HVAC

Ghosts in the Basement

My wife usually goes to bed before I do. Like a sensible person, when she gets tired, she goes to bed. I prefer to fall asleep on the couch pretending to watch TV. This results in me finally showering and coming to bed after Yolanda has gone to sleep. Last night, when I got out of the shower i was greeted by four of the scariest words most married men can hear, “What was that noise?”

Turns out, that as I was getting ready to bed, and frequently running water, my wife kept hearing a strange sound from under our house. It sounded somewhere between a beep and a moan. After some experimenting, we realized the sound happened each time I turned off a hot water faucet. Since we’d just installed the new tankless hot water heater we had a likely suspect for the noise (that or the ghost of my crazy Aunt Flora).

Today I inspected the tankless again. I heard the noise faintly when I was standing in front of the unit but it was much louder upstairs. I called Noritz customer support and described the problem. The technician I spoke to immediately knew what it was. I never know in these situations to be happy or annoyed. I’m happy that someone knows what my problem is and confirms I’m not crazy. But I’m also annoyed because, if it is a known problem, why haven’t they done something about it?

In the Noritz tankless water heat we purchased, the NRC111, there are tiny servo-valves that cycle through a self-check each time the system shuts down after use. Normally that noise is unobtrusive. However, in some house, especially when in a basement or crawlspace, the vibration is communicated through pipes or structural members in the house and amplified. They suggested two mitigations; installing rubber gaskets between the unit and the mountings and installing flexible hose fittings between the copper supply lines and the unit.

I called the plumber at Bonney Plumbing and explained the problem and they agreed to do the mitigation when they come out to install the hydronics system.So two more items I’m also hopeful that when they spray the new insulating foam in our crawl space that the foam will absorb most of the sound.

So far, here’s the checklist,

1. Place a “T” fitting on the outlet of the exhaust pipe
2) Insulate the new hot water lines
3) The electrical box for the tankless system is missing a wall plate.
4) The exhaust vent on the outside of the house should have a gasket or seal.
5) Rubber gaskets under the tankless water heater mounts
6) Flexible hoses connecting the tankless heater to the water lines

Going Tankless Part 2 - The checklist begins

The plumber finished the installation of the tankless water heater today. The first surprise for me, is how quiet it is. I had some limited experience with tankless water heaters when I lived in Latin America, where they are common. I have distinct memories of hearing the roar as the water heater fired up when I started a shower.

When Andrew, the plumber, called me in to say we had hot water I followed him into the crawl space where the new water heater was installed. From the entrance I could not hear anything. I asked Andrew if the system was running and he assured me it was. I could not hear it until i was standing right in front of it.
tankless
Our new tankless water heater

Having read recently a number of anecdotes from tankless users about problems they had with the system shutting off in the middle of their showers due to insufficient water flow, the first thing I did was tour the house and turning on faucets one by one. It may be my imagination but it feels to me that the water pressure is lower in a couple of rooms. Bt the water temperature is perfect. I ran the shower in the master bath for 15 min. without any problems.



The previous owners of our home had installed a pre-circulation pump on a timer. This pump circulated hot water through the pipes in the house at key times so that when we turned on a faucet we got instant hot water. I had wondered at the additional expense. With the new system I see why. We have to run a lot of cold water out of the faucet before the hot water arrives. We can see this will drive our water usage way up and its painful in drought-plagued California to see all that water going down the drain. We’re going to need a solution for this problem.

Andrew and I walked around and inspected the job. We agreed their were a handful of things that yet to be done. Andrew promised he’d finish them up when he comes back to plumb in the hydronics. I borrowed a best practice from my software project management days and started a checklist. This will be a running list of pending items to be done before we’ll sign-off on the project (and before we’ll cut that final check.)

So far, here’s the checklist,

1. Place a “T” fitting on the outlet of the exhaust pipe
2) Insulate the new hot water lines
3) The electrical box for the tankless system is missing a wall plate.
4) The exhaust vent on the outside of the house should have a gasket or seal.



Change of Plans - Again

The revised timeline called for installation of the new hydronic heating and AC systems to begin today in parallel with day two of the tankless water heater. But our day began with a phone call from our salesman. According to him, our new air exchanger is a top of the line system that the manufacturer, Rheem, only produces in limited runs based on actual orders. Consequently, our air exchanger will not be ready for at least 3 weeks. This is not the end of the world but we have to ask why the folks at Bonney are just finding this out the morning installation is to begin. Their new plan, designed with the best of intentions, was to install a lower grade unit temporarily today and then return in three weeks time to remove that unit and install the higher grade system.
But we’re not actually in a big hurry and it seems a waste of time and money for the folks at Bonney. So we suggested they simply delay the installation until the correct unit is ready. So, the new new plan is for the installation to take place sometime in the first week of August. Here’s crossing our fingers. If things continue to be delayed we’ll make it to autumn and won’t need the new AC until next year. Happy



The Work Begins - Going Tankless


Today the project stared in earnest with the replacement of our standard hot water heater with a tankless water heater. The day began with a lot of decisions. Bonney Plumbing’s guy arrived around 9:00 a.m.. They had not seen our home before nor seemed briefed on the situation other than that the tankless water heater would form a part of a large project that included a hydronic heating system. I showed them around and we began to discussed installation options. It quickly became apparent that , while this might not be their first tankless system, it was their first installation of this model and so job one for them, read the installation manual. I pulled up the installation manual on-line so I could participate intelligently.
oldwaterheater

Old Faithful - Our old industrial strength water heater



The first decision was where to install the unit. In particular, should we simply swap the existing hot water tank or co-locate the tankless system with the new heat exchanger on the crawl space under the house. The considerations were, the maximum run allowed between the water heater and the heat exchanger, the exhausting of the system and the distance limits there, the draining of the condensation, the electrical connection and finally ease of access and lighting. We finally decided to co-locate the water heater in the crawlspace with the heating system. You may recall that one of the reasons given for changing to the lower temp, higher efficiency tankless system was that the shorter plumbing run would enable a lower temp system. We decided on a location near some support joists where we could run some two by fours to hang the system on. A previously installed light in that area provided convenient lighting. As a side benefit of this decision we freed up the old hot water heater cabinet for use as a closet in my home office.

With that decision made, we needed to decide; where to run the exhaust duct. It need to run to an outside wall, could be a maximum of 39 ft. (assuming there was only one elbow), and needed a incline back to the tankless unit so that condensation would run back into the system for collection rather than outside. We decided to vent behind the house under out raised deck. Electrical supply was easily handled by connecting to the circuit powering our Jacuzzi power jests in our master bath tub.

With these decisions made, Bonney’s guys got to work. I was hopeful the installation could be completed in one day. But as the afternoon wained I saw this would not happen. The guys called it quits when they realized they did not have the gas fittings required to finish the job. Fortunately, they’d had the foresight to leave the existing system intact and their plumber promised me we’d have hot water that night from our old system.

That evening Yolanda arrived for the dreaded wife inspection. She was less than happy with the location because the footing in that area is loose dirt and sharply sloped. Also, the light for that are does not come on with the wall switch by the entrance. One must cross in semi-darkness to that are to turn on the light for that area. She pictured late night emergency visits to the tankless water heater and was concerned that poor lighting and poor footing had the potential to make a hot water problem into a trip to the hospital if someone tripped in the dark. I see a small project in my future leveling the ground in that area, putting in some concrete pavers and potentially improving the lighting situation.

Next Yolanda and I discussed the placement of the exhaust. Yolanda pointed out that the exhaust would be directed straight into our poolside patio area. Which, in those 100 deg. days here, is the only cool outdoor place to relax. Hot smelly exhaust might not be the best addition. I promised to discuss moving the duct to the other side of the house with the installers.
Final note, turns out that, despite the best of intentions, something happened to the old hot water heater yesterday. Yolanda noticed the water was not as warm as usual when she took her evening shower. My showers follow hers and by then the residual hot water was gone. No hot water tonight! Lets hope the new system is up and running before tomorrow night.


What the heck is "Hydronic" heating?

We told our HVAC company we were open to (even likely to favor) innovative ideas. The center piece of their solution was Hydronic heating. That, of course, had us googling like crazy people. A quick google search on Hydronic heating yields lots and lots of information.......about “hydronic radiant heating.” Hydronic radiant heating circulates warm water through small pipes or tubes in the walls or floors of a house. The resulting warmth “radiates” into the room. It's a great system for some applications but we realized quickly it made no sense for us. The time to put those little tubes in the floor and ceiling is when you build the house. You can put them in as a retrofit but it means tearing up a lot of the house and that wasn’t what we had in mind.

A few clarifying emails to our HVAC friends quickly confirmed that Radiant Hydronics was not what they had in mind. They were instead proposing a forced air solution using a hydronic heat exchanger. It turns out, this is not such a new solution. Most commercial heating systems are based on this idea i.e. a boiler and forced air. You’d think there would be lots of information on this subject as well. Turns out that is not the case. There is almost no information on this kind of system, how it works, how efficient it is, when to use this vs. a standard heat exchanger. So, check out our Hydronic HVAC page to see the explanation we’ve put together.

The Proposal (s)

The HVAC company came back to us with a Chinese menu of options organized into three scenarios.
Scenario 1 - Basic HVAC Upgrade
AC sizing
Thermostat
A Hydronic Heating and AC System

Scenario 2 - Energy Upgrade
Everything in scenario 1
Per room airflow calculations
Duct sizing
Duct Repair and Resizing
Replace Attic Insulation with Foam insulation
Heat Recovery Ventilator

Scenario 3 - The Rock Star Upgrade
Everything in Scenario 2
Zone Balancing
New Duct Work
Foam Insulation of the Crawl Space Below the House
High Performance Registers
Web Linked Programmable Thermostat
Condensing Tankless Gas Water Heater / Boiler

Naturally, we liked scenario 3 but scenario 2 was closer to our budget. Now we needed to understand better the systems being proposed and the tradeoffs between them so we could decide on a scenario that best worked for us.




The High Performance Home - The Whole House Audit

It started with our furnace going down one cold evening a few weeks ago. I went down in the crawl space and opened her up. The diagnostic lights indicated a problem with the vacuum relief valve. I unhooked the air tube that connects to the VRV and blew through it and then tapped the valve with a screw driver and reassembled everything and wala! Things were auto-magically fixed. While I am happy to bask in my wife's sincere praise for my handinesss, I was suspicious of the fix. Things that easy to fix usually come back at the worst time.
This isn't the first time the unit has gone down and it is getting to be about 20 years old. We decided to call a few HVAC companies for quotes to replace our furnace and AC.  We got a couple of quotes and then we ran into a company whose sales guy, James, said, "Why don't you let us do a free whole house audit?" I like free. So we agreed to have James and his team  audit the energy efficiency of our house.
When they arrived and I watched them unload the gear it reminded me of those movies when the bio-hazard team puts someone's house in lock-down. The "stuff" just kept coming. Finally, the foyer of our house was filled with assorted gizmos and tools and the audit began.
The audit consisted of,
- a visual inspection of the attic and crawl space
- a burn test, in which they  lite a small smoldering flame and  look for drafts
- an infrared camera scan for hot and cold spots
- inspection of the HVAC systems
- inspection of the water heater
- ducting pressure test (we were losing 40% of our HVAC activity to the outside through faulty duct design)
- a blow test in which they seal up the house and put a big fan that pressurizes the entire living space and check for leakages
We knew we didn't have the most efficient home but the audit convinced us we needed to take a more holistic approach to going green. We asked James and the gang to come back to us with a proposal and we emphasized we were open to more innovative solutions. Check in soon to hear about the proposal.

The Backstory

My wife and I purchased a home built in 1992. That's makes it fairly new but old enough that green technology and and the high performance home knowledge have advanced a lot since our home was built. Last year we started getting serious about making our home more energy efficient and more "green."  We found a lot of good general information. But we're both engineers. We need to understand how something works before we invest in it. We've found a real lack of specific information about how do best improve our home.
This blog is about our continuing efforts to improve our home, the challenges, the learnings and the technology. In parallel, we'll be doing a website www.doyourselfgreen.com where we'll post more info, video's of our projects etc. I hope you enjoy the blog and I look forward to your comments.
About the name: FYI I called this site "Do Yourself Green" but its not "Do 
it yourself green". I'm a handier than average guy with more confidence than no how, so I'll tackle a lot of things myself but many of the things we contemplate here are just more than I have time or know-how to tackle. So, don’t be surprise when we bring in the pros.