I need some input on an HVAC balancing question --- I have a raised ranch home with a finished basement and an open stairwell connecting the two floors.  It's an early '90's build originally equipped with a heat pump.  All registers for the basement are along the ceiling and it was equipped with an electric space heating wall unit in the finished front half of the basement and electric baseboard units in the laundry room and half bath down there.  The heat has never balanced properly (probably the reason for the electric space heaters in the basement which we don't use because of the cost).  The difference between the upper floor and the basement is 10-20 degrees or so lower in the winter.  Since purchase we have installed a sealed combustion gas furnace along side and tied it into the ductwork for the heat pump (which has saved a lot of money).  In the past 5 years I have audited the home and sealed bypasses in the kitchen soffit, plumbing chases, cantilevered front facade, sealed most of the wiring penetrations in the attic, dealt with 5 panned returns (one of them which was connected to the back of the bathtub space) and insulated the small space under the front entry.  All this got the BD from 2,500 CFM@50 down to around 1800 CFM@50 (which made it less drafty on the top floor but not warmer in the basement).  Closing registers either partially or all together still doesn't seem to help much either and creates moisture on the upstairs windows(double pane) now that the house is tighter. I'm at a loss as to what to try next.

Views: 1749

Replies to This Discussion

Kari, unless you have mechanical ventilation your home is tight enough.  7 ACH@50 equates to about the .35 ACH natural rate.  If you do have it then make it as tight as possible.

All bathrooms and the kitchen have fans ducted to the outside.  Since I got it down to 1800 I have some moisture on the upstairs windows during heating season I'm working on getting rid of too.

Kari,  You didn't note that you did a duct leakage test.  If not, I would suggest that first (total and leakage to outside), then airflow at each supply & return to be sure the air is getting to/from where it should.  If you don't find a good fix then I would look for a good HVAC designer to look at correct airflows to each room/area.  I have found many homes with very poor air return, just based upon my general knowledge/experience/senses.  Something I regularly see is supplies-only in basements, no returns.  I hope this is of some help to you.

I haven't done a duct leakage test.  I don't have a duct blaster or training for that although I've looked at videos about it.  The ductwork is f/g board trunks and flexible.  The ductwork seems to be installed well although it isn't done with mastic.  There is no ductwork outside the envelope.  I know lack of return seems to be an issue in a lot of homes but this home has 7 returns!  Each bedroom (3 upstairs and 1 in the front corner den of the basement -- also the main upstairs hall and the basement family room and one in the kitchen which we recently blocked off) * As I said in a reply farther up the page, they were all panned into walls and such so we addressed that by stuffing bags of f/g in wall cavities above the return, etc.   In my area/state I haven't come across anybody who is doing duct testing.  Not even WAP agencies.  I know an instructor/trainer who I might be able to twist his arm to come do it when he has time if that is the most helpful next step -- actually skip that, I don't think he has a duct blaster either.

I have been doing test and balance for 20 yr.   most test and balance people use very high end tools, $40K or so  hoods, hot wire, air presser gages, RPM meters, Amp meters, temp, RH gages.   step one find the air flow for that air handler/ motor system its listed on line if its ARI.org  use the right coil.  email me and will send you a list of what is to be done   www.ericsenergy.com  Then I do heat loss heat gain room to room. turn this to CFM per room then use your best ways to test air flow to each grill.  Lets say you need 1000 CFM total  but the air handler can only do 900 CFM then you put 9/10 in each room or grill.  Keep in mind its just plus or minus 10%

RSS

Home Energy Pros

Home Energy Pros was founded by the developers of Home Energy Saver Pro (sponsored by the U.S. Department of Energy,) and brought to you in partnership with Home Energy magazine.  Home Energy Pros is sponsored by the Better Buildings Residential Network.

Latest Activity

Nickie Irvine replied to Linda Wigington's discussion Weigh in - Honorable Mention? 2nd Base? Half-Way There? 50% Better? On the Path? in the group 1000 Home Challenge
"Judy, I like your reasoning in analyzing most of these possible names.  And I agree that…"
4 hours ago
Judy Roberson replied to Linda Wigington's discussion Weigh in - Honorable Mention? 2nd Base? Half-Way There? 50% Better? On the Path? in the group 1000 Home Challenge
"Hi Linda - You're asking some very good questions. I don't have very good answers, but…"
4 hours ago
Blake Shurtz replied to Blake Shurtz's discussion Duct blaster with asbestos?
"I rarely test asbestos- I just perform a visual on-site. I do not think running the duct blaster…"
5 hours ago
Profile IconGreg Hannah, Eric Wilson, Zach Stachura and 2 more joined Home Energy Pros
7 hours ago
Stacy Hunt posted blog posts
12 hours ago
Kirsten Richnavsky added a discussion to the group Building Performance Institute (BPI)
Thumbnail

FREE BPI webinar: OSHA's Confined Spaces Rule Impacts Home Performance Workers

Check out this FREE webinar BPI is hosting on OSHA's Confined Spaces Rule Impacts Home Performance…See More
13 hours ago
SmithWatson posted a blog post

Dealing with the 5 Most Common Furnace and Heating Problems

Most people are reminded of the furnace repair service just when the fall or winter arrives.…See More
19 hours ago
SmithWatson shared Lester Shen's blog post on MySpace
19 hours ago

© 2015   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service