Central Vac - Large Home Installation Tips
With the rapid expansion of the central vacuum market, many installation professionals are being forced to include this popular amenity in their bid whether they like it or not! Installation theory is quite simple for small 2,400 square-foot homes; but how do you insure proper installation in a large home..say a 12,000 square-foot mansion?
The discriminating buyers of these large homes want the assurance that their installer is the best in the business so you don't want to find any "screw-ups" when you finish the job. Hopefully the hints that follow will eliminate most installation pitfalls, provide you the confidence to design a system properly, chose a power unit with adequate power, and overcome obstacles inherent in larger projects.
Similar to small home design technique, you should begin measuring at the far corners of the home and work yourself toward the center employing 30 feet of string or a 30-foot tape measurer. Allow plenty of extra length for beds and furniture. Especially in large rooms, check with the decorator to insure you allowed for any "L" shaped couches in the middle of rooms. You may also be forced to locate valves on exterior walls and columns. Don't forget the option of installing them inside cabinets, in toe kicks, behind curtains and even in the floor. Try to keep them as inconspicuous as possible but yet reaching maximum floor space.
Don't put valves behind doors without considering if the door will be in the way of the cleaning pattern. Inlets in the center of a large wall might be blocked by furniture so attempt to locate them near doorways. Make sure you will be able to reach patios, balconies, garages, and even pool rooms. Locate the garage inlet close to the large garage door so the client does not need to pull his boat or motor home into the garage to clean it.
Always try to reach the hallways from inlets that are outside the bedrooms. You don't want the maid to have to disturb anyone in a bedroom to vacuum outside the bedroom. Often, large homes will require separate inlets for each bedroom.
Consider providing a shorter hose for cleaning major traffic areas. Often, a 20-foot hose will reach all the traffic areas if inlets are properly placed. If needed, many manufacturers offer a 35-foot hose option. The 'Vac Pan' is another unique option for the kitchen and mud room which allow quick cleaning by sweeping debris with a broom to a floor level inlet that activates with the flip of the toe.
If possible, locate the main power unit in a mechanical room but consider the noise that it emits. Don't mount it on a wall that backs up to an office or bedroom! A few manufacturers offer extremely quiet power unit, which can be located within the home if necessary. If the unit requires an exhaust, make sure it won't be an excessive distance that would cause backpressure and overheating. It also would be wise to coordinate your efforts with the decorator, structural engineer, electrician and the HVAC contractor to avoid mistakes and clarify any ambiguities.
How Much Power Do I Need?
While some manufacturers boast that their units are adequate for massive mansions; what are the guidelines for insuring proper suction? Single motor systems that draw about 13 to 15 amps should be limited to homes of about 5000-square-feet. Watch-out though, for small motors that have had their speed increased intentionally. These motors (over 23,000 RPM) will not hold up under the heavy use of a home that's larger than 4,000-square-feet.
Homes above 5,000-square-feet are best served with a two-motored system which will require a separate 30-amp circuit for 110 volt units, or 20-amp circuits for 240-volt units. These stronger units can handle 10,000 to 12,000-square-feet or runs up to 500 feet long corrected. (See correction factors below) Vertical suction is not a problem either as these units can lift dimes and quarters 5-stories straight up! Once a home gets larger than 10,000-square-feet, consider the option of two separate power units. This is not to compensate for power loss but rather for time allocation. The house is so physically large that it will require 2 operators cleaning at the same time and multi-user capabilities. This also extends motor life by a factor of two.
Also consider your altitude factor. If the home will be located in the mountains at the 8000-foot elevation, the air is much thinner. This increases your cubic feet per minute (CFM) but reduced your water-lift (sealed suction.) This might reduce the size home that would require the larger powered power unit.
Correction Factors for Friction Loss in 2" C-Vac Tubing:
Sweep 90 elbow equals 5 feet of tubing
45 elbow equals 2.5 feet of tubing
Loss of CFM in 75 feet of tubing equals 2%
Installation Tips and Tricks
Architects of large homes pride themselves in unique characteristics. These can often catch you unaware, leaving your client a less-than-perfect installation. You should be striving to be flawless in all that you do, so here's your warning: Watch out for varying floor heights. Make sure that your inlet valve heights correspond with those next to them. A double thick sole plate upstairs often signals that a 1 ¾" thick layer of lightweight concrete will be poured. Downstairs ask what type of flooring will be installed. Brick, flagstone, and other aggregates will raise your final inlet valve height.
The industry has wholly embraced inlet valves that contain lowVoltage and highVoltage for operating the electric power brush. Make sure the electrician knows to connect these to his circuits. Electric power brushes have far superior cleaning power than air tools.
Shear-paneled walls will require double plaster guards to insure being found once plastering is completed. Make sure you understand load-bearings on TJI's before drilling them and never cut into the top or bottom support. To circumvent second floor walls that are directly above steel I-beams, consider jogging the pipe in the adjacent room if you know there will be a cabinet or shoe rack covering the pipe.
An often-missed vacuum pipe chaseway is in the pocket of the I-beam. Naturally you cannot drill the steel beam but this makes an excellent collector to reduce the need to drill all the joists in a large room. If you must run underground, don't use schedule 40 pipe but rather incase the vacuum tubing in three-inch irrigation pipe. The fittings and lowVoltage wire fit smoothly inside and provide crush protection as well as a vapor barrier.
Find out what type of wall textures will be applied and coordinate with the wallpaper, sponge painter, or mirror contractor. Certain types of valves are better for wallpapering. You really don't need to locate any "clean-out" points if the system is properly installed.
Make sure the electrician has provided the proper power voltage and amperage. The larger units require 10 Gauge wire with a 30 AMP, 110 volt receptacle; or a 20 AMP, 240 volt receptacle.
All the pre-planning in the world cannot accommodate each job so establish a policy ahead of time on dealing with change orders. Plan on making a few extra trips out to the job on a large home but be encouraged that central vacs have the least amount of call-backs of all the home electronics. Most contractors price the job per inlet plus finish equipment. Don't short-change the client - throw in an extra hose and tool set and a separate garage kit. Make sure your attachments are of the highest grade possible and you will only hear from the client with referrals.