Friends and clients keep asking me if it is really hard and costly to retrofit a non-energy efficient home. My answer is, “It’s very easy,” and, “What is your budget?”
You don’t have to buy a Platinum-designated LEED home to save energy.
There are a wide array of options, but for the purpose of this blog, I’m going to keep the cost of these retrofits low and focus on a casual energy audit on a home in South Kihei. The following is a brief summary of my recommendations:
- Take advantage of tax credits and replace your electric water heater with a solar water heater.
- Replace appliances with energy star-rated appliances.
- Install awnings over (or otherwise shield) South-facing windows.
- Replace all incandescent light bulbs with CFL light bulbs.
- Service and clean the central air conditioning system.
Subject Property, listed at $465,000, was on the market at the time of my inspection but has gone into escrow as of today.
Built in 2003, subject property was constructed with wood siding on the exterior and drywall on the interior, has two levels and, at 1688 sq ft, consists of 2 bedrooms upstairs, a master suite and bath downstairs, a powder room, a living/dining/kitchen area, an inside laundry, and an attached direct access garage. It was determined that the home has insulation in the walls and ceiling. The front door faces North and rear of house faces South. All windows and sliding doors are single-paned glass.
The home has not been remodeled but is in average to good condition. The central air condenser appears to be in need of servicing. Informal testing of insulation, lighting, appliances were done and I determined improvement for the following areas:
Electric water heaters consume 40% of your electricity bill. There are federal and state tax credits to replace your electric water heater with a solar water heater. With these credits and rebates, the payback for a system is approximately 2 years with the amount of energy saved. The cost of an 80 gallon system (without credits) is approximately $3500-$4000.
Electric water heaters are responsible for 40% of your electricity bill
It was observed that all appliances in the kitchen were original to the house (approx 8 years). Normal life expectancy is approximately 10 years. My recommendation would be to replace the appliance as needed to energy star-rated models. The washer and dryer are newer Whirlpool Cabrio top loading. These are very energy efficient and $$$. Fun fact: There is no such thing as an energy star rated electric dryer…they are all energy hogs. My recommendation with respect to the dryer would be to use sparingly to fluff dry then hang on a clothes line for complete drying.
Since the rear of the house faces South (where the sun sets), the home gets pretty warm at the end of the day. The good new is that only one bedroom window was affected and a sliding door on the bottom floor (see below). My recommendation to stop the sun radiating through the single paned windows would be to build an overhang over the paved patio as well as fence or hedge in the space. The sun would not hit the window any more and would not be absorbed by the concrete pad. I would recommend installing an awning over the bedroom window. That should take care of most of the solar heat issues.
Open rear patio allows radiant solar heat through sliding glass door, and thermal mass absorption on concrete pad
Here is the lowest of hanging fruit of which to take advantage. Incandescent lighting not only adds to your energy bill, it adds to the temperature of the house…as in this case. There were a total of 6 ceiling fans throughout the house with 4 bulbs in each fan. There were 3 fans with 4 bulbs at 75 watts each (280 watts per fan) and 3 fans with 4 bulbs at 60 watts each (240 watts per fan) of additional heat. Can you imagine how hot it got upstairs? There were approx 19 recessed lights with 75 and 60 watt bulbs.
All in all, I would advise to replace 50 bulbs with comparable CFL bulbs. Assuming every light was on for 4 hours per day, the homeowners savings would be just under $830/year. We never have all of our lights on at the same time, so the actual savings would be less. But dang, it adds up. See the lighting calculator at the end of the blog.
60 watts/bulb….Is 240 watts/fixture too much light and way too much heat? I think so.
I would suggest to have the unit serviced and cleaned. Problems arise when units are not serviced regularly.
Those would be the immediate, most cost-effective retrofit suggestions. Yet there are additional suggestions for the house as budget permits:
1 ) Replace dark gray roof with lighter color when re-roofing the home. That reduces the amount of solar heat radiation absorbed through the attic into the house.
2 ) Photovoltaic system would be recommended once homeowner has brought down their energy consumption. PV panels are expensive to install if you don’t bring your energy usage down.
3 ) LED lighting for exterior landscaping.
4 ) Solar powered attic fan would help in the heat transfer from roof to attic.
5 ) Landscape with more drought tolerant plants and hardscape instead of grass.
I know it sounds like a lot, but it is all worth it in the end.Â I’ve reduced my electric bill to $75/month by installing a new solar water heating system. You can use the money you save with these retrofits to buy your retirement home!
Peace – Out
|SIR Equation = -PV(%,n,Saving/Year) Ã· Cost|
|CFL lifespan about 6,000 – 10,000Â hours.|
|SIR Calculator||Average Economic Life||Savings/yr||Total Cost||Measure SIR (savings/investment ratio)||Profit after Payback||Simple Payback (years)||Hours usage/day||Economic life for 6000 hr lifespan (yrs)||Economic life for 10000 hr lifespan (yrs)|
|reduce by about 50% if switched a lot|
|CFL Replacement Savings Calculator|
|Existing Wattage||# of bulbs||Usage (hr/day)||CFL Repl. Bulb Wattage||Cost per bulb: Replacement||Replacement cost||Energy $avings/yr||Savings/yr (kWh)||Bulb Economic Life (yrs)||SIR = PV of savings/cost||Simple Payback = cost/savings (yrs)|
|Replacement Wattage Chart||CFL Prices (by type)|
|Incandescent||CFL (high)||CFL (low)||Standard CFLs (all wattages)||4|