Learn about Downflow / Horizontal

ManualsBrandsGoodman Manualsforced air96% 40,000 BTU Downflow/Horizontal Furnace

The two features that can increase your comfort, though, are

noteworthy and valuable. They are two-stage heating, and self-

adjusting blower speeds. Both of these are available for forced

air furnaces.

Before explaining what these features are, rst let’s look at how

a home furnace works:

When the temperature in the room gets about 1 degree colder

than what you’ve set your thermostat for, the heater comes on

at full capacity. The heater runs until the temperature in the

room gets about 1 degree higher than what you’ve set the ther-

mostat for, then the furnace shuts o. And the cycle continues;

on and o. When the heater is on, the ames in the furnace (if

it is gas, oil or propane) are on at full capacity, and when the

unit is o, the ames are completely o; there is no in-between

ame level. The same thing happens with the blower (the fan

inside the furnace that pushes the air through your home’s

ducting). The blower is either on at full speed, or o; there is no

in-between blower speed.

Now, two stage furnaces improve on this operation. These

central heating systems have advanced burners with two ame

levels, high and low. When your home needs less heat, the fur-

nace will operate on low ame; when your home needs more

heat it will automatically operate on high ame.

Self-adjusting blowers come in two types, multi-stage and

variable speed. Multi-speed means the blower operates on two

speeds in heating, low and high, changing automatically as

heating demand changes. Variable speed is a smooth ramping

blower that increases or decreases rotational speed as needed.

The benets of a two-stage furnace with variable speed blower

are that it makes you more comfortable due to more even

temperatures throughout the home, maintains a more steady

temperature (keeps the house at nearly the exact tempera-

ture you set your thermostat), increases your air conditioning

eciency about 8% (if you have air conditioning), has a lower

operating cost (due to a DC voltage variable blower motor),

increases eciency of any attached air cleaner, and is quieter

than other furnaces.

The benets of a two-stage furnace with multi-speed blower

are similar to the Two-Stage Variable Speed models. However

the Two-Stage Variable Speed models are even more quiet,

even more electrically ecient, and even more comfortable.

Still, they are the second-best furnace available, and an out-

standing heater for the price.

Brand

There are many dierent equipment brands available. The top

two selling companies by sales volume in the USA are

1) Bryant / Carrier, and 2) Goodman Manufacturing.

Everyone seems to have an opinion about which brand is best

or worst. Contractors often claim their brand is the best, and ev-

eryone else’s brand inferior because they want to sell you their

brand. Unfortunately, much information available is biased and

unreliable, whether it is from a contractor or in an online article.

So how do you know which brand is a good buy? The best

approach is to compare objective facts about the equipment,

found on manufacturer’s web sites or the manufacturer’s prod-

uct specication sheets. Three fundamental things to know and

compare among brands are:

Features –1 What is the furnace fuel eciency (AFUE)? How

many stages of heat does it have? Does it have a self-adjust-

ing blower fan? Make sure to compare “apples-to-apples”

(features-to-features) when looking at dierent brands.

Warranty –2 How long is the manufacturer’s standard war-

ranty? The longer the warranty, the better the value. Length

of warranty is also a good indication of product quality. If

a manufacturer is willing to “put their money where their

mouth is” so to speak by backing up their product, it is likely

well built. Keep in mind that manufacturer’s warranties are

for parts only, not labor costs in the event of a repair.

Price –3 Price alone doesn’t tell you whether the furnace

brand is a good deal or not. A low priced brand doesn’t mean

it is a good or bad product, and a high price doesn’t mean

the brand will be high quality or not. However, when com-

bined with feature and warranty information, pricing is very

useful in selecting a brand. Your goal should be to select a

furnace brand with the features and warranty you want at

the lowest price.