What Horsepower Model is the Condensing Unit?
This is an important question when comparing bids or quotations.
In High Temp applications, the
horse power of a condensing unit is closely related to its cooling capacity. Or, for comparison, you could request the BTU capacity and match quote those numbers. Approximately 12000 Btu will equate to 1 HP in a High Temp.
Application. Likewise, 12000 BTU will equate to 1 Ton of Refrigeration (High Temp). Either way you do it, compare KNOWN capacities.
With High Temp. Applications, another condensing unit question to ask is what capacity
model is the condenser? High Temperature ? or Medium Temperature
This is an area where most Commercial Consumers get caught up in a lot of "Summer Problems" with their High Temp refrigeration equipment. When speaking of a 1 HP High Temp Condensing Unit vs. a 1 HP Med. Temp Condensing Unit, there is a WORLD of difference between the two, in physical size, in appearance, in function and in, yes, price also, and yet, they are the same Horse Power.
You might be wondering why this "Mismatching" of Compressor Models is so widely practiced in the industry. Basically, I think the answer lies somewhere between the realm of Economics and the pressures of the Competitive bidding process. The Medium Temperature Compressor is less expensive, lighter, and more compact than that of its counter part, the High Temperature model. Interesting !? But, the Functional difference between the two when used in High Temp applications, is very substantial. Where this difference will most likely be noticed by the Consumer is when the Med. Temp. Model condenser that is being used in a High Temp application, is subjected to High ambient Temperatures and extreme interior walk in box heat loads,
then this difference between the two can be enough to cause your system to buckle at its knees.
Not to mention anything about the amount of electrical power it is consuming while it pounding its way to get to that point !
The reason the Medium Temperature Model can not handle these high loads is that it is primarily designed to operate at much lower suction temperatures (lower walk-in box temperatures.) This can be best distinguished by the physical size of condensing coil (mounted right in front of the compressor.) The condensing coil on the Medium Temperature model is much smaller than that of the equally matched HP High Temperature Model. Therefore, the High Temp Model will have the capacity to "Reject" much greater heat loads, operate at much lower condensing pressures, which will lower energy consumption, extend the compressor life, and increase overall system reliability.
Another difference between these two models, that I would like to mention, is the Weight Difference. The High Temp Model is much heavier than that of the Medium Temp Model. This difference in weight can sometimes require additional equipment or man power at the job site to elevate the condenser to the roof, which could mean, but not always, more expense. This could be yet another reason why the "Bidding War" can work against you.