This is a continuation of these these threads: http://www.greenbuildingtalk.com/Forums/tabid/53/aff/13/aft/80332/afv/topic/Default.aspx
and
http://www.greenbuildingtalk.com/Forums/tabid/53/aff/13/aft/80100/afv/topic/Default.aspx
To summarize, I've purchased a 2100 sqft ranch in Essex MA with 2.3 acres of land. The current heating system is electric baseboard. To date, I've had three heating companies out. One is proposing a 3 ton ASHP system made by Bryant (the Bryant Evolution). The quote includes duct work (there isn't any - basement is open) and is coming in at $19k.
The second was a geo quote which broke down as follows: 48,000 BTU heating, 23,000 BTU Cooling Domestic hot water assist, Two zones, air handler, water furnace series 5: $16k
4 horizontal loops: $7k
Ductwork: $12k
Equipment Installation: $14k
Discount: $4k
TOTAL: $46k

The third comes in as follows:
A new Climate Master Tranquility 27 #TTV049 packages two stage variable speed geothermal heat pump rated at 48,000 BTU with a COP of up to 5.0. The desuper heater on the geothermal heat pump would be connected a new Sepco 80 gallon stone lined water heater with a 10 year warranty. Sheet metal work consists of designing, fabricating and installing a new custom made sheet metal duct system. The duct work would be sealed and insulated to meet Energy Star standards. The system would be balanced for proper air flow. Total cost, $22,325.00 excluding loop installation. I've gotten a quote for vertical loops, 2 of which at 340' for an additional $14k bringing the total to $36k. This specific HVAC guys is specifying a heat load of 42,000 BTU by manual-J.
I'm still struggling to find other contractors to quote me. I'm also working with an excavator to get me a price on horizontal loops which are being spec'd at 3 150' trenches 10' O/C.
I am adding additional insulation through the mass saves program taking my attic to R-30 and air sealing the attic and basement. I currently have R-13 on the walls and a total of 212 sqft of glass, none of which is western facing.
My sweet spot for pricing is $25-$30k, otherwise I won't go forward. I'm hoping the excavator will come in low, and that might take care of my pricing problems, but I can't help but wonder what it will take for me to get my heat load down 6,000 to 36,000 BTU. Any input is greatly appreciated

Posted By sbeausol on 28 Sep 2012 03:10 PM The desuper heater on the geothermal heat pump would be connected a new Sepco 80 gallon stone lined water heater with a 10 year warranty.

This specific HVAC guys is specifying a heat load of 42,000 BTU by manual-J.

I can only hope that there is also a buffer tank included, otherwise the DSH will not work well.
Also, with 42KBTU/H you should be down to a 3 ton system.

Wanna try and re-post that using a different browser tool? (A little white space makes it much more readable, and the formatting scripts from some browsers get trashed in translation on this site.)

For the load reduction aspects, build yourself an I=B=R estimate with a spreadsheets tool and calculate the heat losses from different elements by U-factor and surface area.

Assume R13s in 2x4 framing runs ~R10 on average with the thermal bridging.

U factor= 1/R, so for walls that's (1/R10 =) 0.1 BTU per degree F across the assembly. With an interior temp of 70F and a design temp of +5F (about right for Essex) that's 65F delta, so for every square foot of wall you get (65F x 0.1=) 6.5 BTU of heat load at design temp.

Add up the square footage and multiply. An inch of exterior foam under new siding would reduce that by 1/3, two inches of exterior foam would reduce it by half. (If you got that route it's worth blowing in cellulose from the exterior to pack out the bays with the R13 to tighten them up prior to the exterior foam. If the R13s have foil facers rather than kraft, do NOT use foam with facers of any type, only unfaced.)

If the windows are reasonably tight wood framed single pane double hungs, plus clear storm windows, figure a U-factor of 0.5, which would be (65F x 0.5=) 32.5BTU per square foot, so at 212 square feet window losses would be (32,5 x 212=) 6980 BTU/hr @ design condition. Replacing them with better-grade U0.25 double panes would cut that in half, but that's a pricey proposition.

If the windows are reasonably tight wood framed single pane double hungs, and NO storm windows, figure the U-factor is about 0.9, so at 65F delta that's a loss of 58.5 BTU/ft. For 212 feet that's (58.5 x 212=) 12,402 BTU/hr. Adding low-E storm windows would cut that by about 65% for about $200/window bringing the loss down to (0.35 x 12,402=) 4340 BTU/hr (which would by-itself get you the 6K load reduction you're looking for.)

If the windows are clear thin double panes, call it U0.6, if half-inch or 3/4" call it U0.5. You do the math.

On the R30 attic, figure with the thermal bridging joists/trusses an average R value of about R26, and a U-factor of (1/R26=) 0.038 BTU/degree-foot At a 65F delta-T that's (65F x 0.038=) 2.47 BTU per square foot of attic. The interior floor area of the attic of a 2100' ranch is about 2000', so call that (2000 x 2.47= ) 4900 BTU/hr.

If there's room to blow another 3" of cellulose on top of that you'd cut that by about 1/4, if you can accommodate another 6" in there it would cut it by about 1/3.

Any amount of above-grade exposed foundation that has no insulation has a U-factor of over 1, but let's call it 1, and assume you have 2' of exposed foundation and a total perimeter of 180', for 360 square feet. Let's also assume the basement isn't directly heated and it's only running 60F, not 70F, for a 55F delta-T. With a U1.0 that's 1 BTU/degree-foot, times 55F is 55 BTU/ square foot, times 360 square feet is 19,800 BTU/hr. Putting 2" of reclaimed roofing iso on the basement walls (or virgin-stock, if you must) would bring that down by 90% to ~1900BTU/hr. Adding a 2x4 wall with unfaced batts trapping the iso to the wall brings it down to under 1KBTU/hr. Even if you only have half that square footage you're looking a 10,000 BTU/hr that is cost-effectively reducible to 1KBTU/hr. (Try insulationdepot.com or these guys- boston.craigslist.org/gbs/mat/3290546791.html ) Reclaimed roofing iso is cheaper per unit R than virgin stock batts, comparable to low-density cellulose. It's typically 2.5-3.5 cents per R per square foot, eg:

2" (R12) 4' x 8' iso @ at $10-12/sheet

3" (R18) at about $15-20/sheet

etc.

Sometimes it's cheaper, but rarely more, and that's roughly 1/4-1/3 virgin-stock f.o.b. the distributor's yard.

So make a spreadsheet with your real dimensions & R total it all up. It'll probably come in a bit under the Manual-J calc since we're not factoring in air leakage or other factors, but it'll be in the right range. Then figure out what's most cost-effective for you. From a BTU-reduction/$ I'm betting the basement-R trumps all if done as a DIY using reclaimed goods (or even if you hire somebody to do it), followed by low-E storms if single-pane, or buffing up the attic-R (since it's easy) if the existing windows have storms. In most somewhat-insulated homes in this area that have no wall insulation on the foundation, even if there's batts stuffed in the basement ceiling the basement walls are usually the single largest conducted heat loss, and its pretty easy to fix in an unfinished basement.

A quick note - the windows are Andersen casement double pain. All are in good shape (seals good etc), one is brand new and thus low-e with a u-factor still on it ( 0.2 off the top of my head but I can check)...

I will build the spreadsheet

Most U0.20 windows are triple pane, but there are many double panes in the mid to high 2s. If it's clear-glass assume U0.5 even for newer stuff, but if you can see a hint of a low-E sheen or tint, figure U0.34. IIRC Andersen makes a U0.24 double-pane, but U0.28-0.34 low-Es are far more common.

Either way, with casements you won't be putting cheap low-E storms over them, and replacing them with better performance triple panes would be out-of-sight painful to the pocket book. Assuming your window average is U0.30, at a 65F delta that's 19.5 BTU per square foot, times 212 is 4134 BTU/hr.

Stealing half your sister's retirement savings to replace them with U0.20 windows would only take 1/3 off that, peeling only ~1400 BTU/hr off the total heat load. Only if you're going all the way with a deep energy retrofit would replacing "pretty-good" windows with "excellent" windows have any rationale and even then...

Go ahead and include the window losses in the I=B=R spreadsheet, but know that window upgrades are going to be one of your LEAST cost-effective load reductions (usually is, unless it's a storm-window upgrade rather than a window replacement.)

BTW: If the spreadsheet is telling you 30K and the pro calc came up with 42K, reality is almost certainly in-between. Manual-J type calculations are inherently padded, often overshooting by as much as 25-30% even with meticulous data entry. I=B=R methods without fudge-factors for ventilation are on the low end, but often pretty close if the house is really tight (=under 2ACH/50 on a blower door test.) Without knowing the actual framing fractions the U-factors for the wall and attic have a bit of error, but it's probably less than 10% off, and it could be in either direction. Not knowing where the basement temp actually settles in winter introduces another factor- if runs 65F instead of 60F the un-insulated estimate is an undershoot, but the error in post-insulated number isn't enough to dramatically affect the total- it WILL run warmer down there, but the losses will be much lower. I'm betting it's over 10K BTU/hr now and it would be in the 1 KBTU/hr range after insulating, which is less than the inherent estimation error on the rest of the house. Typically on a 1 story an uninsulated basement on a nominally insulated house is about 15% of the total heat load, sometimes a bit more, rarely much less. So if the 42K number looks pretty real, knocking 15% off the 42K delivers the desired result.