Building Air-Tightness Test Form, and ASHRAE Ventilation Worksheet.
Owner's Name: Property Address: Date of Test:
Contact: AckBS: Tom Barnes - 508-631-6633 Email: buildingscience.ack@gmail.com Facebook: Nantucket Building Science
Sample 116 Walsh Street, Medford, MA 02155 4/15/13
n-factor table: (Source: lawrence Berkley National Labs) Stories 1 n factor 16.7 Conditioned Floor Area and CFA Volume Calculations: Bedrooms Area basement 1st (loft)2nd other Sub-Total
SF: 815 192 1,007 1,007
Input Variables: Blower Door Test Results: n-factor: CFA Volume:
1.5 15
2 13.3
2 Baths
Test Type: Blower door for homeowner use
3 < - height of building determines n-factor 11.7 < - use these for Nantucket - windy, coastal 1
Ceil Ht (ave) CF (volume) Note: Only include basement space in CFA if purposefully conditioned (HVAC 10 8,150 ducts/radiant/baseboards/etc in the space), or if basement walls are insulated (edge of 3 576 thermal boundary). 8,726 CFA 8,726 CFA VOLUME
433 CFM50 16.7 8,726
Calculations and Formulas: ACH50 - air changes induced by BD ACH50=(CFM50*60)/CFA Volume Inputs: 433 60 8,726
=
2.98 ACH 50 - Good is 5-7 range (2009 IECC code is 7 ach) This is a tightly built home
ACHnatural - ASHRAE min. standard ACHn=((CFM50*60)/(n*CFA Volume) = Inputs: CFM50 60 16.7 8,726 If ACHn (calculated) is less than 0.35, mechanical ventilation (makeup air) is needed.
0.18 ACHn - below 0.35 requires mechanical makeup air/ventilation
Minimum (Mechanical) Ventilation Requirements (MVR CFM50): USE HIGHER OF A OR B A = (15 CFM) x (# of occupants) x (n) B = (.35 x Volume x n)/60 Use Greater of A or B:
Typically adjustable bath fans do thisâ&#x20AC;Ś 752 CFM50 850 CFM50 850 If CFM50 reading on BD test is less than this, mechanical ventilation required. 433 CFM50 18.04 417 CFM50 17.38 Adjust bath fan to above CFM rate, 24/7
Actual BD Reading (CFM50) Makeup Air CFM Needed Air Sealing Reduction Opportunity - if any ASHRAE 62.2 Standard MVR ASHRAE 62.2 = (.01*CFA) + (7.5*(# BRs +1)) Formulas:
ACHn = ACH50/n ACH50 = ACHn * n CFMn = CFM50/n CFM50 = CFMn * n
2.98 0.18 433 26
THIS HOME NEEDS MAKEUP AIR
33 CFM - set/use exhaust only bath fan, running 24/7 continuous 16.7 16.7 16.7 16.7
0.18 2.98 26 433
ACHn ACH50 CFMn CFM50
Conclusion/Recommendation:
Certified By:
Thomas Barnes, Certified HERS Rater RTIN# 4583495
Date:
15-Apr-13