finishing.

Detail sanders: Electric detail sanders are great for getting into the tiny details of already-completed furniture and other finely-detailed spaces. This makes them wonderful for refinishing jobs. They have replaceable, triangular sanding pads which match their heads. Many kinds also come with other attachments, which allow them to cut or polish as well as sand.

Random-Orbit sanders: This electric sander is the closest thing to a do-it-all sanding machine. It has a spinning disk combined with an orbital motion. Used with coarse sanding disks, it removes material quickly. But with fine-grained disks, it can provide a smooth, swirl-free finish. Ports in the sanding pads allow for automatic dust pickup. There are both one-handed and two-handed versions, with the power and size matched accordingly.

Stationary sanders:
For truly serious levels of sanding, there are stationary electric sanders which either permanently attach to a bench, or come as their own benches. These are more likely to be found in commercial settings or serious home wood shops. Among these, you can find:

Belt-Disc electric sanders: These use a single motor to drive both a big belt, and a big disc. Each sander has its own cast-iron table to support the piece you’re working on. The belt can be moved into either a horizontal or vertical position, depending on the work you are doing. You will need to connect a Shop Vac or dust collector to handle all the sanding dust they put out.

Spindle sanders: Sanding pieces which have been cut with a jigsaw or bandsaw can take a long time when done by hand. An electric spindle sander uses rotation and an up-and-down motion to do the job quickly while minimizing visible scratches. Cleanup is also faster.

Drum sanders: These electric sanders take care of the unevenness which results from gluing together large boards. They come as a unit with their own table, which features a rotating sanding drum above a power feeder. Just put one end of the glued board in, and the electric drum sander pulls the rest through and sands it along the way. These make a lot of dust, so like with the belt-disk variety, you will need to attach them to a dust collection system.

With all these types of electric sanders, there is one for every possible sanding job. Choose the ones which are right for the type of woodworking you usually do, and you will save yourself a whole lot of tedious and time-consuming work.

November 12, 2010
Posted in DIY — Knowledge Buff @ 10:57 PM

Why Rotary Tools Are So Great

Rotary tools are some of the “cool” power tools you might have heard about. A favorite of amateur handymen, they are often described as indispensible, or other, similarly-glowing, adjectives. But just what is a rotary tool, and what exactly can it really do? Turns out that these handheld wonders are indeed quite versatile!

First, here’s what a rotary tool is:
A rotary tool, also commonly called a “Dremel Tool” (since that’s the most popular brand) is a handheld tool which looks like a fat-handled screwdriver. There is a thin shaft at one end, which is spun at extremely high speeds by the motor. The usefulness of a rotary tool comes from the attachments which fit onto this shaft. The other thing which makes these tools so versatile is their small size: They can fit into spaces which large tools cannot.

Unlike many electric tools, the power of a rotary tool isn’t in raw horsepower. It’s in the speed at which the bits or attachments are turned—around 30,000 RPM or more. Therefore, it’s important to refrain from pushing hard on the tool. Let the bit and the speed do the work.

Here are some things a rotary tool can do:
Cutting is one of the popular uses of a rotary tool. With a cutoff wheel attached to the tool, you can even salvage worn-down bolts by making a slot for a screwdriver. You can also cut through other types of metal, and other materials depending on the cutting wheel.

Grinding is another common use of a rotary tool. Various shapes of grinding attachments allow different things to be ground. You can grind out a hole for a door’s strike plate by using a tapered grinding stone. You can also use a round grinding attachment for grinding off protrusions or smoothing surfaces.

Sanding of tiny items is easy with a sanding drum attachment. The rotary tool’s small size makes it possible to power-sand things which would be impossible to do with a larger power sander, and which would be tedious to do by hand.

Grout removal is made quick and easy with the rotary file bit. What would take hours of tedious work by hand can be done in minutes with a rotary tool. Just be sure not to miss and gouge the tile.

Engraving, something which used to require a tool of its own, is another thing made easy with a rotary tool. There are different engraving tips to be used with the various materials which can be engraved. Metal, plastic, and wood all have different characteristics and there are engraving tips for all of them.

With all of these uses, a rotary tool is indeed very versatile! Their small size, rather than making them wimpy, makes them very powerful. They can handle jobs in spaces which larger tools can’t even get into, and with the huge variety of attachments, can do a wide range of jobs.

Posted in DIY — Knowledge Buff @ 10:51 PM

How to Stop Water Hammer

Do your pipes make a loud banging noise when the water has been turned off? It’s probably water hammer. Water hammer is caused by the built-up energy of flowing water suddenly not having anywhere to go. It therefore forces the pipes to flex and bang into whatever is nearby. It is especially prominent when water-using appliances like dishwashers and washing machines turn off, because they are able to close their water valves almost immediately. Fortunately, there are ways to stop water hammer.

The reason for stopping water hammer isn’t just because the sound can be annoying. Water hammer can also cause wear on flexible pipes, as well as the soldered joints of copper pipes. This can cause early pipe failure.

There are a few solutions which will stop or reduce water hammer. Sometimes, all you need to do is add some supports to the affected pipes. A step up from that is adding a piece of felt as a damper to deaden the noise more and absorb some of the force. If a pipe is hammering because it is too tightly anchored, the felt can make a big difference. You can tell if a pipe is anchored too tightly by listening for clicks coming from it when hot water goes through it and causes expansion.

If those cheap-and-easy fixes don’t work well enough, there are various water hammer arrestors you can buy to stop water hammer. These work by isolating a cushion of air to absorb the extra force of suddenly-shut-off water.

Vertical air chambers are a capped length of pipe which is added to a water line. Eventually, the air in them gets absorbed into the water. To fix this, you have to turn off the main water supply and open the faucets to drain the lines, allowing air back into the chamber. Once this is done, you can turn the water back on. While this method of stopping water hammer may work fine while it has air, I could see it becoming a chore to have to re-aerate it. Therefore, you may want a different type of hammer arrestor.

Manufactured water hammer arrestors are a more permanent solution. These have a piston which isolates the air. It is best to install them as close to the affected valves as possible. Fortunately, the supply lines for dishwashers and water softeners—the most likely culprits for causing water hammer—are usually easily accessible.

Screw-in water hammer arrestors are good for use with washing machines. If you’ve ever seen odd, short pipes sticking up from the faucet leading to a washing machine, that’s what those are. To stop the water hammer caused by a washing machine, you simply need to screw these in between the faucet and the machine’s supply hoses. There are also built-in washing machine outlet boxes which come complete with water hammer arrestors already installed.

If you have water hammer arrestors already and the hammering keeps going on anyway, chances are your arrestors need maintenance or replacement.

Whether with simple supports and felt, or with specialized arrestors, stopping water hammer is fairly easy. Since repeated sudden flexing is bad for pipes, if you are hearing a lot of hammering, it is probably best to go ahead and take the time to install a solution to stop water hammer. Not only will your pipes have less strain on them, you won’t have to listen to such loud banging anymore.

Posted in Home — Knowledge Buff @ 10:45 PM
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