Thank you for your reply. Your response leads me to two more questions:<br><br>1) In the case of an 180 kBTU/h instantaneous heater is it standard practice to use EF equal to 0.80 (or some other number based on a "bottom of the heap" instantaneous heater) as you suggested rather than the
0.62 listed in the standard?<br><br>2) How does one translate EF (this or any other) to HIR (Heat-input-ratio) for use in eQUEST? Or might it be acceptable to simply look up the "bottom of the heap" HIR values for instantaneous heaters and use one of them as a baseline?
<br><br>I would appreciate responses from any and all - thanks in advance for your help!<br><br>Best,<br>Andy<br><br>-- <br>Andrew McNamara, LEED AP<br>tel: 212.803.5868<br>fax: 866.379.8026<br>cell: 917.974.4499<br><br><div>
<span class="gmail_quote">On 1/8/08, <b class="gmail_sendername">Alex Lekov</b> <<a href="mailto:ABLekov@lbl.gov">ABLekov@lbl.gov</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div bgcolor="#ffffff" text="#000000">
Andrew,<br>
<br>
It is probably incorrect to baseline the instantaneous water heater
using the current minimum efficiency standard for the residential size
gas instantaneous water heaters (EF=0.62). According to GAMA's
Consumer's Directory of Certified Efficiency Ratings for Heating and
Water Heating Equipment's directory, very few gas instantaneous water
heater models have EF below 0.80.<br>
<br>
Alex Lekov, Ph.D., P.E.<br>
office 925-486-6849<br>
<br>
<br>
Andrew McNamara wrote:
<blockquote cite="http://midfa4b841d0801080913r6b150b6dq4f3d7ae49fdd2915@mail.gmail.com" type="cite"><div><span class="e" id="q_1175a9a0dc0a9862_1">Hello all,<br>
<br>
I am modeling a building with eQUEST that has a
tankless, a.k.a. instantaneous, gas-fired hot water heater. I am
uncertain of how to baseline the system according to ASHRAE 90.1-2004
Appendix G. The standard states that for a 180,000 BTU/h system the EF
(Energy Factor) = 0.62-0.0019V. So, I set V equal to zero for the
tankless/instantaneous gas water heater and get an EF =0.62. <br>
<br>
The question I have for everyone is: How do I translate this baseline
EF to HIR (Heat-input-ratio) for eQUEST? Is there an accepted method
for doing so? I saw in a previous post from David Eldridge on 3/21/07
that
calculating HIR = 1/EF leads to unreasonably high values for HIR (In my
example, 1/0.62 = 1.61), but I'm having trouble seeing how else to come
up with a baseline.<br>
<br>
Thanks in advance for your help.<br>
<br>
Best,<br>
Andy<br clear="all">
<br>
-- <br>
Andrew McNamara, LEED AP<br>
tel: 212.803.5868<br>
fax: 866.379.8026<br>
cell: 917.974.4499
</span></div><pre><hr size="4" width="90%">
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