# Relationship between btu and cfm

### CFM per Ton - HVAC/R engineering - Eng-Tips

kW to cfm's. I don't see a direct relationship between power and flow rate. Convert the kW to BTU (British thermal units) as these are. 1 - Electric heat - temperature rise method: CFM = BTU's / (ΔT x ) Input: Temp . rise(°F) ΔT, Volts & Amps. single, three. phase formula: CFM = (Volts x Amps. enthalpy = Btu/lbm (dry air) humidity ratio = (psychrometric data from PMTHERM) Given we have cfm of air, the mass flow of.

Special topics relating to electricity Gross and net electricity production. The gross electricity generation for example, in kWh is the amount of energy measured at the terminals of the generating unit. The net generation is measured at the output transformer of the power plant.

Electricity sales differ from net generation due to transmission losses. Infor example, the ratio of U. Efficiency for fossil fuel and nuclear sources. Actual generation efficiencies, limited by the Second Law of Thermodynamics and design practicalities, fall short of this.

### Cubic Feet Of Natural Gas to British Thermal Units | Kyle's Converter

More specifically, for U. The end-use energy and the energy losses are then individually tabulated, with the losses roughly twice as great as the end-use energy. However, this separation creates a possibly misleading asymmetry in comparisons among modes of energy use, because end-use losses are neglected for fossil fuels used directly and these losses sometimes are substantial.

From the standpoint of energy resources, the interesting number is the primary energythe total energy consumed at the generating plant, whether used efficiently or wasted. Thus, it is usually desirable to consider energy budgets in terms of the energy content of the resource originally consumed, i. When this is done, the energy corresponding to 1 kWh of electricity depends upon the conversion efficiency, and is typically above 10, Btu.

Energy equivalent for non-fossil fuel sources. To facilitate comparisons between different energy sources, a conversion factor is assigned to non-fossil fuel sources which relates electricity generated to a nominal primary energy.

For nuclear energy, this is done on the basis of the heat content of the steam produced 3. A similar approach can be used for geothermal plants. Poorly ducted installations can result in less efficient, louder range hood operation. To take the mystery out of ducting, rely on these simple rules.

## Refrigeration tons to BTU per hour conversion

Always duct your range hood to the outside for peak performance. Use a recirculating kit only if absolutely necessary. Keep duct runs as short and straight as possible.

Like any other appliance or gadget, the better you use it the better it will perform and the happier you will be with your purchase over time. First and foremost, realize that CFM and Sone levels are rated at maximum. Using your range hood on maximum will lead to the loudest sound emission and may make your cooking experience less enjoyable.

Sones Be pragmatic about how much ventilation power you need when cooking. This gives you ample room to install your range hood at the desired height without running the risk of heat damage or loss of performance. The exhaust air quantity depends on the room conditions. Codes only specify minimum exhaust air requirements.

Rooms that have to be exhausted are always maintained at negative pressure relative to the conditioned adjacent spaces.

This is achieved by exhausting more air than is supplied or by exhausting air with no supply as in closets. The exhausted air comes from adjacent spaces through cracks around the door or by intentionally undercutting the door to the closet or by providing louvers in the door.

Examples of Toilet Exhaust are: Any opening between the toilet and the adjacent space will also transmit sound. The solution is to provide a vestibule space 2 doors. When an air handling unit AHU or System is supplying air to several rooms with different percent outdoor air requirements then the designer must determine the basis for the System or AHU percent outdoor air.

It could be 1 the average percent outdoor of all the rooms served by the System as in office buildings or 2 the System outdoor air percent could be set at the room requiring the highest out air as in hospitals. Use average percent outdoor air of all the rooms. The supply air quantity was determined to offset the sensible heat gain SHG in the space. It was based on a selected ceiling supply air temp of 55oF.

The air is discharged through ceiling diffusers that are typically located at a height of 8' in corridors, 9' in residential and 10' in commercial.

The supply air will mix with the room air to produce an average 75oF temp at the occupied level range of 0 to 6 feet. Supply Air Moisture Content. The moisture content of the supply air must offset the latent heat gain LHG in the space. Moisture content of supply air must be less than the moisture content of the room air by the amount of the Room LHG. Wr and Ws are the humidity ratios moisture content lbs moisture per lb of air of the room air and supply air.

This means that the air entering the cooling coil must be cooled to 48oF in order to remove the moisture and then reheated back to 55oF. So dehumidification consumes a lot of energy in terms of refrigeration cooling and re-heating.

In an office space LHG is due to people only whereas the SHG is due to outdoor temp, solar heat, people, lighting and equipment. Calculate cooling coil leaving temp.