What Is It?

An important part of the inspection process is ensuring clients understand the operation of the various systems in the house or business. Occasionally clients inquire about items around the house with function not always obvious. Here are some images you won’t see in every structure, see how many you recognize.

What Is It

[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00002_0.jpg]13070Plumbing under the water heater?
<FONT SIZE="+2">These red pipes are Cross Linked Polyethylene (PEX) radiant heat supply lines connected to supply manifolds. The white are supply shut-off valves and on the left (return side) are the temperature wells that allow monitoring of the water temperature in each loop. </FONT>
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00004.jpg]8880Water supply equipment?
<FONT SIZE="+2">The bottom is the supply line from the street, connected to a pressure regulator then the 1/2" supply to the rest of the house. The regulator allows adjustment of the incoming water pressure. I've measured up to 130 psi (without regulators) when the recommended range is 40-80 psi at your fixtures, toilets etc..</FONT>
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00005.jpg]7380Occupants graffitti?
<FONT SIZE="+2">I'm probably one of only a few that have seen Eric's message.</FONT>
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00008.jpg]6400Sorry its so dark, best I could do (looking up at a roof eave)
<FONT SIZE="+2">If you look closely in the middle of the image there is a critter looking back from a hole in a soffit. I informed the client who was living there and turns out it was a flying squirrel!
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00009.jpg]6210This is a tough one. The clue is: this image taken in a gable attic space (over a front porch) is looking down.
<FONT SIZE="+2">The arc in the image is the visible edge of a fiberglass porch column, the column is architectural not structural. Note the laminated beam going across the top which is supporting the span.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00010.jpg]5790This is a well water treatment system. What is the white cylinder in the middle?
<FONT SIZE="+2">The cylinder is a Reverse Osmosis (RO) pressure vessel membrane housings. RO residential systems are rare but fairly common in commercial applications where water quality for manufacturing processes are important.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00012.jpg]5690Green Roof?
<FONT SIZE="+2">No, this isn't a state of the art green roof, it's neglect.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00013.jpg]6490Metal box with some wires?
<FONT SIZE="+2">These are very common, if you have a door bell you have one of these usually in a closet. It is a transformer that converts your 120V AC house voltage into a DC voltage used for door bells and other low voltage applications.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00013_1.jpg]5250Metal box with some wires2
<FONT SIZE="+2">There's a reason the low voltage transformers are usually in closets now. This is a very early version of a door bell transformer. Someone obviously didn't like the color of this one.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00014.jpg]6290Two shiny metal things at the clothes washer hookup.
<FONT SIZE="+2">These are water hammer arrestors and their function is to reduce the pressure wave sent down you water lines when the clothes washer valves close abruptly. Notice anything else? The washer drain "standpipe" cap (on the left) hasn't been removed yet, typical new construction observation.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00015.jpg]4980Round dial usually found in the laundry room of newer homes.
<FONT SIZE="+2">This is a programmable timer for the laundry ceiling exhuast fan, you can run the fan manually, off or programmed to run at predetermined times.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00016.jpg]4620White tank above the water heater?
<FONT SIZE="+2">As water is heated by the water heater it expands increasing the pressure in your lines that isn't relieved until you open you faucet. The expansion tank has a rubber bladder that expands and contracts with pressure. Anything wrong with this installation? Manufactures recommend the tanks be installed on the cold water side. This one is on the hot water side.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00018.jpg]4340
<FONT SIZE="+2">This is a backflow check valve that prevents water from flowing back into the crawl space after the pump stops operating. #1 item that inexperienced installers don't install when putting a sump system.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00019.jpg]4320Plastic pipe exiting the garage wall?
<FONT SIZE="+2">Clue is the 20 amp outlet and low voltage conductor. This is a whole house vacuum system location without the vacuum installed.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00020.jpg]4250Rusted steel pipes in the crawl space?
<FONT SIZE="+2">This is called a "Meter Bar". When Natural gas service was first installed in our area the meters were sometimes installed in the crawl space. The lines in this picture were abandoned long ago and the meter is now outside the house, where it should be.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00021.jpg]4680Four pipes exiting a crawl space vent, what is each for?
<FONT SIZE="+2">The black plastic line that is turned up (with white grill) is the combustion air vent for the high efficiency furnace, shorter black pipe is the combustion exhaust vent. The small white pvc pipe on the left is the condensate drain for the furnace and the lower right is the temperature pressure relief TPR vent for the water heater.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00022.jpg]4500Knob and Tube Conductor Splice
<FONT SIZE="+2"> This image is included because I appreciate the workmanship of the splice between older Knob and Tube wiring and modern "NM" romex conductors. Usually the splices are accomplished by persons unfamiliar with specific requirements for safe conductor splices. Modern standards require wire clamps where conductors exit the receptacle box.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00024.jpg]4170The right way to flash at the drip edge
<FONT SIZE="+2">The intersection of a roof line and vertical wall is very high risk for water intrusion, yet I see the flashing detail done wrong a lot, even new construction.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00025.jpg]4080Clue is: Condensing Furnace
<FONT SIZE="+2">This is a condensate pump, high efficiency furnaces generate condensate (water) that is very acidic and needs to be pumped to a sewer drain that is plastic.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00026.jpg]3890This house won't run out of hot water
<FONT SIZE="+2">This is two "On Demand" also called "Tankless" water heaters plumbed in series so if one can't handle demand the other fires up.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00028.jpg]3860Clue: Boiler for heating water
T<FONT SIZE="+2">his is a electronically controlled damper that rotates a door in the combustion exhaust flue that moderates airflow across the burner for combustion efficiency.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00029.jpg]3710R2D2?
<FONT SIZE="+2">This is a late model whole house vacuum system.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00030.jpg]3730Earthquake country?
<FONT SIZE="+2">Here in the northwest we are in
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00031.jpg]3640Professionally installed crawl space insulation
<FONT SIZE="+2">This is a shot of galvanized heating ducts very nicely insulated and wraped (white) and perfectly installed insulation in the joist bays. Don't see that every day!
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00032.jpg]3600Crawl space view of supply plumbing
<FONT SIZE="+2"> Wanted to post this because its nice to see someone do a good job of insulating water lines. Looks like the tape is coming off a bit but still nice work.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00033.jpg]3530Metal boxes on the closet wall
<FONT SIZE="+2">There are two different electrical components at top and bottom of the receptacle box. One is the step transformers for converting 120VAC to 24VDC and the grey rectangles are relays that switch on the AC voltage for the baseboards based on commands from the low voltage thermostat. Some baseboard thermostats control their supply voltage at the thermostat and some control it by low voltage thermostat that sends signals to relays as in this case.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00035.jpg]3570Electrical Service Panel
<FONT SIZE="+2">Obvious that we are looking at circuit breakers but a lot of people aren't familiar with the ones with the blue buttons. They are Arc Fault circuit breakers intended to detected electrical arcs (fire hazards), presently only required in bedrooms. The blue buttons are test buttons.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00036.jpg]3590Vented hole in garage wall
<FONT SIZE="+2">Depending on the age of your house, you may see vents in your exterior wall if you have combustion appliances. These are for air vents for supply of combustion air to the combustion appliance. Without these vents your appliance could have problems such as back drafting combustion gases into the garage or living space.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00037.jpg]3580Sheet metal ducts in attic space
<FONT SIZE="+2">The center vent is known as a B-vent which is venting both a furnace and water heater. The sheet metal shroud around the base is to ensure the one inch clearance from combustibles (insulation or wood) The reason I posted this image is I rarely see such nice sheetmetal work that ensures the clearance is always maintained. Kudos to whoever did the work.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00038.jpg]3630A capped pipe exiting a roof
<FONT SIZE="+2">Some times interior drain waste and vent lines DWV are decommisioned. When that happens it ok to just cap the vent, as in this case. Side note the metal flashing around the vent is made of lead, today it would be galvanized sheet metal.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00039.jpg]4540Two plastic ABS pipes exiting a roofline
<FONT SIZE="+2">These are the supply air and combustion air vent for a high efficiency furnace. The furnace captures enough of the heat of combustion so only plastic vent is needed.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00040.jpg]3640Clue: this located near the side of a house which is at the base of a small hill
<FONT SIZE="+2">The leaves are covering a plastic sealed "basin" or well as some call it. So is it a sump pump or a sewage ejection pump? Clue is "sealed" basin. Sump pumps usually aren't sealed basins but sewege ejection pump are always sealed. This one moved the house waste to a municipal sewer line that was up hill from the house.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00041.jpg]3390Clue: Earthquake country
<FONT SIZE="+2">This is a sill plate seismic bracket that is securing the house (wood sill) to the concrete foundation.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00043.jpg]3460Brown mechanical connected to the hot water line
<FONT SIZE="+2">This is a circulation pump to reduce the wait time for hot water at faucets. The dial on the end of it is a timer so you can set it to run when you are likely to use hot water not 24 hours.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00045.jpg]3430From a cabin on Lummi Island
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[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00047.jpg]3440Clue is: woodstove
<FONT SIZE="+2">Current building standards require that a freestanding wood stove be "decoupled" combustion air from outside living space known as a combustion device. This is a vent in the crawl space that supplies air to the wood stove above.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00048.jpg]3430Old school plumbing?
<FONT SIZE="+2">Not really, flow is actually controlled by the hot and cold handles at the base.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00049.jpg]3250Hand rails for big people and little people.
<FONT SIZE="+2">Interesting idea, notice the baby gate at the top of the stairs.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00050.jpg]3230Shiny chrome box on the wall next to the bath sink
<FONT SIZE="+2">next picture for the answer
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00051.jpg]3350glass and toothbrush holder
<FONT SIZE="+2">Obviously not used anymore but it has an interesting retro appeal.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00052.jpg]3370Metal rods extending across the ceiling?
<FONT SIZE="+2">These threaded rods and adjustable turnbuckles are functioning as ceiling joists, resisting the outward forces exerted on the walls by the roof rafters. Sometimes these are installed more midspan of the roof rafters and then they are technically collar ties.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00053.jpg]3250Turnbuckle for adjusting the tension of the threaded rod
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[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00054.jpg]3210Sheetmetal pan around the dryer?
<FONT SIZE="+2"> Not for water leaks! Clue is: this is a propane dryer. Propane has special capture and venting requirements because it's heavier than air and a leak could accumulate at floor level. Next image is related.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00055.jpg]3270This is the back corner of the previous image of a dryer pan.
<FONT SIZE="+2"> The hole is a vent for any leaking propane to vent to the exterior. See the next image of the vent discharge at the side of the house. Disregard the white bucket full of water, that was a separete issue.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00056.jpg]3240Screened propane vent.
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[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00057.jpg]3270Horizontal vent out of a gable wall
<FONT SIZE="+2">This is Z-Vent stainless steel vent pipe which is designed for use with boilers, high efficiency gas and oil heaters and water heaters where cool flue gases are vented under pressure. Intended to withstanding the harmful effects of corrosive condensates created<br />by partially or fully condensing high-efficiency natural gas and propane-fired heating appliances.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00062.jpg]3140Bathroom slider hardware
<FONT SIZE="+2"> Window lock on a 1950's house. See the next image to see how it works
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00063.jpg]3080Old school window lock
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00064.jpg]3140Under the utility sink plumbing
<FONT SIZE="+2">This is called a "drum" trap, which is an early drain trap design replaced by the modern P-trap that you should under your sink.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00065.jpg]3010Shiny brass thing connected to the copper water supply line
<FONT SIZE="+2">This a a p-trap primer, its function is to keep rarely used plumbing p-traps from drying out. P-traps are designed to have water in them all the time to keep sewer gases out. The primer keeps the trap full of water.
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00066.jpg]3210Labyrinth of plumbing
<FONT SIZE="+2">Admittedly there is a lot going on in this image. The question is; what is the rectangular box looking thing in the middle of the picture? It is a heat exchanger used in an "indirect heating system" which uses a high efficiency water heater for both space heating and domestic hot water needs while keeping the two systems separete through the heat exchanger. Curious about how it works? <br />Search term: radiant indirect heating system
[img src=https://www.insidenout.net/wp-content/flagallery/what-is-it/thumbs/thumbs_image00067.jpg]3200Red box on the house side of the gas meter
<FONT SIZE="+2">This is a earthquake shut off valve called a Northridge Valve. During a seismic disturbance of approximately 5.0 or greater on the Richter scale, the stainless steel ball falls from a pedestal and plugs the outlet stopping the flow of gas. The gas can only be turned back ON by manually resetting the valve.