Home \ FAQ \ Air Conditioner and Furnace Sizing Air Conditioner and Furnace Sizing WHAT SIZE AIR CONDITIONER OR FURNACE DOES MY HOUSE REQUIRE? Many factors are involved when determining what size of an air conditioner or furnace would have the required power output to cool or heat your home. These factors include the extent of exposure to the sun and the outside air, the thickness and type of outside wall insulation, the size, type and number of windows and outside doors, the ceiling height, etc. Generally speaking, however, if you live in Southern Ontario, you may use the following charts to estimate the correct size of the heating or cooling product that you may need for your home. Keep in mind that the following furnace output power estimates are aside from the furnace’s nominal power ratings. For example, a 95% rated efficiency furance with a power rating of 80,000 BTU/hr has a power output of 0.95 x 80,000 BTU/hr = 76,000 BTU/hr. Furnace Output and Air Conditioner size for a Bungalow

Air Conditioner size [ton] Built after year 1980 Built before year 1980 * The above square footages do not include the area of the basement. Furnace and Air Conditioner size for a semi-detached 2-storey home *The above square footages do not include the area of the basement. Furnace and Air Conditioner size for a detached 2-storey home *The above square footages do not include the area of the basementSolar AssistedServer Rooms / Indoor GardensMulti Zone (2-5 Rooms)Ceiling CassetteSlim DuctedFloor & Ceiling Mount9000 Btu Prices 3/4 Ton (400Sq Feet Or Under)12000 Btu Prices 1 Ton (400-600Sq Feet)18000 Btu Prices 1.5 Ton (600-800Sq Feet)24000 Btu Prices 2 Ton (800-1200Sq Feet)30000 Btu Prices 2.5 Ton (1200-1500Sq Feet)36000 Btu Prices 3 Ton (1500-1800Sq Feet)48000 Btu Prices 4 Ton (1800-2000Sq Feet)60000 Btu Prices 5 TonEnergy Star /Advanced Inverter TechnologyBest Priced Mini Split'sPortable AC UnitsWall and Window UnitsFlat PanelMini Split ImportingSplit States / Cities

1. Midea Custom Built Multi Zone Ductless Mini Split System2. Mini Split Wifi Thermostat Controller With 7 Day Schedule3. best brand portable ac unitDaikin Custom Built Multi Zone Ductless Mini Split System4. air conditioning unit small officeMidea 24000 Btu 19 SEER Super Inverter Mini Split Heat Pump AC5. mobile air handling unitMidea Custom Built Multi Zone 48,000 BTU Mini Split System6. Midea 21 Seer 2x9000btu Dual Zone Mini Split Heat Pump AC The sizing chart below is useful to help you determine your approximate Central / ductless Mini split air conditioner size requirements. If you are still not sure , give us a call at 813-770-7441 6,000Btu= .5 Ton    12,000Btu= 1Ton Mini-Split Air Conditioners FAQs How do I choose a ductless mini split air conditioner?

Like all air conditioners you need to know how many BTUs you need to cool the area you are trying to cool. You also need to consider the number of air handles that you need normally one air handler per room is what you would need but, if your home has open areas you may be able to cool multiple rooms. There are many options for types of air vents that you can purchase some sit in the home and are mounted on the walls and some can be mounted in the ceiling. It is important that you talk to a person who is certified to install air conditioning about your options to help you decide which would meet your needs. What are the pros and cons of a ductless mini split air conditioner? Ductless Mini split air conditioners is a cost effective choice to center air conditioning. Since the compressor sits outside they mini split air conditioners are very quiet and efficient. How do I install a ductless mini split air conditioner, why do I need a HVAC Professional? How big will the hole be in my wall?

Do some ductless mini split air conditioners have heat? What is ductless dual zone and triple zone? General Air Conditioner FAQs What is the difference between manual and electronic controls? Could you explain the difference from between electric heat and a heat pump? What does Energy Star mean? What are EER and SEER Ratings? What is a chassis and do I want one that slides out? How do I determine the noise level? What are air flow and output options? What are fan settings? How do I determine my plug type or how many volts I need? -A Light at the End of the Tunnel -Ductless, Mini-Split Heat Pumps -The Future of HVAC -How an Air Conditioner Works -How a Heat Pump Works -Improving Indoor Air Quality -Seeing the Future from the PastSizing a data center air conditioner is not like choosing a refrigerator. Bigger is not necessarily better! Sign in for existing members sizing is even more critical to effective operation and energy efficiency than right-sizing the uninterruptible power supply (UPS).

But with so many factors that determine capacity, it can be a bit tricky. When someone plays with the thermostat at home (not you of course!), the temperature is never right. It gets too hot, then too cold. It's worse with computer room air conditioners (CRACs). The unit that's the wrong size can mess up cooling. Wrong settings or improper location will make it even worse. Under-sizing can't cool effectively -- that's obvious. But over-sizing won't either. Thankfully, many CRACs will adjust to a range of loads, but there are many that won't. They all need to be sized realistically, but over-sizing will always result in cooling going on and off too often. It's called "short cycling," which is hard on the machine and does a lousy job of maintaining room temperature and humidity. Yes, temperature swings do hurt computing hardware! Computer room air conditioners with refrigeration compressors -- the true CRACs -- are available in "multi-step" designs. A 20-ton, four-step unit may activate 5 tons of cooling before enabling the next step, as heat increases to 10, 15 and 20 tons of load.

Chilled-water units (more properly called computer room air handlers, or CRAHs) have internal valves that adjust water flow to match the load. They usually work effectively down to about 20% of capacity. But what is capacity, and what the heck is a "ton" of air conditioning? It's actually pretty simple, but comes from old practices (as do most crazy American measurements). Early air conditioning simply blew air across blocks of ice into the room. Melting 2,000 pounds of ice in 24 hours was defined as a ton of cooling. It happens to take 12,000 British Thermal Units (BTU) per hour (another nutty unit) to do that, so 1 ton of air conditioning = 12,000 BTU per hour. Today we are starting to rate cooling in kilowatts (kW). A ton of air conditioning can cool about 3.5 kW of heat, so a 20-ton CRAC should cool around 70 kW. If we know our data center power loads, we can choose a unit with the right capacity: no more than 20% over-sized for a fixed-capacity unit, and, if we need growth capacity, maybe as much as 50% larger for a chilled-water or multi-step.

But hold on -- there are too many different "capacities" on the data sheets. Which one do we use? We still need to know a couple of tidbits. Air conditioners have to deal with two kinds of heat. Sensible heat -- the kind we can feel -- is what our computers give off. Latent heat is what evaporates moisture. Simplistically, dealing with moisture or humidity requires more latent capacity from our air conditioners, which steals from sensible capacity. There's not much reason to keep a data center above 45% relative humidity (RH), but if you over-cool you'll pull moisture out of the air (latent cooling) and have to use more energy to re-humidify. The problem is that relative humidity is "relative" to temperature. Warmer air has a lower relative humidity for the same moisture content because it can hold more vapor than cool air. Temperatures in a data center vary widely, so RH depends on where it's measured, which is why we're trying to get away from using it. However, RH is still the most common way to determine humidity.

Most air conditioners are controlled by return air temperature. Believe it or not, hotter return air enables the CRAC to provide more actual cooling capacity. So if you dial down the temperature in a heavily loaded room, you'll get less heat removal, and the place may actually get warmer -- and you'll waste a lot more power doing it! The following chart shows how humidity level and return air temperature can affect performance from the same nominal 22-ton chilled-water air conditioner. Note that at high temperatures, RH must be lower to keep moisture content below maximums. If you use ducts or the ceiling plenum to channel warm air back to the CRACs, and keep the return air at 80 degrees Fahrenheit or higher by preventing it from mixing with cold, you can get more actual cooling capacity from the same machine. And keeping humidity lower makes it even better at any return air temperature.Air conditioning takes both cooling capacity and air flow. Opening the refrigerator door won't cool the room.

Air movement has to carry the heat away from the equipment and back to the CRAC, just like a nice breeze in summer. So more air should be better, right? If the floor is low, too much air from too big a CRAC means higher velocity, and that means lower pressure. (That nasty physics comes into play again.) Air can actually be sucked down through perforated tiles as far as 8 to 10 feet from the CRAC, which wastes air and energy and also reduces cooling. Too much air can also create under-floor turbulence, like small tornados. That makes under-floor pressure uneven, which further reduces cooling effectiveness. And it's worse if CRACs are placed at right angles to each other. High pressures also make the CRAC fans work harder, wasting more energy. Thankfully, today we can use variable frequency drives (VFDs) to automatically adjust fan speeds for appropriate air flow, controlled by sensors in the room. These can be retro-fit to most existing CRACs, and can save a lot of energy. (A professional computational fluid dynamics, or CFD, analysis is a good idea before buying any expensive air conditioner.)

So Step 1 is to know your real loads, as covered in a previous article. Step 2 is to see if you can get higher temperature return air back to the CRACs. Step 3 is to decide cold air temperature. The American Society of Heating, Refrigeration & Air Conditioning Engineers (ASHRAE) Technical Committee 9.9 has recently increased the temperature envelope, so there's no need to over-cool the equipment. Step 3 is to set your humidity standard. ASHRAE TC 9.9 now recommends dew point monitoring and control, but existing CRACs may not be able to do that, so you'll still need to control relative humidity. Then, if possible, pick an air conditioner that can adjust to load and choose a sensible capacity that will operate Day 1 in its midrange. That will give the best stability and control. Let's look at three other important issues before we finish: reheat, humidification, and water temperature. If you have more than three or four CRACs, it should not be necessary to put humidifiers on every unit.

Moisture diffuses and stabilizes in the room pretty quickly (another reason for dew point sensing). Putting humidifiers on every air conditioner can be counterproductive if one unit humidifies while another de-humidifies. That's wasted energy for no better result. Reheat was the norm for years, and it's the biggest energy waster of all. The CRAC over-cools the air and a heater warms it back up to discharge temperature. In many situations it's possible to design without reheat, or to use minimal reheat. But it takes a knowledgeable engineer to make that determination and to provide a proper design. If you're using chilled-water computer room air handlers, you'll need to have a knowledgeable engineer involved. Published capacity ratings are based on specific entering water temperature and water temperature rise. Chiller plants today may be designed on higher numbers to improve energy efficiency, but that reduces the effective cooling capacity of the CRAHs. Finally, don't overlook opportunities to use "source-of-heat" cooling.