David Butler
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  • Huachuca City, AZ
  • United States
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David Butler's Discussions

RESNET gets serious about modeling platform consistency

Started Jan 12 0 Replies

A critical element in ensuring the consistency of HERS Ratings is enhancing the consistency which RESNET accredited HERS Software Programs calculate the HERS Index Score. There are currently…Continue

Belgium’s Lavish Energy Use Sheds Light on More Than Just Its Roads

Started this discussion. Last reply by Don Hynek Dec 18, 2017. 1 Reply

As an avid amateur astronomer, the mitigation of light pollution is one of my passions, notably dovetailing with my professional passion for efficient design. The most efficient outdoor lighting…Continue

Beginners Guide: Managing Subscriptions on Home Energy Pros

Started this discussion. Last reply by Diane Chojnowski Nov 21, 2017. 2 Replies

New members may find subscriptions a bit confusing at first. I know I did. As you'd expect, when you create a new discussion or post a comment, you're automatically subscribed to comment…Continue

 

David Butler's Page

Latest Activity

David Butler replied to David Meiland's discussion Air gap above floor insulation--how big is the impact?
"Charles wrote: "if the floor is properly insulated how can the floor be a different temperature than the room temperature" Any time you have a steady-state delta-T across an assembly, the indoor surface will be cooler (or warmer) than room…"
yesterday
David Butler replied to David Meiland's discussion Air gap above floor insulation--how big is the impact?
"Adding an airspace changes the temperature gradient, as noted in Joe's doc, thus making the floor slightly warmer, with slight increase in heat loss. However, the real issue here is encapsulation, or lack thereof.  Without 6-side…"
Thursday
David Butler replied to David Byrnes's discussion When can an oversized A/C be a good thing?
"Keep in mind that for all but the hottest hours, a tightly sized system already has excess capacity. Even at design conditions, it doesn't take much extra capacity to recover from setback. Many of my clients use setback (actually 'set…"
Thursday
David Butler replied to Brett Little's discussion Do ductless systems do better on the HERS?
"Hi Sean, my comment re: actionable cooling load was about the application of ductless, not related to Brett's question on impact on HERS. Sorry if I conflated the two."
Nov 16
David Butler replied to Brett Little's discussion Do ductless systems do better on the HERS?
"By 'actionable', I mean the load is such that the homeowner actually needs to use A/C, as opposed to what the software might predict. Most of the US has actionable cooling loads, except higher elevations. I explain my logic for not using…"
Nov 15
David Butler replied to Brett Little's discussion Do ductless systems do better on the HERS?
"Since the Home Performance Forum archives are hosted on a different server with different software, the only way to 'promote' an archive thread is by posting a link here, as you have done. Perhaps Diane (moderator) will promote this…"
Nov 15
David Butler replied to Brett Little's discussion Do ductless systems do better on the HERS?
"Hi Brett, since the archive discussion you linked is locked to new posts, I think the best way to continue the conversation would be cite something specific from that thread to stimulate additional discussion. To answer the question posed in your…"
Nov 10
David Butler replied to Kent Kjellgren's discussion Sealed crawl space for new construction
"Lots of excellent comments here. A few more from an old-timer who has specified more than a few closed crawls in the southeast... * Nearly all closed crawls I've seen in your climate use 1.5 or 2 inch foil-faced polyiso board on foundation…"
Nov 5
David Butler replied to Jerry Needham's discussion Blower door test for small apartment building
"It depends on purpose of test. If it's not for program or code compliance, then testing the building as one unit makes sense. It eliminates the pesky adiabatic leakage that would occur if you tested each unit individually. If you're…"
Oct 6
David Butler replied to Randall Olsen's discussion How to measure room pressures
"Daniel wrote: "Any air not returning to the system from each room will be gained from elsewhere." Not necessarily. Notwithstanding combustion safety testing (which predates green building programs), zonal pressure testing is an important…"
Oct 1
David Butler replied to Randall Olsen's discussion How to measure room pressures
"Sean wrote: > never knew manufacturers would ramp down fan speed for fan only Two ways this happens: In fan-only mode (i.e., continuous fan), variable speed blowers typically operate at 50% of the selected speed setting. For multi-tap blower…"
Sep 30
David Butler replied to Randall Olsen's discussion How to measure room pressures
"Sean wrote: HVAC fan only not on heat or cool Hi Sean, do you know if that is specified anywhere? With many (most) newer systems, in fan-only mode,  the blower operates at a significantly lower speed than in heat or cool mode. Sorta defeats the…"
Sep 29
David Butler replied to Jan Green's discussion Mini split installation location
"I'm not sure if I'm making myself clear. You don't want to 'squeeze' the outdoor unit between the building and block wall. The installation manual will call out specific clearances for outdoor unit for rear, sides, front and…"
Sep 24
David Butler replied to Jan Green's discussion Mini split installation location
"Hi Jan, actually, I said you'd be find putting it on the west wall since you wanted a larger window. There's no need to set the outdoor unit on the same wall as the indoor unit. According to your drawing, the room (excluding closet and…"
Sep 24
David Butler replied to Jan Green's discussion Mini split installation location
"Hi Jan, in a room like that with a relatively balanced aspect ratio, flat ceiling and not much glass, the mini-split could probably be located on any wall. With the information provided, the west wall looks good, preferably near the center.  In…"
Sep 20
David Butler replied to Jan Green's discussion Mini split installation location
"Really hard to advise without knowing the layout. But you're asking good questions. Any chance you can post the floor plan or 'sketch and scan'?"
Sep 17

Profile Information

Company
Optimal Building Systems
Role in Home Performance Marketplace
Building energy modeler, Researcher (Lab. academia. etc.), Other
Professional Certification
Other
Website URL
http://optimalbuilding.com
LinkedIn Profile
https://www.linkedin.com/in/davidbutler52/

Comment Wall (1 comment)

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At 9:43am on November 1, 2011, Diane Chojnowski said…

Hi David,

Welcome to Home Energy Pros! Feel free to join the conversation in the Forum and Groups. And share your energy efficiency photos, videos and upcoming events. If you're blogging about home performance, this is the place for you!

Don't forget to add your location on our Member Map!


Thanks!
Diane, HEP Moderator

 
 
 

Latest Activity

Sean Lintow Sr replied to David Meiland's discussion Air gap above floor insulation--how big is the impact?
"Yes & no - newer codes added in "Exception: As an alternative, the floor framing-cavity…"
15 hours ago
Dan Phillips replied to tedkidd's discussion It is time for government programs to end. They become monopolies that block market solutions.
"Not all states used deemed savings or modeled savings.  Don't throw the baby out with the…"
17 hours ago
Dan Phillips replied to David Meiland's discussion Air gap above floor insulation--how big is the impact?
"I wonder if you could do an experiment.  Leave a section of the floor insulation as is. …"
18 hours ago
Dennis Heidner replied to Tim Kendzia's discussion Cooling effect from solar panels
"I had missed your query originally made a couple of years ago.   Yes it does make a…"
yesterday
Dannie Jackson replied to Tom Smith's discussion Are Energy Efficient Windows worth the investment?
"If you look at the R factor of the window and compare it to old school single pain glass windows…"
yesterday
Dannie Jackson replied to tedkidd's discussion It is time for government programs to end. They become monopolies that block market solutions.
"Something that bothers me which is very similar to the concerns about agencies and programs…"
yesterday
Dannie Jackson replied to Tim Kendzia's discussion Cooling effect from solar panels
"I would assume two things about this idea, first of all you would definitely shade the roof and…"
yesterday
Charles Buell replied to David Meiland's discussion Air gap above floor insulation--how big is the impact?
"You want to install enough insulation that the room temp line is within the insulation---not…"
yesterday

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