Energy and Construction - Clima2007

Annie Said:

Gas-Fired Boiler Efficiency? Which would you choose?

We Answered:

www.titanheater.com
less than $300

Brett Said:

I have a gas boiler from 1967. The energy assessment last year said that it had 77% efficiency.?

We Answered:

Insulation materials used in 1927 are next to zero in efficiency compared to present state of the art materials. If you spend the money to get 90% efficiency from a new unit, just think how much more efficiency you would realize if you had the insulation of the structure up-graded as well.

Would be an economic fact finding plus to see if up-grading the present structure's insulation would be cost effective in terms of replacing the 77% efficient boiler with a 90%. They say, "Follow the money."

Herman Said:

Why is a cold air intake in a car efficient but in a powerplant boiler the air is heated for more efficiency?

We Answered:

Steven gives you a good review of the situation but sadly misses the central issue in his answer to your question:

There is no contradiction. The intake of cold air by the car engine is not more efficient; in fact (just like the boiler!) it is less so. The lower temperature of the air simply allows a higher mass flow of air which creates a need for more fuel (to reach the same hot gas temperature). This provides a higher output power than warmer air would, but not a higher efficiency!! Some of the extra fuel is needed to heat the air from its initially lower temperature up to the hot gas temperature! You may recall that it is the latter temperature which basically determines the efficiency (see Carnot).

They sometimes boost the output power of gas turbines in power plants for peak loading by injecting water or steam into the burner, which basically does the same thing i.e. increases the mass flow. But it needs disproportionally more fuel input as well and the efficiency loses out quite badly.

Note1:The bit about "more complete combustion" is folklore, not thermodynamics. You can have a correct mixture of fuel and air at any normal air temperature.

Note 2. A lower ambient temperature should improve the car motor efficiency (Carnot again) a little but since much of the heat is rejected to the cooling water of which the temperature is held constant, this won't make much difference.

Russell Said:

I live in privately rented accommodation, how can i increase it's energy efficiency?

We Answered:

You can plug the gaps in your sash window with newspaper to reduce draughts, buy a special type of shrink film which you stick to your window frames with double sided tape to give secondary glazing, fit foam on your door jambs and use draught excluders on the bottoms (make your own ?). Doubtful you have many rights as a tenant. Always wear a jumper and even a coat when sitting.

Jon Said:

Has anyone heard of the Energy Efficiency Campaign UK? Is it genuine? Or the Real Energy Heating company?

We Answered:

Dear check this:
http://helpkorner.com
I hope that resolves your problem.
Keep using answers.yahoo.com