A tankless heater, then HVAC replacement
We bought our home in August, 2006. The home is an energy hog. Immediately, we noticed several things that just sucked up the energy:
- Skylights with old glass (no IR/UV protection)
- Single pane windows throughout
- Old (ok, ancient) HVAC system
- limited attic insulation
- Old, near end of life 50-gal water heater in an inside closet
To be fair, the house did have two big things going for it which are design things that cannot change:
- The house is situated on the lot and 80% of our windows face north/south.
- We also have two beautiful Live Oak trees on the south side, shading the windows about 80% of the time - minimizing solar heat gain.
These two things are definite plusses, as it’s very hard to move your house. When we first moved in, we bought an energy star Fridge/Freezer. The house had a washer/dryer, so we decided to use that for a bit until we get some other items fixed up first.
The very first thing (besides some interior redecorating) we did was pull out that old water heater. It was about 10 years old. It was also inside the envelope of the conditioned portion of the home - which means it is “negatively” pressurizing the home (pulling outside air through all the cracks in the home to feed it’s gas burner). I understand that negative pressure = bad. The closet it was located in shared the wall to the garage.
We installed a Bosch 250NG tankless heater on the other side of that wall, inside the garage.
This took care of several things: (1) removed this source of negative pressure, (2) removed the passive heat exchange between the tank and the inside conditioned air and (3) gave us another closet - one can never have too much storage! This install is going to save us $80-100/year and the tankless units last a lot longer - so in the long run, this unit is going to save us money every month… and last longer - more than paying for itself over the life of the unit. Economical and environmentally friendly… this is the model that more products need to gain traction and get mass deployment.
Next month, we are getting our HVAC replaced. Our current unit was built in ‘86… so it’s 21 years old. the AC compressor has stuck valves (per the HVAC guy) further decreasing it’s capacity. We are replacing the whole system with a 16-SEER multispeed, dual stage system. We aren’t going for the top of the line systems, as there is a breaking point between capital cost and operating cost - I am not going to pay a ton of money just to save a little energy… these things must make economic sense. During the summer, we are going to save a TON on electric charges with this new, much more efficient unit. For the record, we set our thermostats back (automatically) when we are both at work.
We decided to wait on replacing the skylight glass - and take advantage of the solar gain all winter. In the next couple months, we are going to get the glass replaced in both our units with IR/UV blocking glass from the manufacturer of the skylights. When we first moved in, I climbed up on a ladder to clean the blinds in the skylight… and just about burned my fingers, as it was letting in that much heat. That can’t be good for the AC bill! This is going to cost about $400 for two skylights - that will EASILY pay for itself over the life of the glass (and cut down on sun bleaching of our home’s interior).
After the HVAC is in, I am going to climb in the attic and seal all the rigid duct work myself (rigid duct work is more efficient, as it has less drag internally, but it leaks like crazy - causing a HUGE negative pressure issue - unless you seal the seams) and put on additional duct insulation, then install additional attic insulation.
These two projects are going to also be relatively inexpensive ($600-800 total) and pay back huge dividends ($125-150/year). By removing the negative pressure created by leaky ducts (at just a couple hundred bucks), I suspect this project will pay for itself in the first year - two at max. Again… economical and environmentally friendly.
The windows are something that will take a bit longer, but over the next 2-3 years, we will be replacing the windows. I’ve actually ran simulation programs (RESFEN 5.0) to compare windows in our home. I was really disappointed in the savings for all the marketing hoopla that’s out there (but to be fair, the trees and position of our windows were limiting the savings - if you have more exposed windows, your savings will be greater). Going from single pane to dual pane with argon gas and low-e… we are only going to save about $250-300 per year at a cost of $7-8K. That’s about a window a year. Economics simply don’t work in the favor of window replacement. I was really bummed by this. We have decided to make a conscious decision that the better sound insulation and lower energy usage (from an environmental perspective, NOT an economical one) is worth the upgrade, but we are prioritizing other things first.
That leads us to those “other things”. We are planning to replace out top loader washer with a Bosch front loader. We are also looking at replacing the old, inefficient dishwasher with an Asko highly efficient model. We have done some things that are certainly not what all environmentalists would want - we are installing a larger jacuzzi type tub in the master bath, we have a dedicated 20-amp circuit for a fancy shmancy espresso maker and we have an outdoor jacuzzi. I believe in helping the environment, but I also believe in enjoying life - we just try to limit our impact on it.
All things considered, I think these upgrades will take this environmentally unfriendly house and dramatically lower it’s “carbon footprint” (as that’s the current buzz phrase).
I would certainly entertain grey water catchment systems - but think they may be a bit more economical on new construction, where you could install TWO meters - one going to places you are going to recapture the water/hook to the lawn sprinkler and one for the rest of your water - since the sewage costs are the highest part of your water bill… without removing that, I find it hard to believe that grey-water system could pay for itself.
I would love to install solar or wind or some sort of alternative energy generation solution… but they just aren’t economically practical at this point in time. I’m definitely watching the thin film solar industry with great anticipation. If they can cut the overall initial costs in half… I think we would have something that would be adopted on a massive scale.
on March 8th, 2007 at 11:11 pm
Thought I’d post an update. The hot water heater is working wonderful. I can’t say that I’ve noticed a change in our bill, because we weren’t in the home long enough to know our normal usage patterns.
We just got our HVAC installed. It’s a 16-SEER, dual speed unit. The HVAC company also installed another air return, as they thought the old unit was starving and couldn’t draw enough air in to satisfy the blower motor. We should have more than enough return air supply now!
Next stop: Dishwasher. We’re buying a Bosch unit that will use about half the energy of our current one, along with only using 7 gallons of water per load.
The house is slowly becoming more and more efficient.
on June 25th, 2007 at 3:15 pm
Time for another update!
Last Saturday, we prepared a portion of the attic space for additional insulation. Since the house was built in 1976, a period when energy was cheap and “abundant”, the attic insulation was, well, sub-par. Some areas had 3″ of insulation, some areas had one. The previous owners covered one guest room with some additional R-19 fiberglass batts, but that was about it.
I spent several joyous hours in the attic, repurposing the fiberglass batts to add insulation to the skylight boxes. They had R19 already, but now have two layers (R38). That allowed me to see all the ceiling joists and to prepare some new, elevated walkways.
According to the US Dept of Energy, the North Texas region’s recommended attic insulation levels are R-49. That’s about 15″ of blown in cellulose insulation, which is incidentally mostly recycled paper. Cheap and relatively environmentally friendly (and is treated with a very good fire retardant). A few calculations, a few trips to the home improvement store and our garage is half full of insulation bags.
We spent a few hours blowing insulation in and completed roughly 20% of the attic. Unfortunately, we ran into some issues with the blower (kept shutting itself off). We started at 6am, by 11am, we decided instead of exchanging blowers, with the heat coming on, we would delay finishing the project until next weekend.
So, with a little luck and some hard work, next Saturday morning, we will finish insulating our attic space with a level of R-49.
We are also installing solar screens over our two skylights to reduce the solar heat gain. We will remove them in the winter to take advantage of the free heat.
I hope these updates encourage the readers to take on some home improvement projects of their own or to think about ways to improve the efficiency of your own home and hire a contractor to implement them.
on March 10th, 2008 at 10:13 pm
How much should a 16-SEER unit cost in Dallas? We have two, one that covers 2000 square feet downstairs and one that covers 1100 square feet upstairs.
on March 11th, 2008 at 6:02 pm
We paid $6600 for a unit that covers just shy of 2600 sq ft, but I’ve been told that this was quite cheap by several folks.
While I’m at it, a quick update:
- We finally replaced the dishwasher with a Bosch unit. We got the lowest water AND electric bill ever that month.
We’ve been looking at new washer/dryers, as ours are really on their last leg. I expect this to lower our water and electricity usage a little more, and we also have two more new windows to install. All the windows in our master bath and master bedroom will now be replaced. The new windows are also much quieter than the old ones!
on September 7th, 2009 at 11:15 am
bestdallashvac.combestdallashvac.comHi ,
Thanks for writing such an interesting article. It’s really good to know about the heating and air conditioning in detail. Whether it’s staying warm or keeping cool, every home depends on indoor climate control for comfort. An HVAC contractor is an important aspect of keeping your heating and cooling systems running smoothly. An HVAC contractor installs, maintains and repairs heating, ventilating, and air conditioning systems and related equipment. The right Dallas HVAC contractor is as essential to the success of your system’s function as buying the proper equipment.
It should be a simple task to find a good Dallas HVAC contractor. Yet the simple fact is that a lot of people don’t have any idea what they should be looking for when they need to find a knowledgeable HVAC contractor. You need to find a dependable HVAC contractor that can give you quality installation and dependable follow-up service, whether for a new system or repairs on an existing one.
Thanks,
Sarah Clark
on April 20th, 2010 at 9:33 pm
those galvinized unions and nipples are going to kill that heater. if the house has galvy for distrubution you should have installed a sediment pre filter transitioning to non ferrous piping brass or copper.. Also the gas cock shoild be replace to a full port ball valve .