# Estimating E savings from air sealing in huge leaky house

I'm asked to estimate the heating energy savings from air sealing a 10,000 sf house built in 1900. The former mansion has 6 undampered chimneys and about 40 windows needing repair as well as doors, some needing replacement and all needing weatherstripping. The house has a semi heated basement, and three stories on top of it.

The house has new radiators in all rooms and a 92% efficient boiler.

How do I estimate the potential heating savings from all the air sealing possible here?

George Matthews

Views: 119

### Replies to This Discussion

"A Journey of a Thousand Miles starts with a single step."

Try breaking the house into smaller pieces and working on the "knowns" first.

The most accurate way would be to have a blower door test conducted.  Once you know how much infiltration you have you should be able to determine the total energy waste associated with that air infiltration.

The Retrotec blower door manual has this chart for estimating the energy wasted due to air leakage. This should help you.

David,

Thanks! That is exactly the information I needed to make sense of the blower door data.

Now I need to learn how to estimate the potential energy savings from changing out a 23 y.o. boiler that was 80% efficient when new. The replacement would be a 95% boiler potentially coupled with solar hot water. There are 25 people here who take showers daily.

Also, I've read about heat exchangers to recapture waste heat from the pipes running from showers. "EcoDrain" is one such unit. Does anyone have experience with these? And if so what type of efficiencies are they finding?

George,

If you know the annual fuel heating energy bill you can make an estimate. If you know the cost per therm of natural gas or per gallon of fuel oil you can estimate the total amount of energy required.  For example, for a 80% efficient propane unit and if we assume 340 gallons of propane for heating...
340 * 91,300 * 0.8 = 24.8 MMBTU produced.  We then divide this by 0.95 and 91300 for the new boiler to get 286 gallons required for the new furnace. (91300 is the # of BTU's in 1 gal of propane).  I hope you see my logic...  Or just divide .8 by .95 to get the ratio of new energy required (84%), 16% less energy.

## Home Energy Pros

Home Energy Pros was founded by the developers of Home Energy Saver Pro (sponsored by the U.S. Department of Energy, under the American Recovery and Reinvestment Act) and brought to you in partnership with Home Energy magazine.

## Latest Activity

"Pat, I think you and I agree on a LOT of things.   One thing I don't want to see is more…"
5 hours ago
"Bob B.   Buying a home is a good investment because it is forced savings more than a good…"
7 hours ago
Joe Huang posted a discussion

### White Box Technologies launches Web-based weather data for building energy simulations

White Box Technologies is pleased to announce under agreement with ASHRAE the launch of WBT Weather…See More
8 hours ago
8 hours ago
"My life changed when I got 'ductalatored' - became familiar with proper sizing guides for…"
9 hours ago
"Thanks Dennis."
9 hours ago
Judi Lyall joined allen p tanner's group

### Energy Auditing Equipment for Sale, Trade or to Purchase

Discuss the pros and cons of the equipment you are interested in prior to purchase. Post equipment…See More
22 hours ago
"Hi there I am selling my equipment and have a great Fluke TIR for sale for 3600.00    If…"
22 hours ago
"66 watts a/sec  -3960 w/min   237600 w/hr   5702400  w/day …"
yesterday
"I think Tom is busting your chops Jim.  The "drivel" part may not have been well…"
yesterday
"Some of the best scientists of the previous 1000 years were also leaders in the Church.  Aside…"
yesterday
Laurie DiDonato posted an event

### HERS Rater Training in Massachusetts at Maki Building Center

June 3, 2013 to June 8, 2013
6-Day HERS Rater Training- The first step to becoming a HERS RaterLast Week To Register!Your Cost…See More
yesterday

© 2013   Created by Lawrence Berkeley National Laboratory.