Question

Jon has 1200 ft2 of roof in his home in Pittsburgh, PA (HDD = 6,000). He is considering upgrading the insulation from R-16 to R-22. The estimate from the contractor was $578. His home is heated with natural gas. Last year, the average price he paid for natural gas was $12/MCF. Assuming an AFUE of 82.9%, how long will it take Jon to recover his investment? (5 points)

Answer 1

1.6 years

Step-by-step explanation:

To find out how long will it take john to recover his investment we will use following formula.

Years to recover = (IcxRfxRixEff) /(Ecx[Rf-Ri]xHDDX24)

Where,

Ic = cost of insulation in $/sft

Rf = final value of R

Ri = Initial value of R

Eff = Efficiency of heating system

HDD = heating degree days/ year

24 = multiplier to convert HDD into 24 hrs/day

Ec = Energy cost

Years to recover = (578x22x16x82.9)/(12x[22-16]x6000x24)

Years to recover = 16866502.4/10368000

Years to recover = 1.6