How much could be saved in retrofits that blanketed a large group of homes with simple measures collected detailed audit information and then came back to custom retrofit the homes in detail?
Sponsored by the U.S. Department of Energy within the Building America program, a Phased Deep Retrofit (PDR) Project is attempting to answer that question. A total of 60 all-electric homes in Florida are being monitored in great detail: all end uses (even TVs!), temperatures and humidity. All of these are being retrofit with a variety of "shallow" measures such as more efficient lighting, tank wraps and pipe insulation, replacement shower-heads and smart power strips.
However, a sub-sample of approximately ten homes will have much more extensive retrofits installed, beginning this summer. In these homes, we anticipate installing Heat Pump Water Heaters (HPWH), advanced air conditioners, better insulation, smart thermostats and other advanced technologies. By evaluating energy use, pre and post retrofit, we should obtain sufficient information to gauge package savings under realistic operating conditions.
Choosing appropriate Energy-Star appliances for the Deep Retrofit group is essential to the success of our project. We are looking for industry partners for the project who may have innovative products which could receive real-world testing.
We anticipate replacing refrigerators, dishwashers, clothes washers and dryers in most of the ten homes with the deep retrofits being installed. We are collecting data on the energy use of each appliance already in the project before retrofit and thus industry partners will have the opportunity to learn from results.
In a follow-on portion of the project in the second year, we plan to install latest cutting edge technologies singly in the homes that have received shallow retrofits. This may include any newly available appliances such as heat pump clothes dryers. The Deep Retrofit homes may receive additional measures: replacement windows, wall insulation and zoned mini-split cooling systems.
You can see the daily monitoring data being collected in the project at this website or graphically illustrated in the graphic below my email.
I also attach a PDF summary description of the project in greater detail. Interested in comments and/or suggestions.
Sample of graphic summary data from yesterday shown below:
That's an interesting study, and it parallels some of our own work.
We perform energy audits and retrofits to varying depths in the Jacksonville area. Our basic premise is that our deep retrofits can cut 50% off the energy bill of a typical production house as young as 8 or so years old - almost any house built before SEER 13 became code minimum.
To hit that number, or get close to it we generally start with a deep audit, looking at the envelope, HVAC, (including ductwork) water heating, cooking, lighting, pool pumping, refrigeration, and media.
A deep retrofit nearly always includes sprayfoam insulation since getting ductwork out of the attic is rarely feasible. We QC the foam with a blower door and fog (theatrical smoke). Done properly, the foam generally cuts HVAC load by 20-40%. We then come in with a right sized two stage heat pump and proper ductwork. Many clients select zoning, up to 4 zones, and we commission the system room-by-room, setting dampers to deliver the airflow called for in the room-by-room manual J.
We rarely install new windows but often deploy low SHGC film at least on west glazing.
We nearly always install either a heat pump water heater and / or a desuperheater coupled with its own preheat storage tank. Choice here is dictated by HVAC operating habits and number of members of household.
We use a Kill-a-Watt to highlight refrigeration, media, and miscellaneous plug load energy use. Sometimes we clock water heater elements to refine payback for more efficient water heating options.
We push front load clothes washers and emphasize the need to be sure clothes dryer takes no more than 30-40 minutes per load...if longer something is wrong.
We support two stage pool pumps but prefer true variables, able to be tuned for individual pools. We have documented savings of 90% using a variable speed pool pump.
We also perform DuctBlaster tests and sometimes deploy multichannel TED (The Energy Detective) systems for longer term monitoring.
We advise on how to select high-efficiency lighting, informing about color temperature and Color Rendering Index, dimmability, etc.
I recently added a discussion of cooking appliances to our audit reports, going over efficiency, speed and control of everthying from gas to induction.
A deep retrofit is obviously no small undertaking, and we are careful to provide accurate likely ROI. We do also emphasize non-quantifiable issues such as improved comfort that follows a tighter envelope, better humidity control, quieter operation, etc.
Greener Solutions Air
Curt- We are in St. Augustine and are in the process of a renewable energy grant study that was funded through the Florida Energy Office .We will have the data monitoring system up and running soon, and we did a variety of retrofits on an affordable housing Energy Star subdivision that our company built over the last few years. I've attached the report on the initiative. We'll update reports quarterly, once we figure out a few other details.
Some of the houses have a high energy use for dryers when compared to the water heater (house #33) and others are just the opposite -- large water heater load for low dryer (#19). Have you broken out which houses use solar hot water and perhaps use a clothes line for drying? Will you be picking up occupant behavior if they hang clothes outside?
I am also intrigued by the nearly equal dryer and pool pump loads on the pie chart. Will you be doing some kind of assessment for the pools, size, piping, filters and current installed pumps?
Dishwashers - when you change them out -- are you going to use the same brand or try a mixture? Single drawer or two drawer?
Does the light load include exterior landscaping?
Houses with very high clothes dryer usage may have problems with dryer exhaust air flow (lint clogs). They may also wash clothes only with cold water, which would help reduce water heating energy compared to dryer energy.
Houses with inordinate water heating usage may have a leak in hot water piping.
Comparing dryer to pool pump consumption isn't very interesting since clothes dryers occur much more frequently than pool pumps.
I DO find interesting the fact that the orange "lights and other" demand profile is relatively constant. That suggests many homes have fairly high vampire or phantom loads...things that burn power while not on / in use.
I wonder what is meant by "spares"?
Homes with high dryer use wash a lot of loads of laundry. You can examine each site to see this at the website. All sites were examined and on audit, any with clogged dryer vents were cleared or avoided for monitoring (danger of dyer fires). What you see is the real variation in clothes dryer energy use-- seen in other studies, most notably that describe by Cadmus at the last ACEEE summer study.
Note that you can examine/download 24-hr data for each individual site seen in the bar chart.
About 30% of homes have pool pumps and the numbers you see here reflect their saturation. About 10 kWh per day in home that have pools-- 2nd largest annual end use! This is typical as we know from previous studies. Pool pumping is a major energy end use.
Generally home with a lot of hot water use comes in households with lots of people and those doing hot water clothes wash.
Spares are 2nd window air conditioners, freezers, home officers (frequent), wine coolers etc. They are described by site in the "Detailed Site Characteristics" tab under the pictures.
Thanks for the background info - good to hear that any clogged dryer vents were cleared. I had trouble seeing information for all houses, instead only three...perhaps a browser issue. I see more this AM.
Have you by chance correlated / seen any correlation between type of clothes washer and drying energy? Front load washers, if used optimally, do a much better job mechanically removing water from clothes, in turn greatly reducing drying energy. I gathered some data correlating kWh used per pound of moisture removed from clothes for varying combinations load size and dryer cycle selection.
You have confirmed my data that pool pumps, if present, often use so much energy that they displace water heating as second largest home energy use. Will some of your deep retrofits include variable speed pool pumps? I'd be willing to bet swapping a single speed pool pump for a properly configured variable speed pool pump will deliver much more savings at similar cost to changing out a fridge and dishwasher.
A heat pump water heater is a no-brainer for any Florida household of 2-4 with a garage water heater. My only reservation is the limited number of 80 gallon models available - one model widely sold under a half dozen major brand names we found to be too noisy to risk likely client dissatisfaction. GE's 50 gallon model is very quiet, but too small for larger families without resorting to EF-killing resistance heat settings.
This is a great study - I wish I were involved in something similar near Jax. Way too many energy audits, no matter how well done, get shelved with little or no action taken. people need to learn / know what works and overcome fear of incurring cost without good result
Why in the world would anybody in their right mind do a deep retrofit when the renowned economist Robert Shiller says they're not worth doing? To waste the U.S. government's money, and therefore the U.S. taxpayer's hard earned due. Please explain how this travesty is happening, and just whose pockets are being lined?
I can think of multiple cases that would fail Robert Shillers example.
1) The owners like the property and intend to stay a there a long time. The house is old and uncomfortable so they want to fix it.
2) They place a value on environment or some other intangible item (#1 above) that makes it worth while to do a deep retrofit.
3) Perhaps the cost of the retrofit isn't as high as expected.
4) The retrofits are done in an opportunistic manner -- carefully staged, planned and cost controlled. Not a "quick gut, rehab, rebuild"
In the US 80%-90% of the homes are old stock. We can either rip them down and start over, or we can figure better ways to tighten them up and make them more efficient possible with as little cost as possible.
While you may find it a travesty -- I am waiting to read the reports and lessons learned. I am doing a deep retrofit on my home at my expense -- and I use the studies that are done through the Building America program to plan my changes.
DH: thank you! t