Mechanical – Custom Riverhouse Construction Blog

Hot Water Temperature Regulator

The hot water to the tub was not hot enough. So, we cranked up the temperature on the water heater, but it didn’t seem to help. The water at the sink was unquestionably hotter than at the tub, which was nearby. Finally, we found this temperature regulator under the sink which controlled the hot water to the tub. It has an adjustment valve that allows you to change the blend and turn up the heat. Problem solved.

Here’s the description from the manufacturer’s website

“How They Work
Upon use of tempered water, a thermostat in the mixing chamber of the valve senses the outlet temperature. The thermostat automatically positions a seat assembly which controls the flow of hot and cold water supplied to the mixing chamber. If the mixed outlet temperature increases, the thermostat will expand moving the seat assembly to allow the cold water inlet port to open more fully and at the same time restricting the hot water inlet port. Conversely, if the mixed outlet temperature decreases, the thermostat will contract moving the seat assembly to allow the hot water inlet port to open more fully and at the same time restricting the cold water inlet port. In both cases the mixed outlet water temperature is automatically and continually maintained at the preset temperature within the tolerances of the valve. In the event of a cold or hot water supply failure, the seat assembly moves to an extreme position shutting off the hot or cold inlet water port. A mechanical adjustment permits selection of the desired outlet water temperature within range of the valve.” www.watts.com

Endless Hot Water – The Tankless Option

We chose a Rinnai tankless water heater with a recirculation pump, instead of a traditional water heater. I think the recirculation pump is the “coolest” feature of all, and I’ll describe it later. The unit is natural gas fired, and mounted on an exterior wall in the garage. Our Model is a Rinnai RUR98.

Here is a picture of the unit installed. As you can see it vents directly outside, so there is no need for a separate through-the-roof exhaust vent. And its easily accessible from the outside, in case of repairs or adjustments.

The heater comes with an external digital controller, shown here, which sits inside the garage on top of the metal case which encloses the water heater. Apparently, there is an option to add a wireless controller, which we have not yet done.

One of the best features is the recirculation pump, which is built into the unit. Since, this house was a new build, our plumber installed a hot water recirculation loop which runs to each bath and sink. That way, when the reciculation cycle is on at the heater, you have nearly instant hot water, similar to what you find at nice hotels.

The controller has a setting where you can configure the daily time for the recirculation pump to run, typically in the morning and at night. Or, you can just manually turn it on from the controller. When the unit is recirculating, it is clear that the heater is firing, so you do pay an energy demand price for the instant hot water.

We are still playing with it all. I am not yet sure of the energy use, especially with the recirculation pump running.

Cast Iron Claw Foot Tub

Clawfoot tub in its native habitat (e.g. discarded in a field).

About the time the foundation was being poured, we made a visit to the Clawfoot Tub Doctor, located near Brenham, Texas to see about purchasing an old cast iron tub. Mike, the owner (and resident tub doctor), showed us the inventory scattered through his field. We selected a 5 footer, which had an old nickel fixture, and made a deal with Mike to refinish it all. He worked more quickly than we did and the tub was ready in about a month, with new white enamel and a working fixture.

With Mike’s help we loaded the tub onto the bed of our F-150, with his forklift. We then drove it back to the house, where I had a couple of burly guys waiting to help us unload. I would guess the tub weighted about 200 – 250 pounds, and could be managed by two strong fellows.

My wife decided to remove the antique claw feet, and our carpenters prepared a wood cradle from some scrap wood from another project. It’s not yet installed — I will post another picture when were are finally done.

Made in the USA
Standard Sanitary Mfg. Co. Louisville
Manufacture Date 2-25-1927

Made in the good old USA and, yes, it really is “old” — 1927.

Electric Service Challenges

There is a temporary electric meter set by our utility provider for construction, but getting the permanent power was more of a challenge than we expected. The old house had the electric meter on the front of the house, which was less than 100 feet to the transformer on a nearby telephone pole. We designed the new house with the meter at the back of the garage, to keep it out of sight and we planned to put the electric line underground for safety and aesthetics.

Old Transformer (background) and Pole to be replaced

Well it turned out that we should have consulted our electric provider earlier in the process. Running the power to the garage was a longer distance than the utility preferred, due to line resistance and potential power “sag”. The extra distance was about 70 feet or so, which on its face does not seem like much. While I never got a clear answer on the maximum distance the meter should be from the transformer, it seems like anything over about 150 feet poses potential problems. The distance is a function of a number of variables including, size of the transformer, size/resistance of the service line, and customer power demand.

Also, running the service line underground required the utility company to replace a telephone pole on the corner of our yard, so that all the utilities (including cable/internet) could be properly dropped down the side of the pole. Time for the new pole and transformer upgrades were 6 – 8 weeks, given the utility’s heavy work schedule. Also, trenching for the new conduit had to be carefully planned to avoid running too close to an existing large pecan tree.

So, all of that caused us to have to re-juggle our schedule for landscaping and related work on the site.

Now we are just awaiting our utility to come and pull the wires through the new underground conduit.

Frost Free Hose Bibs

Protecting outside water hose bibs from freezing is not one of my favorite tasks. Since this is a second home, I was interested in a way to avoid wrapping pipes or dripping water, especially since a cold snap can occur unexpectedly in the Winter.

We found these frost free hose bibs, which are more commonly used up north. The key is the actual water cut-off valve is located at the end of a six inch shaft. When mounted, the cut off is located inside the insulated wall, rather than exposed to the cold weather.

So, when cut off, the water is not exposed to the cold, and any remaining water in the faucet shaft just drains out. A great solution to freeze problems.

Air Conditioning and Duct Work Challenges

Here is a cautionary note, if you are building a two story house. Plan ahead for the location of the A/C heating duct work, in the framing for the second floor.

In our case, the duct work details were not part of the architect’s plans, and it seems the normal process is to work the details out after framing is complete. That works if you have a house with a large attic, but here we had only about 18 inches of space in the joists to run first floor duct work. That led to some changes and compromises in our final layout.

Here’s the story. We planned to put the downstairs air handler in a closet in the garage, since we ran out of interior space in the house. While it struck me, the owner, as a strange location, it was the best to maximize the interior space in the house. But, after framing the house, we had a walk through with the A/C subcontractor, and he immediately made it clear that the garage location was a non-starter. It would not provide needed access to return air and the duct work exiting the plenum did not work with the framing. So, we lost a hall closet, and had to encroach about a foot into the master shower for the air handler.

But, a bigger concern was where to locate the duct work to serve the first floor rooms? Obviously, the duct work needed to run in or under the second floor joists. But, as you can see from this picture the joists are so tightly spaced there was not room for the main duct between them. Lowering the hall ceiling was aesthetically not an option. We debated demoing/moving one joist, to create extra space, but that posed structural and cost issues. We also have a triple glulam beam that runs the length of the house, and presented a barrier to duct work crossing from one side to the other.

Ultimately, our builder found a nice solution.

Duct work running under the orange Glulam Triple

The main duct would cross under the glulam triple in the master shower, and we would lower the shower ceiling about 15 inches. We also lost about 12 inches in the ceiling of the master closet, where another run of duct work crossed under the triple, the orange beam shown in this picture. This fix was much better than exposed duct work, or lowering the ceiling in the main hallway. But, the take-away is to plan ahead, especially for the major mechanical features of a new home.